Final, five-year clinical outcomes from the COAPT trial, evaluating transcatheter mitral valve repair with the first-generation MitraClip (Abbott) device in patients with heart failure and moderate-to-severe or severe secondary mitral regurgitation (MR), indicate that the interventional treatment led to a lower rate of heart failure hospitalisation and all-cause mortality when compared to medical therapy alone.
Presented at the 2023 American College of Cardiology (ACC) annual scientific session (4–6 March, New Orleans, USA) by Gregg W Stone (Mount Sinai Hospital, New York, USA), the results were simultaneously published in the New England Journal of Medicine (NEJM).
Detailing the trial’s results, Stone reported that among the 614 patients enrolled in the trial (average age 72, 36% women) the annualised rate of hospitalisation for heart failure through five years was 33.1% per year in the device group and 57.2% per year in the control group (hazard ratio [HR] 0.53; 95% confidence interval [CI] 0.41 to 0.68).
All-cause mortality through five years was 57.3% in the device group and 67.2% in the control group (HR 0.72; 95% CI 0.58 to 0.89), while death or hospitalisation for heart failure within five years occurred in 73.6% of the patients in the device group and in 91.5% of those in the control group (HR 0.53; 95% CI, 0.44 to 0.64). Device-specific safety events within five years occurred in 4 of 293 treated patients (1.4%), with all the events occurring within 30 days after the procedure.
The results indicate that the study’s primary and secondary endpoints were met.
“These final results show that in a very sick population with mitral valve dysfunction secondary to heart failure, transcatheter mitral valve repair was extremely safe and significantly reduced both hospitalisations due to heart failure and deaths from heart failure or all causes,” said Stone, the lead author of the study. However, Stone also said these patients had a high rate of adverse events even after successful mitral valve repair, indicating the need for further advances to treat these high-risk patients.
“MitraClip made a profound difference for patients with heart failure and severe MR. Based on these findings, appropriate patients should be treated with MitraClip as early as possible,” Stone said. “However, nearly three in four patients still died or were hospitalised for heart failure within five years, even after successful MitraClip, because treating the regurgitant mitral valve does not improve their underlying left ventricular dysfunction. We need to develop better therapies for advanced heart failure if the prognosis of this high-risk patient population is to be further improved.”
Stone highlighted in his presentation that one limitation of the study is that it was not blinded, though he said that independent experts assessed the hospitalisations, deaths and other adverse events in the study based on specific criteria documented in the patient’s chart. The study’s findings also apply only to patients with mitral valve regurgitation secondary to left ventricular failure who were treated with the MitraClip device.
