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.