Influence of mitral regurgitation etiology on long-term survival after successful transcatheter edge-to-edge mitral valve repair (mTEER)

Mitral regurgitation (MR) represents the most common valvular heart disease in Western industrialized nations. In addition to degenerative MR (dMR) and functional MR (fMR), there has been a notable increase in the prevalence of atrial functional MR (a-fMR), which has led to the renaming of fMR as ventricular functional MR (v-fMR). To date, conflicting evidence exists regarding long-term outcomes according to MR etiology after transcatheter edge-to-edge mitral valve repair (mTEER). All mTEER patients from four heart centers whose echocardiographic data were available were retrospectively analyzed. After adjustment for confounders by propensity score matching (PSM), we analyzed long-term survival after mTEER according to MR etiology via the Kaplan-Meier method. Of the 554 patients who met the inclusion criteria, 35.4% had dMR (196/554), 48.4% had v-fMR (268/554), and 16.2% had a-fMR (90/554). The a-fMR patient group had the highest mean age and the highest proportion of female patients. A predisposition to minor bleeding events was observed among patients with a-fMR, while the overall safety profile was comparable to that of patients with other MR etiologies. The long-term survival of patients with v-fMR was significantly worse than that of patients with dMR after PSM (52.1% [102/196] vs. 65.9% [129/196], p = 0.03). No major difference in long-term survival was observed between patients with a-fMR and those with dMR (61.2% [55/90] vs. 68.2% [61/90], p = 0.8). Patients with v-fMR had the poorest long-term survival among the three cohorts. We did not observe any relevant difference in the adjusted long-term survival of patients with a-fMR compared with patients with other MR etiologies.