Sex-related differences in the prognosis of asymptomatic mitral regurgitation: an analysis of nationwide claims data

BACKGROUND: Asymptomatic mitral regurgitation (MR) can lead to long-term morbidity and mortality. While sex differences are well established in cardiovascular disease, data for asymptomatic MR are limited. Systemic factors such as cancer may affect prognosis through shared pathways. RESEARCH DESIGN AND METHODS: We conducted a cohort study using German claims data from the BARMER health insurance, identifying asymptomatic MR by repeated outpatient diagnoses without baseline complications or interventions, matched 1:1 by age and sex to controls without cardiovascular disease. Outcomes included 10-year MR-related complications, mitral valve interventions, incident cancer, and all-cause mortality. Multivariable Cox models adjusted for age, comorbidity (Elixhauser index), and cancer status. Cancer increased mortality risk (adjusted hazard ratios [aHR] 1.88, 95% CI 1.79-1.98), while male sex remained an independent predictor for mortality (aHR 1.42, 95% CI 1.36-1.47). CONCLUSIONS: Asymptomatic MR follows a progressive clinical trajectory, with high complication rates despite low intervention rates. Within this trajectory, males showed a significant survival disadvantage after adjusting for comorbidity and cancer, supporting risk-based and sex-aware follow-up strategies.