The impact of recurrent mitral regurgitation after surgical or transcatheter mitral valve repair: a comprehensive review and a meta-analysis

BACKGROUND: Recurrent mitral regurgitation (MR) is typically defined as MR that is moderate or severe on follow-up echocardiography after the intervention. This meta-analysis summarizes the results of all available studies on the impact of recurrent MR on clinical outcomes after the intervention. METHODS: Medline, EMBASE, PubMed and Web of Science were searched from January 2000 to August 2024 for original studies reporting outcomes about the clinical impact of recurrent MR. Five clinical outcomes were analysed: reoperation, cardiovascular deaths, readmission, heart failure and New York Heart Association (NYHA) functional classification. The summary odds ratio (OR) with the 95% confidence interval (CI) was used to assess the risk of clinical outcomes. RESULTS: A total of 22 studies were included in the final analysis, involving 5,804 patients, of which 960 had recurrent MR. The overall pooled incidence of recurrent MR is 16.54%. Secondary or primary patients with MR with recurrent MR after an intervention had higher rates of reoperation [(OR = 6.25, 95% CI, 2.95–14.41; P < 0.001) or (OR = 22.54, 95% CI, 14.96–33.98; P < 0.001)]or of cardiovascular death [(OR = 5.26, 95% CI, 2.35–11.77; P < 0.001) or (OR = 1.68, 95% CI, 1.32–2.14; P < 0.001)]. The rates were also high for readmission (OR = 3.95, 95% CI, 2.56–6.10; P < 0.001), heart failure incidence (OR = 2.87, 95% CI, 1.75–5.11; P < 0.001) and the number of NYHA functional class III/IV (OR = 5.40, 95% CI, 3.01–9.70; P < 0.001) for recurrent MR of secondary MR. However, no significant association was found between recurrent MR of primary MR and the incidence of NYHA functional class III/IV (OR = 1.02, 95% CI, 0.47–2.22; P = 0.96). CONCLUSIONS: Recurrent MR is associated with higher rates of reoperations, readmissions, cardiovascular deaths, incidences of heart failure and NYHA functional class III/IV numbers. However, recurrent MR of primary MR is not correlated with NYHA functional class III/IV.