Outcomes of Transcatheter Mitral Valve Repair for Secondary Mitral Regurgitation by Severity of Left Ventricular Dysfunction.

BACKGROUND In the COAPT trial, transcatheter mitral valve repair with MitraClip plus maximally-tolerated guideline-directed medical therapy (GDMT) improved clinical outcomes compared with GDMT alone in symptomatic patients with heart failure (HF) and 3+ or 4+ secondary mitral regurgitation (SMR) due to left ventricular (LV) dysfunction. AIMS In this COAPT substudy we sought to evaluate 2-year outcomes in HF patients with reduced LV ejection fraction (HFrEF; LVEF £40%) versus preserved LVEF (HFpEF; LVEF >40%) and in those with severe (LVEF £30%) versus moderate (LVEF >30%) LV dysfunction. METHODS The principal effectiveness outcome was the 2-year rate of death from any cause or HF hospitalizations (HFH). Subgroup analysis with interaction testing performed according to baseline LVEF; 472 patients (82.1%) had HFrEF (mean LVEF 28.0%±6.2%; range 12% to 40%) and 103 (17.9%) had HFpEF (mean LVEF 46.6%±4.9%; range 41% to 65%), while 292 (50.7%) had severely depressed LVEF (LVEF ≤30%; mean LVEF 23.9% ± 3.8%) and 283 (49.3%) had moderately depressed LVEF (LVEF >30%; mean LVEF 39.0% ± 6.8%). RESULTS The 2-year rate of death or HFH was 56.7% in patients with HFrEF and 53.4% with HFpEF (HR 1.16, 95%CI 0.86-1.57, p=0.32). MitraClip reduced the 2-year rate of death or HFH in patients with HFrEF (HR 0.50, 95%CI 0.39-0.65) and HFpEF (HR 0.60, 95%CI 0.35-1.05), pint=0.55. MitraClip was consistently effective in reducing the individual endpoints of mortality and HFH, improving MR severity, quality-of-life, and 6-minute walk distance in patients with HFrEF, HFpEF, LVEF 30%. CONCLUSIONS In the COAPT trial, among patients with HF and 3+ or 4+ SMR who remained symptomatic despite maximally-tolerated GDMT, MitraClip was consistently effective in improving survival and health status in patients with severe and moderate LV dysfunction and preserved LVEF.