CoreValve TAVI Maintains Durability Out to Four Years

Reed Miller

August 28, 2011

August 28, 2011 (Paris, France) — The longest follow-up of patients implanted with the CoreValve (Medtronic) transcatheter aortic-valve implantation (TAVI) device presented so far suggests that it is reliable and durable in high-risk patients, according to the study investigators [1].

"In due time, I'm sure we will see a gradual decrease in the average patient age, treating patients with less comorbidity than was done in the beginning, strengthened by these types of results showing the durability of the implants," study lead-investigator Dr Peter den Heijer (Amphia Hospital, Breda, the Netherlands) told heartwire .

Here at the European Society of Cardiology 2011 Congress, den Heijer presented long-term follow-up results from 52 patients implanted with the second-generation version of CoreValve in 2005 and 2006 in Europe and Canada. All of the patients in the study were at least 80 years old with a logistic EuroSCORE over 20 or over 65 years old with at least one high-risk comorbidity. All of the patients had severe aortic stenosis and an aortic-valve annulus diameter between 20 mm and 24 mm. Two-thirds of the patients had NYHA class 3 heart failure and almost 20% had class 4 heart failure.

Four-year follow-up data was collected on 20 patients, but 26 patients died, including 13 cardiac deaths. Overall survival was 58.5% at two years and 45.1% at four years. At four years, the surviving patients showed significant improvement in heart-failure symptoms, with 61% in class 1 heart failure and 22% in class 2. Nearly a third of patients showed grade 2 or 3 aortic regurgitation at baseline, but after four years 57% showed no regurgitation and 43% showed grade 1 regurgitation. The mean valve gradient decreased from 41 mm Hg at baseline to 12 mm Hg at 30 days and 10 mm Hg at four years.

There were no strokes reported in the study population between three months and four years and no frame fractures, valve migrations, valve endocarditis, or structural valve deteriorations leading to stenosis or regurgitation. "That's important, because the goal of this treatment is to provide patients with severe aortic stenosis, a severely life-limiting disease, with a better prognosis, and it appears to be not at all hampered by the structure of the valve," den Heijer told heartwire .

In a 70-patient study by Dr Ronen Gurvitch (University of British Columbia, Vancouver) colleagues, the Sapien (Edwards Lifesciences) transcatheter aortic valve showed no structural valvular deterioration, stent fracture, deformation, or valve migration over a mean follow-up of 3.7 years [2].

CoreValve is available in Europe and is being tested in a major US clinical trial that Medtronic says will be completed in 2012. The FDA is expected to approve Edward's Sapien TAVI device soon, following a positive appraisal by its advisory committee.

Still Much Too Early to Assess Long-Term TAVI Results

Surgeon Dr Craig Miller (Stanford University, CA), one of the investigators of the pivotal PARTNER trial of Sapien, told heartwire that while the four-year results with CoreValve are "decent," the clinical community will "need much larger numbers of patients followed at two, three, and four years for the hemodynamics to mean much."

PARTNER investigator Dr Michael Mack (Medical City Dallas Hospital, TX) told heartwire , "Although it's reassuring that there are now results out to four years and there's no sign of structural valve deterioration, it really adds minimal information to what we know already.

"There's only 20 patients alive at four years, so how do you know what happened to the other 30 patients [in the trial]? Some died of cardiac death and some died of unknown causes. How do you know they didn't die of structural valve deterioration?" he said. "A better way of doing this study for all aspects is that all the information should be on matched patients."

Mack said that the real long-term durability of transcatheter valves will become more clear with more data from the SOURCE registry and the long-term follow-up of PARTNER trial, which will include annual core-lab–adjudicated echocardiography follow-up out to five years.

den Heijer is a consultant and proctor for Medtronic.

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