Abstract 20524: Effect of Treating Specialty on Stroke Outcomes in Newly-Diagnosed Atrial Fibrillation: Findings From the TREAT-AF Study
Introduction: Prior studies have shown higher rates of oral anticoagulation (OAC) prescription for atrial fibrillation (AF) among physician subspecialists and AF specialty clinics. We evaluated the association of treating specialty with incident stroke among patients with newly-diagnosed AF.
Methods: The TREAT-AF (The Retrospective Evaluation and Assessment of Therapies in AF) study is a retrospective cohort study of patients with newly diagnosed AF treated in the Veterans Health Administration (VA). We identified patients with newly diagnosed, nonvalvular AF from 2004 to 2012 who were seen in primary care (including general medicine) or cardiology clinics (including electrophysiology) and who received any outpatient prescription within 90 days of new AF. Using VA and linked Medicare data, we determined incidence of ischemic stroke from inpatient claims and medical record data using validated algorithms. Multivariate Cox proportional hazards regression and mediation analysis were used to evaluate the association between treating specialty and ischemic stroke.
Results: Among 184,161 patients with newly-diagnosed AF (age 70±11; CHADS-VASc 2.6±1.7), 40% received cardiology care and 60% received primary care only. Despite similar CHADS-VASc scores, cardiology-treated patients had a higher baseline prevalence of hypertension, diabetes, coronary disease, MI, and stroke. For cardiology-treated patients, 90-day anticoagulation prescription was higher (70.3% vs. 58.8%, p <0.001) and stroke incidence rate lower (7.6 vs. 8.8 per 1,000 person-years, p <0.001). After adjustment for demographics, comorbidities, non-OAC medications, and distance to care, cardiology care was associated with a reduced hazard of stroke (HR 0.91, 95% CI 0.86-0.96, p <0.001), and this association was statistically mediated by 90-day anticoagulation prescription. Propensity-matched results were similar.
Conclusions: In patients with newly-diagnosed AF, cardiology care (as compared to primary care only) was associated with higher early OAC use, which mediated a reduced risk of incident stroke. Health care system interventions at the time of new AF diagnosis may be warranted.
Author Disclosures: A.C. Perino: None. J. Fan: None. S. Schmitt: None. M. Askari: None. D.W. Kaiser: None. A. Deshmukh: None. P.A. Heidenreich: None. M. Turakhia: Research Grant; Modest; Medtronic, Inc., iRhythm Technologies. Research Grant; Significant; Janssen Pharmaceuticals, Inc. Consultant/Advisory Board; Modest; Medtronic, Inc., Daiichi, Sankyo Pharmaceuticals., St Jude Medical, Precision Health Economics.
- © 2016 by American Heart Association, Inc.