Survival and long-term outcomes after mitral valve replacement in patients aged 18 to 50 years

Objective To provide long-term data on survival and major morbidity after mitral valve replacement in patients aged 18 to 50 years. Methods Retrospective analysis of 2727 patients aged 18 to 50 years who underwent isolated mitral replacement in California and New York from 1997 to 2006. Median follow-up time was 12.4 years (maximum 15.0 years). The primary endpoint was mortality; secondary endopoints were stroke, major bleeding, and reoperation. Propensity matching yielded 373 patient pairs. Results Bioprosthetic valve use increased from 10% to 34% between 1997 and 2014 (P <.001). Among propensity score-matched patients, actuarial 15-year survival was 74.3% (95% confidence interval [CI], 69.0%-78.7%) after bioprosthetic versus 80.8% (95% CI, 75.1%-85.3%) mechanical valve replacement (hazard ratio [HR], 1.67; 95% CI, 1.21-2.32, P =.002). At 15 years after mitral valve replacement, the cumulative incidence of stroke was similar (9.1% [95% CI, 6.0%-13.0%] vs 9.7% [95% CI, 6.7-13.4]; HR, 0.95 [95% CI, 0.57-1.59]); the cumulative incidence of major bleeding events was similar (7.9% [95% CI, 5.0%-11.5%] vs 11.5% [95% CI, 7.6%-16.2%]; HR, 0.78 [95% CI, 0.46-1.32]); and the cumulative incidence of reoperation after bioprosthetic valve replacement was greater (19.9% [95% CI, 15.4%-24.8%] vs 5.7% [95% CI, 3.5%-8.7%]; HR, 20.3 [95% CI, 4.0-102.8]), respectively. Conclusions The significant survival benefit associated with mechanical mitral valve replacement in adults ≤50 years may be due to the practice of implanting bioprostheses in sicker patients or those judged less likely to comply with long-term medication despite adjustment for baseline characteristics in propensity score matching.