Effect of prior anticoagulation therapy on stroke severity and in-hospital outcomes in patients with acute ischemic stroke and atrial fibrillation

We aimed to assess the prevalence of prior anticoagulation therapy (warfarin or non-vitamin K antagonist oral anticoagulants [NOACs]) among patients with acute ischemic stroke (AIS) and atrial fibrillation (AF) in China and investigate the associations between prior anticoagulation therapy and initial stroke severity and in-hospital outcomes.We included consecutive patients with AIS and known history of AF admitted to hospitals in the China Stroke Center Alliance (CSCA) program from January 2019 to July 2019. Multivariate logistic regression analyses were performed to determine the associations between prior anticoagulation therapy and initial stroke severity and in-hospital outcomes.Of 7181 patients (median [IQR] age, 75.0 [68.0-81.0] years; 48.7% men), 700 (9.7%), 129 (1.8%), and 255 (3.6%) patients received prior subtherapeutic warfarin (international normalized ratio [INR] <2.0), therapeutic warfarin (INR ≥2.0), and NOACs therapy, respectively. A total of 6499 patients had a preadmission CHA2DS2-VASc score ≥ 2, among whom 94.6% were not adequately anticoagulated. Compared with no prior anticoagulation therapy, prior NOACs therapy was associated with reduced risk of moderate or severe stroke at admission (odds ratio [95% CI], 0.64 [0.43-0.94], P = 0.023) and in-hospital mortality or discharge against medical advice (DAMA) (0.46 [0.24-0.86], P = 0.015). However, no significant association was observed between prior therapeutic warfarin therapy and stroke severity or in-hospital mortality or DAMA.Among patients with AIS and AF in China, the proportion of patients with inadequate anticoagulation prior to stroke remained substantially high. Prior NOACs therapy was associated with reduced stroke severity and less in-hospital mortality or DAMA.