Mitral transcatheter edge-to-edge repair in ischemic vs non-ischemic functional mitral regurgitation: differential patterns of reverse remodeling and clinical recovery

Background/Introduction Mitral transcatheter edge-to-edge repair (M-TEER) has emerged as an established therapy for functional mitral regurgitation (FMR). However, ischemic and non-ischemic FMR differ in etiology, remodeling patterns, and prognostic implications. Purpose This study aimed to compare the clinical and echocardiographic effects of TEER in these two patient subsets. Methods We prospectively analyzed 92 consecutive patients with symptomatic (NYHA class III–IV) moderate-to-severe (3+) or severe (4+) FMR who underwent M- TEER between January 2022 and December 2024. Patients were stratified into ischemic (n=58, 63.0%) and non-ischemic (n=34, 37.0%) groups. Procedural success was defined as residual MR ≤2+ without major adverse events at hospital discharge. Clinical outcomes, Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OS), and echocardiographic parameters were assessed at baseline, 30 days, and 1 year. Results Procedural success was achieved in all patients (100%). At 1 year, heart failure hospitalization occurred in 11 patients (12.0%), while all-cause mortality was observed in 9 patients (9.8%). Severe MR was abolished in all cases by 30 days, with MR ≤2+ maintained in 98.9% at 1 year (Figure 1). Mild MR or less was documented in 36.0% of patients at 1 year, compared to none at baseline. Functional status improved markedly: 100% of patients were in NYHA class I–II at 30 days, with 98.9% sustaining this benefit at 1 year; the proportion of asymptomatic individuals increased from 38% at 30 days to 45% at 1 year (Figure 1). KCCQ-OS scores improved from 48 ± 20 at baseline to 62 ± 12 at 30 days and 66 ± 15 at 1 year (p<0.001) (Figure 1). In the ischemic FMR cohort, left ventricular end-diastolic diameter (LVDD) declined from 6.4 cm at baseline to 6.1 cm at 30 days and 5.9 cm at 1 year (p=0.03 and p=0.04), while left ventricular end-systolic diameter (LVSD) decreased from 4.7 cm to 4.4 cm and 4.2 cm (p=0.04) (Figure 2). Effective regurgitant orifice area (EROA) was reduced from 44 mm² to 26 mm² at 30 days and 25 mm² at 1 year (p<0.001) (Figure 2). Non-ischemic FMR patients demonstrated more pronounced reverse remodeling, with LVDD decreasing from 6.0 cm to 5.7 cm and 5.5 cm (p=0.01 and p=0.02), LVSD from 4.3 cm to 4.0 cm and 3.8 cm (p=0.04), and EROA from 40 mm² to 21 mm² and 20 mm² (p<0.001) (Figure 2). Conclusion M-TEER provides durable MR reduction, reverse ventricular remodeling, and sustained functional improvement in both ischemic and non-ischemic FMR. Non-ischemic etiology is associated with greater structural recovery.