30-day results from LRT 2.0 trial also show warfarin plus aspirin does not increase bleeding risk
Oral anticoagulation is associated with a lower incidence of leaflet thrombosis, but does not appear to be associated with increased bleeding, compared to aspirin alone at 30 days after transcatheter aortic valve replacement (TAVR) in low-surgical-risk patients, according to late-breaking trial results presented Tuesday at Cardiovascular Research Technologies (CRT) 2020 in National Harbor, Maryland.
Leaflet thrombosis may negatively impact the durability of transcatheter heart valves.
The Low-Risk TAVR (LRT) 2.0 trial enrolled 124 low-risk patients with symptomatic, severe aortic stenosis who underwent TAVR at nine U.S. centers between July 2018 and October 2019. Of those patients, 94 were randomized to receive either oral anticoagulation (warfarin) plus aspirin or aspirin alone for 30 days. The other 30 patients with other indications for oral anticoagulation (new atrial fibrillation, deep vein thrombosis or pulmonary embolism) or who were at high risk for bleeding were not randomized but were followed in a registry arm.
The primary safety outcomes were all-cause mortality, all stroke, life-threatening or major bleeding, major vascular complications, hospitalizations for valve-related symptoms or worsening heart failure at 30 days. The primary efficacy outcomes were hypoattenuated leaflet thickening (HALT) and at least moderately restricted leaflet motion (RELM) at 30 days.
There were no significant differences in baseline characteristics between patients receiving oral anticoagulation and aspirin only.
At 30 days, there was zero all-cause mortality and zero disabling stroke in both arms of the randomized cohort, and there was no significant difference in any of the safety outcomes in this cohort.
Turning to leaflet thrombosis, there was a trend toward higher HALT in the aspirin arm (OAC 4.7% vs. aspirin 16.3%; p=0.07). Although this was not statistically significant, Toby Rogers, MD, PhD, of MedStar Heart & Vascular Institute, Washington, D.C., said the absolute difference was “clinically meaningful.” When the randomized and registry patients are pooled, the difference does become statistically significant (OAC 3.1% vs. aspirin 16.4%; p=0.01).
In the first LRT trial, which was the first study to report that TAVR was safe and feasible in patients with symptomatic, severe aortic stenosis at low surgical risk, HALT was observed in 13.5% of patients on antiplatelet therapy and in 4.8% of patients on oral anticoagulation.
The LRT 2.0 trial is funded by the MedStar Health Research Institute, Washington, D.C.