Edwards Lifesciences Corp.’s newest aortic valve, Sapien 3, which is implanted through a catheter and allows patients to avoid open heart surgery, has a lower risk of death or stroke than surgery in intermediate-risk Americans who currently can’t get the device.
The findings presented at the American College of Cardiology’s annual meeting build on a report released Saturday that found an older Edwards model was as effective as surgery, which requires doctors to crack open the ribs to get access to the heart. The results suggest that the catheter procedure will become the standard of care for a lower-risk group of patients whose valves narrow as they age, crimping blood flow to the body.
While more than 250,000 patients have received transcatheter aortic valves from Edwards and Medtronic Plc in a procedure called TAVR, their use in the U.S. has been restricted to those who are very sick or face a high risk of dying if they undergo surgery. The findings could improve the treatment options for patients with intermediate risk, who currently make up about 20 percent of people getting aortic valve surgery, said lead author Vinod Thourani, chief of cardiothoracic surgery at Emory University Hospital in Atlanta.
‘Tide Is Turning’
“These two trials, the totality of the evidence, is very positive for the transcatheter approach,” said Roxana Mehran, director of Interventional Cardiovascular Research at Mount Sinai Hospital in New York. “This has huge implications that the tide is turning toward transcatheter valve replacement as the possible new gold standard. The caveat is that we don’t have very long-term data yet on these valves.”
The latest study included more than 1,000 patients with an intermediate risk from undergoing open-heart surgery, all treated with Sapien 3. Their results were compared with a similar group of patients who were enrolled in the earlier Edwards trial. The Irvine, California-based company funded both studies.
After one year:
- 7.4 percent of Sapien 3 patients died, versus 13 percent getting surgery.
- 4.6 percent of Sapien 3 patients had a stroke, versus 8.2 percent getting surgery.
- 1.5 percent of Sapien 3 patients had moderate to severe regurgitation, in which the blood leaks backward, versus 0.4 percent of those getting surgery.
- The combination of death, stroke and regurgitation occurred 9.2 percent less in Sapien 3 patients when the researchers performed a different statistical analysis.
The findings provide a path for U.S. approval of the devices for intermediate-risk patients, which the company expects to receive by the end of the year, Edwards Chief Executive Officer Michael Mussallem said. The company anticipated its Sapien valves would be approved for them when it boosted the projected market size to $5 billion in December. Getting there may happen sooner now that there’s proof they may be superior and improve survival, he said.
About 580,000 Americans suffer from severe aortic stenosis, with half suffering symptoms that can include chest pain, feeling faint, shortness of breath and fatigue. The study results have spawned interest in a randomized trial of even lower-risk patients, Thourani said. They make up about half the market, according to Edwards data.
“We have done extreme risk, we have done high risk,” Thourani said. “We have to see what the future holds for low risk. Having the results of this study gives us confidence.”
The trial for low-risk patients is already beginning, though it will be a few years before the company has results, Mussallem said.
A separate study of Medtronic’s rival CoreValve, the only aortic valve to find a survival difference in high-risk patients, is producing longer-term data showing the benefit is holding up over time in the most vulnerable patients.
After three years, death plus stroke was significantly lower in CoreValve patients:
- 32.9 percent of CoreValve patients died, vs 39.1 percent of surgery patients.
- 12.6 percent of CoreValve patients had a stroke, vs 19 percent getting surgery.
- The benefit was even greater in patients who were healthier at the study start.
- There was no early sign of deterioration in the valve.
“Your patients want to be alive without a stroke, and for them TAVR is still better than surgery at three years,” said Michael Reardon, a cardiothoracic surgeon and chair of cardiovascular research at the Houston Methodist Debakey Heart & Vascular Center.
Additional work is needed to ensure that the TAVR valves last as long as surgically implanted models, and that risks such as blood clots, mechanical problems or mobility issues don’t emerge later, said Mehran, the incoming chair of the ACC’s Interventional Cardiology Council. Patients who have been treated with the devices so far have been elderly and often frail, who may not live long enough for problems to emerge, said Mehran, who wasn’t involved with the study.
“We knew this would be a very important therapy for people who were so sick they otherwise wouldn’t get treated, but now we are looking at intermediate-risk patients,” Mehran said. “As we watch these data, it’s looking better and better.”