Meta-Analysis of CHADS2 versus CHA2DS2-VASc

Two validated scoring systems for predicting embolic risk, CHADS(2) and CHA(2)DS(2)-VASc, contribute to optimizing antithrombotic prescription practices in patients who have atrial fibrillation. However, data about anticoagulated patients are sparse. We compared CHADS(2) and CHA(2)DS(2)-VASc, in terms of their predictive risk evaluation, in patients with atrial fibrillation who were and were not taking anticoagulants. We systematically searched the Cochrane Library, PubMed, and Embase databases for studies of the comparative diagnostic performance of CHADS(2) and CHA(2)DS(2)-VASc. We identified 12 cohort studies for meta-analysis. With regard to the occurrence of cardiovascular events individually, patients with CHA(2)DS(2)-VASc scores >= 2 have a greater risk of stroke (risk ratio [RR]=5.15; 95% confidence interval [CI], 3.85-6.88; P <0.00001) and thromboembolism (RR=5.96; 95% CI, 5.50-6.45; P <0.00001) (P-diff=0.34) than do patients with CHA(2)DS(2)-VASc scores <2, independent of anticoagulation therapy (RR=5.76; 95% CI, 5.23-6.35; P <0.00001 in anticoagulated patients; and RR=6.12; 95% CI, 5.40-6.93; P <0.00001 in patients not taking anticoagulants; P-diff=0.45). The pooled RR estimates indicate an approximate 6-fold increase in the risk of endpoint events in patients with CHA(2)DS(2)-VASc scores >= 2 (RR=5.90; 95% CI, 5.46-6.37; P <0.0001). These results clearly indicate the discriminative capacity of the CHA(2)DS(2)-VASc score for stroke, thromboembolic events, or both, independent of optimal anticoagulation. The CHA(2)DS(2)-VASc score enables the identification of patients who are at genuinely high risk and can direct the selection of appropriate therapeutic approaches.