Risk factors and etiology of recurrent mitral regurgitation after edge-to-edge mitral valve repair

Abstract Background Recurrent MR has been associated with poor prognosis after transcatheter mitral valve repair (TMVR) with the MitraClip system. However, little is known about risk factors and etiology of recurrent mitral regurgitation (MR) after transcatheter edge-to-edge mitral repair with the MitraClip system. Methods Among consecutive patients who underwent MitraClip for MR from January 2011 to March 2019, we identified 240 patients who had MR ≤2+ at discharge and follow-up echocardiography within three years after the procedure. Recurrent MR was defined as MR ≥3+ during the follow-up period. To investigate the risk factors for recurrent MR, we conducted a Cox proportional hazard model. Results During the follow-up period (median 491 days), 38 patients (15.8%) had recurrent MR (≥3+). The most frequent etiology of recurrent MR was degenerative (n=20, 52.6%), including single leaflet detachment (n=2, 5.3%), loss of leaflet insertion (n=11, 28.9%), and leaflet tear or prolapse (n=7, 18.4%), followed by functional MR (n=18, 47.4%). The risk factors for recurrent MR were greater LV end-diastolic volume (adjusted-HR 1.01, 95% CI 1.00–1.02, p=0.03), higher LV ejection fraction (LVEF) (adjusted-HR 1.05, 95% CI 1.01–1.08, p=0.005), and moderate MR upon discharge (adjusted-HR 2.98, 95% CI 1.50–5.95, p=0.002).After stratification according to the etiology of MR, the association of LVEF was more pronounced in patients with degenerative MR (adjusted-HR 1.07, 95% CI 1.02–1.12, p=0.003), while the association of moderate MR upon discharge was more pronounced in patients with functional MR (adjusted-HR 5.02, 95% CI 1.95–12.8, p