Disproportionate functional mitral regurgitation predicts a favourable response after MitraClip implant in patients with advanced heart failure. Real-world evidence of a new conceptual framework

Introduction: Accurate predictors of good clinical response after MitraClip implant in patients with heart failure (HF) are still lacking. Aim of this study was to investigate the role of regurgitant fraction >50% as a marker of disproportionate functional mitral regurgitation (FMR) in identifying best responders to Mitraclip.

Methods and results: Data from 58 advanced HF patients (age 66 ± 8 years, 81% males, 63% NYHA class IV, LV ejection fraction (EF) 25.5 ± 5.5%) with disproportionate and proportionate FMR who underwent successful MitraClip implant were analyzed. After MitraClip all patient achieved mild (≤ 2+/4+) MR. During 12-month follow-up 18 patients (31%) had a major adverse cardiac event (MACE, i.e. cardiac death, urgent LVAD implant or heart transplantation, HF hospitalization). Disproportionate FMR (n = 48, 83%) was associated with a better clinical outcome (p = .003) while regurgitant volume and EROA were not. TAPSE ≤14 mm was associated with worse outcome (p = .018). At multivariable analysis only disproportionate MR and TAPSE ≤14 mm showed a significant association with MACE (p = .017 and p = .02, respectively). A reverse left ventricular remodeling (i.e., reduction on LV end-diastolic diameter and end-diastolic volume) was achieved only in the disproportionate FMR group.

Conclusions: In conclusion, disproportionate FMR assessed by regurgitant fraction and RV dysfunction assessed by TAPSE may help the selection of HF patients candidates for MitraClip therapy.