Tag Archives: aortic stenosis

The truth about TAVI/ TAVR

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It looks like the rest of the medical community is finally speaking up about the overuse and safety issues of TAVI/ TAVR for aortic stenosis, but it’s still few and far between – and in specialty journals…  But in the same week that Medscape, and the Heart.org reported on a newly published article in the British Medical Journal on the overuse of TAVI therapies, and the need for earlier diagnosis and treatment of Aortic Stenosis – the Interventionalists over at the Heart.org (a cardiology specialty journal)  have published a series of articles promoting / pushing the procedure including an article entitled, “The TAVR Heart team roles.”

JAMA recently published a paper by Robert Bonow and Chintan Desnai, discussing the benefits, risks and expectations with TAVI.  This paper discusses the very real need for clinicians to address heightened patient expectations regarding TAVI as an ‘easy’ alternative to surgery.

TAVI is vastly overused – Reed Miller, The Heart.org

Here at Cartagena Surgery – we’ve been doing our own research – contacting and talking to a multitude of practicing cardiologists and cardiac surgeons to get their opinions – in addition to reviewing the latest data.

In related news, a review of the latest research on the ‘transcatheter’ valve therapies demonstrates considerable concern: including data on peri-valvular leaks as reported in the last national TAVI registries in Europe and in the US:

• The incidence of  paravalvular leaks  after TAVI is extremely high  ( > 60%)

• It is technically challenging today to quantify these leaks.

• Most of them are quoted “mild”, but more than 15 % are estimated  “moderate” and “severe”.

• In > 5% of patients, the peri-valvular or valvular regurgitation grade increased significantly over time.

• there is no significant difference between Edwards SAPIEN and Medtronic COREVALVE

As one cardiologist explained:

“Importantly, the thrombogenic potential of mild leaks was recently demonstrated by Larry Scotten ( Vivitro System Inc. Victoria, Canada). High reverse flow velocities expose glycoprotein GP Ib-IX-V  platelet receptors  to circulating Von Willebrand molecule with, as results, platelet aggregation and fibrin formation.  The incidence of brain spots and stroke after TAVI was of great concern in the PARTNER A and B studies.  Whereas, Aspirin is not mandatory  in  patients implanted with bioprosthetic valves,   Plavix +  Aspirin is recommended for all TAVI patients. The rationales of such therapy were not explained so far.”

Valve oversizing – a surgeon explains

“To reduce  these peri-valvular leaks , cardiologists tentatively use large valve size, up to 29-mm.  The very large majority of valve sizes used in conventional aortic valve replacement are smaller than 25-mm.  Oversizing may increase the risk of late aortic aneurysms (aortic rupture has been reported) [emphasis added].

Moreover, atrio-ventricular conduction may be impaired  with the need of permanent pacing. Poorer outcomes have been reported in patients when the need for permanent pacemaker occurs.

“As we like to say about clothes and shoes, you forget the price overnight but you remember the quality for ever . The price of TAVI may be cheaper but patients may experience inferior outcomes. In view of these results, using TAVI would not be appropriate for the great majority of  heart valve candidates.  Moreover trans-catheter delivery and sub-optimal fit are not likely to increase tissue valve durability…  and everybody knows that tissue valves are not enough durable for young adults and children.  TAVI is thus a suitable strategy only for the neglected population of high risk patients who are no longer candidates for surgery [emphasis added].

Worth pointing out again  that there would be no need for TAVI and long-term outcomes of patients would be much better if severe aortic stenosis were correctly managed at the right time.  Enclosed the recommendations of Robert Bonow   (Circulation, July 25, 2012) for early valve replacement in ASYMPTOMATIC  patients.  A large cohort of accurate biomarkers is available today for correct timing of surgery  and consequent prevention of  irreversible myocardium damage. In the study of Lancellotti (enclosed) 55% of “truly asymptomatic patients” with severe aortic stenosis developed pulmonary hypertension during exercise and had  poor clinical outcomes. The measurement of both mean trans-aortic pressure gradient and systolic pulmonary pressure, which are technically easy, rapid and with good reproducibility may improve the management of such patients.

These updates on the natural history of aortic stenosis illustrate the present paradoxical and intriguing  focus of the industry on an experimental procedural innovation for end-stage old patients when more efficient heart valves are today feasible and could be used sooner for the benefit of all patients .

Enclosed an article on The Need For A Global Perspective On Heart Valve from Sir Madgi Yacoub.

Additional Reference / supporting data:

Modified from  Ross J and Branwald E   (Circulation 1968 (Suppl): 61-67)

• The  incidence of stroke was 9% after TAVI in  the 214 patients of the enclosed study published last week in the American Journal of Cardiology. The incidence of stroke with TAVI was >  two times higher than with conventional surgery in the PARTNER study.  Pooled proportion of postoperative stroke was 2.4%  with conventional surgery  in the  large meta-analysis of patients > 80 years old (enclosed)

• Peri-valvular aortic insufficiency is observed in more than  60% of patients undergoing trans-catheter aortic valve replacement.  Moderate or severe aortic insufficiency was seen in 17.3 % of the PARTNER inoperable and high risk cohorts at 1 year.  They have been reportedly associated with dyspnea, anemia,  cardiac failure and diminished survival. Most interestingly,  the FDA does not accept more than  1%   peri-valvular insufficiency in patients implanted with conventional prosthetic heart valves… The SJM Silzone mechanical heart valve was re-called  because of peri-valvular leakage rate of…  1.5 % .

• Traditionally, aortic stenosis involving a 2-cuspid aortic valve has been a contraindication to TAVI.  Of 347 octogenarians and 17 nonagenarians  explanted valves , 78 (22%) and 3 ( 18%) had stenotic congenitally bicuspid aortic valve, respectively.  Because the results of TAVI are less favorable in patients with stenotic congenitally bicuspid valves, proper identification of the underlying aortic valve structure is critical when considering TAVI in older patients . More than 50% of patients with aortic stenosis have bicuspid aortic valve and are not, therefore,  good candidates for TAVI. Most importantly, the great majority of patients with calcified stenotic  bicuspid aortic valves is  young ( < 60 years old)  and not candidate for tissue valve replacement.

•  The French Registry of trans-catheter aortic-valve implantation in high-risk patients was published in the New England Journal of Medicine on May 3,  2012. It reports  3195 TAVI procedures during the last two years at 34 centers.

The mean age was 83 years.  The incidence of stroke was 4.1%.  Peri-prosthetic aortic regurgitation was 64 %. The rate of death was 24% at one year. At the same time, the meta-analysis published in the American Heart Journal reports 13,216     CONVENTIONAL AORTIC VALVE REPLACEMENT in patients > 80 years old.    The rate of death was 12.4%  at one year,   21.3%  at 3 years and  34.6%  at 5 years

 

Full references for works cited in text:

Bonow, R. O. (2012). Exercise hemodynamics and risk assessment in asymptomatic aortic stenosis.  Circulation 2012, July 25.

Lancelloti, P., Magne, J., Donal, E., O’Connor, K., Dulgheru, R., Rosca, M., & Pierard, L. (2012).  Determinants and prognostic significance of exercise pulmonary hypertension in asymptomatic severe aortic stenosis.  Circulation, 2012 July 25.

Takkenberg, J. J. M., Rayamannan, N. M., Rosenhek, R., Kumar, A. S., Carapitis, J. R., & Yacoub, M. H. (2008).  The need for a global perspective on heart valve disease epidemiology: The SHVG working group on epidemiology of heart disease founding statement.  J. Heart Valve Dis. 17 (1); 135 – 139.

Gilard M, Eltchaninoff H, Iung B, Donzeau-Gouge P, Chevreul K, Fajadet J, Leprince P, Leguerrier A, Lievre M, Prat A,Teiger E, Lefevre T, Himbert D, Tchetche D, Carrié D, Albat B, Cribier A, Rioufol G, Sudre A, Blanchard D, Collet F, Dos Santos P, Meneveau N, Tirouvanziam A, Caussin C, Guyon P, Boschat J, Le Breton H, Collart F, Houel R, Delpine S,Souteyrand G, Favereau X, Ohlmann P, Doisy V, Grollier G, Gommeaux A, Claudel JP, Bourlon F, Bertrand B, Van Belle E, Laskar M; FRANCE 2 Investigators. Collaborators (184). Registry of transcatheter aortic-valve implantation in high-risk patients. N Engl J Med. 2012 May 3; 366(18):1705-15 [full abstract below].

BACKGROUND:

Transcatheter aortic-valve implantation (TAVI) is an emerging intervention for the treatment of high-risk patients with severe aortic stenosis and coexisting illnesses.

We report the results of a prospective multicenter study of the French national transcatheter aortic-valve implantation registry, FRANCE 2.

METHODS:

All TAVIs performed in France, as listed in the FRANCE 2 registry, were prospectively included in the study. The primary end point was death from any cause.

RESULTS:

A total of 3195 patients were enrolled between January 2010 and October 2011 at 34 centers. The mean (±SD) age was 82.7±7.2 years; 49% of the patients were women.

All patients were highly symptomatic and were at high surgical risk for aortic-valve replacement. Edwards SAPIEN and Medtronic CoreValve devices were implanted in 66.9% and 33.1% of patients, respectively. Approaches were either transarterial (transfemoral, 74.6%; subclavian, 5.8%; and other, 1.8%) or transapical (17.8%).

The procedural success rate was 96.9%. Rates of death at 30 days and 1 year were 9.7% and 24.0%, respectively.

At 1 year, the incidence of stroke was 4.1%, and   the incidence of periprosthetic aortic regurgitation was 64.5%.

