Prognostic Significance of Right Ventricular Dysfunction in Patients With Functional Mitral Regurgitation Undergoing MitraClip

Functional mitral regurgitation (MR) is common in patients with heart failure and left ventricular (LV) dysfunction. MitraClip (MC) is a novel therapeutic option for patients with high-risk MR. Similar to LV dysfunction, right ventricular dysfunction (RVD) is an important predictor of patients with heart failure. We aimed to clarify the effect of RVD on outcomes of functional MR and LV dysfunction after MC implantation. We examined 117 patients with severe functional MR and reduced LV ejection fraction (≤40%) treated with MC. RVD was defined as tricuspid annular plane systolic excursion <15 mm and was observed in 41 patients (35%). Mean age and gender were similar between patients with and without RVD. Atrial fibrillation was more common in patients with RVD. MR grades at baseline and discharge and LV ejection fraction were not different between the groups. Six months after MC implantation, responders to the N-terminal pro-B-type natriuretic peptide were less common in patients with RVD than those without (29% vs 65%, p = 0.005). Kaplan-Meier curves showed that survival rates of patients with RVD were significantly lower than those without (36.2% vs 69.6%, p = 0.008). After adjusting for covariates, RVD was still associated with all-cause mortality (hazard ratio 1.975, p = 0.042). The present study's results suggest that RVD is associated with worse survival of functional MR and LV dysfunction in patients undergoing MC in association with no response to N-terminal pro-B-type natriuretic peptide. The indication for MC should be carefully considered in functional MR patients with RVD.