Aspirin plus rivaroxaban efficacy and safety in embolic stroke of undetermined source: A randomized, placebo-controlled, outcome assessor-blind, feasibility study.

Introduction: The high prevalence of patients with embolic stroke of undetermined source (ESUS), the considerable risk of ischemic stroke, and the need for novel antithrombotic strategies highlight ESUS as an important priority in stroke research in the coming years. This study is designed to investigate the effectiveness and safety of rivaroxaban along with aspirin in reducing stroke recurrence in patients with ESUS.

Materials And Methods: The present study is a parallel-group, placebo-controlled, randomized, outcome-assessor blind, on patients in whom ESUS has recently (7-60 days) identified and had one risk factor of a potential embolic source. The recruited patients were randomly assigned to: rivaroxaban 2.5 mg two times daily plus ASA 80 mg once daily (intervention) or ASA 80 mg once daily plus placebo (control) (1:1 ratio). All patients were followed up every 3 months until 12 months. Any side effects or outcome events were recorded. The primary outcome was clarified as the rate of stroke recurrence and major bleeding occurrence.

Results: Forty-two patients with ESUS were recruited in this study (21 in each group). Stroke recurred in 3 patients in the comparator group and 1 patient in the intervention group (OR: 0.30; 95 % CI = 0.02-3.14, P = 0.31; RR= 0.33; 95 % CI = 0.03-2.95, P = 0.32). No major hemorrhagic event occurred in either group.

Conclusions: It seems reasonable to test, in a larger study, the effect of rivaroxaban (2.5 mg BID) plus aspirin on the prevention of stroke recurrence in patient with ESUS and a potential embolic source.