ABSTRACT

OBJECTIVES - The aim of this study was to evaluate clinical outcomes and transcatheter heart valve hemodynamic parameters after transcatheter aortic valve replacement (TAVR) in low-risk patients with bicuspid aortic stenosis (AS).

BACKGROUND - TAVR is approved for low-risk patients in the United States. However, patients with bicuspid AS were excluded from the randomized cohorts of the pivotal low-risk trials.

METHODS - The LRT (Low Risk TAVR) trial was an investigator-initiated, prospective, multicenter study and was the first and only U.S. Food and Drug Administration–approved investigational device exemption trial to evaluate the feasibility of TAVR with either balloon-expandable or self-expanding valves in low-risk patients with bicuspid AS. The primary endpoint was all-cause mortality at 30 days. Baseline and follow-up echocardiography and computed tomography to detect leaflet thickening were analyzed in an independent core laboratory.

RESULTS - Sixty-one low-risk patients with symptomatic, severe AS and bicuspid aortic valves (78.3% Sievers type 1 morphology) underwent TAVR at 6 centers from 2016 to 2019. The mean age was 68.6 years, and 42.6% were men. At 30 days, there was zero mortality and no disabling strokes. The rate of new permanent pacemaker implantation was 13.1%; just 1 patient had a moderate paravalvular leak at 30 days. Hypoattenuated leaflet thickening was observed in 10% of patients at 30 days.

CONCLUSIONS - TAVR appears to be safe in patients with bicuspid AS, with short length of hospital stay, zero mortality, and no disabling strokes at 30 days. Subclinical leaflet thrombosis was observed in a minority of patients at 30 days but did not appear to be associated with clinical events.