Underdosed Direct Oral Anticoagulants in Atrial Fibrillation Patients Reduce Stroke Severity and Improve Outcome

Abstract

<b><i>Background and Purpose:</i></b> Anticoagulant drugs, including vitamin K antagonist (VKA) and direct oral anticoagulants (DOACs), can reduce stroke severity and are associated with good functional outcomes. Some patients are prescribed lower-than-recommended doses of DOACs; whether these have similar effects has not been clarified. <b><i>Methods:</i></b> We retrospectively evaluated 1,139 consecutive ischemic stroke and transient ischemic attack patients with atrial fibrillation. Patients were divided into 5 groups according to their preceding anticoagulant drug therapies: no anticoagulant therapy (AC<sub>n</sub>), undercontrolling VKA doses (VKA<sub>uc</sub>), recommended, controlling VKA doses (VKA<sub>rec</sub>), prescribed underdoses of DOAC (DOAC<sub>ud</sub>), and recommended doses of DOAC (DOAC<sub>rec</sub>). We investigated the associations between these anticoagulant drug therapies and patients’ initial stroke severity and 3-month outcomes. <b><i>Results:</i></b> Median National Institutes of Health Stroke Scale scores at admission were as follows: AC<sub>n</sub>: 16, VKA<sub>uc</sub>: 15, VKA<sub>rec</sub>: 9, DOAC<sub>ud</sub>: 5, and DOAC<sub>rec</sub>: 7. When the AC<sub>n</sub> group was used as a reference, regression analysis showed that VKA<sub>rec</sub> (odds ratio [OR] 1.49, 95% confidence interval [CI] 1.01–2.21), DOAC<sub>ud</sub> (OR 2.84, 95% CI: 1.47–5.66), and DOAC<sub>rec</sub> (OR 1.83, 95% CI: 1.23–2.74) were associated with milder stroke severity, while VKA<sub>uc</sub> was not. Median 3-month modified Rankin Scale scores were 2 in the DOAC<sub>ud</sub> and DOAC<sub>rec</sub> groups and 4 in all other groups. After adjusting for confounding factors, DOAC<sub>ud</sub> (OR 3.14, 95% CI: 1.50–6.57) and DOAC<sub>rec</sub> (OR 1.67, 95% CI: 1.05–2.64) were associated with good 3-month outcomes while VKA<sub>uc</sub> and VKA<sub>rec</sub> were not. <b><i>Conclusions:</i></b> In patients with atrial fibrillation, recommended doses and underdoses of DOACs reduced stroke severity on admission and were associated with good 3-month outcomes.

Determinants of 1-Year Unfavorable Outcomes of Intravenous Alteplase Thrombolysis for Acute Ischemic Stroke

“…Atrial fibrillation is a common risk factor for acute ischemic stroke and is significantly associated with the severity of ischemic stroke, high incidence of complications, and poor prognosis. [30][31][32][33] Similar to previous studies, the results at 1 year after intravenous thrombolysis showed that the proportion of patients with combined atrial fibrillation was significantly higher in the poor outcome group than in the good outcome group (29.3% vs 9.8%), and further analysis showed that mRS scores were significantly higher in patients with acute ischemic stroke with combined atrial fibrillation than in those without atrial fibrillation, and that atrial fibrillation was a predictor of poor outcome at 1 year after intravenous thrombolysis in acute ischemic stroke. The results show that atrial fibrillation is a predictor of poor prognosis 1 year after intravenous thrombolysis in acute ischemic stroke.…”