Abstract T MP102: Antithrombotic Therapy After Acute Ischemic Stroke in Patients With Atrial Fibrillation

Abstract

Background: For patients with atrial fibrillation (AF) and ischemic stroke (IS), current guidelines recommend oral anticoagulation (OAC) alone for secondary stroke prevention. In a large prospective cohort of patients with acute IS and AF, we describe adherence with antithrombotic guidelines at hospital discharge and the association between antithrombotic regimen on discharge and risk of major vascular events and bleeding. Methods: Consecutive patients admitted with acute IS and AF included in the Registry of the Canadian Stroke Network (Jul 03-Mar 08). Multivariable Cox proportional hazards models were used to determine the association between antithrombotic regimen on discharge and time to the composite of death or readmission for recurrent stroke, myocardial infarction or major bleeding. Results: 2,162 patients were hospitalized with acute IS and AF; 42% had severe stroke (mRankin 4-5 on discharge) and 29% had prior coronary heart disease (CHD). Median duration of follow-up was 3.3 (IQR 1.0-5.4) years. At discharge, 8.0% were prescribed no antithrombotic therapy, 21.6% antiplatelet (AP) alone, 39.3% OAC alone and 31.1% combination OAC and AP. Compared to OAC alone, no antithrombotic (HR 1.51, 95% CI 1.23-1.86) and AP therapy (HR 1.31, 95% CI 1.14-1.50), were associated with an increased risk of the primary outcome, while combination OAC and AP was associated with a trend towards a reduced risk of the composite (HR 0.91, 95% CI 0.80-1.04). No antithrombotic (HR 1.23, 95% CI 0.80-1.90) and AP therapy alone (HR 1.13 95% CI 0.86-1.48), were associated with a trend towards an increased risk of admission for a thrombotic event (recurrent IS or MI), while combination OAC and AP was associated with a trend towards a reduced risk (HR 0.85, 95% CI 0.66-1.09), compared to OAC alone on discharge. Results were consistent in subgroups with severe stroke. In those with CHD, use of OAC and AP was associated with a suggestion of a reduced risk of the composite (HR 0.79, 95% CI 0.61-1.02). Conclusions: Following IS in patients with AF, 30% of patients are not managed according to current antithrombotic guideline recommendations. Compared to antiplatelet therapy, OAC on discharge reduces the composite of mortality and major vascular events, even in patients with severe stroke.