Global Prevalence of Mitral Regurgitation: A Systematic Review and Meta-Analysis of Population-Based Studies

Background/Objectives: Mitral regurgitation (MR) is the most common left heart valve disease, but its exact prevalence remains uncertain. To estimate the prevalence of MR we conducted a systematic review and meta-analysis of population-based studies. Methods: We searched the Medline/PubMed, Embase, and Scopus databases, in January 2023, for studies reporting or allowing for the calculation of the prevalence of moderate-to-severe MR in the general population. Eligible studies included those using echocardiography or primary care databases from countries with universal healthcare. Studies where echocardiography was performed for medical indications were excluded. Random-effects meta-analysis was used to calculate the pooled estimates. Subgroup and meta-regression analyses were employed to investigate the reasons for heterogeneity. Mixed-model multivariable meta-regression was used to estimate age- and sex-specific prevalence. Results: After screening 13,847 records, we identified 20 eligible studies (22 study populations) including 6,036,691 individuals. The global prevalence of moderate-to-severe MR was 0.67% (95% CI, 0.33-1.11). Prevalence increased greatly with age, and it was estimated to be approximately 0.63% (0.25-1.16) at age 50, 2.85% (1.96-3.90) at 70, and 6.45% (4.17-9.16) by 90 years. North America showed the largest crude prevalence (1.11%; 0.52-1.88), followed by Europe (0.60%; 0.34-0.92), Asia (0.24%; 0.00-0.92), and Africa (0.16%; 0.03-0.37). Differences in prevalence by geographic region and ethnic group were primarily attributable to population age. Prevalence did not differ by sex, study year, or diagnostic criteria. Conclusions: Moderate-to-severe MR is a prevalent condition, particularly among elderly people. With rising life expectancy worldwide, ensuring universal access to interventions will be vital to reduce morbidity and mortality.