Stroke or systemic embolism during the initial three-month anticoagulation period after stroke/transient ischemic attack was not frequent as compared to previous findings regardless of warfarin or non-vitamin K antagonist oral anticoagulants were used. Intracranial hemorrhage was relatively uncommon in non-vitamin K antagonist oral anticoagulant users, although treatment assignment was not randomized. Early initiation of non-vitamin K antagonist oral anticoagulants during the acute stage of stroke/transient ischemic attack in real-world clinical settings seems safe in bleeding-susceptible Japanese population.
Stroke/TIA patients receiving DOACs for secondary prevention were younger and had lower stroke severity and risk indices than those receiving warfarin. Estimated cumulative incidences of stroke and systemic embolism within 2 years were similar between warfarin and DOACs users, but those of death and intracranial hemorrhage were significantly lower among DOAC users.
Background
We aimed to clarify associations between prior anticoagulation and short‐ or long‐term clinical outcomes in ischemic stroke or transient ischemic attack patients with nonvalvular atrial fibrillation.
Methods and Results
A total of 1189 ischemic stroke or transient ischemic attack patients with nonvalvular atrial fibrillation who were hospitalized within 7 days after onset were analyzed. Of these, 813 patients (68.4%) received no prior anticoagulation, 310 (26.1%) received prior warfarin treatment with an international normalized ratio (
INR
) <2 on admission, 28 (2.4%) received prior warfarin treatment with an
INR
≥2 on admission, and the remaining 38 (3.2%) received prior direct oral anticoagulant treatment. Prior warfarin treatment was associated with a lower risk of death or disability at 3 months compared with no prior anticoagulation (
INR
<2: adjusted odds ratio: 0.58; 95% CI, 0.42–0.81;
P
=0.001;
INR
≥2: adjusted odds ratio: 0.40; 95% CI, 0.16–0.97;
P
=0.043) but was not associated with a lower risk of death or disability at 2 years. Prior warfarin treatment with an
INR
≥2 on admission was associated with a higher risk of ischemic events within 2 years compared with no prior anticoagulation (adjusted hazard ratio: 2.94; 95% CI, 1.20–6.15;
P
=0.021).
Conclusions
Prior warfarin treatment was associated with a lower risk of death or disability at 3 months but was not associated with a lower risk of death or disability at 2 years in ischemic stroke or transient ischemic attack patients with nonvalvular atrial fibrillation. Prior warfarin treatment with an
INR
≥2 on admission was associated with a higher risk of ischemic events within 2 years.
Clinical Trial Registration
URL
:
http://www.clinicaltrials.gov
. Unique identifier:
NCT
01581502.
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