Atrial and ventricular strain remodeling after M-TEER

Background Mitral transcatheter edge-to-edge repair (M-TEER) effectively reduces mitral regurgitation (MR) and improves symptoms, yet the ventricular and atrial mechanical changes underlying clinical benefit remain incompletely characterized. Purpose To evaluate left ventricular (LV), right ventricular (RV), and left atrial (LA) reverse remodeling using strain imaging after M-TEER and examine associations with functional and quality-of-life outcomes. Methods Between January 2022 and January 2025, 118 patients with symptomatic (NYHA III–IV) moderate-to-severe (3+) or severe (4+) degenerative or functional MR underwent TEER. Clinical, echocardiographic, and quality-of-life data were collected at baseline, 30 days, and 1 year. LV global longitudinal strain (GLS), RV free-wall strain (RV-FWS), and LA reservoir strain (LARS) were assessed. Endpoints included NYHA class, heart failure hospitalization, and Kansas City Cardiomyopathy Questionnaire–Overall Summary (KCCQ-OS). Results Procedural success was 100%, with short device (27 min [IQR 21–35]) and total procedure times (56 min [IQR 48–66]), low complication rates, and median hospital stay of 3 days; 1-year mortality was 9.3%. MR reduction was durable (MR ≤2+ in 98.3% at 1 year), accompanied by sustained NYHA improvement (97.4% NYHA I–II at 1 year) and KCCQ-OS increase (52 ± 19 to 71 ± 15; p<0.001) (Figure 1). High-quality strain analysis was available in 92 patients (78%), with no baseline differences versus excluded patients. LV GLS improved from −11.8 ± 3.2% at baseline to −13.6 ± 3.1% at 30 days and −14.1 ± 3.3% at 1 year (p<0.001), despite no significant change in LVEF (42 ± 11% vs 43 ± 10% at 1 year; p=0.38) (Table 1). Improvement in LV GLS correlated with NYHA class improvement (r=0.42, p<0.001) and KCCQ-OS gain (r=0.39, p<0.001) and predicted KCCQ-OS improvement (β=2.6 points per 1%; p=0.002) (Table 2). RV-FWS also improved from −15.4 ± 4.1% at baseline to −17.1 ± 4.0% at 30 days (p=0.002) and −18.2 ± 4.3% at 1 year (p<0.001), paralleling a significant reduction in pulmonary artery systolic pressure (48 ± 12 to 38 ± 10 mmHg; p<0.001). Patients with ≥2% RV-FWS improvement had fewer heart failure hospitalizations at 1 year (7.8% vs 19.4%; p=0.04). LARS showed the most pronounced response, increasing from 13.2 ± 5.1% at baseline to 18.6 ± 5.4% at 30 days and 21.1 ± 5.9% at 1 year (both p<0.001). LARS correlated strongly with NYHA improvement (r=0.48, p<0.001) and KCCQ-OS gain (r=0.51, p<0.001) and emerged as the strongest independent predictor of quality-of-life improvement (β=1.9 points per 1% increase; p<0.001). Combined improvement in LV GLS and LARS explained 46% of the variance in KCCQ-OS gain (adjusted R²=0.46), outperforming conventional echocardiographic parameters. Conclusions M-TEER induces early and sustained ventricular and atrial reverse remodeling which independently predicts functional recovery and quality-of-life improvement,Figure 1