ACASA-TAVI RCT shows NOAC monotherapy halves subclinical leaflet thrombosis versus aspirin after TAVI

The investigator-initiated RCT randomized patients 65-80 years across three Norwegian centers to apixaban, edoxaban or rivaroxaban versus aspirin or clopidogrel. Primary efficacy was 4D-CT assessed leaflet thickening at 12 months; safety was VARC-3 composite of bleeding, thromboembolism and death. NOAC achieved 45% relative reduction (RR 0.55, 95% CI 0.37-0.82) while meeting noninferiority on safety (7.5% vs 10.6%).

This addresses durability concerns as TAVI expands to younger cohorts where bioprosthetic valve failure risk accumulates over decades. Earlier trials like GALILEO tested rivaroxaban plus antiplatelet and stopped early for harm; ACASA-TAVI isolates monotherapy, avoiding that excess bleeding signal. Numerically fewer deaths occurred with NOAC, though event rates remain low.

Longer follow-up is required to link imaging endpoints to clinical valve failure or stroke. Ongoing 10-year tracking will test whether reduced thrombosis translates into lower reintervention rates or sustained hemodynamic benefit.

Guidelines may shift if durability data confirm benefit; current ESC and ACC recommendations reserve anticoagulation for patients with atrial fibrillation or other indications.