Thomas Meinel, MD
Jung YH, Kim YD, Kim J, Han SW, Oh MS, Lee JS, Lee K-Y. Initial Stroke Severity in Patients With Atrial Fibrillation According to Antithrombotic Therapy Before Ischemic Stroke. Stroke. 2020;51:2733–2741.
Direct oral anticoagulants (DOAC) have proven at least equally effective in the prevention of acute ischemic stroke in patients with atrial fibrillation as compared to the vitamin K antagonists (VKA). They are recommended in stroke prevention for DOAC-eligible atrial fibrillation patients (without moderate-to-severe mitral stenosis or mechanical heart valve) as the oral anticoagulation of choice since their net clinical benefit arises mainly from a reduced risk of intracranial hemorrhage.1,2 Despite a significant reduction of stroke risk,1 recurrent ischemic stroke in patients on DOACs still occurs with an estimated rate of 1-2% per year.3 The randomized controlled trials did not report exact data on the stroke severity in patients on DOACs. Real-world data are conflicting, limited by arbitrary dichotomization of stroke severity scores, and mostly did not look at laboratory assessment of DOAC activity or information on compliance.4–8
In the August 2020 issue of Stroke, Jung et al. used a prospective, multicenter, hospital-based national stroke registry in Korea to evaluate trends of antithrombotic medication use in 6786 stroke patients with atrial fibrillation recruited between 2008 and 2018. The study aim was to explore the association between preceding antithrombotic medication use and initial stroke severity. 4009 patients were candidates for anticoagulation defined by a CHA2DS2-VASc score ≥2 and ATRIA score ≤4 prior to the acute ischemic stroke event. Among those, the overall prevalence of anticoagulation use was 27% and increased from 25% in 2010 to 41% in 2018 (P<0.001). Whereas the percentage of patients on VKA decreased in the recent years, the fraction of patients suffering ischemic stroke on DOACs increased from 4% in 2015 to 25% in 2018. Authors also found that stroke severity was higher in patients who were not on antithrombotics compared to those on antiplatelets or anticoagulants (median NIHSS: 8 versus 7 versus 6, P<0.001). Anticoagulation was also independently associated with mild stroke severity defined as NIHSS ≤5 (adjusted odds ratio, 1.31 [95% CI, 1.15–1.50]). However, there was no difference between antiplatelet agents and anticoagulation in terms of stroke severity.