In a multivariate model, a higher logistic risk score on the European System for Cardiac Operative Risk Evaluation (EuroSCORE), New York Heart Association functional class III or IV symptoms, the use of a transapical TAVI approach, and a higher amount of periprosthetic regurgitation were significantly associated with reduced survival.

CONCLUSIONS:

This prospective registry study reflected real-life TAVI experience in high-risk elderly patients with aortic stenosis, in whom TAVI appeared to be a reasonable option.

Rutger-Jan Nuis, MSc,  Nicolas M. Van Mieghem, MD,  Carl J. Schultz, MD, PhD,  Adriaan Moelker, MD, PhD ,  Robert M. van der Boon, MSc, Robert Jan van Geuns, MD, PhD, Aad van der Lugt, MD, PhD,  Patrick W. Serruys, MD, PhD, Josep Rodés-Cabau, MD,  Ron T. van Domburg, PhD,  Peter J. Koudstaal, MD, PhD,  Peter P. de Jaegere, MD, PhD.  Frequency and Causes of Stroke During or After Trans-catheter Aortic Valve Implantation. American Journal of Cardiology Volume 109, Issue 11 , Pages 1637-1643, 1 June 2012 [full abstract provided].

Transcatheter aortic valve implantation (TAVI) is invariably associated with the risk of clinically manifest transient or irreversible neurologic impairment. We sought to investigate the incidence and causes of clinically manifest stroke during TAVI. A total of 214 consecutive patients underwent TAVI with the Medtronic-CoreValve System from November 2005 to September 2011 at our institution. Stroke was defined according to the Valve Academic Research Consortium recommendations. Its cause was established by analyzing the point of onset of symptoms, correlating the symptoms with the computed tomography-detected defects in the brain, and analyzing the presence of potential coexisting causes of stroke, in addition to a multivariate analysis to determine the independent predictors.  Stroke occurred in 19 patients (9%) and was major in 10 (5%), minor in 3 (1%), and transient (transient ischemic attack) in 6 (3%). The onset of symptoms was early (≤24 hours) in 8 patients (42%) and delayed (>24 hours) in 11 (58%). Brain computed tomography showed a cortical infarct in 8 patients (42%), a lacunar infarct in 5 (26%), hemorrhage in 1 (5%), and no abnormalities in 5 (26%). Independent determinants of stroke were new-onset atrial fibrillation after TAVI (odds ratio 4.4, 95% confidence interval 1.2 to 15.6), and baseline aortic regurgitation grade III or greater (odds ratio 3.2, 95% confidence interval 1.1 to 9.3).

In conclusion, the incidence of stroke was 9%, of which >1/2 occurred >24 hours after the procedure. New-onset atrial fibrillation was associated with a 4.4-fold increased risk of stroke. In conclusion, these findings indicate that improvements in postoperative care after TAVI are equally, if not more, important for the reduction of peri-procedural stroke than preventive measures during the procedure.

Sinning JM, Hammerstingl C, Vasa-Nicotera M, Adenauer V, Lema Cachiguango SJ, Scheer AC, Hausen S, Sedaghat A, Ghanem A, Müller C, Grube E,Nickenig G, Werner N. (2012).  Aortic regurgitation index defines severity of peri-prosthetic regurgitation and predicts outcome in patients after transcatheter aortic valve implantation.  J Am Coll Cardiol. 2012 Mar 27;59(13):1134-41. [full abstract provided].

OBJECTIVES:

The aim of this study was to provide a simple, reproducible, and point-of-care assessment of peri-prosthetic aortic regurgitation (periAR) during trans-catheter aortic valve implantation (TAVI) and to decipher the impact of this peri-procedural parameter on outcome.

BACKGROUND:

Because periAR after TAVI might be associated with adverse outcome, precise quantification of periAR is of paramount importance but remains technically challenging.

METHODS:

The severity of periAR was prospectively evaluated in 146 patients treated with the Medtronic CoreValve (Minneapolis, Minnesota) prosthesis by echocardiography, angiography, and measurement of the aortic regurgitation (AR) index, which is calculated as ratio of the gradient between diastolic blood pressure (DBP) and left ventricular end-diastolic pressure (LVEDP) to systolic blood pressure (SBP): [(DBP – LVEDP)/SBP] × 100.

RESULTS:

After TAVI, 53 patients (36.3%) showed no signs of periAR and 71 patients (48.6%) showed only mild periAR, whereas 18 patients (12.3%) and 4 patients (2.7%) suffered from moderate and severe periAR, respectively. The AR index decreased stepwise from 31.7 ± 10.4 in patients without periAR, to 28.0 ± 8.5 with mild periAR, 19.6 ± 7.6 with moderate periAR, and 7.6 ± 2.6 with severe periAR (p < 0.001), respectively. Patients with AR index <25 had a significantly increased 1-year mortality risk compared with patients with AR index ≥25 (46.0% vs. 16.7%; p < 0.001). The AR index provided additional prognostic information beyond the echocardiographically assessed severity of periAR and independently predicted 1-year mortality (hazard ratio: 2.9, 95% confidence interval: 1.3 to 6.4; p = 0.009).

CONCLUSIONS:

The assessment of the AR index allows a precise judgment of periAR, independently predicts 1-year mortality after TAVI, and provides additional prognostic information that is complementary to the echocardiographically assessed severity of periAR.

Gotzmann M, Lindstaedt M, Mügge A. (2012). From pressure overload to volume overload: Aortic regurgitation after transcatheter aortic valve implantation.  Am Heart J. 2012 Jun;163(6):903-11.  [full abstract provided].

Severe aortic valve stenosis is a common valvular heart disease that is characterized by left ventricular (LV) pressure overload. A lasting effect of pressure overload is LV remodeling, accompanied by concentric hypertrophy and  increased   myocardial stiffness. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement for patients with severe symptomatic aortic valve stenosis and high surgical risk.   Although TAVI has  favorable hemodynamic performance, aortic valve regurgitation (AR) is the most frequent complication because of the specific technique used for implantation of transcatheter valves.

During  implantation, the calcified native valve is pushed aside, and the prosthesis usually achieves only an incomplete prosthesis apposition. As a consequence, the reported prevalence of moderate and severe AR after TAVI is  6% to 21%,  which is considerably higher than that after a surgical valve replacement. Although mild AR probably has minor hemodynamic effects, even moderate AR might result in serious consequences. In moderate and   severe  AR  after TAVI,  a normal-sized LV with increased myocardial stiffness has been exposed to volume overload. Because the noncompliant LV is unable to raise end-diastolic volume, the end-diastolic pressure increases, and  the  forward stroke volume    decreases. In recent years, an increasing number of patients have successfully undergone TAVI. Despite encouraging overall results, a substantial number of patients receive neither symptomatic nor prognostic benefits from TAVI.   Aortic valve regurgitation has been considered a potential contributor to morbidity and mortality after TAVI. Therefore, various strategies and improvements in valve designs are mandatory to  reduce the prevalence of AR after TAVI.

Walther T , Thielmann M, Kempfert J, Schroefel H, Wimmer-Greinecker G, Treede H, Wahlers T, Wendler O. (2012). PREVAIL TRANSAPICAL: multicentre trial of transcatheter aortic valve implantation using the newly designed bioprosthesis (SAPIEN-XT) and delivery system (ASCENDRA-II).  Eur J Cardiothorac Surg. 2012 Aug;42(2):278-83. Epub 2012 Jan 30.  [full abstract provided].

OBJECTIVE

Transapical (TA- aortic valve implantation (AVI) has evolved as an alternative procedure for high-risk patients.  We evaluated the second-generation SAPIEN xt ™ prosthesis in a prospective multicentre clinical trial.

METHODS

A total of 150 patients  (age : 81.6;  40.7 % female) were included. Prosthetic valves (diameter :23 mm (n= 36), 26 mm (n= 57) and 29 mm (n= 57) were implanted. The ASCENDRA-II™ modified delivery system was used in the smaller sizes.   Mean logistic EuroSCORE was  24.3%  and mean STS score was 7.5 ± 4.4%.  All patients gave written informed consent.

RESULTS:

Off-pump AVI was performed using femoral arterial and venous access as a safety net.  All but two patients receivec TA-AVI, as planned.  The 29-mm valve showed similar function as the values of two other diameters did.  Three patients (2%) required temporary bypass support.

Postoperative complications included renal failure requiring long-term dialysis in four, bleeding requiring re-thoracotomy in four, respiratory complication requiring re-intubation in eight and septsis in four patients, respectively.

Thirty day mortality was 13 ( 8.7%)  for the total cohort and 2/57  (3.5%) receiving the 29 mm valve respectively.   Echocardiography at discharge showed none or trivial incompetence (AI) in  71%  and mild-AI in 22% of the patients.  Post-implantation AI was predominantly para-valvular and > 2+  in 7% of patients.  One patient required re-operation for AI within 30 days.

CONCLUSION

The PREVAIL TA multicenter trial demonstrates good functionality and good outcomes for TA-AVI, using the SAPIEN xt ™ and its second generation ASCENDRA-II™ delivery system, as well successful  introduction of the 29-mm  SAPIEN XT ™ valve for the benefit of high-risk elderly patients.

Subramanian S, Rastan AJ, Holzhey D, Haensig M, Kempfert J, Borger MA, Walther T, Mohr FW. (2012).  Conventional Aortic Valve Replacement in Transcatheter Aortic Valve Implantation Candidates: A 5-Year Experience.  Ann Thorac Surg.   July 19 2012  [full abstract provided].

BACKGROUND:

Patient selection for transcatheter aortic valve implantation (TAVI) remains highly controversial. Some screened patients subsequently undergo conventional aortic valve replacement (AVR) because they are unsuitable TAVI candidates. This study examined the indications and outcomes for these patients, thereby determining the efficacy of the screening process.

