Prevalence and prognostic role of left atrial reverse remodeling in patients undergoing mitral transcatheter edge-to-edge repair: insights from the Multicenter Echocardiographic Registry of patients undergoing mitral Transcatheter Edge-to-Edge Repair

Aims – Atrial enlargement is a complex maladaptive process related to pressure and volume overload. Left atrial reverse remodeling (LARR) has been described as a result of medical and interventional therapies. We sought to explore LARR prevalence and its prognostic implications following mitral transcatheter edge-to-edge repair (M-TEER). Methods and results – Four-hundred and twenty-five patients from the MERIT-TEER (Multicenter Echocardiographic Registry of patients undergoing M-TEER) who received a successful procedure from 2012 to 2024 with available left atrial volume (LAV) have been analyzed. LARR was defined as a reduction in LAV of at least 15%. LARR prevalence and its association with the risk of heart failure hospitalization and all-cause mortality at 4 years’ follow-up were evaluated in the overall population and according to mitral regurgitation etiology. At short-term follow-up, LARR was observed in 124 patients (29.20%). LARR was more prevalent among primary mitral regurgitation (PMR) patients compared with those with ventricular secondary (vSMR) and atrial secondary mitral regurgitation (aSMR) (37.23, 27.19, and 18.33%; P = 0.017). At long-term follow-up, the composite outcome occurred in 153 patients (36.2%). LARR was independently associated with lower risk of events in the overall population [adjusted hazard ratio 0.59, 95% confidence interval (CI) 0.43–0.85, P = 0.005] and among vSMR patients (adjusted hazard ratio 0.43, 95% CI 0.26–0.71, P = 0.001), but not in aSMR or PMR. Conclusion – LARR was observed in less than one-third of patients undergoing M-TEER (29.2%), occurring more frequently in PMR. LARR was independently associated with lower risk of all-cause mortality and heart failure hospitalization in the overall population and particularly in patients with vSMR.