New Clinical Data Supports Clinical Efficacy of Medtronic’s CoreValve

The good clinical news just keeps coming for Medtronic Inc.’s CoreValve transcatheter aortic valve replacement (TAVR) device.

Minneapolis, Minn.-based Medronic has been part of a protracted legal battle in international and U.S. courts with Irvine, Calif.-based Edwards Lifesciences Corp. accusing its rival of patent infringement. Most recently, Medtronic was successful in briefly delaying an injunction that would have halted U.S. sale of CoreValve. The legal wrangling is ongoing.

On April 29, the company reported new study data demonstrating positive outcomes for extreme risk patients with severe aortic stenosis who were treated with the CoreValve system via alternative access approaches. The data was announced during a late-breaking clinical session at the 94^th annual meeting of the American Association for Thoracic Surgery in Toronto, Canada.

The study evaluated 150 patients from the CoreValve U.S. Pivotal Trial (23 percent of the extreme risk patient group) who were not suitable for traditional TAVR through the femoral artery (in the leg), and were treated via subclavian (arteries of the upper chest below the collar bone) or direct aortic approaches. This patient group was more ill and frail than patients treated transfemorally, with higher rates of peripheral vascular disease (61.3 percent of alternate access patients versus 35.2 percent of transfemoral patients, p=0.001). These patients also had significant rates of severe lung disease (39.3 percent of alternate access patients versus 23.5 percent of transfemoral patients.

The rate of all-cause mortality or major stroke for these patients was 39.4 percent at 12 months (compared to 26.0 percent in patients treated transfemorally), an acceptable rate given the higher risk nature of these patients. Rates of moderate or severe aortic regurgitation were low (2.4 percent at one year) and 85.7 percent of these patients improved at one year.

After completion of the extreme-risk study, 339 additional patients were treated via a subclavian or direct aortic approach in the a continued-access study. The mortality rate in the pivotal alternate access patients was 11.3 percent, and in the Continued Access Study this rate improved to 9.5 percent (both at 30 days).

Also in the continued-access study, compared to the pivotal trial, rates of major stroke at 30 days (3 percent vs. 7.5 percent, p=0.03) and major vascular complications (4.2 percent vs. 8.7 percent, p=0.04) were significantly reduced, the company reported.

“The data presented today demonstrate that multiple implant approaches with the CoreValve System provide positive alternatives for very sick patients who have no other options. These data show that more patients can safely and successfully be treated,” said Michael Reardon, M.D., professor of cardiothoracic surgery at the Methodist DeBakey Heart & Vascular Center in Houston, Texas.

The CoreValve System was designed to serve a broad range of TAVR patients. The device has a small 18Fr profile for all valve sizes, which minimizes trauma at implant and allows physicians to treat patients with small or calcified vasculature. Its Nitinol frame is designed to prevent unwanted leakage and optimize blood flow. In addition, the CoreValve System is available in the broadest range of sizes available, so patients who have smaller, larger or in-between sizes can be accommodated.

The Medtronic CoreValve U.S. Pivotal Trial`s extreme risk study evaluated the self-expanding device in patients who were considered too ill or frail to have their aortic valves replaced through traditional open-heart surgery.

The CoreValve System was approved by the U.S. Food and Drug Administration (FDA) in January for patients considered extreme risk for surgery. Since receiving CE mark in 2007, the CoreValve System has been implanted in more than 50,000 patients in more than 60 countries.