Current guidelines recommend dual antiplatelet therapy early after transcatheter aortic valve implantation (TAVI) to prevent thromboembolic events. Given that this recommendation is based mainly on expert consensus, investigators in the GALILEO trial assessed an antithrombotic strategy with a low dose (10 mg daily) of the direct factor Xa inhibitor rivaroxaban compared with an antiplatelet-based strategy in patients without an established indication for oral anticoagulation after successful TAVI. However, the trial was terminated early owing to safety concerns. Results presented at the AHA Scientific Sessions 2019 indicate that a strategy with low-dose rivaroxaban is associated with a higher risk of death or thromboembolic events and a higher risk of bleeding than an antiplatelet-based strategy.

A total of 1,644 patients were randomly assigned to receive rivaroxaban 10 mg daily (with aspirin 75–100 mg daily for the first 3 months) or aspirin 75–100 mg daily (with clopidogrel 75 mg daily for the first 3 months). After a median of 17 months, the intention-to-treat analysis showed that the rivaroxaban group had a higher incidence of death or a first thromboembolic event (105 versus 78 patients; HR 1.35, 95% CI 1.01–1.81, P = 0.04) and of major, disabling or life-threatening bleeding events (46 versus 31 patients; HR 1.50, 95% CI 0.95–2.37, P = 0.08) than the antiplatelet group.

By contrast, an imaging substudy of the trial indicates that the rivaroxaban-based strategy is more effective than antiplatelet therapy in preventing subclinical leaflet-motion abnormalities. Among 231 patients who underwent 4D CT evaluation at 90 days after randomization, reduced leaflet motion (grade ≥3) in one or more leaflets was less frequent in the rivaroxaban group than in the antiplatelet group (2.1% versus 10.9%), as was subclinical thickening of one or more leaflets (12.4% versus 32.4%). Nevertheless, the investigators caution that given the findings of the main trial they cannot recommend routine imaging for leaflet-motion evaluation or routine use of anticoagulation after TAVI for preventing leaflet-motion abnormalities.