Even with Anticoagulation Therapy, Higher CHADS2 Scores Predict Worse Outcomes

In a RE-LY substudy, the correlation was present and similar in all treatment arms.


The CHADS2 (Congestive heart failure, Hypertension, Age ?75, Diabetes, Stroke history [2 points]) risk score for stroke was validated in patients with atrial fibrillation (AF) who were not treated with an anticoagulant. To evaluate CHADS2 as a predictor of stroke in AF patients taking anticoagulants, investigators conducted subgroup analyses of data from the RE-LY trial of dabigatran versus warfarin in patients with AF (JW Cardiol Sep 1 2009).

Dividing the RE-LY cohort (>18,000 patients) into rough tertiles according to CHADS2 score resulted in three subgroups with scores of 0–1, 2, and 3–6, respectively. Baseline characteristics differed significantly among the subgroups; of patients with CHADS2 scores of 3–6, >90% had hypertension, and most had a history of stroke or transient ischemic attack or were aged ?75. Mean percentage of time in therapeutic range (TTR) with warfarin fell slightly but significantly with higher CHADS2 scores. Overall, the annual rate of stroke or systemic embolization (the primary outcome) increased significantly with each 1-point increase in CHADS2 score, as did the annual rates of major bleeding and vascular mortality. Patients with a CHADS2 score of 3 or higher had a >2% annual risk for stroke or systemic embolization, a >4% annual risk for major bleeding, and a >5% annual risk for all-cause death, regardless of anticoagulant type. The reduction in stroke or systemic embolization with 150-mg dabigatran compared with warfarin was consistent across the CHADS2 risk groups.


Citation(s):

Oldgren J et al. Risks for stroke, bleeding, and death in patients with atrial fibrillation receiving dabigatran or warfarin in relation to the CHADS2 Score: A subgroup analysis of the RE-LY trial. Ann Intern Med 2011 Nov 15; 155:660.

Beyth RJ and Landefeld CS. Learning the respective roles of warfarin and dabigatran to prevent stroke in patients with nonvalvular atrial fibrillation. Ann Intern Med 2011 Nov 15; 155:714.