Alternative-Access Results From the Extreme-Risk Study in Medtronic's CoreValve US Pivotal Trial Presented

October 30, 2013—Medtronic, Inc. (Minneapolis, MN) announced results of patients treated with transcatheter aortic valve replacement (TAVR) via alternative access routes as part of the Extreme Risk study within the CoreValve United States pivotal trial. David H. Adams, MD, Chair of the Department of Cardiothoracic Surgery at The Mount Sinai Medical Center in New York, New York and National Co-principal Investigator of the trial, presented the data at the TCT 2013: Transcatheter Cardiovascular Therapeutics conference in San Francisco, California. Results from patients treated via transfemoral access in the Extreme Risk study of the CoreValve pivotal trial were also presented on October 29 at TCT.

According to Medtronic, the observational analysis found that the CoreValve device provided life-saving and quality-of-life benefits to patients treated via the subclavian and direct aortic (noniliofemoral) access routes despite the higher-risk nature of the patient population. The study evaluated the self-expanding, low-profile (18 F) CoreValve system with three valve sizes (26, 29, and 31 mm). Medtronic intends to seek approval for these access routes as part of its Extreme Risk submission to the US Food and Drug Administration.

As part of the Extreme Risk study, 146 patients were treated via alternative access approach after extensive screening showed they were considered too ill or frail to have their aortic valves replaced through traditional open-heart surgery and were ineligible for the more common transfemoral TAVR.

Medtronic reported that through 1 year, these patients demonstrated high rates of procedural success and valve performance, consistent with transfemoral patients. The results were achieved in spite of statistically significant differences between transfemoral and alternative access patients, which showed an increased presence of peripheral vascular disease (35.3% vs 61.6%; P < .0001), chronic lung disease/chronic obstructive pulmonary disease (58.8% vs 73.3%; P = .0017), Society of Thoracic Surgeons-rated severe chronic lung disease (24% vs 40.4%; P = .0002), and diffusion capacity of < 50% (22.3% vs 40.4%; P < .0001) in the alternative access patients.

The major stroke rate was 6.3% at 1 month, which trended higher than patients receiving the device via the femoral artery (2.4%) but still lower than previously reported rates; in the CoreValve Continued Access Study, the rate of major stoke in alternate access patients was 2.3% at 1 month.

Medtronic stated that similar to patients treated transfemorally, these patients experienced significant and sustained functional and quality-of-life improvements, with most patients (91.6%) in New York Heart Association (NYHA) Class III and IV at baseline, improving to 25% at 1 month and 12% at 1 year (as measured by NYHA Class). Quality-of-life scores improved 22.9 points at 1 year, as measured by the Kansas City Cardiomyopathy Questionnaire 100-point scale, in which a 20-point change is considered highly significant). At 1 year, the rate of survival was 63% for the alternative access patients.

In the company's press release, Dr. Adams commented, “For the 20% to 25% of extreme-risk patients who are not eligible for transfemoral TAVR due to vascular anatomy, this study confirms that TAVR can be successful in these patients as well. These results demonstrate a noniliofemoral approach is a viable option for patients with severe aortic stenosis who are not candidates for surgery or transcatheter valve replacement through traditional peripheral access.”