METHODS:

Between January 2006 and December 2010, 79 consecutive patients (49% men), aged older than 75 years with high surgical risk, were screened for TAVI, but subsequently underwent conventional AVR through a partial or complete sternotomy. The indications, demographics, and outcomes of this cohort were studied.

RESULTS:

Mean age was 80.4 ± 3.6 years. Mean left ventricular ejection fraction was 0.55 ± 0.16, and the mean logistic European System for Cardiac Operative Risk Evaluation was 13% ± 7%. Of the 79 patients, 6 (7.6%) had prior cardiac surgical procedures. Indications for TAVI denial after patient evaluations were a large annulus in 31 (39%), acceptable risk profile for AVR in 24 (30%), need for urgent operation in 11 (14%), and concomitant cardiovascular pathology in 5 (6%). Mean cross-clamp time was 55 ± 14 minutes, and cardiopulmonary bypass time was 81 ± 21 minutes. Concomitant procedures included a Maze in 12 patients (15%). Postoperative morbidity included permanent stroke in 2 (2.5%), respiratory failure in 9 (11%), and pacemaker implantation in 2 (2.5%). Hospital mortality was 1.3% (1 of 79). Cumulative survival at 6, 12, and 36 months was 88.5%, 87.1% and 72.7%, respectively.

CONCLUSIONS:

Our existing patient evaluation process accurately defines an acceptable risk cohort for conventional AVR. The late mortality rate reflects the advanced age and comorbidities of this cohort. The data suggest that overzealous widening of TAVI inclusion criteria may be inappropriate.

Industry fights back

Now it looks like Edwards Lifesciences,  the company that manufacturers the Sapien valve is speaking out to dispute recent findings that show TAVI to have less than optimal results.  Of course, the author at the site, Med Latest says it best, “Setting aside the conflict of interest stuff, which might be a red-herring, what we’re left with is a situation where evidence-based medicine, while being something all would sign up to, is not that straightforward.”

[1] Several cardiologists and cardiac surgeons contributed to this article.  However, given the current politics  within cardiology, none of these experts were willing to risk their reputations by publically disputing the majority opinion.  This is certainly understandable in today’s medico-legal climate in wake of widespread scandals and credibility issues. However, all quotes are accurate, even if unattributable with minor formatting (such as the addition of quotations, and paragraph headings have been added for increased clarity of reading in blog format.)  I apologize for the ‘anonymous nature’ of my sources in this instance – however, I can assure you that these ‘experts’ know what they are talking about.

  [All commentary by Cartagena Surgery are in italics and brackets]. 

Readers write in: TAVI

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Thanks again to ‘Lapeyre’, who as it turns out is Dr. Didier Lapeyre, a renowned, French cardiothoracic surgeon credited with the development of the first mechanical valves.

Dr. Didier Lapeyre was gracious enough to send some additional literature to add to our ongoing discussions regarding severe aortic stenosis and TAVI/ TAVR therapies.  He also commented that the best way to avoid these ‘high risk situations’ is by earlier intervention with conventional surgery – something we discussed before in the article entitled, “More patients need surgery.”

He also points out that ‘elderly’ patients actually do quite well with aortic valve replacement and offers a recently published meta-analysis of 48 studies on patients aged 80 or older.

As readers know, on June 13, 2012 – the FDA ruled in favor of expanding the eligibility criteria for this therapy.  Previously, this treatment modality, due to its experimental nature and high rate of complications including stroke and serious bleeding, has been limited in the United States to patients deemed ineligible for aortic valve replacement surgery.

Now on the heels of the Partner A trial, in which researchers reported favorable results for patients receiving the Sapien device, the FDA has voted to approve expanding criteria to include patients deemed to be high risk candidates for surgery.  As we have discussed on previous occasions, this opens the door to the potential for widespread abuse, misapplication of this therapy and potential patient harm.

In the accompanying 114 page article, “Transcatheter aortic valve implantation (TAVI): a health technology assessment update,” Belgian researchers (Mattias, Van Brabandt, Van de Sande & Deviese, 2011) looking at transcatheter valve procedures have found exactly that in their examination of the use of TAVI worldwide.

Most notably, is the evidence of widespread abuse in Germany (page 49 of report), which has become well-known for their early adoption of this technology, and now uses TAVI for an estimated 25 – 40% of valve procedures*.  Closer examination of the practices in this country show poor data reporting with incomplete information in the national registry as well as a reported mortality rate of 7.7%, which is more than double that of conventional surgery.  Unsurprisingly, in Germany, TAVI is reimbursed at double the amount compared to conventional surgery**, providing sufficient incentive for hospitals and cardiologists to use TAVI even in low risk patients. (and yes, german cardiologists are often citing “patient refused surgery” as their reason, particularly when using TAVI on younger, healthy, low risk patients.)

In their examination of the data itself, Mattias et al. (2011) found significant researcher bias within the study design and interpretation of results.  More alarmingly, Mattias found that one of the principle researchers in the Partner A study, Dr. Martin Leon had major financial incentives for reporting successful results.  He had recently received a 6.9 million dollar payment from Edward Lifesciences, the creators of the Sapien valve for purchase of his own transcatheter valve company.   He also received 1.5 million dollar bonus if the Partner A trial reached specific milestones.  This fact alone, in my mind, calls into question the integrity of the entire study.

[Please note that this is just a tiny summary of the exhaustive report.]

Thank you, Dr. Lapeyre for offering your expertise for the benefit of our readers!

* Estimates on the implantation of TAVI in Germany vary widely due to a lack of consistent reporting.

** At the time of the report, TAVI was reimbursed at 36,000 euros (45,500 dollars) versus 17,500 euros (22,000 dollars) for aortic valve replacement.

For more posts on TAVI and aortic stenosis, see our TAVI archive.

References

Mattias, N., Van Brabandt, H., Van de Sande, S. & Deviese, S. (2011).  Transcatheter aortic valve implantation (TAVI): a health technology assessment .  Belgian Health Care Knowledge Centre.

Vasques, F., Messori, A., Lucenteforte, E. & Biancari, F. (2012).  Immediate and late outcome of patients aged 80 years and older undergoing isolated aortic valve replacement: a systematic review and meta-analysis of 48 studies.  Am Heart J 2012; 163: 477-85.

Update: Medicare to cover TAVI/ TAVR

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In an update to a previous story here at Cartagena Surgery, in the attached article, “Medicare to pay for TAVI” from Medpage.com by Chris Kaiser, the guidelines for CMS payment for TAVI/ TAVR have been released.   These criterion include the restriction that only surgery ineligible patients be included and that implanting surgeons must participate in the TAVI registry.

More importantly, this criteria requires that TWO cardiac surgeons determine the patient’s suitability to withstand surgery versus TAVI.  This is a crucial requirement as we’ve discussed before, since only a surgeon can accurately decide/ predict how a patient might tolerate surgery.  (Multiple previous studies showed that primary care providers and cardiologists were poor judges of patient’s surgical risk. )  Also, the lack of this requirement in Europe has caused several ethical problems as interventional cardiologists began the widespread implantation of experimental technologies in lower risk patients (particularly in Germany.)

Blue Cross/ Blue Shield of Mexicali & Dr. Cuauhtemoc Vasquez Jimenez

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Note:  I owe Dr. Vasquez a much more detailed article – which I am currently writing – but after our intellectually stimulating talk the other day, my mind headed off in it’s own direction..

Had a great sit down lunch and a fascinating talk with Dr. Vasquez.  As per usual – our discussion was lively, (a bit more lively than usual) which really got my gears turning.  Dr. Vasquez is a talented surgeon – but he could be even better with just a little ‘help’.  No – I am not trying to sell him a nurse practitioner – instead I am trying to sell Mexicali, and a comprehensive cardiac surgery program to the communities on both sides of the border..  Mexicali really could be the ‘land of opportunity’ for medical care – if motivated people and corporations got involved.

During lunch, Dr. Vasquez was explaining that there is no real ‘heart hospital’ or cardiac surgery program, per se in Mexicali – he just operates where ever his patients prefer.  In the past that has included Mexicali General, Issstecali (the public hospitals) as well as the tiny but more upscale private facilities such as Hospital Alamater, and Hospital de la Familia..

Not such a big deal if you are a plastic surgeon doing a nip/tuck here and there, or some outpatient procedures – okay even for general surgeons – hernia repairs and such – but less than ideal for a cardiac surgeon – who is less of a ‘lone wolf’ due to the nature and scale of cardiac surgery procedures..

Cardiac surgery differs from other specialties in its reliance on a cohesive, well-trained and experienced group – not one surgeon – but a whole team of people to look out for the patients; Before, During & After surgery..  That team approach [which includes perfusionists, cardiac anesthesiologists (more specialized than regular anesthesia), operating room personnel, cardiology interventionalists and specialty training cardiac surgery intensive care nurses]  is not easily transported from facility to facility.

just a couple members of the cardiac surgery team

That’s just the people involved; it doesn’t even touch on all the specialty equipment; such as the bypass pump itself, echocardiogram equipment, Impella/ IABP (intra-aortic balloon pump), ECMO or other equipment for the critically ill – or even just the infrastructure needed to support a heart team – like a pharmacy division that knows that ‘right now’ in the cardiac OR means five minutes ago, or a blood bank with an adequate stock of platelets, FFP and a wide range of other blood products..

We haven’t even gotten into such things such as a hydrid operating rooms and 24/7 caths labs – all the things you need for urgent/ emergent cases, endovascular interventions – things a city the size of Mexicali should really have..

