"This is really a just like a plumbing problem -- you fix the broken valve, you get better flow, everything works better," Bonow explained.
The device is approved and has been in use in Europe for several years.
The average age of patients in PARTNER was 83 and more than 80 percent were men.
The results reported here and in the journal represent one cohort in the trial -- 358 patients who were judged unsuitable for surgery because a risk score developed by the Society of Thoracic Surgeons (STS) predicted that their risk of dying within 30 days of surgery was 50 percent.
Another group of high-risk aortic stenosis patients -- those whose chance of dying within 30 days of surgery was closer to 15 percent -- made up cohort A of the PARTNER trial. Patients in that group were randomized to either a surgical valve repair or to TAVI. Results from that cohort are expected to be reported next spring at the American College of Cardiology meeting.
Dr. Richard Shemin, a thoracic surgeon at UCLA, who was not involved in the study, told MedPage Today/ABC News that those anticipated results represent a truly randomized trial -- comparing TAVI with surgery -- and those results are likely to be more helpful in guiding clinical decisions. "But for patients who are not candidates for surgery, this approach appears to be a good option. It's just that this doesn't tell us that percutaneous implant is the way to go for all patients," Shemin said.
The authors agreed that the study was limited by the exclusion of several important subgroups including patients with coronary stenosis and those with severe peripheral vascular disease. Moreover, assessing the durability and long-term safety of the bioprostethic valve will require more than an one-year follow-up.
While warning that the results cannot be extrapolated to other patient groups, the authors concluded that on the basis of "a rate of death from any cause at one year that was 20 percentage points lower with TAVI than with standard therapy, balloon-expandable TAVI should be the new standard of care for patients with aortic stenosis who are not suitable for surgery."