Impact of mitral valve intervention and frailty on outcomes of severe mitral regurgitation due to severe mitral annular calcification

BACKGROUND: Mitral annular calcification (MAC) can be complicated by mitral regurgitation (MR). However, data on outcomes of severe MR caused by MAC are limited. This study evaluated outcomes of severe MR due to MAC and the prognostic significance of frailty and comorbidities in guiding management. METHODS: In this single-center, retrospective cohort study, we reviewed our echocardiographic database to identify patients with isolated severe MR due to severe MAC. The primary endpoint was all-cause mortality. The Society of Thoracic Surgeons (STS) risk score, Charlson Comorbidity Index (CCI), and a 3-point frailty index (hemoglobin, albumin, inactivity) were calculated. Echocardiographic parameters were recorded. RESULTS: Between January 2010 and August 2023, out of 10,061 patients with severe MAC on echocardiography, 128 patients with severe MR due to severe MAC were identified, and followed for a median of 134 days (IQR: 33-1812). Median age was 81 years; 72.7% were female. Forty-five patients (35.2%) underwent mitral valve (MV) intervention, and 83 (64.8%) received conservative management. During follow-up, 63 patients (49.2%) died. MV intervention improved survival, even after propensity score matching (p < 0.001). Higher frailty scores predicted poorer outcomes in the entire cohort (p = 0.004) and the conservative subgroup (p = 0.014) but not the surgical group (p = 0.406). CCI did not influence mortality when stratified by treatment. CONCLUSION: Patients with severe MR due to MAC were frail with multiple comorbidities and often managed conservatively. Frailty is associated with all-cause mortality, and MV intervention improves survival regardless of frailty status.