SCAI: MitraClip shows promise for high-risk patients at one year
Data from the Endovascular Valve Edge-to-Edge REpair STudy (EVEREST II) High-Risk Registry showed that, in patients who are not healthy enough to undergo surgery to repair a leaky mitral valve, use of the MitraClip valve repair system is safe and, in the majority of patients, effective in relieving symptoms that limit the ability to engage in day-to-day activities. According to the researchers, there has never been a treatment option for this high-risk group of patients in the past.
“The MitraClip system is a first-in-class treatment and a remarkable innovation—the beginning of a very exciting era for treating valvular disease with minimally invasive devices,” said Saibal Kar, MD, director of interventional cardiac research at the Heart Institute, Cedars-Sinai Medical Center in Los Angeles.
The MitraClip (Evalve, recently acquired by Abbott) is an investigational device that has not yet been approved by the FDA.
For the study, Kar and colleagues recruited 78 patients with significant MR (classified as moderate-to-severe or severe) who were considered to be at very high risk for surgery. The average age of patients was 77 years.
Patients with significant mitral regurgitation (MR) in NYHA Class III/IV have a poor quality of life and limited survival without surgery. High risk of surgical mortality due to advanced age and co-morbidities sometimes limits treatment options.
The researchers included patients with grade 3 or 4 MR and a Society of Thoracic Surgery Mortality Risk Model or cardiac surgeon predicted mortality risk of at least 12 percent. Patients with left ventricular ejection fraction less than 20 percent and end systolic internal dimension more than 60 mm were excluded.
Of the patient population, some 60 percent of patients had previously undergone cardiac surgery, 85 percent had coronary artery disease, 35 percent had chronic lung disease and 23 percent had moderate-to-severe kidney failure. According to a formula developed by the Society of Thoracic Surgeons, the average predicted risk of surgery-related death was 18.2 percent.
The placement of the MitraClip was successful in 96 percent of patients, with no procedural deaths. Within the first 30-days, mortality was 7.7 percent, which was significantly lower than the predicted 18.2 percent surgical mortality and not significantly different from the 8.3 percent mortality in a matched control group who were treated with medications alone.
At 30-day follow-up, Kar and colleagues found that 75 percent of survivors were in NYHA class I or II, meaning no or only slight limitation in physical activity. Survival at one year was 75 percent, better than the 55 percent in the medication-only control group.
At one year, 74 percent of survivors who were treated with the MitraClip were still in NYHA class I or II and average heart function was improved by several measures. In addition, there was a 45 percent reduction in readmissions to the hospital for congestive heart failure. None of the patients in the study developed more severe symptoms, worse mitral regurgitation or underwent surgery within that time period.
Researchers concluded that treatment with the MitraClip valve repair system can be performed safely in high-risk patients and provides long-lasting relief of symptoms.
“Patients who couldn’t walk across a room without being short of breath are now able to walk up a flight of stairs, go shopping, and exercise,” said Kar. “The MitraClip procedure can be transformational for patients.”
The study was sponsored by Evalve, now part of Abbott. Kar received research grants from Evalve.