Abstract 18044: Comparison of the CHADS2 and CHA2DS2-VASc Scores in Predicting Stroke Events in Patients With Atrial Fibrillation
Introduction: The CHADS2 score is the most frequently used measure to evaluate stroke risk in patients with atrial fibrillation (AF). However, this measure does not capture all known risk factors. Recently, the CHA2DS2-VASc score, a modified version of the CHADS2 score, was introduced with the advantage of considering additional risk factors.
Hypothesis: Compared to the CHADS2 score, the CHA2DS2-VASc score may better distinguish between patients at a low and intermediate risk of stroke.
Methods: A population-based cohort study was conducted using the United Kingdom's General Practice Research Database population. The cohort included all patients at least 18 years of age with a first ever diagnosis of chronic AF between January 1, 1993 and December 31, 2008. During follow-up, all subjects who experienced a stroke were identified. Person-time at risk was measured from cohort entry (date of AF diagnosis) to time of event (stroke) or end of follow-up. Crude stroke rates (with 95% confidence intervals) were calculated, and stratified according to CHADS2 and CHA2DS2-VASc at cohort entry.
Results: The cohort included 70,766 patients newly diagnosed with chronic AF, of whom, 5,855 experienced a stroke during a mean follow-up of 3.7 years. The stroke rate was 22.4 per 1000/year. The Table below presents stroke rates by CHADS2 and CHA2DS2-VASc scores. Compared to the CHADS2, the CHA2DS2-VASc appeared to better distinguish between patients at a low (score 0) and intermediate (scores 1 or 2) risk for stroke.
Conclusions: The results of this study indicate that, compared to the CHADS2, the CHA2DS2-VASc may better in discriminating between patients at a low and intermediate risk of stroke.
- © 2010 by American Heart Association, Inc.