Data Presented on Edwards Sapien TAVR Device for Treating High-Risk, Severe Stenosis

January 30, 2012—Edwards Lifesciences Corporation (Irvine, CA) announced that new data were presented on high-risk surgical patients with severe aortic stenosis who were treated with transapical transcatheter aortic valve replacement (TAVR) during the continued access period of cohort A of the PARTNER trial. PARTNER is evaluating the Edwards Sapien transcatheter heart valve.

Todd M. Dewey, MD, presented the findings at the annual meeting of the Society of Thoracic Surgeons (STS) in Fort Lauderdale, Florida.

According to Edwards Lifesciences, after the randomized enrollment of 104 transapical patients in PARTNER, another 822 patients were treated transapically during the nonrandomized continued access (NRCA) program that enrolled patients between September 2009 and September 2011.

The average predicted risk of operative mortality at 30 days, according to the STS Adult Cardiac Database, was 12.2%. During continued access, mortality at 30 days was 8.2%, and at 1 year, it was 23.6%.

The randomized portion of the PARTNER trial had previously demonstrated that for patients treated with transapical TAVR, mortality at 30 days and 1 year was 8.7% and 29.1%, respectively. The STS score of average predicted risk of operative mortality at 30 days in this group of patients was 12.1%. Patients not randomized to TAVR received valve replacement via conventional open heart surgery.

After the procedure, early symptom improvement was observed as defined by New York Heart Association (NYHA) class, measured I through IV. At baseline, 5% of continued access patients were assessed as NYHA classes I or II, and at 30 days, this number increased to 77%. At 1 year, the benefits of aortic valve replacement were evident in all groups, as measured by improvements in NYHA class, stated the company.

NYHA class I is defined as asymptomatic heart disease; class II is comfortable at rest, with symptoms during normal activity; class III is comfortable at rest, with symptoms during a less-than-normal level of activity; and class IV is symptomatic at rest.

In the nonrandomized continued access, transapical group (n = 822), the rate of all-cause mortality was 8.2% (66 patients) at 30 days and 23.6% (148 patients) at 1 year. The stroke rate was 2% at 30 days and 3.7% at 1 year. The rate of death or stroke was 9.9% at 30 days and 25.7% at 1 year.

In the PARTNER aortic valve replacement group (n = 92), the rate of all-cause mortality was 7.6% (7 patients) at 30 days and 25.3% (23 patients) at 1 year. The stroke rate was 5.5% at 30 days and 7% at 1 year. The rate of death or stroke was 12% at 30 days and 29.7% at 1 year.

In the PARTNER transapical group (n = 104), the rate of all-cause mortality was 8.7% (9 patients) at 30 days and 29.1% (30 patients) at 1 year. The stroke rate was 7% at 30 days and 10.8% at 1 year. The rate of death or stroke was 15.4% at 30 days and 34.8% at 1 year.

The company noted that all percents are Kaplan-Meier estimates. Comparisons of NRCA and randomized cohorts are limited, as the continued access group was not randomized.

The measurement of treatment outcomes were calculated for survivors evaluated at 30 days and 1 year postprocedure through September 2011. For survivors, NYHA classes I and II was achieved in 76.6% of patients in the NRCA transapical group at 30 days and 88.7% at 1 year. In the PARTNER aortic valve replacement group, NYHA classes I and II were achieved in 61% of patients at 30 days and in 87.5% of patients at 1 year. In the PARTNER transapical group, NYHA classes I and II were achieved in 64.4% at 30 days and 82.9% at 1 year.

The company advised that the Edwards Sapien transcatheter heart valve for the treatment of high-risk patients is currently an investigational device in the United States. In November 2011, the US Food and Drug Administration approved the device for the treatment of certain inoperable patients. In cohort A of the PARTNER trial, high-risk surgical patients were randomized to determine whether a less-invasive transcatheter approach could provide equivalent clinical results to conventional open heart surgery. The data from cohort A demonstrated that the study achieved its primary endpoint at 1 year, stated Edwards Lifesciences.