Biological or mechanical mitral valve replacement in patients 50-70 years of age – a propensity matched cohort

Objective: The choice of a bioprosthetic valve (BV) over a mechanical valve (MV) in middle aged adults in the mitral valve is still under debate. Each valve type has benefits and drawbacks. We examined the long-term survival of patients 50-70 years old after BV versus MV mitral valve replacement (MVR).

Methods: We conducted a multicenter, retrospective analysis of patients 50-70 years old undergoing MVR from 2005 to December 2018 in 4 medical centers in Israel. To control for between group differences, we used propensity score matching (PSM). The primary end point was all-cause mortality. Secondary end points included reoperation, cerebrovascular accident (CVA), and bleeding.

Results: Of all eligible patients, 1002 (63%) patients underwent MV replacement and 589 (37%) BV replacement with a steep rise in the percentage of BV used within the study period. PSM yielded 181 matched pairs for analysis, noteworthy for high rates of rheumatic heart disease and AF. Median follow up was 62 months. The hazard ratio (HR) for mortality was (1.09 [0.74-1.59], p=0.665). The HR for CVA was (1.0, [0.48- 2.06], p=0.988), bleeding (1.06, [0.45, 4.4], p=0.897), and reoperation (1.96, [0.59-6.53], p=0.270). Reoperation was a strong predictor of mortality during the study period (72.2%).

Conclusions: We found no difference in mortality or secondary endpoints between the two valves. This implies that the use of either valve type is reasonable in this age group and must be decided on individual patient basis by a heart team with special attention to the frequent use of anticoagulation in this specific patient population.