Porcine vs Bovine Bioprosthetic Aortic Valves: Long-Term Clinical Results

Abstract

Previous studies have reported superior hemodynamic performance with bovine bioprosthetic aortic valves compared with porcine valves. However, conflicting results mean the long-term effect on survival is not well known. The aim of this study was to examine long-term survival, rate of aortic valve reoperations, and heart failure hospitalizations after surgical aortic valve replacement (AVR) with porcine vs bovine bioprosthetic valves. This was a population-based cohort study including all patients who had undergone AVR in Sweden from 1995 to 2012, with or without concomitant coronary artery bypass grafting. Patients were identified through the SWEDEHEART (Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies) registry. Baseline and outcome data were gathered from national registries. Propensity scores and inverse probability of treatment weighting were used to control for intergroup differences. Analyses accounted for competing risk of death when appropriate. A total of 12,845 patients underwent AVR with porcine (n= 4198) or bovine (n= 8647) prostheses. We found a small but significant difference in mortality favoring porcine prostheses: 78% vs 76%, 47% vs 43%, and 17% vs 15% at 5, 10, and 15 years, respectively (hazard ratio, 0.90; 95% confidence interval, 0.85-0.96). Porcine prostheses were associated with an increased risk of reoperation (hazard ratio, 1.48; 95% confidence interval, 1.11-1.98), but no difference in the risk of heart failure hospitalization. Results were similar in patients who underwent isolated AVR. Consistent with previous reports, we found that patients receiving porcine prostheses had a higher rate of reoperation compared with bovine prostheses. However, porcine prostheses were associated with improved long-term survival compared with bovine prostheses.