Abstract 11: Use of Novel Anticoagulants Among Atrial Fibrillation Patients Hospitalized with Ischemic Stroke or Transient Ischemic Attack: A Get With The Guidelines-Stroke Registry Analysis

Abstract

Background: The FDA recently approved the direct thrombin inhibitor dabigatran (DTI) and factor Xa inhibitor rivaroxaban for atrial fibrillation (AF) stroke prophylaxis based on large randomized trials showing non-inferiority to warfarin for stroke prevention. However, real-world utilization patterns and predictors of use for these novel anticoagulants (NAC) remain poorly characterized. Methods: Using the AHA Get With The Guidelines Stroke Registry, we analyzed patients with AF who were hospitalized for ischemic stroke or transient ischemic attack (TIA) and discharged on warfarin or NAC. The first NAC approved by the FDA was dabigatran in 10/2010, so we chose a 2-year study period from 10/2010-9/2012. We excluded patients with contraindications for anticoagulation. Patient and hospital variables associated with discharge anticoagulant use were evaluated using Pearson chi-square and Wilcoxon tests. Results: Of 61,655 patients meeting inclusion criteria, 6,835 (11.1%) were discharged on NAC, of which 86.7% were prescribed DTI. Warfarin was prescribed in 54,820 (88.9%) patients. For patients discharged on NAC vs. warfarin, 51.8% vs. 53.3% (p=0.016) were female and median age was 77 [IQR 69-84] vs. 79 [IQR 70-85] (p<0.001). The majority of patients discharged on NAC or warfarin were white (82.7% vs. 80.8% respectively, p=0.005). Slightly higher proportions of patients discharged on NAC vs. warfarin had private/HMO insurance (41.7% vs. 37.6%, p<0.001) than Medicare (39.0% vs. 42.3%, p<0.001). Patients discharged on NAC vs. warfarin had less severe ischemic stroke (NIH stroke scale=3 [IQR 1-8] vs. 5 [IQR 2-11], p<0.001), shorter length of stay (3 [IQR 2-5] vs. 4 [IQR 2-6] days, p<0.001), and higher proportions of patients who could ambulate at admission (32.5% vs. 26.1%, p<0.001) and discharge (47.5% vs. 39.2%, p<0.001). CHADS2 scores were lower among those discharged on NAC (Figure). More patients discharged on NAC were discharged to home (65.0%) than a healthcare facility, compared to 52.4% of patients prescribed warfarin being discharged to home (p<0.001). Conclusion: Among patients with AF and acute ischemic stroke or TIA discharged on oral anticoagulants, NAC use remains low and is prescribed to younger, more functional, and lower risk patients.