Elevated mitral valve pressure gradient following transcatheter edge-to-edge repair is independently associated with inferior outcomes in atrial, but not in ventricular secondary mitral regurgitation

Abstract Background In transcatheter mitral valve edge-to-edge repair (M-TEER), the goal of optimizing post-procedural residual mitral regurgitation inadvertently carries the risk of generating relevant mitral stenosis, resulting in an elevated mean mitral valve pressure gradient (MPG). In patients with primary mitral regurgitation, an elevated post-procedural MPG has been found to independently predict impaired outcomes. However, the effect of elevated post-procedural MPG on outcome after M-TEER in patients with secondary mitral regurgitation (SMR) has yet to be fully elucidated. This study investigated the impact of elevated MPG on outcome in the EuroSMR registry, a large, multi-center real-world cohort of patients with SMR. Methods This retrospective study included patients who underwent M-TEER for SMR between 2009 and 2021 in 12 centers. Patients were stratified into two groups based on SMR etiology: (1) ventricular SMR (vSMR), and (2) atrial SMR (aSMR). The etiology was considered as vSMR in patients with a left ventricular ejection fraction (LV-EF) 5 mmHg. The primary endpoint was all-cause mortality after 5 years, with statistical analysis conducted using Kaplan-Meier and uni- and multivariable Cox Regression analysis. Results Among the 1703 patients in the study (vSMR: n=1420; aSMR: n=283), elevated post-procedural MPG was observed in 9.4% (n=133) of vSMR and 19.1% (n=54) of aSMR patients. Atrial fibrillation was significantly more prevalent in aSMR (78.4% vs. 57.1%, p