Mechanical Versus Biologic Prostheses for Surgical Aortic Valve Replacement in Patients Aged 50 to 70

The use of biologic prosthesis is increasing in surgical aortic valve replacement (SAVR). Recent US guidelines recommend either biologic or mechanical prosthesis for SAVR in patients aged 50 to 70 years. We set out to study long-term outcomes of mechanical versus biologic prosthetic valves in this patient group.

All patients (excluding infective endocarditis and concomitant surgery other than coronary artery bypass grafting) aged 50 to 70 with first-time SAVR in Finland between 2004 and 2014 were retrospectively studied (N = 2928). Propensity score matching (1:1) was used to identify patients with comparable baseline features (n = 1152). Outcomes were 10-year all-cause mortality, aortic valve reoperation, major bleeding, ischemic stroke, and infective endocarditis. Mean follow-up was 6.7 years.

Ten-year all-cause mortality was 18.6% with mechanical valves and 27.6% with biologic valves (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.54-0.97; P = .028). Prosthetic valve reoperation was performed in 1.4% with mechanical valves and in 8.5% with bioprosthetic valves (HR, 0.30; 95% CI, 0.12-0.74; P = .009). Major bleeding occurred in 21.5% with mechanical valves and in 16.9% with biologic prostheses (HR, 1.19; P = .402). Rates of intracranial bleeding were also comparable. Ischemic stroke rates within 10 years were 12.7% with mechanical valves and 9.3% with biologic valves (HR, 1.29; P = .316). Infective endocarditis occurred in 3.7% of mechanical valves and in 7.3% of biologic valves (HR, 0.46; 95% CI, 0.24-0.88; P = .018).

Mechanical valve prostheses were associated with lower mortality, lower rates of reoperation, and lower occurrence of infective endocarditis compared with bioprostheses within 10 years after SAVR in matched patients aged 50 to 70 years. Our results do not support the routine use of biologic valve prostheses in this patient group.