A trial testing the use of rivaroxaban (Xarelto) after transcatheter aortic valve replacement (TAVR) has been halted following a raised risk of adverse events with the anticoagulant compared to patients receiving clopidogrel and aspirin.

In a letter to healthcare professionals rivaroxaban manufacturer Bayer noted that back in August the data safety monitoring board had recommended stopping the phase III GALILEO trial after preliminary results suggested an “imbalance” in all-cause mortality, thromboembolic and bleeding events between the two study groups.

Adverse events in the rivaroxaban group (n=826) and the antiplatelet group (n=818) respectively were 11.4% vs 8.8% for death or first thromboembolic event, 6.8% vs 3.3% for all-cause mortality  and 4.2% vs 2.4% for bleeding events.

The company noted that the current results were preliminary and regulatory authorities would assess the final data, including an assessment of any implications for approved indications, as soon as it became available.

In the meantime, the letter advised that rivaroxaban was not approved for thromboprophylaxis in patients with prosthetic heart valves, including patients who have undergone TAVR.

“Rivaroxaban treatment should be stopped in patients who undergo TAVR and switched to standard of care,” the letter advised.

Participants in the study were randomly assigned to 10 mg rivaroxaban and aspirin once daily for 90 days, followed by rivaroxaban alone at the same dose or a dual antiplatelet group (DAPT; 75-mg clopidogrel and aspirin once daily for 90 days, then aspirin alone). Atrial fibrillation patients were excluded from the study.