Bioprosthetic Versus Mechanical Valve Replacement for Infective Endocarditis: Focus on Recurrence Rates

Abstract

Background: Consensus guidelines for prosthesis selection in infective endocarditis recommend bioprosthetic or mechanical valve replacement based on life expectancy and comorbidity. However, contemporary outcome data are limited to institution series.

Methods: The outcomes of 3,447 patients identified from mandatory discharge databases in California and New York who had either primary isolated mitral (n = 1,603) or aortic (n = 1,844) valve replacement for active endocarditis between 1998 and 2010 were compared according to whether they received bioprosthetic (n = 1,673, 48.5%) or mechanical (n = 1,774, 51.5%) valves. Drug abusers were analyzed as a separate cohort. The primary outcome was endocarditis recurrence. Median follow-up time was 6.8 years (range, 0 to 12). Last follow-up for survival was December 31, 2015.

Results: Patients receiving bioprosthetic valves were older (60.4 ± 14.9 versus 53.4 ± 14.3 years, p < 0.001), with more comorbidity. There was no significant difference in 12-year survival with bioprosthetic versus mechanical valves after mitral (adjusted hazard ratio 1.14, 95% confidence interval [CI]: 0.98 to 1.34, p = 0.10) or aortic (adjusted hazard ratio 1.10, 95% CI: 0.93 to 1.29, p = 0.26) valve replacement. Bioprosthetic and mechanical valves were associated with similar recurrence rates at 12 years: 10.4% (95% CI: 8.0% to 13.1%) versus 8.8% (95% CI: 6.9% to 10.9%), adjusted Cox p = 0.79 after mitral replacement; and 9.4% (95% CI: 7.5% to 11.6%) versus 10.0% (95% CI: 8.0% to 12.4%), adjusted Cox p = 0.81 after aortic valve replacement.

Conclusions: Bioprosthetic and mechanical valves are associated with similar survival and freedom from endocarditis recurrence. These data support guideline recommendations that patient factors guide prosthesis choice in infective endocarditis.