Background: In patients with primary degenerative MR, MVR is curative, with the transcatheter approach being safer than surgical repair. However, it is unknown whether patients with secondary MR from left ventricular dilatation would confer the same benefit of MVR.
Study design: Multicenter, randomized, controlled, parallel-group, open-label trial.
Setting: 78 sites in the United States and Canada.
Synopsis: From December 2012 to June 2017, 614 patients from 78 centers in the United States and Canada with symptomatic MR were enrolled with 302 patients assigned to the device group (transcatheter MVR and medical treatment) and 312 to the control group (medical therapy). Over 2 years, the device group’s annual rate for heart failure hospitalizations was significantly lower (35.8%/patient-year versus 67.9%/patient-year in the control group), as was all-cause mortality (29.1% for the device group versus 46.1%). The rate of freedom from device-related complications was 96.6%, better than the goal of 88%. There was improvement in quality of life, functional capacity, severity of MR, and left ventricular remodeling.
Limitations include that investigators were not blinded because the device was visible on imaging. Longer follow-up in the device group may have contributed to the observed decreased mortality. It is unknown whether less-symptomatic patients would attain the same benefit.
Bottom line: In patients with symptomatic, moderate to severe, and severe secondary MR, MVR lowers rates of hospitalization, decreases mortality, and improves quality of life.
Citation: Stone GW et al. Transcatheter mitral-valve repair in patients with heart failure. N Engl J Med. 2018 Sep 23.
Dr. Kochar is an assistant professor of medicine in the division of hospital medicine at Mount Sinai Hospital, New York.