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WASHINGTON (FRONTLINE MEDICAL NEWS) – U.S. heart teams have used the mitral valve transcatheter clip repair device for fixing leaky mitral valves exactly the way it was designed to be used once the device hit the U.S. market in 2013.
In the first review of periprocedural and 1-year outcomes of U.S. patients treated with the MitraClip repair device and entered in the national device registry, the results showed “acute effectiveness and safety of transcatheter mitral valve repair,” Paul Sorajja, MD , said at the annual meeting of the American College of Cardiology.
Although 1-year outcomes, gleaned from Medicare records, showed a high, 1-year mortality rate of 22% among patients who achieved a low mitral regurgitation grade of 0 or 1 (none or mild) following their procedure, and even higher mortality among patients with higher residual valvular regurgitation, this high mortality is attributable to the patients advanced age, frailty, and high prevalence of comorbidities rather than any apparent failures of the valve repair procedure, he said.
“We need to be keenly aware of the impact of comorbidities on the prognosis of these patients. The data show that untreated comorbidities really impact prognosis,” said Dr. Sorajja, an interventional cardiologist and director of the Center of Valve and Structural Heart Disease of the Minneapolis Heart Institute.
“The clip is for the no-option patient, meaning patients at high risk who have no surgical option. The data show that these are the patients who are being treated” in routine U.S. practice. “The data show that, even for these patients, you can still get pretty good results,” Dr. Sorajja said in an interview. “These are the first data on clip use in routine U.S. practice, and they are really reassuring. The data show that the clip is being used in the correct way, without risk creep, on patients with prohibitive surgical risk based on their STS [Society of Thoracic Surgeons] predicted mortality and frailty scores.”
The data he and his associates reviewed came from the 2,952 U.S. patients who underwent a transcatheter mitral valve clip repair following the devices premarketing approval from the Food and Drug Administration in November 2013, and through September 2015 at any of 250 U.S. sites offering the procedure.
The data on patient demographics and clinical status came from the STS/American College of Cardiology Transcatheter Valve Therapy registry , and data on 1-year outcomes came from Medicare records for 1,867 (63%) of the patients.
The mitral valve repair patients averaged 82 years old, 85% had a New York Heart Association functional class of III or IV, 93% had a mitral valve regurgitation grade of 3 or 4, half were judged frail, and their STS predicted mortality risk from mitral valve repair was about 6% and from valve replacement about 9%.
Immediately after their procedure, 93% of patients had a valve regurgitation grade of 2 or less, the periprocedural mortality rate was just under 3%, and 86% of patients were discharged home following a median length of stay of 2 days. Acute procedural success occurred in 92% of patients, Dr. Sorajja reported .
At 1 year, the mortality rate among the patients followed through their Medicare records showed that 26% of patients had died, 20% had been hospitalized at least once for heart failure, and 38% had at least one of these two outcomes. In addition, 6% underwent a repeat procedure of transcatheter mitral repair, and 2% had mitral valve replacement surgery.
Although patients who had a successful repair with a residual regurgitation grade of 0 or 1 still had a substantial mortality rate of 22% during 1-year follow-up, survival was worse in patients with higher grades of residual mitral regurgitation. One-year mortality among those with residual grade 2 regurgitation was 29%, and for those with residual grade 3 or 4 regurgitation, 1-year mortality was 49%.
Many patients also had at least one comorbidity, and when these were present, 1-year survival was significantly worse. In a multivariate model, patients on dialysis had twofold greater mortality than did those not on dialysis, patients with severe tricuspid valve regurgitation had twice the mortality of those with lesser or no tricuspid regurgitation, and patients with moderate or severe lung disease had a 50% higher mortality, compared with those with milder or no lung disease.
The study was supported in part by Abbott Vascular, the company that markets the MitraClip. Dr. Sorajja has been a consultant to and speaker on behalf of Abbott Vascular. He has also been a consultant to Integer, Lake Region Medical, and Medtronic, and a speaker on behalf of Boston Scientific.
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