Abstract W MP106: Clinical Effectiveness of Anticoagulation with Warfarin among Ischemic Stroke Patients with Atrial Fibrillation: Findings from the Patient-Centered Research into Outcomes Stroke Patients Prefer and Effectiveness Research (PROSPER) Study

Abstract

Background: Oral anticoagulation is recommended for ischemic stroke patients with atrial fibrillation, based on clinical trials done in selected populations. However, little is known about whether the clinical benefit of warfarin is preserved outside the clinical trial setting, especially in older patients with ischemic stroke. Methods: PROSPER, a PCORI-funded research program designed by stroke survivors and stakeholders, used American Heart Association Get With The Guidelines (GWTG)-Stroke data linked to Medicare claims to evaluate the association between warfarin treatment at discharge and long-term outcomes among ischemic stroke survivors with atrial fibrillation (AF) and no contraindication to or prior anticoagulation therapy. The primary outcome prioritized by patients was home-time (defined as days spent alive and not in inpatient post-acute care facility) within 2-year follow-up after discharge. Results: Of 12,552 ischemic stroke patients with AF admitted from 2009-2011, 11,039 (88%) received warfarin treatment at discharge. Compared with those not receiving any anticoagulation, warfarin-treated patients were slightly younger (mean 80 vs. 83, p<0.001), less likely to have a history of prior stroke or coronary artery disease, but had similar stroke severity as measured by NIHSS (median 5 [IQR 2-12] vs. 6 [2-13], p=0.09). After adjustment for all observed baseline characteristics using propensity score inverse probability weighting method, patients discharged on warfarin therapy had 45 more days of home-time during 2-year follow-up than those not receiving any oral anticoagulant (513 vs. 468 days, p<0.001). Warfarin use was also associated with a lower risk of all-cause mortality, cardiovascular readmission or death, and ischemic stroke (Table). Conclusions: Among ischemic stroke patients with atrial fibrillation, warfarin therapy was associated with improved long-term outcomes.