Clinical Predictors of Mortality in Patients with Moderate to Severe Mitral Regurgitation

Background: Mitral regurgitation is the most common form of valvular heart disease worldwide, however, there is an incomplete understanding of predictors of mortality in this population. This study sought to identify risk factors of mortality in a real-world population with mitral regurgitation. Methods: All patients with moderate or severe mitral regurgitation were identified at a single center from January 1, 2016 to August 31, 2017. Multivariate regression was performed to evaluate variables independently associated with all-cause mortality. Results: A total of 490 patients with moderate (76.3%) or severe (23.7%) mitral regurgitation due to primary (20.8%) or secondary (79.2%) etiology were identified. The mean age was 66.7 years; 50% were male. At a median follow-up of 3.1 years, the incidence of all-cause mortality was 30.1%, heart failure hospitalization 23.1%, and mitral valve intervention 11.6%. Of 117 variables, multivariate analysis demonstrated 5 that were independently predictive of mortality: baseline creatinine (hazard ratio [HR] 1.2; 95% CI, 1.0-1.3; P =.02), right atrial pressure by echocardiogram (HR 1.3; 95% CI, 1.07-1.55; P =.008), hemoglobin (HR 0.65; 95% CI, 0.52-0.83; P =.001), hospitalization for heart failure (HR 1.6; 95% CI, 1.1-2.4; P =.015), and mitral valve intervention (HR 0.40; 95% CI, 0.16-0.83; P =.049). Conclusion: In this retrospective, pragmatic analysis of patients with moderate or severe mitral regurgitation, admission for heart failure exacerbation, elevated right atrial pressure, renal dysfunction, anemia, and lack of mitral valve intervention were independently associated with increased risk of all-cause mortality. Whether these risk factors may better identify select patients who may benefit from more intensive monitoring or earlier intervention should be considered in future studies.