Introduction: Trials have demonstrated that antithrombotic medications can prevent ischemic stroke, but it is unclear if prior therapy can also improve outcomes from those still having an acute ischemic stroke.
Hypothesis: Antithombotics are the mainstay of treatment in primary and secondary prevention of stroke and thus their use prior to an acute event may be associated with better outcomes.
Methods: We studied 540,993 patients with acute ischemic strokes between Oct 2011 and Mar 2014 from 1661 hospitals participating in Get With The Guidelines-Stroke. The associations between prior antithrombotic use and hospital discharge outcomes were examined, controlling for patient and hospital characteristics.
Results: There were 250,104 (46%) stroke patients not receiving any antithrombotic prior to stroke; of whom 31.4% had a documented prior vascular indication. Patients taking antithrombotics prior to stroke were older and had more vascular risk factors. After adjustment for baseline prognostic factors, patients on chronic antithrombotics had better outcomes compared with those who did not (Table 1), regardless of whether a prior vascular indication was present or not. Similar results were observed in a subset of patients in whom NIHSS was available (n=415,034).
Conclusions: Prior antithrombotic therapy was independently associated with improved clinical outcomes after acute ischemic stroke. Ensuring use of antithrombotics in appropriate patient populations may be associated with benefits beyond stroke prevention.