Long-term Outcomes of Mechanical Vs Biologic Aortic Valve Prosthesis in Patients Older Than 70 Years

Biologic prostheses are preferred for surgical aortic valve replacement (SAVR) in patients more than 70 years of age in clinical practice. This study investigated differences in long-term outcomes between SAVR-treated patients more than 70 years of age who received mechanical or biologic prosthetic valves.

All patients (excluding those with endocarditis) who were more than 70 years of age and who underwent isolated first-time SAVR (with or without coronary artery bypass grafting) in Finland between 2004 and 2014 were retrospectively studied (n = 4227). Propensity score matching (1:3) was used to account for baseline differences (n = 296 with mechanical prostheses and n = 888 with biologic prostheses). Outcomes were 10-year survival, major bleeding (all, gastrointestinal, intracranial), ischemic stroke, infective endocarditis, and aortic valve reoperation. Mean age was 75.8 years, and mean follow-up was 8.3 years.

Survival at 10 years was 46.1% with mechanical prostheses and 57.8% with biologic prostheses (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.21 to 1.80; P < .001; number needed to harm = 7.0). The 10-year major bleeding rates were 37.0% with mechanical valves and 18.8% with biologic valves (HR, 1.77; 95% CI, 1.25 to 2.49; P = .001; number needed to harm = 7.4). Both gastrointestinal bleeding (26.5% vs 8.9%; HR, 2.63; 95% CI, 1.63 to 4.23; P < .001) and intracranial bleeding (8.8% vs 6.0%; HR, 2.12; 95% CI, 1.09 to 4.15; P = .028) were significantly more frequent with mechanical valve prosthesis. Occurrence of ischemic stroke (18.9% with mechanical prosthesis vs 16.1% with biologic prosthesis; P = .341), infective endocarditis (3.7% vs 2.8%; P = .242), or aortic valve reoperation (0.8% vs 2.8%; P = .707) did not differ between study groups.

Mechanical aortic valve prosthesis is associated with worse long-term survival and increased bleeding after SAVR in patients more than 70 years old. The study results suggest caution when considering mechanical aortic valve prostheses in elderly patients.