Abbott Laboratories' MitraClip device for minimally invasive repair of the mitral heart valve in patients with advanced heart failure and severe mitral regurgitation significantly reduced both hospitalizations and mortality at two years in a study presented Sunday at the Transcatheter Cardiovascular Therapeutics meeting in San Diego.
"To be able to reduce hospitalizations and improve survival is a breakthrough for patients who previously had few treatment options," Gregg Stone, co-principal investigator of the study, said in a press release from NewYork-Presbyterian/Columbia University Irving Medical Center, where he is director of cardiovascular research and education at the Center for Interventional Vascular Therapy.
Patients in the study who underwent the MitraClip procedure had 47% fewer heart failure-related hospitalizations and 38% fewer deaths than those who were treated with medical therapy alone.
The results were unexpectedly robust, one Wall Street analyst said, opening up a significant pool of patients for Abbott, potentially 1 to 2 million.
"Based on precedent studies, there was zero expectation coming into the results that the trial would be positive," Jefferies analyst Ray Denhoy wrote in a Monday morning note.
It's also good news for Abbott because data on another trial for the company's Percutaneous Heart Pump (PHP), on hold since February, were murky, Denhoy wrote.
Mitral regurgitation occurs when the valve that connects the left ventricle and left atrium doesn't close properly, allowing blood to flow backward and forcing the heart to pump harder.
For patients who have mitral regurgitation due to left ventricular dysfunction, the prognosis is considered poor. The Coapt study focused on this form of mitral regurgitation, known as functional or secondary, in which the left ventricle enlarges after damage from a heart attack or other cause.
The MitraClip device works by fastening a portion of the mitral valve leaflets together to reduce the backflow of blood, allowing the heart to pump more efficiently. FDA approved the device in 2013 to treat the primary form of mitral regurgitation caused by an anatomic defect of the valve.
The Coapt trial showed treatment with MitraClip plus medical therapy was superior to medical therapy alone in reducing rates of heart failure hospitalizations and improving survival at two years. The study of 614 heart failure patients with moderate-to-severe or severe secondary mitral regurgitation met both the primary safety and effectiveness endpoints and all secondary endpoints.
As reported in the New England Journal of Medicine, the annualized rate of all hospitalizations for heart failure within 24 months was 35.8% in the device group, compared with 67.9% in the control group. Death from any cause within 24 months occurred in 29.1% of the patients in the device group, compared with 46.1% in the control group. Freedom from device-related complications at 12 months was 96.6%, which exceeded the performance goal of 88% for the primary safety endpoint.
According to Abbott, the intervention is the first to demonstrate positive outcomes in a clinical trial for heart failure patients with significant secondary mitral regurgitation.
The Coapt trial outcomes were "substantially better" than those for lower-risk patients receiving the MitraClip in an earlier study called Everest II, the NEJM article noted. The researchers said the Coapt findings "probably reflect operators' increased experience with implantation and improved echocardiographic guidance."