But all of those things take money – and commitment, and I’m just not sure that the city of Mexicali is ready to commit to supporting Dr. Vasquez (and the 20 – something cases he’s done this year..) It also takes vision..

This is where a company/ corporation could come in and really change things – not just for Dr. Vasquez – and Mexicali – but for California..

It came to me again while I was in the operating room with Dr. Vasquez – watching him do what he does best – which is sometimes when I do what I do best.. (I have some of my best ideas in the operating room – where I tend to be a bit quieter.. More thinking, less talking)..

Dr. Vasquez, doing what he does best..

As I am watching Dr. Vasquez – I starting thinking about all the different cardiac surgery programs I’ve been to: visited, worked in – trained in.. About half of these programs were small – several were tiny, single surgeon programs a lot like his.. (You only need one great surgeon.. It’s all the other niceties that make or break a program..)

All of the American programs had the advantages of all the equipment / specialty trained staff that money could buy***

[I know what you are thinking – “well – but isn’t it all of these ‘niceties’ that make everything cost so darn much?”  No – actually it’s not – which is how the Cardioinfantils, and Santa Fe de Bogotas can still make a profit offering world-class services at Colombian prices…]

The cost of American programs are inflated due to the cost of defensive medicine practices (and lawyers), and the costs of medications/ equipment in the United States****

the possibilities are endless – when I spend quality time in the operating room (thinking!)

Well – there is plenty of money in Calexico, California** and not a hospital in sight – just a one room ‘urgent care center’.  The closest facility is in El Centro, California – and while it boasts a daVinci robot, and a (part-time?) heart surgeon (based out of La Mesa, California – 100 + miles away)– patients usually end up being transferred to San Diego for surgery.

Of course, in addition to all of the distance – there is also all of the expense..  So what’s a hard-working, blue-collar guy from Calexico with severe CAD going to do?  It seems the easiest and most logical thing – would be to walk/ drive/ head across the street to Mexicali.. (If only Kaiser Permanente or Blue Cross California would step up and spearhead this project – we could have the best of both worlds – for residents of both cities.. 

 A fully staffed, well-funded, well-designed, cohesive heart program in ONE medium- sized Mexicali facility – without the exorbitant costs of an American program (from defensive medicine practices, and outlandish American salaries.)  Not only that – but as a side benefit, there are NO drug shortages here..

How many ‘cross-border’ cases would it take to bring a profit to the investors?  I don’t know – but I’m sure once word got out – people would come from all over Southern California and Arizona – as well as Mexicali, other parts of Baja, and even places in Sonora like San Luis – which is closer to Mexicali than Hermasillo..  Then Dr. Vasquez could continue to do what he does so well – operate – but on a larger scale, without worrying about resources, or having to bring a suitcase full of equipment to the OR.

The Mexican – American International Cardiac Health Initiative?

But then – this article isn’t really about the ‘Mexican- American cross-border cardiac health initiative’ –

It is about a young, kind cardiac surgeon – with a vision of his own.

That vision brought Dr. Vasquez from his home in Guadalajara (the second largest city in Mexico) to one of my favorite places, Mexicali after graduating from the Universidad Autonomica in Guadalajara, and completing much of his training in Mexico (D.F.).  After finishing his training – Dr. Vasquez was more than ready to take on the world – and Mexicali as it’s first full-time cardiac surgeon.

Mexicali’s finest: Dr. Vasquez, (cardiac surgeon) Dr. Campa(anesthesia) and Dr. Ochoa (thoracic surgeon

Since arriving here almost two years ago – that’s exactly what he’s done.. Little by little, and case by case – he has begun building his practice; doing a wide range of cardiovascular procedures including coronary bypass surgery (CABG), valve replacement procedures, repair of the great vessels (aneurysm/ dissections), congenital repairs, and pulmonary thrombolectomies..

Dr. Vasquez, Mexicali’s cardiac surgeon

Dr. Cuauhtemoc Vasquez Jimenez, MD

Cardiac Surgeon

Calle B No. 248 entre Obregon y Reforma

Col. Centro, Mexicali, B. C.

Email: drcvasquez@hotmail.com

Tele: (686) 553 – 4714 (appointments)

Notes:

*The Imperial Valley paper reports that Calexico makes 3 million dollars a day off of Mexicali residents who cross the border to shop.

***In all the programs I visited  – there are a couple of things that we (in the United States do well..  Heart surgery is one of those things..)

**** Yes – they charge us more in Calexico for the same exact equipment made in India and sold everywhere else in the world..

Six month TAVI/TAVR data released

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The Core Valve by Medtronic

Medtronic, the makers and financial backers of a recent study on the Core Valve used for percutaneous aortic valve replacement (aka non-surgical valve replacement) released their findings showing the six month mortality data on patients receiving this valve.

This study which was performed using data from European cardiologists (who have been using this technology longer) were unsurprising – with a higher risk of stroke and overall mortality.  Notably, this study was performed on patients deemed to be ‘at high risk’ for surgery, not ineligible for surgery.  As we’ve discussed before, the term ‘high risk’ is open to considerable interpretation.

“ A total of 996 frail, elderly patients at high risk for heart surgery were  implanted with Medtronic’s CoreValve device, used to treat severe narrowing of  the aortic valve. Mortality rates at one month and six months were 4.5% and  12.8%, respectively. Stroke rates were 2.9% and 3.4%.

Medtronic said the rates  were consistent with previously reported data from national registries in Europe.”

Unfortunately, the general media’s coverage of these findings have been less than straightforward as Bloomberg proclaims in blazing headlines, “Edwards heart valve skirts rib-cracking for a 2.5 billion dollar market.”  That’s a pretty eye-opening headline that manages to avoid mentioning the real issues – longevity and durability.

Another article from business week proclaims, “Heart Valves found safe.”  Safe, I guess is a relative term – if you aren’t one of the 12.8% that died within six months..

Illustration showing the core valve in place

More about Aortic Stenosis and Valve Replacement therapies at Cartagena Surgery:  (you can also find a link to these stories under the TAVI tab on the sidebar.)

Aortic Stenosis as Heinz 57

More patients need surgery

Aortic Stenosis, surgery and the elderly

Aortic stenosis and TAVI

Aortic Stenosis: New Recommendations for TAVI

Transcatheter Valve Therapies: an overview

TAVI and long-term outcomes

Peri-operative outcomes with TAVI

Talking about TAVI/ TAVR with Dr. Kevin Brady

Will Medicare cover TAVI?

Will Medicare cover TAVI/ TAVR?

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Updates to this story have been posted here.

In an article re-post from the Heart.org, Lisa Nainggolan discusses a recent memo issued by Medicare & Medicaid services (CMS) on potential coverage for TAVI/ TAVR.    This memo lays out the necessary criteria and conditions that must be met for CMS coverage.

Don’t have medicaid or medicare?  Well, the privately insured should still sit up and take notice:  CMS decisions usually set the pace for everyone else – meaning, if Medicare won’t pay for it – then Blue Cross, Anthem and most of the big private insurances won’t either.

CMS draft of proposed coverage – the Heart.org 

Lisa Nainggolan

Baltimore, MD – The US Centers for Medicare & Medicaid Services (CMS) has issued a memo detailing its proposed coverage for transcatheter aortic-valve replacement (TAVR) [1]. The move follows a request for national coverage determination (NCD) from the ACC and Society for Thoracic Surgeons (STS), made last September.

The memo—which is a draft and will be open for public comment until March 3—outlines the conditions under which the CMS will cover TAVR, also known as transcatheter aortic-valve implantation (TAVI), and follows hard on the heels of an expert consensus document on the new technology, published earlier this week.

An estimated 45 000 patients have received TAVI worldwide, with most procedures so far being performed in Europe. US approval of the Edwards Sapien valve at the end of last year means that the country must now gear up to introduce this technology nationwide, and the expert guidance has been designed to act as a roadmap for the rollout of TAVI in the US.

Five conditions must be met for Medicare coverage of TAVR

TAVR will be covered for the treatment of severe symptomatic aortic-valve stenosis only, says the CMS, and the following five conditions must be met:

  • The procedure is performed for an approved indication with a valve and implantation system that has received FDA approval for this indication.
  • Two cardiac surgeons have evaluated the patient’s suitability for open valve-replacement surgery. (traditional cardiac surgery)
  • The procedure is performed in a facility that meets certain requirements with regard to surgical and interventional cardiology expertise. In addition, institutions with prior TAVR experience must participate in ongoing trials or postapproval studies, and all centers performing TAVR must commit to the “heart-team” concept and enroll in a prospective national TAVR study.
  • TAVR must be carried out by sufficiently qualified and experienced physicians.
  • The treating team must participate in a national registry that enrolls TAVR patients and tracks the following outcomes: major stroke; all-cause mortality; minor stroke/transient ischemic attack; major vascular events; and acute renal injury.

For unlabeled uses of TAVI, the CMS proposes coverage only in the context of a clinical trial, for which it lists 13 conditions.

The CMS also indicates that it will not cover TAVR for any other indications not specified in its memo, nor will it cover the procedure in patients who also have concomitant conditions, including: mixed aortic-valve disease; isolated aortic regurgitation; untreated clinically significant coronary artery disease requiring revascularization; hypertrophic cardiomyopathy; echocardiographic evidence of intracardiac mass; significant aortic disease; and severe obstructive calcification or tortuosity of the iliofemoral vessel or small vessel size.

It’s a mixed win for American cardiologists and cardiac surgeons – and certainly opens the door to the expanded use of this criteria.  The good news is that CMS is taking the initiative to stem off a flood of inappropriate procedures.  The release of this memo, along with the recent publication of new guidelines re-affirming the role of CABG, and relegating PCI to specific circumstances  is almost certainly a response to the numerous scandals and allegations affecting cardiology in 2011 (and ongoing.)

