Evolut Low Risk
Michael J. Reardon, MD, coprincipal investigator for the Evolut Low Risk study and professor of cardiovascular surgery at Houston Methodist Hospital, reported on 1,468 patients randomized to TAVR with a Medtronic self-expanding, supra-annular bioprosthetic valve or to SAVR. Of them, 22% of patients got the most recent version of the valve, known as the Evolut PRO, 74% got the Evolut R, and the remainder received the first-generation CoreValve.
Bruce Jancin/MDedge News
Dr. Michael J. Reardon
The primary endpoint – death or disabling stroke – was slightly different from that in PARTNER 3. At 1 year, the rate was 2.9% in the TAVR arm and 4.6% with SAVR, a statistically significant difference, while at 2 years the rate was 5.3% with TAVR and 6.7% with SAVR, a difference that was not significant. Impressively, the rate of the composite of death, disabling stroke, or heart failure hospitalizations through 1 year was 5.6% with TAVR versus 10.2% with SAVR.
“We’ve shown that, with TAVR, you’re more likely to be alive, without a stroke, and outside the hospital. This is exactly what my patients tell me they want when we sit down for shared decision-making and talk about their expectations,” Dr. Reardon said.
Noting the striking similarity of across-the-board outcomes in the two trials, Dr. Reardon concluded, “I think what we’re seeing here is a class effect of TAVR, and we have to recognize it as such.”
Dr. Leon agreed, with a caveat. “I think the class effect for these two versions of TAVR systems is very real. I wouldn’t presume to think that every TAVR device will perform the same way, so I think we need a lot more data on the newer devices that are being introduced.”
The reaction
During the question-and-answer session, the two investigators were asked about stroke rates, which were significantly lower in the TAVR patients even though in the early randomized trials in high-risk patients the stroke rates were twice as high with TAVR than SAVR. The explanation probably lies in a mix of device refinements over time, better techniques, standardized procedures, and careful patient selection, they said.
“If you look at stroke in the TAVR arm in both these trials, we’re almost approaching the background stroke rate in a group of 74-year-olds sitting around in a room,” Dr. Reardon observed.
Both trials will continue to assess participants both clinically and by echocardiography through 10 years, in part to assess TAVR valve durability, but also to evaluate the durability of surgical valves, which isn’t nearly as well established as most people think, according to the investigators.
“There is a myth of surgical bioprosthetic valve immortality. It’s based upon relatively few numbers of patients, largely sponsor-based studies, with numbers at risk at 15-20 years that are extremely low,” Dr. Leon asserted. “The majority of surgical valves being used today and touted as being durable are backed by only 2-4 years of data.”
In contrast, he added, “We have 5-year TAVR data which is absolutely definitive of no early structural valve deterioration.”
Discussant Mayra E. Guerrero, MD, of the Mayo Clinic in Rochester, Minn., expressed concern that “this paradigm shift to ‘TAVR for all’ ” could break the bank for many institutions because the cost of TAVR valves is far greater than for SAVR valves. But she was heartened by the fresh PARTNER 3 and Evolut Low Risk data showing TAVR patients had fewer ICU days, shorter hospital stays, fewer strokes, more frequent discharge home, and a lower rehospitalization rate.
Dr. Reardon was reassuring on this score.
“I am 100% convinced that when we do the financials for these two trials, TAVR is going to be a cost saver and a huge winner,” the surgeon said.
He reported serving as a consultant to Medtronic and receiving research grants from Medtronic and Boston Scientific. Dr. Leon reported receiving research grants from Edwards Lifesciences and St. Jude Medical and acting as a consultant to several medical device companies.
The two trials have been published online by the New England Journal of Medicine.
SOURCES: Leon MB et al. N Engl J Med. 2019 Mar 16. doi: 10.1056/NEJMoa1814052; Reardon MJ et al. N Engl J Med. 2019 Mar 16. doi: 10.1056/NEJMoa1816885.