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

Abstract

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.