Letter by Grover et al Regarding Article, “Percutaneous Implantation of the CoreValve Self-Expanding Valve Prosthesis in High-Risk Patients With Aortic Valve Disease: The Siegburg First-in-Man Study”
To the Editor:
We believe that transvascular and transapical implantation of cardiac valves is an important developing technology. In our opinion, however, the article “Percutaneous Implantation of the CoreValve Self-Expanding Valve Prosthesis in High-Risk Patients With Aortic Valve Disease: The Siegburg First-in-Man Study”1 inaccurately describes results of current therapy in order to favorably portray the 80% hospital survival with this device.
The authors claim “up to 50%” operative mortality for surgical aortic valve replacement, citing 3 references. Reference 1 reports an overall mortality of 6%. Reference 2 reveals a mortality of 6% for aortic valve replacement in elderly patients. Reference 3 focuses on long-term survival. The Society of Thoracic Surgeons (STS) risk model (www.sts.org/sections/stsnationaldatabase/)2 estimates a current 5% mortality for an “average” CoreValve patient on the basis of Table I: age 80 years, hypertensive, diabetic, class III, female, 54% ejection fraction. If we add to this average patient all the major risk factors in Table I (redo operation, prior percutaneous coronary intervention, prior myocardial infarction, class IV, and peripheral vascular disease), the predicted mortality becomes 12.8%. A median EuroSCORE for the studied patients is presented and indicates a predicted mortality of 11%, a fact not clearly stated in the article. Neither contemporary mortality predictions nor the cited references support the “up to 50%” claim. That both study patients who required emergency surgery survived is not surprising. Both the STS risk model and the EuroSCORE prediction tell us that they had a 9 out of 10 chance of surviving surgical intervention.
The authors state that “surgery often is not performed in high-risk patients,” citing Reference 4. In fact, this survey reported that comorbid conditions were a factor in not performing an intervention in 17.6% of class III/IV patients with severe single-valve disease, half the 33% figure claimed by the authors. We also disagree with the authors’ statement that the studied patients rarely undergo surgery in Europe. The EuroSCORE database included a high-risk group of 4293 patients (32% of operated patients) with an observed mortality of 11.2%,3 remarkably similar to the 11% predicted mortality in this study. Many European surgical patients have risk characteristics similar to those of the study patients. In our opinion, surgical results and utilization of surgery are both importantly misrepresented.
When it is considered that the observed mortality was nearly twice what would be expected from conventional surgery, we must question the authors’ statement that “clinical outcomes were robust” and also must challenge the authors’ enthusiasm for continued and extended application of the device.
Sources of Funding
Dr Mayer has received National Institutes of Health current and pending grants on tissue-engineered hearts and valves and a grant from the Center for Integration of Medicine and Innovative Technology on tissue-engineered heart valves. Dr Kouchoukos has received a research grant from the National Marfan Foundation on the Comparison of Valve-Sparing and Aortic Root Procedures.
Dr Mayer has served as a Medtronic consultant on percutaneous heart valves. Dr Kouchoukos has done Grand Rounds, University of Pennsylvania, Brain Protection for Aortic Arch Surgery and has served as Edwards Life Sciences Chair, Data Safety and Monitoring Board for a new aortic valve. Dr Guyton has received honoraria from Guidant Inc and has served as a consultant on the Medtronic Advisory Board. The remaining authors report no conflicts.
Grube E, Laborde JC, Gerckens U, Felderhoff T, Sauren B, Buellesfeld L, Mueller R, Menichelli M, Schmidt T, Zickmann B, Iversen S, Stone GW. Percutaneous implantation of the CoreValve self-expanding prosthesis in high-risk patients with aortic valve disease: the Siegburg First-in-Man Study. Circulation. 2006; 114: 1616–1624.