Five-year outcomes similar for low-risk patients receiving transcatheter, surgical aortic valve replacement: Study

Patients with severe aortic stenosis at low surgical risk who underwent supra-annular, self-expanding Evolut transcatheter aortic valve replacement (TAVR) had similar rates of death or disabling stroke at five years compared with those whose valves were replaced through standard open heart surgery, based on new follow-up data from the Evolut Low Risk trial presented at the American College of Cardiology’s Annual Scientific Session (ACC.25).

Evolut Low Risk is a large, prospective trial that initially enrolled 1,478 patients at 86 centers in the United States, Canada, Europe, Japan, Australia and New Zealand to compare the safety and efficacy of Evolut TAVR to surgery. Patients were randomized to TAVR (n=737) or surgical aortic valve replacement (SAVR) (n=741). Both groups were well-matched in terms of baseline characteristics such as hypertension, coronary disease and lung disease; patients were 74 years old, on average, and one-third were women.

Follow-up data was available for 91% of TAVR patients and 87.4% of SAVR patients for the five-year analysis. Of these patients, the primary endpoint of death or disabling stroke occurred in 15.5% of those receiving Evolut TAVR and 16.4% of those undergoing SAVR.

“The outcomes of all-cause mortality and disabling stroke remain similar between TAVR and surgery, though numerically TAVR remains better,” said Michael J. Reardon, MD, professor and Allison Family Distinguished Chair of Cardiovascular Research at Houston Methodist Hospital and the study's senior author. “TAVR has also shown similar improvements in terms of symptom and functional class and there’s no difference in the rate of reinterventions, so the supra-annular, self-expanding Evolut TAVR looks really good at five years in this group of patients.”

In addition to the combined rates of death and disabling stroke being similar between the two groups, the rates of disabling stroke were also comparable at five years (3.6% for TAVR and 4% for surgery) with no difference between year four and year five. All-cause mortality widened slightly during this period, though deaths remained similar between the two groups (13.5% for TAVR and 14.9% for surgery), Reardon said. Cardiovascular-related deaths were similar from two years to five years post-intervention and there was also no difference in reintervention rates between the groups at five years.

When examining all-cause mortality between the groups, Reardon said the deaths were primarily driven by non-cardiovascular events, including cancer-related deaths (seven in the TAVR group and one in SAVR), sepsis (three in TAVR) and COVID-19 (three in TAVR and two in SAVR).

“The difference in cardiovascular deaths is maintained over the five years of the trial, which is reassuring as these deaths are related to how well the aortic valve works,” Reardon said. “In looking at cardiovascular deaths alone, they occurred in 7.2% of people with TAVR at 9.3% at five years—the curves looked similar, the delta was 1.1% at two years and now at five years is 2.1%, which gives us strong confidence that the performance of the valve compared with surgery remains very good.”

Quality of life, measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ), which allows patients to report their functional ability and wellness, stayed high through five years for both Evolut TAVR and surgery. Based on the scores, researchers report that approximately 70% of patients in both groups are alive and well at five years.

As shown previously, patients receiving TAVR had significantly fewer cases of atrial fibrillation, superior hemodynamics (blood flow through the heart), more pacemakers and more paravalvular regurgitation (leakage around the valve), which decreased over time.

TAVR, which involves threading a replacement valve through a catheter in the groin or chest, has emerged as the leading procedure for treating symptomatic severe aortic stenosis in the U.S., irrespective of the patient's surgical risk. With TAVR, most patients are out of the hospital within a few days and back to their normal activities within a week versus more extended recovery time with surgery. Patients randomized to TAVR in this study received the Medtronic Evolut R, PRO or CoreValve bioprosthesis as new generation valves became available during the study.

Aortic stenosis-when the valve in the heart's main artery doesn't open fully-forces the heart to work harder to pump blood and can be life-threatening. TAVR is now FDA approved for use in high, intermediate and low surgical risk patients with severe aortic stenosis. Low risk was defined as a predicted 30-day mortality of 3% or less for 30 days post-surgery and was based on a combination of clinical judgment from the local heart team and an independent screening committee.

Reardon and team plan to follow patients for 10 years, which should yield important long-term data about TAVR’s durability compared with surgically implanted valves, as well as the life of the valves themselves.

Reference:

Five-year outcomes similar for low-risk patients receiving transcatheter, surgical aortic valve replacement, American College of Cardiology, Meeting:American College of Cardiology's Annual Scientific Session.