Whether a bovine or porcine aortic valve bioprosthesis carries a higher risk of endocarditis after aortic valve replacement is unknown. The aim of this study was to compare the risk of prosthetic endocarditis in patients undergoing aortic valve replacement with a bovine versus porcine bioprosthesis.
This nationwide, population-based cohort study included all patients who underwent surgical aortic valve replacement with a bovine or porcine bioprosthesis in Sweden from 1997 to 2018. Regression standardization was used to account for intergroup differences. The primary outcome was prosthetic valve endocarditis, and the secondary outcomes were all-cause mortality and early prosthetic valve endocarditis. During a maximum follow-up time of 22 years, we included 21 022 patients, 16 603 with a bovine valve prosthesis and 4419 with a porcine valve prosthesis. The mean age was 73 years, and 61% of the patients were men. In total, 910 patients were hospitalized for infective endocarditis: 690 (4.2%) in the bovine group and 220 (5.0%) in the porcine group. The adjusted cumulative incidence of prosthetic valve endocarditis at 15 years was 9.5% (95% CI, 6.2%-14.4%) in the bovine group and 2.8% (95% CI, 1.4%-5.6%) in the porcine group. The absolute risk difference between the groups at 15 years was 6.7% (95% CI, 0.8%-12.5%).
The risk of endocarditis was higher in patients who received a bovine compared with a porcine valve prosthesis after surgical aortic valve replacement. This association should be considered in patients undergoing both surgical and transcatheter aortic valve replacement.