Comparisons of CHADS2 and CHA2 DS2 -VASc scores for stroke risk stratification in atrial fibrillation: Which scoring system should be used for Asians?

• Published in: Heart rhythm Vol. 13; no. 1; pp. 46 - 53
• Main Authors: Chao, Tze-Fan, MD, Liu, Chia-Jen, MD, Tuan, Ta-Chuan, MD, Chen, Su-Jung, MD, Wang, Kang-Ling, MD, Lin, Yenn-Jiang, MD, Chang, Shih-Lin, MD, Lo, Li-Wei, MD, Hu, Yu-Feng, MD, Chen, Tzeng-Ji, MD, Chiang, Chern-En, MD, PhD, Chen, Shih-Ann, MD
• Format: Journal Article
• Language: English
• Published: 2016
• Subjects: Cardiovascular; non–vitamin K antagonist oral anticoagulant; APHRS; Asia Pacific Heart Rhythm Society; oral anticoagulant; International Classification of Diseases, Ninth Revision, Clinical Modification; NOAC; Ischemic stroke; NHI; CHADS 2 score; atrial fibrillation; ICD-9-CM; NHRI; receiver operating characteristic; CHA 2DS 2-VASc score; Asians; National Health Research Institutes; AF; CI; ROC; transient ischemic attack; NHIRD; TIA; OAC; National Health Insurance Research Database; confidence interval; National Health Insurance
• ISSN: 1547-5271
• DOI: 10.1016/j.hrthm.2015.08.017

Background Both U.S. and European guidelines recommend use of the CHA2 DS2 -VASc rather than CHADS2 score for stroke risk stratification in atrial fibrillation (AF). However, the CHA2 DS2 -VASc score has not been proved to be better than CHADS2 score for Asians in a large-scale study. Objective The purpose of this study was to compare the accuracies of CHADS2 and CHA2 DS2 -VASc scores in predicting ischemic stroke in Chinese patients. Methods This study used the National Health Insurance Research Database in Taiwan. A total of 186,570 AF patients without antithrombotic therapies were selected as the study cohort. The clinical end-point was occurrence of ischemic stroke. Results During follow-up of 3.4 ± 3.7 years, 23,723 patients (12.7%) experienced ischemic stroke. The CHA2 DS2 -VASc score performed better than CHADS2 score in predicting ischemic stroke assessed by c-indexes (0.698 vs 0.659, P <.0001). Among 25,286 patients with a CHADS2 score of 0, the CHA2 DS2 -VASc score ranged from 0 to 3, and the annual stroke rate ranged from 1.15% to 4.47%. Compared to patients with a CHA2 DS2 -VASc score of 0, the hazard ratio of ischemic stroke for patients with a CHA2 DS2 -VASc score of 3 was 3.998. Conclusion Patients with a CHADS2 score of 0 were not necessarily “low risk,” and the annual stroke rate can be as high as 4.47% when patients were further stratified by the CHA2 DS2 -VASc score. In contrast, patients with a CHA2 DS2 -VASc score of 0 had a truly low risk of ischemic stroke, with an annual stroke rate around 1.15%. As with Caucasians, the CHA2 DS2 -VASc score should be used for stroke risk stratification in Asians.