Which hospitals should have TAVR/ TAVI programs?

This article outlines the basic requirements for a safe and successful TAVR program – including the minimum skill requirements for surgeons and interventionalists.

But I suspect – it won’t be long before more and more hospitals open their own programs.  This article highlights the financial gains for hospitals with TAVR programs.

Aortic Valve Replacement & the elderly

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I just read an interesting article in the Annals of Thoracic Surgery.

Unfortunately, the full-text article is not available for free – but I did find a nice article abstract (which I’ve posted below.)  It confirms some of the previous discussions we’ve had here at Cartagena Surgery on the role of surgery in Aortic Stenosis, even in ‘elderly’ patients.  [I put elderly in quotes since the definition can be fairly elastic depending on who is doing the judging.]

The article below is from Medscape.com

Aortic valve replacement in the elderly: the real life.

Ann Thorac Surg. 2012; 93(1):70-8 (ISSN: 1552-6259)

Langanay T; Flécher E; Fouquet O; Ruggieri VG; Tour Bde L; Félix C; Lelong B; Verhoye JP; Corbineau H; Leguerrier A Department of Cardiovascular and Thoracic Surgery, University Hospital, Rennes, France.

BACKGROUND: Aortic stenosis is of concern in the elderly. Although aortic valve replacement provides good long-term survival with functional improvement, many elderly patients are still not referred for surgery because of their age. Percutaneous aortic valve implantation offers an alternative to open-heart surgery. Concerns about the management of aortic valve stenosis in the elderly will be reviewed.

METHODS: We retrospectively analyzed 1,193 consecutive aortic valve replacements, performed in octogenarians since January 2000. A total of 657 patients (55%) had at least one associated comorbidity (eg, respiratory failure) and 381 (32%) associated coronary lesions. Valve replacement was the only procedure in 883 patients (74%), and was associated with coronary revascularization in 262 cases, or with another cardiac procedure in 48 patients.

RESULTS: Overall operative mortality was 6.9% (83 of 1,193 patients); 5.5% for single replacement and 11.5% if associated with coronary artery bypass surgery. Univariate and multivariate analyses identified 11 operative risk factors related to general status, cardiologic condition, and the procedure itself: older age (p< 0.015); respiratory failure (p <0.03); aortic regurgitation (p <0.001); emergency surgery (p <0.0029); New York Heart Association class IV (p < 0.0007); right heart failure (p < 0.03); atrial fibrillation (p < 0.04); impaired ejection fraction (p < 0.001); coronary disease (p < 0.01); redo surgery (p < 0.02); associated coronary revascularization (p < 0.008).

CONCLUSIONS: Today, valve replacement has acceptable low hospital mortality, even in the elderly. Thus, older patients should not be denied surgery due to their advanced age alone. Conventional surgery remains the gold standard treatment for aortic stenosis; the decision should be made on an individual basis. If several risk factors suggest very high-risk surgery, then percutaneous valve implantation should be considered instead.

In more disturbing news:

As predicted, the unproven ‘easy option’ of TAVI is now being pursued by more low-risk patients.  These lower risk patients are people who should have been encouraged to undertake the more durable, safe and proven surgical therapy [Aortic Valve Replacement.]  I guess this just shows how quickly those new recommendations [for patient protection and safety] were thrown out the window.

In this article (posted below) by Kurt Ullman at Medpage Today – German researchers discuss their preliminary findings and discuss the use in low risk patients.

The bar for transcatheter aortic valve implantation (TAVI) is dropping as more lower-risk patients are undergoing the procedure and their outcomes are favorable, a single-center study from Germany found. [Unfortunately – as we’ve seen so many times in the past, and as I am finding out while preparing this presentation on the Syntax trial – studies such as this can be quite deceiving – and LONG term data is needed. – Cartagena Surgery].

When stratified by quartiles based on enrollment date, Q1 patients had higher logistic EuroSCOREs, higher Society of Thoracic Surgeons (STS) scores, and higher median N-terminal pro-B-type natriuretic peptide levels compared with those enrolled later in Q4, noted Nicolo Piazza, MD, PhD, and colleagues from the German Heart Center in Munich.

Although there were significant decreases in 30-day and six-month mortality from Q1 to Q4 in the crude analysis, after adjustments for baseline characteristics, the significant differences disappeared (HR 0.29 for 30-day mortality and HR 0.67 for six-month mortality), according to the study published online in the Journal of the American College of Cardiology.

“These results suggest that underlying comorbidities play an important role in acute and intermediate-term survival after TAVI,” the researchers wrote.

The researchers noted anecdotal information suggesting a shift toward using TAVI in patients who are less sick than those enrolled in premarket trials. Additionally, the next wave of trials involving the CoreValve (Medtronic) and the Sapien XT (Edwards Lifesciences) devices will involve intermediate to high surgical risk patients, providing “yet another indication that TAVI is being directed at the treatment of lower and lower surgical risk patients,” Piazza and colleagues wrote.  [There are significant ethical considerations here which seem to be ignored – similar to criticisms of the Syntax trial – Cartagena Surgery.]

A single-center French study of low-risk TAVI patients found the procedure to be safe in this population. The study was presented at the European Society of Cardiology meeting in Paris.

The impact on this shift in patient selection was uncertain, they said, prompting a retrospective review of 420 patients who underwent TAVI at their institution from June 2007 to June 2010.

The consensus that a patient was suitable for TAVI was derived from a team that comprised cardiologists, cardiac surgeons, and anesthesiologists. This team approach is exemplified by the recent announcement that the American College of Cardiology and the Society of Thoracic Surgeons will jointly sponsor a TAVI registry to monitor the safety and efficacy of the procedure as it rolls out in the U.S.

Patients received either the CoreValve or Sapien device, the latter of which was just approved for use in the U.S. based on the PARTNER trial. PARTNER found that TAVI was as good as surgery in high-risk patients with severe aortic stenosis. [‘as good as’ – ah.. another ‘non-inferiority’ study….. view with skepticism folks..]

Researchers divided patients into four quartiles of 105 patients each. Those in Q1 were seen earlier in the study time frame than those in Q4.

Compared with Q4, Q1 patients had higher EuroSCOREs (25.4% versus 17.8%, P<0.001), STS scores (7.1% versus 4.8%, P<0.001), and NT-proBNP levels (3,495 versus 1,730 ng/dL, P<0.046).

There were significantly less transfemoral access approaches from Q1 to Q4, with a concomitant rise in transapical approaches. There also were significantly less intubations moving from Q1 to Q4, and the use of contrast significantly decreased over time.

Researchers noted that transfemoral complications decreased by 17% from Q1 to Q4 (P=0.008), but found no significant differences in the rate of stroke or transient ischemic attack or the need for a permanent pacemaker.

However, there was a shift in the later quartiles toward the treatment of younger patients with fewer comorbidities and lower surgical risk scores, Piazza and colleagues wrote.

Univariable analysis for 30-day mortality showed it was associated with age, STS score, atrial fibrillation, previous heart surgery, and previous stroke (P<0.10).

The factors associated with six-month mortality were age, logistic EuroSCORE, STS score, left ventricular ejection fraction, atrial fibrillation, previous cardiac surgery, chronic obstructive pulmonary disease, and N-terminal pro-B type natriuretic peptide (P<0.10).

Because only baseline characteristics were included, the authors noted the possibility that procedure-, operator-, or device-related factors might influence both 30-day and six-month mortality. The study is also limited by potential unmeasured confounding.

The investigators cautioned that little is known of the long-term durability of these devices should they be routinely implanted in younger patients with a longer expected life span.  [especially since the lifespan of the patients these valves were designed for was six months to one year..]

Piazza is a consultant and proctor for Medtronic and CardiAQ. Other authors revealed consultant status with Medtronic and Edwards Lifesciences, or instuctors for Medtronic

It looks like TAVI is here.

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The FDA recently approved the first TAVI device for aortic stenosis.   Currently the device is only eligible for patients who are unable to withstand surgery.   But who will end up making that determination?  The cardiologist who will be implanting the device?  At present – the company manufacturing the Sapien aortic device is recommending that patients be evaluated by a heart surgeon – but if this follows the typical course, I am sure that this recommendation will be abandoned as a matter of course.

Hopefully, the industry (interventional cardiology) will proceed cautiously, after being ‘omce bitten, twice shy” in light of the epidemic overstenting catastrophies.

For more on Aortic stenosis, TAVI and the overstenting controversies – look under the cardiology and cardiac surgery tab.

Long-term outcomes with TAVI

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As many readers know, I advise caution to patients prior to pursuing TAVI (or transcatheter aortic valve implantation, primarily because there is no long-term data on durability or long-term effects.

One of these days, I may have to eat my words – and when that day comes; I will be happy to do so (and will do it with a 14-point font).  But that day is not today.

As reported by Reed Miller over at Heartwire, there are the first results of a very small Canadian study with average follow-up 3.7 years after implantation..  Unfortunately, its way too small of a sample – and mean follow-up falls short of the five-year mark.

But given the rate of implantation in Europe (Germany, in particular) and the fact that these valves are used in younger patients over there – we should have some large (thousands of patients enrolled) studies with five-year data in just a year or two.. One of two well designed studies with a large study population would sure make a lot of us over here (in the USA) feel a lot more comfortable about the safety and efficacy of these devices in our patients.

Now, I bet most of you have gotten pretty good at picking through these Heartwire articles to get to the bit of truth inside – and the experts quoted here do a much better job at providing straight forward answers (unlike the cast of characters quoted for many of the articles regarding the stent scandals.)

(I’ll re-post below so you can see for yourself.)  I’ve also included links to our little collection of TAVI articles here – or the ‘TAVI library” for first-time readers to catch up.

