Abstract 4347641: Impact of Mitral Valve Intervention and Frailty on Outcomes of Severe Mitral Regurgitation due to Severe Mitral Annular Calcification

Background: Mitral annular calcification (MAC) is the degenerative deposition of calcium in the fibrous mitral annulus, and is increasingly associated with cardiovascular morbidity and mortality. It may lead to mitral stenosis or mitral regurgitation (MR), but outcomes of severe MR due to MAC remain poorly defined. This study evaluated the prognosis of patients with severe MR due to MAC and assessed the predictive value of comorbidities and frailty. Methods: We conducted a single-center retrospective cohort study. Patients with severe MAC were identified by echocardiographic review, and those with isolated severe MR were included. The primary outcome was all-cause mortality. Charlson Comorbidity Index (CCI), Society of Thoracic Surgeons (STS) score, and frailty score were recorded. Frailty was defined using a 3-point index: one point each for low hemoglobin, low albumin, and physical inactivity. Comprehensive echocardiographic data were collected. Results: From 2010 to 2023, 10,061 patients had severe MAC. After exclusions, 128 with isolated severe MR were analyzed. Median follow-up was 134 days (IQR: 33–1,812). Median age was 81 years (IQR: 71–88), and 35% were male. Mean LVEF was 61% ± 13%; mitral valve area 1.9 ± 0.49 cm2; MR volume 60 ± 20.8 mL; RVSP 54 mmHg (IQR: 42–71). Mean CCI was 5.7 ± 2.0; frailty 1.46 ± 0.98; STS score 9.6% ± 7.1. A total of 45 patients (35.2%) underwent mitral valve (MV) intervention; 83 (64.8%) received conservative management. STS and frailty scores were higher in the medical group (STS: 11.4% vs. 6.2%, p < 0.001; frailty score: 1.63 vs. 1.17, p = 0.014). CCI trended higher in the medical group (5.9 vs. 5.2, p = 0.053). In the intervention group, 37 had MV replacement (34 with bioprosthetic), 5 had repair, and 3 had percutaneous mitral clip. Overall, 63 patients (49.2%) died. MV intervention was associated with lower mortality (p < 0.001), including after propensity matching. Frailty, but not CCI, predicted mortality (p = 0.004), especially in the medical group (p = 0.014), but not in the surgical group (p = 0.406). In the surgical group, lower STS scores were linked to better outcomes (p = 0.037). On multivariable analysis, frailty independently predicted mortality (HR: 1.472; 95% CI: 1.115–1.945), and MV intervention reduced mortality risk (HR: 0.168; 95% CI: 0.073–0.387). Conclusion: Frailty, but not CCI, independently predicted mortality. MV intervention improved survival in selected patients with severe MR due to MAC.