Abstract 11276: Is the CHA2DS2-VASC Score a Predictor of Ischemic Stroke in Patients with Atrial Fibrillation Taking Oral Anticoagulation?
Background: The CHA2DS2-VASc score [congestive heart failure, hypertension, age ≥75 (double), diabetes, stroke (double), vascular disease, age 65-74, and female gender] has been proposed to determine the need for oral anticoagulation (OAC) in patients with atrial fibrillation (AF). However, whether the CHA2DS2-VASc score predicts ischemic stroke in patients with AF taking OAC remains to be elucidated.
Methods: We performed a retrospective cohort study at 4 Japanese hospitals. The study sample consisted of a cohort of 1160 patients (mean age, 67±10 years; males, 64 %; 521 paroxysmal AF) who had documented AF on electrocardiograms before August 2002 and who also visited our hospitals after September 2002. We calculated the CHA2DS2-VASc scores of each patient in September 2002 and assessed the incidence of ischemic stroke. OAC was prescribed for 363 patients (31.3%). A Cox proportional hazards analysis was performed to control for any baseline differences.
Results: During a follow-up of 69 months with a range of 2-103 months, 153 patients experienced an ischemic stroke. The cumulative incidence of ischemic stroke in AF patients with OAC according to the CHA2DS2-VASc score was 0% for a score of 0, 6.1% for a score of 1, 6.1% for a score of 2, 16.1% for a score of 3, 17.5% for a score of 4, 27.5% for a score of 5, 37.7% for a score of 6, and 100% for a score of 7. Even if OAC was prescribed, the cumulative incidence of ischemic stroke in AF patients with a CHA2DS2-VASc score ranging from 5-7 was 35.1%. For patients with a CHA2DS2-VASc score ranging from 5-7 taking OAC, patients treated with ACE inhibitors or angiotensin II type 1 receptor blockers (ACEI/ARB), exhibited a trend toward a lower incidence of ischemic stroke than those not receiving ACEI/ARB (22.6% vs. 49.7%, P = 0.09). After adjustment for differences in baseline clinical variables, ACEI/ARB use was found to be significantly associated with a lower incidence of ischemic stroke (hazard ratio, 0.65; 95% confidence interval, 0.43 to 0.98; P = 0.038),
Conclusions: The CHA2DS2-VASc score can be a predictor of ischemic stroke in patients with AF taking OAC. In addition to OAC, the inhibition of the renin-angiotensin system might be effective in high-risk patients with AF.
- © 2011 by American Heart Association, Inc.