Thrombosis is a most common complication of cardiac procedures. It is unknown whether direct oral anticoagulant edoxaban can reduce leaflet thrombosis and the accompanying cerebral thromboembolic risk after transcatheter aortic-valve replacement (TAVR). Also, the causal relationship of subclinical leaflet thrombosis with cerebral thromboembolism and neurological or neurocognitive dysfunction remains unclear.

A multicenter, open-label randomized trial revealed that in patients who have no indication for long-term anticoagulation after successful TAVR, the incidence of leaflet thrombosis was numerically lower with edoxaban than with DAPT. The effect on new cerebral thromboembolism and neurological or neurocognitive function were also not different between both the groups. The study is published in Circulation journal.
The trial compared edoxaban with dual antiplatelet therapy (DAPT; aspirin plus clopidogrel) in patients who had undergone successful TAVR and did not have an indication for anticoagulation. The primary end point was an incidence of leaflet thrombosis on four-dimensional computed tomography (CT) at 6-month. Key secondary end points were the number and volume of new cerebral lesions on brain magnetic resonance imaging (MRI) and the serial changes of neurological and neurocognitive function between 6-month and immediate post-TAVR.
The results of the study were
• A total of 229 patients were included in the final intention-to-treat population. There was a trend toward a lower incidence of leaflet thrombosis in the edoxaban group than in the DAPT group (9.8% vs. 18.4%; absolute difference, −8.5%; −17.8% to 0.8%.
• The percentage of patients with new cerebral lesions on brain MRI (edoxaban vs. DAPT; 25.0% vs. 20.2%; difference, 4.8%; 95% CI, −6.4% to 16.0%) and median total new lesion number and volume were not different between two groups.
• Also, the percentages of patients with worsening of neurological and neurocognitive function were not different among the groups.
• The incidence of any or major bleeding events were not different between two groups. No significant association of the presence or extent of leaflet thrombosis with new cerebral lesions and a change of neurological or neurocognitive function was found.
Researchers concluded that "In patients without an indication for long-term anticoagulation after successful TAVR, the incidence of leaflet thrombosis was numerically lower with edoxaban than with DAPT, but this was not statistically significant. The effect on new cerebral thromboembolism and neurological or neurocognitive function were also not different between two groups. Because the study was underpowered, the results should be considered hypothesis-generating, highlighting the need for further research."
Reference: https://doi.org/10.1161/CIRCULATIONAHA.122.059512