1.  Aortic Stenosis – more patients need surgery  – for some background on the issue (more articles on Aortic stenosis under cardiology)

2.  TAVI  – ‘a new stent scenario’ – discussing concerns with the widespread adoption of this therapy

3.  TAVI recommendations and guidelines –  the most recent established US guidelines for therapy

4.  TAVI – an overview – getting back to the basics

5.  TAVI – mortality data – this had some pretty frightening results, another reason for caution.

6. TAVI and FDA approval: what does it mean? – talking about the implications of FDA approval, and the history of FDA approval of medical devices.

CoreValve TAVI maintains durability out to four years in small study

(Reed Miller)

[Bold type from original article]

Paris, France – The longest follow-up of patients implanted with the CoreValve (Medtronic) transcatheter aortic-valve implantation (TAVI) device presented so far suggests that it is reliable and durable in high-risk patients, according to the study investigators [1].

“In due time, I’m sure we will see a gradual decrease in the average patient age, treating patients with less comorbidity than was done in the beginning, strengthened by these types of results showing the durability of the implants,” study lead-investigator Dr Peter den Heijer (Amphia Hospital, Breda, the Netherlands) told heartwire.

Here at the European Society of Cardiology 2011 Congress, den Heijer presented long-term follow-up results from 52 patients implanted with the second-generation version of CoreValve in 2005 and 2006 in Europe and Canada. All of the patients in the study were at least 80 years old with a logistic EuroSCORE over 20 or over 65 years old with at least one high-risk comorbidity. All of the patients had severe aortic stenosis and an aortic-valve annulus diameter between 20 mm and 24 mm. Two-thirds of the patients had NYHA class 3 heart failure and almost 20% had class 4 heart failure.

Four-year follow-up data was collected on 20 patients, but 26 patients died, including 13 cardiac deaths. Overall survival was 58.5% at two years and 45.1% at four years. At four years, the surviving patients showed significant improvement in heart-failure symptoms, with 61% in class 1 heart failure and 22% in class 2. Nearly a third of patients showed grade 2 or 3 aortic regurgitation at baseline, but after four years 57% showed no regurgitation and 43% showed grade 1 regurgitation. The mean valve gradient decreased from 41 mm Hg at baseline to 12 mm Hg at 30 days and 10 mm Hg at four years.

There were no strokes reported in the study population between three months and four years and no frame fractures, valve migrations, valve endocarditis, or structural valve deteriorations leading to stenosis or regurgitation. “That’s important, because the goal of this treatment is to provide patients with severe aortic stenosis, a severely life-limiting disease, with a better prognosis, and it appears to be not at all hampered by the structure of the valve,” den Heijer told heartwire.

In a 70-patient study by Dr Ronen Gurvitch (University of British Columbia, Vancouver) colleagues, the Sapien (Edwards Lifesciences) transcatheter aortic valve showed no structural valvular deterioration, stent fracture, deformation, or valve migration over a mean follow-up of 3.7 years [2].

CoreValve is available in Europe and is being tested in a major US clinical trial that Medtronic says will be completed in 2012. The FDA is expected to approve Edward’s Sapien TAVI device soon, following a positive appraisal by its advisory committee.

Still much too early to assess long-term TAVI results

Surgeon Dr Craig Miller (Stanford University, CA), one of the investigators of the pivotal PARTNER trial of Sapien, told heartwire that while the four-year results with CoreValve are “decent,” the clinical community will “need much larger numbers of patients followed at two, three, and four years for the hemodynamics to mean much.”

PARTNER investigator Dr Michael Mack (Medical City Dallas Hospital, TX) told heartwire, “Although it’s reassuring that there are now results out to four years and there’s no sign of structural valve deterioration, it really adds minimal information to what we know already.

“There’s only 20 patients alive at four years, so how do you know what happened to the other 30 patients [in the trial]? Some died of cardiac death and some died of unknown causes. How do you know they didn’t die of structural valve deterioration?” he said. “A better way of doing this study for all aspects is that all the information should be on matched patients.”

Mack said that the real long-term durability of transcatheter valves will become more clear with more data from the SOURCE registry and the long-term follow-up of PARTNER trial, which will include annual core-lab-adjudicated echocardiography follow-up out to five years.

In an email to heartwire, Dr Grayson Wheatley (Arizona Heart Institute, Phoenix) pointed out that although the study had a high percentage of cardiac-related deaths, the arrhythmia-related deaths were a smaller proportion than in some other recent studies. But Mack and Wheatley also pointed out that because there was no echocardiographic core lab in this study, the functional assessments of the valve may not have been always accurate.

Wheatley also pointed out that this study used an older version of the CoreValve, so “this study doesn’t relate too well to real-world use of the CoreValve due to new design changes in the valve system, but it does show that, in general, TAVI procedures can be used in high-risk cardiac patients and that there will be long-term survivors.”

 

TAVI overseas –

As mentioned above, TAVI has rapidly been implemented in Europe.  Latin American medicine has begun to embrace this emerging technology as well.  In fact, US physicians are travelling outside the country to perform this procedure on their patients (since it’s not FDA approved.)

From a statement by the University of Miami Medical School – International Medicine Institute: [verbatim]

“New Technology Treats Aortic Heart Valve Disease Without Surgery

 At 86, Dr. Isaac Hariton is back to walking three miles a day since getting a new aortic valve this past June. To avoid surgery, this retired surgeon traveled to Cali, Columbia, for his procedure.  Hariton’s doctor is Eduardo de Marchena from UHealth – University of Miami Health System, who traveled with him to implant a valve not FDA approved for use in this country.”

Peri-operative mortality with/after TAVI for aortic stenosis

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More on TAVI: A newly published analysis of the existing/ reported data for peri-operative mortality after transcatheter aortic valve implantation looking at 12 previous studies was recently (June) published in the journal of Interventional Cardiology.  (While the study looks at the causes of death – we here at Cartagena Surgery – are going to talk about the rate of death in this study.)

Article information:

Causes of Peri-Operative Mortality After Transcatheter Aortic Valve Implantation: A Pooled Analysis of 12 Studies and 1,223 Patients.  The Journal of Invasive Cardiology 2011;23(5):180-184.

Raul Moreno, MD; Luis Calvo, MD; Pablo Salinas, MD; David Dobarro, MD; Jimenez Valero Santiago, MD; Angel Sanchez-Recalde, MD; Guillermo Galeote, MD; Luis Riera, MD; Isidro Moreno-Gomez, MD; Jose Mesa, MD; Ignacio Plaza, MD; Jose Lopez-Sendon, MD

Abstract re-posted below.

Background. In order to improve technique and to prevent serious procedural complications during transcatheter aortic valve implantation (TAVI), it is crucial to identify the causes of death of patients undergoing this procedure.
Objective. The objective of this study was to identify the causes of death during the procedure and at 1 month in patients with severe aortic stenosis undergoing TAVI.

Methods. 12 published studies with information about the causes of death in patients undergoing TAVI were selected. Overall, 1,223 patients were included in these studies, and 249 deaths were reported (119 at 1 month and 130 at > 1 month post-procedure).

Mortality during the procedure and at 1 month was 2.3% and 9.7%, respectively. The proportion of cardiac deaths was higher at < 1 month in comparison with > 1 month (56% versus 34%, respectively; p = 0.001). At 1 month, the most frequent causes of death were cardiac failure/multi-organ failure (24%), sudden death/cardiac arrest (17%), vascular and bleeding complications (17%), stroke (11%), sepsis (11%), and cardiac tamponade (10%). During the procedure, the most frequent causes of death were cardiac tamponade (39%), cardiac failure (21%), cardiac arrest (18%), and vascular and/or bleeding complications (18%).

In patients treated with the CoreValve system (Medtronic, Minneapolis, Minnesota) versus those treated with Edwards valves (Cribier-Edwards, Edwards-SAPIEN or SAPIEN XT valve, Edward Lifesciences, Irvine, California), deaths at 1 month due to vascular and bleeding complications were less frequent (3% versus 22%, respectively; p = 0.019), but those due to cardiac tamponade (26% versus 6%, respectively; p = 0.019), and because of aortic regurgitation (10% versus 0%, respectively; p = 0.03) were more frequent.

Conclusion. In this pooled analysis, mortality at 1 month after TAVI was 9.7%. The causes of death were widely variable, and of both cardiac and non-cardiac origin. There were some important differences between both devices in the cause of mortality.

How does this compare with conventional aortic valve replacement surgery (AVR)?

In cardiac surgery – surgeons use database calculators.  The most popular one is called the STS risk calculator to determine or estimate the surgical risk for specific patients.  This calculator is based on thousands and thousands of patients over decades of research to give approximate surgical risk of morbidity (post-operative complications) and mortality by looking at the planned procedure as well as patient risk factors (age, poor heart function, co-morbidities).  Other calculators include a European calculator called EUROscore, and a score used  by the VA (veteran’s hospitals.)

Well, how accurate are these calculators?

Interestingly enough – at the same time as the TAVI article, an article (Basreon et. al) discussing and comparing each of these calculators to actual results was published in the June 23 issue of the Annals of Thoracic Surgery.  (I’ve re-posted the abstract below.)

In their research – Basreon et. al. found the overall peri-operative mortality for aortic valve replacement surgery to be 5.9%  which is well under the 9.7% reported in the article by Moreno, et. al (re-posted above) for TAVI.

While the argument can be made that the higher than expected peri-operative mortality in the TAVI group may be secondary to other factors (patient condition at time of TAVI) without more information on patient demographics – it is hard to know.

