ABSTRACT

BACKGROUND - In the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial, transcatheter mitral valve repair (TMVr) resulted in fewer heart failure hospitalizations (HFHs) and lower mortality at 24 months in patients with heart failure (HF) with mitral regurgitation (MR) secondary to left ventricular dysfunction compared with guideline-directed medical therapy (GDMT) alone.

OBJECTIVES - This study determined if these benefits persisted to 36 months and if control subjects who were allowed to cross over at 24 months derived similar benefit.

METHODS - This study randomized 614 patients with HF with moderate-to-severe or severe secondary MR, who remained symptomatic despite maximally tolerated GDMT, to TMVr plus GDMT versus GDMT alone. The primary effectiveness endpoint was all HFHs through 24-month follow-up. Patients have now been followed for 36 months.

RESULTS - The annualized rates of HFHs per patient-year were 35.5% with TMVr and 68.8% with GDMT alone (hazard ratio [HR]: 0.49; 95% confidence interval [CI]: 0.37 to 0.63; p < 0.001; number needed to treat (NNT) = 3.0; 95% CI: 2.4 to 4.0). Mortality occurred in 42.8% of the device group versus 55.5% of control group (HR: 0.67; 95% CI: 0.52 to 0.85; p = 0.001; NNT = 7.9; 95% CI: 4.6 to 26.1). Patients who underwent TMVr also had sustained 3-year improvements in MR severity, quality-of-life measures, and functional capacity. Among 58 patients assigned to GDMT alone who crossed over and were treated with TMVr, the subsequent composite rate of mortality or HFH was reduced compared with those who continued on GDMT alone (adjusted HR: 0.43; 95% CI: 0.24 to 0.78; p = 0.006).

CONCLUSIONS - Among patients with HF and moderate-to-severe or severe secondary MR who remained symptomatic despite GDMT, TMVr was safe, provided a durable reduction in MR, reduced the rate of HFH, and improved survival, quality of life, and functional capacity compared with GDMT alone through 36 months. Surviving patients who crossed over to device treatment had a prognosis comparable to those originally assigned to transcatheter therapy. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation [COAPT]; NCT01626079)