Trial Tentatively Backs DOACs After TAVR

A recent trial suggests that direct oral anticoagulant (DOAC) therapy may help prevent subclinical leaflet thrombosis after transcatheter aortic valve replacement (TAVR) in some patients, though the results were not strong enough to significantly change current practice. In the ACASA-TAVI trial, DOAC monotherapy was associated with a lower incidence of hypoattenuated leaflet thickening (HALT) on cardiac CT scans at 12 months compared to aspirin or another antiplatelet therapy (16.2% vs 28.6%, RR 0.55, 95% CI 0.37-0.82, P=0.004 for superiority).

However, the degree of leaflet involvement was higher in the antiplatelet group when HALT occurred. The DOAC approach also showed noninferior safety regarding bleeding events, thromboembolic events, and all-cause death at 12 months. Study author Øyvind Lie, MD, PhD, noted that while DOAC effectively reduces HALT, it is not durable and has not conclusively shown to improve clinical outcomes.

The trial included 360 participants aged 65-80 with successful TAVR for severe aortic valve stenosis, and a substantial number of treatment deviations, interruptions, and crossovers occurred. Despite the promising findings, a follow-up trial (NOTION-4) found that short-term DOAC therapy did not provide long-term benefits and increased the risk of all-cause mortality, stroke, or major/life-threatening bleeding.

Clinicians should currently continue using single antiplatelet therapy as recommended in guidelines, but the findings emphasize the need to optimize TAVR implantation to reduce the risk of HALT.