AimTo evaluate the impact of preinterventional moderate-to-severe functional tricuspid regurgitation (FTR) on early outcome after percutaneous edge-to-edge mitral valve repair (pMVR) with MitraClip procedures for functional mitral regurgitation (FMR) in patients with heart failure with reduced ejection fraction (HFrEF).Methods and resultsFrom January 2013 to December 2017, 80 patients with HFrEF (ejection fraction 22%±5.3%) and FMR (grade 3.0±0.36) underwent successful pMVR. The 3-year actuarial survival was 58%. However, 73% (n=22) of non-survivors died of cardiac failure within 1 year. Patients were categorised into none-to-mild (n=36) and moderate-to-severe (n=44) postinterventional FTR groups according to pre-MitraClip tricuspid regurgitation grade. Cox regression analysis on 1-year survival demonstrated an impact of FTR severity (HR=1.8, 95% CI 1.01% to 3.09%, p=0.047), preoperative New York Heart Association class (HR=2.8, 95% CI 1.2% to 6.5%, p=0.015) and peripheral artery disease (HR=5.4, 95% CI 1.6 to 18, p=0.0054). Kaplan-Meier analysis showed that 1-year cardiac death was higher in the moderate-to-severe FTR group (p=0.048). In our study, 77% of pre-MitraClip moderate-to-severe FTR cannot be significantly reduced. Post-MitraClip moderate-to-severe FTR grade was related to lower survival (p<0.001).ConclusionIn patients with HFrEF treated with MitraClip for FMR, moderate-to-severe FTR was an independent predictor of cardiac death within 1 year. To improve survival, additional therapy to residual FTR should be considered in early phase after MitraClip therapy.