Mechanical Versus Bioprosthetic Aortic Valve Replacement in Patients Aged 50 Years and Younger

Background: This study evaluated outcomes in younger patients, specifically aged 50 years and younger, after mechanical aortic valve replacement (mAVR) and bioprosthetic AVR (bAVR). Methods: From 1994 to 2016, 643 patients underwent AVR (411 mAVR and 232 bAVR) at age 50 or younger. Concomitant coronary artery bypass grafting and mitral valve procedures were also included. Propensity score-matching methods resulted in 170 evenly matched patient pairs. Primary end points were operative mortality and long-term survival. Secondary end points were stroke, major bleeding, and redo AVR. Median observation time was 8.1 years (range, 0 to 23.6 years). Results: Overall, mean age was 41.9 years, and 29.3% were women, with an increasing trend toward use of bAVR. Mean age in the matched patients was 43.3 years for both cohorts (p = 0.68). Operative mortality, stroke, atrial fibrillation, reoperation for bleeding, and readmission rates within 30 days were all similar between the two groups. bAVR patients were at higher risk for redo AVR (13% vs 1.6%, p < 0.001), and mAVR patients were at higher risk for major bleeding events (8.5% vs 2.2%, p = 0.006). However, when adjusted, there were no differences in midterm and long-term survival between unmatched and matched cohorts. Conclusions: The increased risk of reoperation for bAVR and major bleeding incidents for mAVR was not reflected in midterm and long-term survival differences between the two groups. Our results suggest that bAVR may be an acceptable prosthesis choice for some patients aged 50 years and younger, although the results should be taken with caution.