Abstract 11838: The Hospital Volume-Outcome Relationship in Aortic Valve Surgery in the Elderly: An Analysis of Medicare-Fee-for-Service Patients From 2000-2009
Introduction: The effect of volume on outcomes in cardiovascular and other surgeries has been documented. Still, there remains a lack of current data describing this effect in aortic valve replacement (AVR) on a national level. We examined outcomes among Medicare fee-for-service beneficiaries between 2000-2009 stratified by annual hospital procedural volume.
Methods and Results: We used the Medicare database to identify 277,928 patients who underwent AVR from 2000-2009. Operative mortality and use of mechanical prostheses were analyzed according to hospital annual procedural volume. Mechanical valves were used in 64.5% of AVRs in hospitals with annual AVR volume <10 in contrast to only 25.4% in hospitals with annual AVR volume >70. In general, mechanical valve use decreased with increasing hospital volume. After adjustment, the use of mechanical valves was independently associated with increased operative mortality HR=1.20 (95% CI 1.16-1.24) and reduced long-term survival (HR 1.05; 95% CI 1.04-1.06). The overall observed operative mortality rate was 7.3%, while for those undergoing isolated AVR the operative mortality rate was 5.5%. Lower volume hospitals exhibited increased adjusted operative mortality: ≤10 cases/year OR=1.51 (95% CI 1.36-1.68), 11-20 cases/year OR=1.31 (95% CI 1.20-1.43), 21-40 cases/year OR=1.13 (95% CI 1.04-1.23), 41-70 cases/year OR=1.08 (95% CI 1.00-1.19), relative to those hospitals performing >70 cases/year. The discrepancy in operative mortality between low and high-volume hospitals diverged during the course of the study.
Conclusions: Low volume centers were characterized by increased adjusted operative mortality and greater use of mechanical prosthesis, a trend that persisted during the 10-year course of the study. These data would support the center of excellence concept for AVR and this may be particularly relevant in the elderly.
Author Disclosures: C. McNeely: None. S. Markwell: None. C. Vassileva: None.
- © 2014 by American Heart Association, Inc.