I, for one, would like to know the average ages of patients in both groups – was the TAVI group made up of non-surgical fragile, 95 year-olds?  What specific factors raised their EUROscores? Was it overall heart function, or was it a specific co-morbidity?

It’s difficult to know since it’s a composite of other research data from multiple studies (and since TAVI is widely used in Europe, accounting for as many as 40% of all aortic procedures in Germany, for example) – this data may also reflect many of these patients (who are not frail elderly, for example.)

Reading through the Moreno study – there is little discussion of the actual patient population, except for one small paragraph (re-posted below). Both of these limitations are probably due to the nature of the study – where investigators were pooling the results of several different studies – which is a good strategy to get a wide overview.  However, this can make it impossible to go back and look at questions like ours, particularly if the investigators on the original, smaller studies didn’t record / report this information.

[my comments in brackets/ italics].  I have placed data within the article in bold or italics. 

“In this study, pooling the results of 12 series, mortality at 1 month in patients treated with TAVI was 9.7%, and mortality during the procedure was 2.3%. These data compare favorably with the predicted surgical mortality, since EuroSCOREs ranged from 12–28%.  [this is the risk calculator that Basreon et. al found that grossly overestimated risk in the study re-posted below.]

In the randomized PARTNER trial, a significant reduction (~20% absolute risk reduction) in the 1-year mortality was obtained for patients with severe aortic stenosis and considered not suitable for surgery due to a very high surgical risk when treated with TAVI in comparison with medical treatment. [as you know from previous discussions – medical treatment is exceedingly ineffective for this condition.  It would be more helpful if authors had better defined their ‘very high’ risk patient group since multiple studies show that cardiologists, etc. overestimate patient’s surgical risk.] 

Importantly, mortality significantly reduced through the years, from 2004 to 2010, probably reflecting not only the learning curve and the technical improvements, but also a better patient selection process. [meaning patients that are ineligible for surgery may also be ineligible for TAVI in some cases.]   This reduction in mortality over time has also been observed in single-center experiences.“

Although not statistically significant, mortality at 30 days was higher in patients treated by transapical approach in comparison with transfemoral approach. Probably, the worse clinical profile of patients undergoing transapical TAVI justifies, at least in part, these findings.[7,12]

Ann Thorac Surg. 2011 Jun 23. [Epub ahead of print] Comparison of Risk Scores to Estimate Perioperative Mortality in Aortic Valve Replacement Surgery.

Source

Division of Cardiology, Veterans Administration Medical Center and University of Minnesota, Minneapolis, Minnesota.

Abstract  (bolding/ italics from original article)

BACKGROUND:

Transaortic valve implantation has recently been introduced as an alternative to aortic valve replacement (AVR) for high-risk patients with aortic stenosis. However, accurate assessment of surgical risk is critical for appropriate patient selection. We compared the accuracy of The Society of Thoracic Surgeons (STS) risk score, the European System for Cardiac Risk Evaluation (EuroSCORE), and the Veterans Administration (VA) risk score in predicting perioperative mortality after AVR.

METHODS:

We included 537 consecutive patients who underwent AVR for severe aortic stenosis at the Minneapolis VA Medical Center between 1997 and 2008. Observed and predicted perioperative (30-day) mortality rates were compared. Hosmer-Lemeshow goodness-of-fit test and receiver operating characteristic curves were performed to assess the performance of the scores.

RESULTS:

Perioperative mortality rate was 5.9% (n = 32). Predicted mortality rates for the EuroSCORE, STS score, and VA score were 15.6%, 3.6%, and 6.7%, respectively (p = 0.001). The EuroSCORE overestimated mortality in all patients, most notably among those with ejection fraction less than 35% (49% predicted versus 9% observed). The EuroSCORE had poor calibration (goodness-of-fit test p < 0.008), whereas the STS and the VA scores were well calibrated. However, all three scores displayed good discrimination characteristics per the areas under the receiver operating characteristic curves: STS score 0.73 (95% confidence interval: 0.69 to 0.77); VA score 0.66 (95% confidence interval: 0.62 to 0.70); and EuroSCORE 0.68 (95% confidence interval: 0.64 to 0.72; p > 0.05).

CONCLUSIONS:

The EuroSCORE substantially overestimates perioperative mortality risk in AVR, particularly in patients with low ejection fraction. These data have implications when deciding the appropriate intervention (transaortic valve implantation versus AVR) for high-risk aortic stenosis patients.

In general – the majority of the literature cites peri-operative mortality for AVR at 2.0 – 5.0% (but this is an average of ALL patients, making the calculators our best estimate of predicted risk.)

So what does this mean?

Clearly, when the data from Moreno et. al shows a thirty-day (peri-operative) mortality of almost 1 in 10 patients – it’s a signal we need to proceed with caution, and continue to follow the research.

1.  Since the authors report many of these patients at very high surgical risk (presumably due to cardiac status as well as co-morbidities) and 2. we know that in most people aortic stenosis progresses slowly  – it stands to reason that we need to consider intervening earlier in the course of the disease.  (Before the heart is significantly weakened).

For people with Aortic Stenosis – I’d want to get second/ third opinions from a cardiac surgeon before proceeding with any catheter based valve procedures.  I’d bring all of my information, and studies (echocardiogram results, lab results, medication lists) to have a serious talk to the surgeon about my surgical risk – (and ask him to calculate and show my risk based on the STS calculator).  I certainly wouldn’t let anyone make any decisions about my health/ care based on my age alone.  [we’ve talked about a ‘good 80’ versus a ‘bad 80’ or even a ‘bad 50’ before.]

Then, I would weigh all of the information – and do my best to make an informed decision.

Other posts about Aortic Stenosis/ TAVI/ AVR:

1. TAVI overview

2. TAVI: a stent scenario

3. TAVI recommendations

4. Aortic Stenosis and TAVI

5. Aortic Stenosis as Heinz 57

6. Aortic stenosis and surgery

Aortic Stenosis and TAVI: a new ‘stent’ scenario?

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I am re-posting an article published in May on the heart.org by Reed Miller regarding the use of Transcutaneous Aortic Valve Intervention (TAVI).  TAVI is when a device is implanted in the cardiac cath lab (through an artery) to treat aortic stenosis.  Right now, this therapy is still in limited use in the United States, but is used more extensively in Europe where the guidelines are less restrictive.

I was a little disappointed here because I think some of his introductory language shows significant bias – but I think this article certainly adds to some of the discussions we’ve had here at Cartagena Surgery.  Even the title reflects a cardiology bias – cardiothoracic surgeons certainly aren’t the only ones who think we should be cautious about the overimplementation of new, experimental technologies in patients who are good candidates for existing (and proven) surgical treatments.   I would think that any prudent health care provider, or consumer would be hesitant to wholeheartedly embrace this therapy given the previous and recent cardiology lessons related to both carotid and cardiac stenting.

New technology is great – when it is selectively targeted to specific populations (high-risk surgical candidates such as extreme elderly (90+) or patients with multiple high risk co-morbidities) who would otherwise be ineligible for surgical intervention.  But let’s not put our patients at unnecessary risk by selling TAVI as an ‘easy’ fix to people who we know we benefit from aortic valve replacement surgery before we have all the data.

There are still multiple issues to be addressed with transcutaneous valve therapies – we don’t even know the durability of this technology (how long with they last?)  or the long-term complications..   Also when we compare ourselves to European practices, we need to remember that ‘acceptable thresholds’ may differ significantly.  At what level of risk of stroke are YOU willing to accept?  5 % ?  10% ?  25% ?  And doesn’t that depend on whether you are eligible to have other therapies, and what the risks of those therapies are?

Lastly, it’s important to note that the study in question – which revealed a higher than expected stroke rate was funded by the corporations that manufacture and supply these valves.  We’ve seen before how this can influence the practice of cardiology and cardiology guidelines.

Article re-post below: [my comments in brackets.]

Surgeons caution against

 overenthusiasm for TAVI in light of

PARTNER A stroke data

May 10, 2011            |            Reed Miller

Philadelphia, PA – The neurological injury data from the PARTNER cohort A trial of transcatheter aortic-valve intervention (TAVI) underscore the importance of the collaboration between surgeons and interventionalists when making decisions on how to treat patients in need of a new aortic valve, surgeons here at the American Association for Thoracic Surgery (AATS) 2011 Annual Meeting agreed.

As reported by heartwire, Dr Craig Miller (Stanford University, CA) presented new details on the neurological-event data from PARTNER cohort A, which included high-risk patients eligible for either surgery or TAVI. [‘high risk’ needs to be better defined if the patients were considered acceptable surgical candidates.] 

The data showed that the risk of neurological adverse events (transient ischemic attack [TIA] and stroke) was slightly higher with TAVI than surgery in the “as-treated” patients, especially in the patients who underwent transapical TAVI because their vessels were too small to accommodate a transfemoral implant, usually because they were obstructed with arteriosclerosis. Rates of major stroke, however, were not statistically different between the two groups in the as-treated analysis.  [numbers/ percents – I need hard data..]

Because of the added neurological risk, Miller believes TAVI should not replace surgery for most patients who can withstand surgery. So he is dismayed that it has grown so rapidly in some European countries where TAVI devices are commercially available, even though the durability of these devices has not been proven. “This is not going to be cost-effective, and civilization cannot afford this if they do not last a good amount of time, and a good amount of time would mean something different to a 95-year-old who is inoperable and to somebody under 70 with a very low surgical risk who should have 10- to 20-year life expectancy. So we have to look at valve durability,” he said.  [I wholeheartedly agree. All of Dr. Miller’s concerns are valid.]

