Low-risk patients who underwent transcatheter aortic valve replacement (TAVR) for symptomatic severe aortic stenosis had outcomes and valve durability that were comparable to those who underwent surgery after 7 years, according to a new clinical trial analysis.

In the PARTNER 3 clinical trial, investigators enrolled 1000 patients at 71 centers in the US and Canada between March 2016 and October 2017. They underwent TAVR with the Edwards Sapien 3 valve or standard surgical aortic valve replacement. The patients had low surgical risk and suitable anatomy for either procedure.

In 2019, results showed that the rate of the composite primary endpoint of death, stroke, or rehospitalization at 1 year was significantly lower among low-risk patients who had TAVR vs surgery. Subsequent primary analyses at 2 years, 5 years, and 7 years also favored TAVR or showed no difference compared with surgery for the trial’s primary endpoint. Now, in a new ad hoc analysis published in JAMA Cardiology, researchers reported on the Sapien 3 valve’s durability over 7 years.

“The more we advance on the follow-up, the more durability becomes an issue,” said study author Philippe Pibarot, DVM, PhD, head of Cardiology Research at the Québec Heart and Lung Institute, Quebec City, Quebec, Canada. “If the life expectancy of the patient is less than 7 years, durability is not an issue. But now we have patients who have a life expectancy of 10 or 15 years and durability is very important to demonstrate.”

Similar Durability at 7 Years

The average age of patients in the study was 73.5 years, and nearly 70% were men. The rates of severe prosthesis-patient mismatch and moderate paravalvular regurgitation (PVR), indicators of nonstructural bioprosthetic valve dysfunction, were similarly low for both groups at 30 days.

However, mild PVR was significantly higher in the TAVR group. Severe prosthesis-patient mismatch or high residual gradients at 30 days were not associated with all-cause or cardiovascular mortality at 7 years. Nor was there an association between mild PVR at 30 days and 7-year mortality among patients with TAVR.

In the TAVR group, 7.3% of patients had structural valve dysfunction compared with 7.6% in the surgery group (hazard ratio [HR], 0.96; 95% CI, 0.59-1.57; P = .88). After 7 years, 73.2% of patients in the TAVR group and 74.2% of those in the surgery group were alive and free of stage 2 or 3 structural valve dysfunction.

More patients who underwent TAVR vs surgery had stage 2 or stage 3 thrombosis-related bioprosthetic valve dysfunction (5.2% vs 0.9%; HR, 5.52; 95% CI, 1.92-15.85; P < .001). However, many of those cases occurred early and either resolved on their own or with treatment.

In the entire study cohort, stage 2 or stage 3 structural valve deterioration was significantly associated with all-cause mortality but not cardiovascular mortality, stroke, or heart failure rehospitalization over 7 years. The deterioration was also linked to an increased risk for reintervention.

The trial investigators previously reported that the cumulative incidence of bioprosthetic valve failure at 7 years was not significantly different between TAVR and surgery patients, at 6.9% and 7.5%, respectively. The two study groups also had comparable rates of aortic valve reintervention (TAVR, 6%; surgery, 5.5%).

The most common factor leading to bioprosthetic valve failure was progressive stenosis related to structural valve deterioration. Researchers also found a link between small aortic annulus and an increased risk for stage 2 or stage 3 structural valve deterioration and bioprosthetic valve failure, regardless of the type of intervention.

Lifetime Management

“This is the first and largest randomized trial to demonstrate that TAVR is as good as surgery for long-term valve durability, with implications for lifetime management,” Pibarot said, adding that the results are practice-changing for doctors. Until now, he said doctors were uncertain if a relatively younger patient, aged 65 or 70 years, might need a reintervention. “Now we can say doing the first intervention as a TAVR with an expandable valve is a good option.”

Patrizio Lancellotti, MD, PhD, a cardiologist at University of Liège Hospital in Liège, Belgium, who was not involved in the study, said he would describe it as “practice-confirming” for physicians, rather than practice-changing.

“[The study] provides robust, long-term evidence supporting the use of balloon-expandable TAVR in appropriately selected low-risk patients and reinforces the current guideline recommendations,” he said. “However, it does not eliminate the need for individualized decision-making. Valve selection should therefore continue to be based on a Heart Team approach that incorporates both immediate procedural success and long-term lifetime management.”

Lancellotti co-authored an editorial published alongside the PARTNER 3 ad hoc analysis in JAMA Cardiology, writing that the study “reframes durability as a mechanistic and prognostic concept shaped by anatomy and expressed through distinct clinical trajectories.”

Lancellotti cautioned that the results only apply to a select population of low-risk patients with favorable anatomy and should not be extrapolated to younger patients, patients with bicuspid valves, or patients with complex coronary artery disease. He added that the findings are specific to the balloon-expandable Sapien 3 platform and should not be generalized to all transcatheter heart valves.

There is one remaining analysis prespecified at 10 years in the PARTNER 3 protocol. “If the valves still hold and are still as good as surgery, that’s going to be an excellent milestone,” Pibarot said.

Pibarot reported receiving grant funding from Edwards Lifesciences, Cardia, Novartis, and Boston Scientific. Lancellotti reported having no relevant financial relationships.

Catherine Shaffer is a freelance science and medical writer with a background in molecular biology and pharmaceutical research. Her work has appeared extensively in scientific trade and mainstream publications and on public radio.