The results of the study were presented as part of the late-breaking clinical trials at the American College of Cardiology’s 65th Annual Scientific Session (ACC.16) in Chicago, and simultaneously published online in The New England Journal of Medicine.

The PARTNER II Trial is the first randomized clinical trial comparing outcomes of severe, symptomatic aortic stenosis patients who were at intermediate risk for open-heart surgery. The composite primary endpoint of the trial was all-cause mortality or disabling stroke at two years.

The event rate was 19.3 percent for transcatheter aortic valve replacement (TAVR) with the SAPIEN XT valve, which was non-inferior, compared with 21.1 percent for surgery. For the 76 percent of SAPIEN XT patients receiving the transfemoral approach, the as-treated event rate was 16.3 percent, which was superior to surgery (p=0.04).

"The PARTNER II Trial is unique in size, distinctive in rigor of execution and exceptional in patient outcomes," said Craig Smith, M.D., chair, Department of Surgery, and surgeon-in-chief, NewYork-Presbyterian Hospital/Columbia University Medical Center. Smith is the co-principal investigator of the PARTNER II Trial.

"In intermediate-risk patients, transcatheter and surgical valve replacements were similar with respect to the combination of mortality and disabling stroke. In this study, TAVR significantly shortened ICU and hospital stays, and, in patients who are candidates for transfemoral access, the SAPIEN XT valve may have additional clinical advantages."

The PARTNER II Trial randomized 2,032 patients at 57 centers in the United States and Canada between December 2011 and November 2013. Patients were stratified into the transfemoral or transapical/transaortic cohorts and then randomly assigned to undergo either transcatheter aortic valve replacement with the SAPIEN XT valve or surgical aortic valve replacement with any commercially available surgical valve.

All patients were followed for at least two years. Strokes were assessed by a neurologist.
Data on intermediate-risk patients treated with the advanced SAPIEN 3 valve – with comparisons to surgical patients treated in the PARTNER II A Trial via a pre-specified propensity-score model – will be presented tomorrow during the joint ACC/TCT late-breaking clinical trials session.

The SAPIEN XT valve and, more recently, the SAPIEN 3 valve, are approved in the United States for the treatment of high-risk patients with severe, symptomatic aortic stenosis; the valves are not approved for the treatment of intermediate-risk patients. The SAPIEN family of valves has been used in the treatment of more than 150,000 patients globally.