“There are many [inoperable patients like] the people in PARTNER cohort B, who gained 1.9 quality-adjusted life-years, and it only cost $55K per QALY to achieve that. So for the inoperable cohort, it is cost-effective and actually provides meaningful rehabilitation, but the jury is out for the younger patients,” he said. “But the cost economics of the not-so-sick operable patients is going to be different; they’re still beaucoup sick and old in PARTNER A, but to take this down to younger, healthier patients is a huge question mark in my mind and in the FDA‘s mind, because we already have the gold standard of low-risk, durable, surgical [aortic-valve replacement],” Miller said.

Surgeon/interventionalist collaboration is critical

Miller thinks one reason that TAVI has become “a runaway train” in Europe is that in some countries there, interventionalists are able to decide to implant a transcatheter valve without consulting a surgeon or, in some cases, even having a surgeon on site. “The German Federal Ministry of Health didn’t have the backbone to stand up and legislate appropriate use, so it’s a free-for-all. But that would be wrong, especially since we don’t have durability data,” Miller said. Miller said he learned that about a quarter of aortic-valve replacements in 2010 in Germany were TAVI procedures, but Dr John Mayer (Children’s Hospital Boston, MA) reported at the meeting that the figure is now around 40%.

A good amount of time would mean something different to a 95-year-old who is inoperable and to somebody under 70 with a very low surgical risk who should have 10- to 20-year life expectancy.

Mayer and Dr Grayson Wheatley III (Arizona Heart Institute, Phoenix) echoed Miller’s concerns about overenthusiasm for TAVI during a staged luncheon debate on whether or not expensive technologies like TAVI ought to be somehow rationed to control healthcare costs. Mayer took the position of defending rationing and Wheatley argued against it, but they both agreed that physicians and their professional societies ought to work to ensure appropriate use of TAVI.

Wheatley said, “We’re probably going to see something along the carotid-stent paradigm, where it’s FDA approved, but [the Centers for Medicare & Medicaid Services] CMS has restricted [coverage] of an FDA-approved device, based on the data and economics, to the highest-risk patients. I see a lot of parallels there.”

“The Medicare national coverage decision process is going to undoubtedly come into play,” Mayer agreed. “That’s one way to control it, and that’s probably the biggest weapon in the arsenal.” Mayer said that the CMS is already discussing a future Medicare coverage policy for TAVI with the Society of Thoracic Surgeons (STS).

“But the other way to control it is to take the combined cardiology/cardiothoracic surgery approach to be careful about how this gets rolled out,” he said. The STS and the American College of Cardiology (ACC) are currently working on a joint position paper that will call for TAVI appropriateness guidelines based on the PARTNER results, Mayer pointed out. That paper will likely be published this summer. “That’s an extremely important step, and I think the government will understand and accept a lot of the recommendations in there.”

Meanwhile, the Society for Cardiac Angiography and Interventions (SCAI) will be contributing to the STS/ACC position paper and is also developing an expert consensus document with representatives from the AATS, STS, and ACC that will outline training and facility standards for performing TAVI. That document will be published prior to the TCT 2011 conference, according to SCAI.

“The difference between how this was rolled out in Europe and how the investigators in the PARTNER trial would like to roll it out in the United States is that a heart team with a surgeon and cardiologists—and not just the interventional cardiologists, but general cardiologists—make the decisions jointly. That is the model that we think should be imposed going forward,” Mayer said. This collaboration will “be a way of us fulfilling our professional responsibility and making sure that this gets rolled out with high quality and will have the side benefit of keeping it from going nuts like it has in Europe.”

While some may be better off undergoing surgery than transfemoral TAVI, there are also some patients whose risk of neurological injury is so high due to arteriosclerotic burden that they are probably not suitable for either surgery or TAVI, Miller said. “The only thing that’s going to change that is more rigorous patient selection and just saying no,” Miller told heartwire. “That might not go over well in the US where everybody demands everything yesterday, [but] since these are patient-disease-related predictors, more rigorous patient selection is the only thing that will reduce the late hazard of neuro events [in patients with very high arteriosclerotic burden].”

What does PARTNER cohort A reveal about the cause of strokes?

STS president and PARTNER investigator Dr Michael Mack (Medical City Dallas Hospital, TX) told heartwire, “There was an initial thought for the past few years that the transapical might be more neuroprotective than the transfemoral because you don’t transverse the aortic arch with the device, and I think this puts to bed that that was not the case. In fact, the stroke rate was higher in the transapical than in transfemoral, but the presentation showed that it was clearly related to the patient substrate.” The one-year stroke rate in the transfemoral-eligible surgery patients was 1.9%, while the one-year stroke rate for the same surgical procedure in transfemoral-ineligible patients was 9.7%, Mack pointed out. “That says they’re different patients [with] a higher atherosclerotic burden.”

[Collaboration will make] sure that [TAVI] gets rolled out with high quality and will have the side benefit of keeping it from going nuts like it has in Europe.

Mack pointed out that the version of the Sapien valve (Edwards Lifesciences) tested in PARTNER was a first-generation device that did not have the nose cone that newer versions will have, “so you basically had this snowplow that could go across the aortic arch and scrape stuff off; smaller delivery devices with nose-cone protection may be expected to be of benefit,” Mack said. However, previous studies with transcranial Doppler show that the majority of the emboli come from the valve during balloon valvuloplasty and deployment of the valve and not from the aortic arch. “[This is] why you don’t see a benefit of the transapical here, because you’re still blowing up that valve [inside the native valve].”

This explanation is consistent with the study’s finding that, in the first few weeks following the procedure, a smaller valve opening area, which is usually a sign of high calcification around the opening, was associated with a higher risk of neurological events in the TAVI patients. Embolic-protection devices, such as Edwards’s Embrella, may catch some of these emboli released during the valve deployment, Mack said, but clinical experience with these devices is very limited so far.

Better devices may stop a lot of the periprocedural events, but about half of the neurological events happened after the periprocedural period. In this period, the most important risk factor—other than undergoing TAVI instead of surgery or being transfemoral ineligible—was a stroke or TIA within the previous six to 12 months. Atrial fibrillation, which was predicted by some to possibly be a risk factor for strokes, was not associated with an increased risk of neurological events in the study. Dual antiplatelet therapy was recommended for all patients in the trial, but the trial could not track how compliant patients were with that therapy.

“We have absolutely no clue if these strokes were device related or not. We don’t know if the device is thrombogenic, or if all that calcium left in the aorta hanging out eventually breaks out, or if it’s a nidus for clot formation and that breaks off. We just don’t have any insight on that,” Mack said.

PARTNER was sponsored by Edwards Lifesciences. Miller has consulting arrangements with Medtronic CardioVascular, Abbott Vascular, and MitraClip. Mack consults for Edwards Lifesciences and Medtronic.

Aortic Stenosis as Heinz 57

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“Aortic Stenosis as Heinz 57”

I apologize, but the best analogy I can use – is a squeeze ketchup bottle.

okay, it's not heinz.. but you get the picture..

In normal valve functioning, the three valve leaflets open and close fully to permit and control the flood of blood from the left ventricle to the aorta, where it is then circulated throughout the body.

normal valve diameter

During diastole (the filling phase) the leaflets are shut to prevent blood from leaking backwards from the aorta into the heart.  (When leaflets don’t close properly this is called aortic regurgitation.)

During systole, the ventricle contracts like a big fist,  squeezing the ketchup bottle to shoot blood out of the heart into the aorta.  (The force of this is measured in millimeters of mercury, and is the top number on your blood pressure cuff).  When the valve is working normally, it opens fully and the blood is ejected out to the aorta, and the whole cycle begins again.

In Aortic Stenosis – the valve leaflets have become fused together, either from age or disease.
(Some people are born with only two valve leaflets and this means that they are more likely to develop aortic stenosis as they age.)  As aortic stenosis progresses, the opening for blood to pass thru becomes smaller and smaller since the leaflets can not longer open fully,  In many people – at the time of surgery – this opening is about the size of the pinhole in the ketchup bottle that squirts ketchup.      (The normal sized opening is 2 to 3 centimeters).

average valve opening in severe aortic stenosis

Now, think about how hard a person has to squeeze that ketchup bottle to get some ketchup for hamburgers, fries (and all the other foods I usually scold about in other posts).
In the heart – this pressure is magnified (and can be measured in the cath lab during cardiac catheterization).

As this pressure gets higher and higher to compensate for the narrowed opening, the delicate structures of the heart become damaged, with the heart muscle becoming thicker and less flexible (just like any other muscle with exercise.)  Except unlike biceps, a big thick heart muscle is not a good thing, and can lead to heart failure, arrhythmias and sudden cardiac death.

Eventually, as the heart pushes against the increased pressure, over and over (at least sixty times per minute) the heart gets tired from working so hard.  As the heart fatigues, it is unable to keep up with demand and patients will begin to develop symptoms.

These symptoms include:

Syncope/ near syncope (fainting or near fainting) as not enough blood is pushed into central circulation and to the brain.

Chest pain – because not enough blood is pushed out to the coronary arteries during diastole.  (In a person with aortic stenosis, nitroglycerin can cause problems – as it lowers blood pressure  (and force of contraction even further in someone who needs the extra force.)

Heart failure – the weakened and thickened heart can no
longer keep up and blood begins to back up in the left ventricle.

What these symptoms predict:

Once these symptoms develop, doctors can readily estimate the approximate longevity for patients who do not subsequently have surgery.

From the natural history of aortic stenosis (from before we had surgery to treat it) we know that 50% of people with Syncope will die within 5 years.

Fifty percent of people with chest pain die within three years.

And ultimately, fifty percent of people with heart failure die within two years.

These numbers are important, and I want you to remember them for our subsequent discussions on aortic valve replacement because they need to be factored into a patient’s decision whether or not to pursue surgery.