Long-Term Clinical and Echocardiographic Outcome in Patients with CRT and Functional Mitral Regurgitation: MitraClip versus Optimal Medical Therapy

Objectives: This study sought to evaluate the clinical outcome in cardiac resynchronization therapy (CRT) patients with residual moderate-to-severe functional mitral regurgitation (FMR) who underwent percutaneous treatment with the Mitraclip System or were managed with medical therapy alone. Background: Significant FMR can persist in 20-25% of patients after CRT and its management can be a challenge, due to the advanced heart failure (HF) and a variety of concomitant comorbidities. Methods: From a single center, two different groups of patients with CRT (MitraClip and no-MitraClip group) were compared. Clinical follow-up was scheduled at 30-day, 12 months and 24 months in all patients. The primary endpoint was the composite of all-cause death or HF hospitalizations at 24-month follow-up. Results: Forty patients (56%) were treated with the Mitraclip System (MitraClip group) and 31 patients (44%) only with medical therapy (no-MitraClip group). MitraClip group presented higher surgical risk than no-MitraClip group, as older age, chronic kidney disease, higher NYHA functional class and lower left ventricular ejection fraction. At 24-month no differences in all-cause mortality were detected between the two groups (Kaplan-Meier curves log-rank p = 0.947), although the MitraClip group presented lower rate of HF hospitalizations than the no-MitraClip group (log-rank p = 0.048). After adjustment for confounding factors, time to HF hospitalization or death was significantly delayed in MitraClip group (hazard ratio: 0.38; p-value 0.018). Conclusion: In CRT patients, the treatment of moderateto-severe FMR with the Mitraclip System if compared to medical therapy alone is a safe and effective approach in reducing cardiac symptoms and the rate of hospitalizations for HF.