Long-term outcomes of bioprosthetic valves in the mitral position a systematic review of studies published over the last 20 years

OBJECTIVES Although the use of bioprostheses for mitral valve replacement (bMVR) is on the rise, their long-term durability is not well described. Defining bMVR durability will be instrumental in setting the standard against which the performance of transcatheter mitral replacement is to be judged against. The authors of this systematic review aimed to identify, assess the quality and review the outcomes in studies reporting on long-term outcomes after bMVR published over the last 20 years. METHODS Medline, Embase and Cochrane CENTRAL were searched for studies that have reported outcomes beyond a minimum of 5 years of follow-up after bMVR. Cohort characteristics, definitions of structural valve deterioration (SVD) and outcomes were summarized. The risk of bias in included studies was assessed using the Cochrane QUIPS tool. RESULTS Twenty-one studies, including 15 833 patients, were identified. Sixty-four percent of all implants were porcine and the remaining bovine pericardial. Freedom from SVD at 10 years ranged from 58.9% to 100% and at 15 years from 58.3% to 93%. Freedom from reoperation ranged from 65% to 98.7% at 10 years and 78.5% to 91% at 15 years. Information on native valve pathology or dominant haemodynamic lesion was missing in 25% and 66% of studies, respectively. Reports of postoperative echocardiography were lacking, despite the heavy reliance on echocardiography for SVD diagnosis. CONCLUSIONS There is considerable variability in reporting bMVR long-term outcomes. As such, it is difficult to generate an unbiased, generalizable understanding of long- term outcomes after bMVR across the spectrum of mitral disease phenotypes.