RELAXED: Recurrent Embolism Lessened by Rivaroxaban for Acute Ischemic Stroke

Early recurrence of cardioembolic stroke in patients with atrial fibrillation is common, reaching approximately 6% within 30 days after initial stroke. Therefore, it is preferable to provide early anticoagulation for cardioembolic stroke. However, early anticoagulation may increase the risk of hemorrhagic transformation of cerebral infarcts. It is difficult to decide the timing of initiation for anticoagulant therapy in stroke patients with non-valvular atrial fibrillation (NVAF). In 2013 the European Heart Rhythm Association presented the practical guides for oral anticoagulants in NVAF patients, which recommend that the optimal time to start anticoagulant therapy should be determined according to the stroke severity. However, this recommendation is principally an experts' opinion and is not suitable in the clinical practice in Japan. RELAXED, a multicenter observational study is planned to evaluate the efficacy and safety of an oral direct activated coagulation factor Xa inhibitor, rivaroxaban, for acute ischemic stroke patients with NVAF in consideration of the infarct size, timing of initiation for rivaroxaban medication, and other patient characteristics, and thereby to determine the optimal timing of the initiation during acute ischemic stroke. The consecutive acute ischemic stroke / transient ischemic attack (TIA) patients with NVAF who are treated with rivaroxaban will be enrolled. The infarction size at 0-48 hours after stroke onset will be measured by the diffusion weighted image (DWI) MRI. The primary efficacy endpoint is recurrent ischemic stroke within 3 months. The primary safety endpoint is major bleedings within 3 months. The optimal timing to initiate rivaroxaban during acute ischemic stroke is determined by analysis of co-relation between primary endpoints and the infarct size / time to initiate rivaroxaban.