Self-expanding TAVR system shows durable benefits in low-risk patients at 3 years
NEW ORLEANS — At 3 years, patients with severe aortic stenosis at low surgical risk who had transcatheter aortic valve replacement with a self-expanding valve continued to have lower risk for death or stroke than those who had surgical AVR.
In the main results of the Evolut Low Risk Trial, risk for all-cause mortality or disabling stroke at 2 years was numerically lower and noninferior in patients assigned TAVR with the self-expanding valve (CoreValve, Evolut R or Evolut PRO, Medtronic) compared with those assigned surgery, as Healio previously reported. John K. Forrest, MD, director of interventional cardiology and the structural heart program at Yale University School of Medicine and Yale New Haven Health System, presented 3-year results at the American College of Cardiology Scientific Session.
The analysis, simultaneously published in the Journal of the American College of Cardiology, included 1,414 patients (mean age, 74 years; 35% women) from the trial who had attempted implants.
“Data in low-risk patients have shown promising short-term mortality, stroke and recovery benefits, but understanding how durable these outcomes are is going to be critically important in these low-risk patients who are going to live longer,” Forrest said during the presentation.
The primary endpoint of all-cause mortality and disabling stroke occurred in 7.4% of the TAVR group and 10.4% of the surgery group at 3 years (HR = 0.7; 95% CI, 0.49-1; P = .051), Forrest said, noting the results were consistent across subgroups.
The difference between treatment arms in the primary outcome was –1.8% at 1 year, –2% at 2 years and –2.9% at 3 years, according to the results.
“We see what we have come to expect early on, which is an early separation of the curves,” Forrest said during the presentation. “But what’s unique here, and seen for the first time, is that this early separation is maintained in year 1 and then in year 2, and then between years 2 and 3, [the curves] didn’t start to come together, but actually, if anything, separated a little bit.”
Compared with the surgery group, the TAVR group was more likely to have mild paravalvular regurgitation (20.3% vs. 2.5%; P < .001) and pacemaker placement (23.2% vs. 9.1%; P < .001) at 3 years, Forrest and colleagues found.
Rates of moderate or worse paravalvular regurgitation at 3 years were low and similar between the groups, Forrest said.
Valve hemodynamics were better in the TAVR group (mean gradient, 9.1 mm Hg; effective orifice area, 2.2 cm2) compared with the surgery group (mean gradient, 12.1 mm Hg; effective orifice area, 2 cm2; P < .001) at 3 years.
The TAVR group had lower rates of AF at 3 years compared with the surgery group (13.1% vs. 40%; P < .001), Forrest said.
Moderate or worse patient-prosthesis mismatch was less common in the TAVR group than the surgery group at 3 years (10.6% vs. 25.1%; P < .001), according to the researchers.
“The excellent valve performance and durable outcomes out to 3 years in low-risk patients affirms the role of TAVR with the Evolut valve in this patient population,” Forrest said.
In a discussion after the presentation, Forrest acknowledged that pacemaker implantation “is not a benign event” and noted that after the trial began, advancements in the technology and adoption of a “cusp overlap technique” have reduced the incidence of pacemaker implantation after TAVR with the self-expanding valve, reaching single digits in 2022.
Reference:
Perspective
Back to Top
The Evolut results were very impressive in terms of superiority for TAVR at endpoints such as all-cause mortality and disabling stroke compared with surgery for this low-risk population. That is going to be extremely impactful and hit home for the patients. This frames the conversation about shared decision-making, as TAVR is now approved for all surgical risk indications and stratifications. Patients can have a real discourse with the providers and make the right choice in terms of disposition, and that is going to be extremely impactful. Also important is that the study showed superiority for TAVR across all time points in mean gradient and effective orifice area. It confirms the way we are practicing TAVR in the United States. TAVR is applicable to the younger, low-risk patient population. I am interested to see how that continues to transpire.
Perspective
Back to Top
The most important take-home message is that at 3 years, the TAVR patients are doing as well as the surgery patients with respect to the primary endpoint of all-cause mortality and major stroke. Of note, we do not know the long-term durability of the technology. This is the longest-term follow-up data that we have in low-risk patients who underwent TAVR. We are going to follow these patients for 10 years, so there is clearly more to come, but it is certainly promising that the durability of TAVR compared to surgery has been sustained at 3 years.
We are seeing a lot of low-surgical-risk patients with aortic stenosis, so we use shared decision-making to determine whether TAVR is a reasonable alternative to surgery in this population. These data suggest that it is, but more follow-up will be needed to see the potential long-term benefits. The event rates in this study were quite low. That is because 3 years is not long enough to see some of the things we are concerned about, such as structural valve deterioration. In this study it was very low in both groups, as expected, but what we can see is promising and reassuring.
The reality is that most patients are looking for a treatment option that has a low rate of adverse events, quick recovery and short length of stay in the hospital so they can get back to their normal lifestyle as soon as possible. That is one of the big benefits TAVR offers compared with surgery: most patients feel better quicker. So most patients come in wanting and expecting to be offered the TAVR, but when we are getting into lower-risk, younger patient populations, the concern is whether it is reasonable to offer, because we do not necessarily know the long-term durability of those devices.
Interestingly, at 3 years, both groups experienced similar improvement in quality of life according to Kansas City Cardiomyopathy Questionnaire metrics. That is because the surgical patients have fully recovered from their surgery. Most of the benefits of TAVR are in the acute short term, but that is what most patients are looking for these days. During the pandemic, the demand for TAVR was even greater, because patients were afraid of spending too much time in the hospital. When we offer a procedure where the patient can potentially go home the next day, and about 80% of them do, that is an added boost.
Collapse
Forrest JK, et al. Joint American College of Cardiology/New England Journal of Medicine Late-Breaking Clinical Trials. Presented at: American College of Cardiology Scientific Session; March 4-6, 2023; New Orleans (hybrid meeting).
Read more from American College of Cardiology
View all
Read more about