Comparison of the CHADS2, CHA2DS2-VASc and R2CHADS2 Scores in Japanese Patients with Non-valvular Paroxysmal Atrial Fibrillation Not Receiving Anticoagulation Therapy.

Abstract

Objective It remains unclear whether the CHADS2, CHA2DS2-VASc, or R2CHADS2 score is the most useful for the risk stratification of ischemic stroke/systemic thromboembolism (IS/SE) in Japanese patients with paroxysmal non-valvular atrial fibrillation (PNVAF). Methods We investigated the incidence of IS/SE on the basis of the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores in 332 consecutive PNVAF patients (224 men, mean age: 65±13 years) who had not been administered anticoagulation therapy but who were administered antiarrhythmic drug therapy to maintain sinus rhythm between August 1995 and July 2008 before the 2008 Japanese Circulation Society guideline was issued (mean follow-up period: 53±35 months). Results The annual rates of IS/SE without underlying antiarrhythmic drug therapy are shown in the table included in this article. Higher CHADS2, CHA2DS2-VASc, and R2CHADS2 scores were associated with greater annual rates of IS/SE (p<0.001). In a multivariate logistic regression analysis adjusted for potentially confounding variables, the CHADS2 scores [odds ratio (OR): 4.74, 95% confidence interval (CI): 2.80-8.00, p<0.001], CHA2DS2-VASc scores (OR: 4.15, 95% CI: 2.57-6.71, p<0.001), and R2CHADS2 scores (OR: 1.94, 95% CI: 1.48-2.53, p<0.001) were significant independent predictors of IS/SE. The area under the receiver-operator characteristic curve for predicting IS/SE was 0.89 for CHA2DS2-VASc scores, 0.87 for CHADS2 scores, and 0.85 for R2CHADS2 scores (all, p<0.001), with no significant difference among the three scores. Conclusion In Japanese patients with PNVAF, the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores are all useful for the risk stratification of IS/SE cases.