Comparison of Mitral Valve Replacement and Repair for Degenerative Mitral Regurgitation: a Meta-analysis and Implications for Transcatheter Mitral Procedures

Purpose of Review Surgical mitral valve repair is considered superior to replacement to treat primary mitral regurgitation. However, the heterogeneity of cohorts and the lack of consideration of confounding in the published literature raise potential biases. The aim of this study was to pool all available matched data comparing outcomes of mitral valve repair and replacement in the setting of primary mitral regurgitation. Recent Findings We searched Medline, Embase and the Cochrane Library Central Register of Controlled Trials to identify propensity-matched studies or reports with multivariable adjustment comparing repair and replacement in patients with primary mitral regurgitation. The primary outcome was all-cause mortality. DerSimonian and Laird random effects were used to perform the meta-analysis. Eight observational studies were selected including 4599 patients (3064 mitral repairs and 1535 replacements). Mean age ranged from 62 to 69 years, and the mean follow-up duration ranged between 3 and 9 years. Replacement was associated with an increased risk of long-term all-cause mortality compared to repair (HR of 1.68, 95% confidence interval 1.35–2.09, p < 0.001, τ 2 = 0.03). Surgical era and atrial fibrillation impacted the risk of mortality but not mitral anatomy. Neither repair nor replacement impacted significantly on the risk of re-operation after mitral surgery (HR 1.18, 95% CI 0.85–1.63, p = 0.33, τ 2 < 0.01). Summary Mitral valve replacement is possibly associated with higher long-term mortality than mitral valve repair in primary mitral regurgitation but often used as a bailout option in more complex anatomy. Despite this observation, both techniques have similar risk of re-operation.