Six years after undergoing either surgery or TAVR with a CoreValve, Evolut R or Evolut PRO, low-risk patients with aortic stenosis (AS) experienced no significant differences in terms of all-cause mortality or disabling stroke, according to findings from the Evolut Low Risk trial published in JACC. However, researchers observed higher reintervention rates among those assigned to TAVR compared with surgery, largely due to increased incidence of aortic regurgitation (AR).

The newest follow-up analysis from John K. Forrest, MD, FACC, and Steven J. Yakubov, MD, FACC, et al., found the composite endpoint of all-cause mortality or disabling stroked was 23.3% among those assigned to TAVR vs. 20.4% among those assigned to surgery at the six-year mark. Of note, however, reintervention rates varied significantly between the two groups starting at year six, with 5.5% in the TAVR cohort requiring reintervention compared with 3.3% in the surgery cohort. Given this finding, Forrest, et al., performed additional analysis of available seven-year data, which indicated further increases in the incidence of reintervention among those in the TAVR group (9.8%) vs. surgery (6%). Broken down by AR vs. AS, the rate of reintervention for regurgitation was 5.6% in the TAVR group compared with 1.6% in the surgery group and 3.6% vs. 3.5%, respectively for stenosis.

In further discussing the findings, the researchers noted that TAVR and valve model were identified as predictive factors for reintervention and said the study “highlights the critical importance of transparent, robust, long-term clinical and real-world data in low-surgical-risk patients undergoing TAVR.” They added that while the seven-year data was incomplete, they felt it important to publish at this time in order to “support heart teams and patients in navigating a shared decision-making process.”

Looking ahead, yearly follow-up of Evolut Low Risk trial participants is planned through 10 years to continue to monitor and compare mortality rates, structural valve deterioration and reintervention rates.

In a related editorial, Ziad A. Ali, MD, DPhil, says that while the findings “are real, clinically relevant and deserving of wide dissemination … the interpretation must remain proportional to what the data can reliably support.” He writes: “As transcatheter valve therapy continues to evolve … these data remind us that durability is multifaceted, that failure phenotypes may vary by platform and anatomy, and that procedural decisions made at the time of implant may have consequences that unfold years later.”

In another editorial, Aakriti Gupta, MD, MS, FACC, and David J. Cohen, MD, MSc, say the findings highlight a number of key insights, including the importance of long-term follow-up; the importance of lifetime management in patients with AS; the critical role of heart team-based discussions with patients that transparently address both known benefits and remaining uncertainties; and recognition that “reintervention is an imperfect surrogate for valve performance.”

In a separate study published in JACC: Cardiovascular Interventions, researchers conducted an ex-vivo bench study to evaluate both the acute and long-term effects of different post-dilation strategies on the integrity and function of Evolut THV leaflets, specifically 23-, 26-, 29- and 34-mm. When post-dilation was performed according to “Instructions For Use” (IFU) recommendations, the Evolut THV frame geometry was preserved, with no damage to the leaflets, and the regurgitant fraction remained below the minimum performance requirements. However, when performed using larger than IFU-recommended balloon sizes, post-dilation resulted in an outward over-expansion of the Evolut THV waist, proportional to the size of the balloon used, researchers said. This was associated with a spectrum of immediately observed leaflet damage, ranging from microscopic to macroscopic and partial to complete tears.

More broadly, JACC Editor-in-Chief Harlan M. Krumholz, MD, SM, FACC, and Sanket S. Dhruva, MD, MHS, FACC, say the Evolut Low Risk findings offer lessons to be learned about post-market device surveillance. In an Editors’ Page, they write that the recent analysis offers “an instructive example of what it looks like when our post-market device surveillance system functions as it should,” while at the same time exposing “how dependent such success remains on extraordinary effort rather than on routine, reliable infrastructure.” They stress the need to “move beyond a post-market surveillance model that is largely passive, fragmented, and dependent on extraordinary effort” to an infrastructure that “prioritizes automatic, timely, and complete longitudinal follow-up as a core responsibility of device-based care.”

ACC Chief Medical Officer Richard J. Kovacs, MD, MACC, highlights the opportunities inherent in registries like those under the NCDR umbrella to understand device safety and efficacy in both the short and long term. “Broad and sustained registry participation can allow for device comparison and early identification of safety signals, performance gaps and unintended consequences that may not be evident in clinical trials alone,” he says.