CHA₂DS₂-VASc Performs Better Than CHADS₂ in Predicting Stroke Risk

The CHADS₂ scoring system is used to stratify stroke risk in patients with nonvalvular atrial fibrillation. Guidelines (Circulation 2006; 114:e257) recommend aspirin for patients with CHADS₂ scores of 0 (low risk), warfarin or aspirin for patients with scores of 1 (intermediate risk), and warfarin for patients with scores of ≥2 (high risk). CHADS₂, however, classifies many patients as intermediate risk, and clinicians struggle with committing these patients to long-term warfarin anticoagulation. In this study involving 74,000 patients with nonvalvular atrial fibrillation, Danish investigators compared CHADS₂ with a new system, CHA₂DS₂-VASc. CHA₂DS₂-VASc also classifies patients with scores of 0 as low risk, 1 as intermediate risk, and ≥2 as…