At a Crossroads, Mitral Regurgitation Therapy Awaits EVEREST Results
A substudy of clips to grasp mitral-valve leaflets will help define the efficacy of such devices.
As a growing area in interventional cardiology, mitral valve regurgitation therapy may depend on the results of EVEREST, a trial to evaluate a percutaneous mitral valve repair system in patients with grade-3 or grade-4 mitral regurgitation.
The trial’s principal investigator, Ted Feldman, MD, from Evanston Hospital and Northwestern University in Chicago, spoke on TCT TV about the current state of percutaneous mitral valve treatment. At TCT, Feldman is awaiting incremental updates on the progress of percutaneous mitral valve interventions and the accrual of patients into clinical trials with a variety of new devices.
Mitral clips
Feldman is particularly interested in an EVEREST substudy of MitraClips (Evalve, Inc.), a device that grasps and coats the leaflets of the mitral valve. The researchers are looking at patients with severe mitral regurgitation in 26 centers. The substudy began with a phase-1 registry and is now comparing the device with a surgical technique. Patients were randomized to clip or surgery in a 2:1 ratio.
Feldman said this was a pivotal trial that will help define the effectiveness of such devices. Patients in the study had mitral regurgitation from any cause, met AHA and ACC class I criteria for moderate-to-severe regurgitation and had symptoms of left ventricular failure. MitraClips are not the only device available to treat mitral regurgitation. Six other devices have already been used in patients as permanent implants or tested intraoperatively.
Clinical trials
Over the past five years, there has been exponential growth in trials testing percutaneous mitral valve repair. In 2003, only two patients were enrolled in trials of mitral valve repair devices. To date, according to Feldman, there are about 159 patients enrolled in similar trials. The increase in trial enrollment will greatly benefit cardiologists when treating mitral valve regurgitation patients, he said, but more work is needed.
Cardiologists have made progress in percutaneous therapy thanks to decades of surgical experience considering the nuances of pathology in mitral regurgitation. The assessment of percutaneous mitral valve therapy has been a void in percutaneous therapy research, as well as the quantitative echo and core lab assessment of mitral regurgitation patients and surgical therapy vs. medical therapy for the condition.