Registry analysis finds 91% of patients receiving the MitraClip have procedural success

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 - MitraClip
MitraClip mitral valve repair system.
Source: Abbott Vascular

Approximately 91 percent of patients with primary mitral regurgitation had procedural success after undergoing transcatheter mitral valve repair with the MitraClip, according to a registry analysis.

The researchers defined procedural success as a reduction to moderate or less mitral regurgitation in the absence of cardiac surgery or in-hospital mortality.

Lead researcher Paul Sorajja, MD, of the Minneapolis Heart Institute at Abbott Northwestern Hospital, and colleagues published their results online in the  Journal of the American College of Cardiology  on March 7.

“Overall, these results demonstrate the effectiveness and safety of transcatheter [mitral valve] repair with this device in the treatment of prohibitive risk patients with symptomatic [mitral regurgitation],” they wrote. “Procedural success, clinical outcomes, and the rate of adverse events were comparable with pre-approval research studies and other commercial registries.”

The researchers mentioned that approximately 600,000 people in the U.S. have mitral regurgitation. Guidelines recommend patients with degenerative mitral regurgitation and those with symptoms or left ventricular dysfunction undergo surgery.

However, patients with significant comorbidities who cannot undergo surgery are candidates to transcatheter mitral valve repair with the MitraClip (Abbott Vascular). The FDA approved the MitraClip in October 2013. The researchers mentioned the MitraClip is available at approximately 100 sites in the U.S.

In this study, the researchers evaluated data from 564 patients who were part of the Society of Thoracic Surgeons (STS)/American College of Cardiology (ACC) Transcatheter Valve Therapy (TVT) registry. The Centers for Medicare & Medicaid’s national coverage determination requires all patients who receive the MitraClip to enroll in the registry, which launched in 2011 as a joint initiative of the STS and ACC.

The patients all underwent commercial therapy with the MitraClip from November 2013 to August 2014 at 61 U.S. hospitals. The median age was 83 years old, while 56 percent of patients were men, 86 percent had severe symptoms and 60.5 percent had been hospitalized for heart failure in the year prior to transcatheter mitral valve repair.

The median STS predicted risk mortality scores were 7.9 percent for mitral valve repair and 10 percent for mitral valve replacement. The researchers mentioned that 57.3 percent of patients had fraility, while 90.8 percent of patients had degenerative disease.

They added that transcatheter mitral valve repair reduced mitral regurgitation to moderate or less in 93 percent of patients. In addition, 13 patients died in the hospital, including four for cardiac-related reasons.

Further, 90.6 percent of patients had procedural success, 8 percent had procedural complications, 3.9 percent of patients had major bleeding, 1.4 percent of patients had device-related adverse events. The incidence of in-hospital stroke was 1.2 percent.

At 30 days, the mortality rate was 5.8 percent, the stroke rate was 1.8 percent, the incidence of life-threatening or disabling bleeding was 2.6 percent and the hospitalization rate was 3.1 percent.

The researchers mentioned a few limitations of the study, including that data entry in the registry was voluntary and subject to bias reporting and that the echocardiographic variables were reported on-site and not in a core laboratory. They added that data adjudication was limited and that poor outcomes may have been under-reported. They also did not analyze data on functional status or quality of life.

“These data highlight the utility of the TVT Registry for post-market surveillance and support the continued role of transcatheter [mitral valve] repair by heart teams in the treatment of prohibitive-risk patients with symptomatic [mitral regurgitation],” the researchers wrote. “Ongoing evaluation should be performed to assess long-term functional and cardiovascular outcomes.”