Comparisons of CHADS2 and CHA2DS2-VASc scores for stroke risk stratification in atrial fibrillation: Which scoring system should be used for Asians?
BACKGROUND
Both U.S. and European guidelines recommend use of the CHA2DS2-VASc rather than CHADS2 score for stroke risk stratification in atrial fibrillation (AF). However, the CHA2DS2-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 CHA2DS2-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 CHA2DS2-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 CHA2DS2-VASc score ranged from 0 to 3, and the annual stroke rate ranged from 1.15% to 4.47%. Compared to patients with a CHA2DS2-VASc score of 0, the hazard ratio of ischemic stroke for patients with a CHA2DS2-VASc score of 3 was 3.998.


CONCLUSIONS
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 CHA2DS2-VASc score. In contrast, patients with a CHA2DS2-VASc score of 0 had a truly low risk of ischemic stroke, with an annual stroke rate around 1.15%. As with Caucasians, the CHA2DS2-VASc score should be used for stroke risk stratification in Asians.
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.
Tze-Fan
TF
Chao
Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Public Health and School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Chia-Jen
CJ
Liu
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.
Ta-Chuan
TC
Tuan
Institute of Public Health and School of Medicine, National Yang-Ming University, Taipei, Taiwan; Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital Su-Ao and Yuanshan branch, I-Lan, Taiwan.
Su-Jung
SJ
Chen
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.
Kang-Ling
KL
Wang
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.
Yenn-Jiang
YJ
Lin
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan. Electronic address: cechiang@vghtpe.gov.tw.
Shih-Lin
SL
Chang
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.
Li-Wei
LW
Lo
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.
Yu-Feng
YF
Hu
Department of Family Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
Tzeng-Ji
TJ
Chen
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan; General Clinical Research Center, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan. Electronic address: epsachen@ms41.hinet.net.
Chern-En
CE
Chiang
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.
Shih-Ann
SA
Chen
D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000150:complications / Q000453:epidemiology; D000068598:Data Accuracy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D057216:Propensity Score; D018570:Risk Assessment / Q000379:methods / Q000592:standards; D012307:Risk Factors; D013223:Statistics as Topic; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D013624:Taiwan / Q000453:epidemiology
Asians; Atrial fibrillation; CHA(2)DS(2)-VASc score; CHADS(2) score; Ischemic stroke