Abstract 13727: Contemporary Rates and Correlates of Warfarin Use in 33,570 Adults with Atrial Fibrillation: The ATRIA2-CVRN Study
Background: Atrial fibrillation (AF) is a potent risk factor for ischemic stroke and affects 10% of adults aged 80+ years. Warfarin substantially reduces the risk of ischemic stroke but recent use and predictors of its use in persons with incident AF is not well understood.
Methods: The ATRIA2-CVRN Study identified all adult members of Kaiser Permanente Northern and Southern California with incident AF or atrial flutter between January 2006–June 2009. Baseline demographic characteristics, stroke risk factors and contraindications for warfarin were ascertained from health plan databases using validated algorithms. Warfarin use was defined as >=1 dispensed prescription <90 days before or anytime on or after the AF diagnosis date. Multivariable correlates of warfarin use in patients without any contraindications to warfarin were identified using logistic regression.
Results: Among 33,570 adults with incident AF, mean (SD) age was 71.4 (12.9) years, 47% were women, with 6.4% black, 7.8% Asian and 10.5% Hispanic. Stroke risk factors were common: prior ischemic stroke (3.9%), other thromboembolic event (0.5%), heart failure (17.9%), hypertension (75.0%) and diabetes mellitus (27.3%). The distribution of CHADS2 stroke risk score was 0 (15.6%), 1 (27.7%), 2 (33.4%), 3 (16.9%) and 4–6 (6.4%). Among the 30,202 subjects without a relative or absolute contraindication to warfarin, 61.1% received warfarin, with greater use of warfarin in those with CHADS2 score >0: 0 (50%), 1 (63%), 2 (64%), 3 (62%), 4–6 (61.4%). Multivariable predictors of receiving warfarin included age, gender, Hispanic ethnicity, prior stroke, heart failure, hypertension, and absence of diagnosed coronary disease (Table).
Conclusion: Among a large, contemporary, community-based population with incident AF, >61% of patients without contraindications received warfarin. Patient demographic characteristics and selected stroke risk factors were independent correlates of receiving warfarin.
- © 2010 by American Heart Association, Inc.