Safety and efficacy of non-vitamin K oral anticoagulant treatment compared with warfarin in patients with non-valvular atrial fibrillation who develop acute ischemic stroke or transient ischemic attack: a multicenter prospective cohort study (daVinci study)

The safety and efficacy of non-vitamin K oral anticoagulant (NOAC) compared with warfarin in treating patients with non-valvular atrial fibrillation (NVAF) who developed acute ischemic stroke or transient ischemic attack (AIS/TIA), particularly those receiving tissue-plasminogen activator (tPA) therapy, remains unclear. Between April 2012 and December 2014, we conducted a multicenter prospective cohort study to assess the current clinical practice for treating such patients. We divided the patients into two groups according to the administration of oral anticoagulants (warfarin or NOACs) and tPA therapy. The risk of any hemorrhagic or ischemic event was compared within 1 month after the onset of stroke. We analyzed 235 patients with AIS/TIA including 73 who received tPA therapy. Oral anticoagulants were initiated within 2-4 inpatient days. NOACs were administered to 49.8 % of patients, who were predominantly male, younger, had small infarcts, lower NIHSS scores, and had a lower all-cause mortality rate (0 vs. 4.2 %, P = 0.06) and a lower risk of any ischemic events (6.0 vs. 7.6 %, P = 0.797) compared with warfarin users. The prevalence of all hemorrhagic events was equivalent between the two groups. Early initiation of NOACs after tPA therapy appeared to lower the risk of hemorrhagic events, although there was no significant difference (0 vs. 5.6 %, P = 0.240). Although more clinicians are apt to prescribe NOACs in minor ischemic stroke, NOAC treatment may provide a potential benefit in such cases. Early initiation of NOACs after tPA therapy may reduce the risk of hemorrhagic events compared with warfarin.