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

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.

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.

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.

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.