Transcatheter aortic valve replacement (TAVR) continued to be safe in patients with symptomatic, severe aortic stenosis who are at low surgical risk 4 years after the procedure, new trial results show. Ron Waksman, MD, of MedStar Washington Hospital Center, Washington, D.C., presented the results as a late-breaking trial Monday at Cardiovascular Research Technologies (CRT) 2022. The Low Risk TAVR (LRT) trial, an investigator-initiated, prospective, multicenter study, was the first U.S. Food and Drug Administration-approved investigational device exemption trial to evaluate the feasibility of TAVR in low-risk patients. The trial enrolled 200 low-risk patients with symptomatic, severe aortic stenosis to undergo TAVR at 11 centers. Their mean age was 73.6 years, and 61.5% were men. At 4-year follow-up, 174 patients were available. The all-cause mortality rate was 12.1%, the stroke rate was 7.9% (disabling stroke 2.0%), and the permanent pacemaker implantation rate was 12.3%. Four subjects (2.7%) underwent surgical reintervention for endocarditis. At 30 days, 14% of TAVR subjects had hypoattenuated leaflet thickening (HALT), but there was no evidence that this impacted valve hemodynamics, endocarditis or stroke at 4 years, Waksman said. There was no significant difference in left ventricular ejection fraction between patients with HALT (65.5% ± 4.2%) and those who without HALT (64.9% ± 5.8%; p=0.84). The same was true of left ventricular end-diastolic dimension (HALT 4.1 ± 0.4 cm vs. no HALT 4.3 ± 0.6 cm; p=0.48). The following measurements were also similar between HALT and no-HALT patients: mean gradient, aortic valve area and dimensionless index Also, at 4 years, no greater than mild paravalvular leak was reported, and 6.1% of subjects had been rehospitalized for heart failure. Waksman concluded that LRT showed excellent outcomes at 4 years, including low rates of mortality and stroke and that excellent hemodynamics were maintained. “TAVR is safe and effective in low-risk patients, with low adverse event rates, excellent valve hemodynamics and low pacemaker rates through 4 years,” Waksman said. “Sub-clinical leaflet thrombosis (HALT) at 30 days did not significantly affect transcatheter valve hemodynamics or rate of stroke at 4 years.”