Antithrombotic Treatment and Stroke Severity and Outcomes

Study Questions:

What is the prevalence of patients with acute ischemic stroke with a known history of atrial fibrillation (AF) who were not receiving guideline-recommended antithrombotic treatment before stroke? And what are the associations of preceding antithrombotic therapy with stroke severity and in-hospital outcomes for patients with AF-related acute ischemic stroke?


The authors performed a retrospective observational study of 94,474 patients with acute ischemic stroke and a history of AF admitted between October 2012 and March 2015 at 1,622 hospitals participating in the Get With the Guidelines-Stroke program. The primary outcome was the National Institutes of Health Stroke Scale (NIHSS) stroke severity and in-hospital mortality.


Of the 94,474 patients (mean age 79.9 ± 11.0 years, 57.0% women), 7,176 (7.6%) were receiving therapeutic warfarin (international normalized ratio [INR] ≥2) and 8,290 (8.8%) were receiving direct oral anticoagulants (DOACs) preceding the stroke. A total of 79,008 (83.6%) were not receiving therapeutic anticoagulation, including 37,674 (39.9%) who were receiving antiplatelet therapy only and 27,583 (30.3%) who were not receiving any antithrombotic therapy. After adjusting for potential confounders, compared to no antithrombotic therapy, preceding use of therapeutic warfarin, DOAC, or antiplatelet therapy was associated with a lower odds of moderate or severe stroke (adjusted odds ratio [aOR], 0.56 [95% confidence interval, 0.51-0.60], 0.65 [0.61-0.71], and 0.88 [0.84-0.92], respectively). In-hospital mortality was similarly less likely (aOR, 0.75 [0.67-0.85], 0.79 [0.72-0.88], and 0.83 [0.78-0.88], respectively).


The authors concluded that among patients with AF who experienced an acute ischemic stroke, inadequate therapeutic anticoagulation preceding the stroke was prevalent and associated with a lower odds of moderate or severe stroke and a lower odds of in-hospital mortality.


The authors leverage a large, multicenter, quality improvement registry to highlight two key points related to anticoagulation therapy for AF patients. First, far too few patients with AF are receiving guideline-appropriate anticoagulation therapy. The most recent iteration of both the European and American guidelines strongly favor oral anticoagulation and discourage antiplatelet therapy for AF patients at intermediate and high risk for stroke. Second, use of anticoagulation therapy, which is known to prevent stroke, can also decrease the severity of an AF-related ischemic stroke when it occurs. Reassuringly, some data have suggested an increase in total percentage of AF patients receiving anticoagulation therapy since the introduction of DOACs. However, we still have a long way to go.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Geriatric Cardiology, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Anticoagulants, Arrhythmias, Cardiac, Atrial Fibrillation, Fibrinolytic Agents, Geriatrics, Hospital Mortality, Ischemia, Platelet Aggregation Inhibitors, Practice Guidelines as Topic, Quality Improvement, Secondary Prevention, Stroke, Vascular Diseases, Warfarin

< Back to Listings