Abstract 13139: Antithrombotic Use at Time of Incident Stroke among Individuals With Recent Atrial Fibrillation
Introduction: Antithrombotic (AT) drugs including antiplatelet (AP) and oral anticoagulants (OAC) are used to mitigate stroke risk in AF. Although treatment with AP vs. OAC is guided by stroke risk-stratification, this strategy is debatable as AP therapy provides little to no risk reduction. We report the utilization of AT drugs in AF patients who present with an ischemic stroke and determine factors associated with AT use.
Methods: Patients admitted with ischemic stroke were identified from 2006-2010 from 3 unique sites: Boston Medical Center (safety net hospital), Geisinger Health System (rural PA), and the University of Alabama (urban stroke belt). To be eligible, patients had to have ECG-confirmed AF during or within 6 months of admission. New AF patients were not eligible. Stroke events and ECGs were confirmed by study physicians. AT use at baseline and INR were determined from admission records.
Results: Across the 3 sites, 760 patients were identified (mean age 78, 43% male, 19% black, mean CHADS2 3.0, and 31% paroxysmal AF (PAF)). At presentation, 181 (24%) patients were on OAC only, 96 (13%) both OAC and AP, 294 (39%) AP only and 189 (25%) were on no AT therapy. In 277 patients taking OAC, the median INR was 1.6. Patients with PAF had lower use of OAC than persistent/permanent AF patients (21% vs. 43%). Increasing stroke risk was associated with greater likelihood of OAC use, but only 39% of patients at highest risk (CHADS2 3-6) were taking OAC at time of stroke. Older patients (age ≥80) were less likely to be taking OAC as were those presenting to BMC and UAB even after adjustment for pre-stroke care. We found no racial differences in use of AT.
Conclusions: Among high risk patients with recent AF, only 36% were taking OAC at the time of stroke. PAF was associated with the highest risk of non-use of OAC despite recent ECG-documented AF. Given the morbidity and mortality related to AF stroke, strategies aimed to address this documented gross undertreatment are of paramount importance.
- © 2013 by American Heart Association, Inc.