Does the CHA2DS2-VASc score better identify truly low-risk atrial fibrillation patients for stroke compared to CHADS2 and ATRIA scores in oral anticoagulant naive patients?
The CHA2DS2-VASc score is superior to CHADS2 and ATRIA scores in identifying truly low-risk Asian patients with atrial fibrillation who may not need antithrombotic therapy.
Background and Purpose— As the threshold of stroke risk for initiating oral anticoagulants is lowered after the introduction of the nonvitamin K antagonist oral anticoagulants, the focus of stroke prevention in patients with nonvalvular atrial fibrillation has shifted away from predicting high-risk patients toward initially identifying patients with a truly low risk of ischemic stroke, who do not need antithrombotic therapy. We tested the predictive ability of the congestive heart failure, hypertension, age ≥75, diabetes mellitus, prior stroke or transient ischemic attack (doubled; CHADS 2 ), congestive heart failure, hypertension, age ≥75 (doubled), diabetes mellitus, prior stroke or transient ischemic attack (doubled), vascular disease, age 65 to 74, female (CHA 2 DS 2 -VASc), and Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) risk stratification schemes in oral anticoagulants naive patients with atrial fibrillation in a Korean nationwide sample cohort. Methods— From January 2002 to December 2008, a total of 5855 oral anticoagulant naive patients with nonvalvular atrial fibrillation aged ≥20 years were enrolled from Korea National Health Insurance Service-Sample Cohort database and were followed-up until December 2013. Results— At baseline, the proportions categorized as low risk using CHADS 2 , CHA 2 DS 2 -VASc, and ATRIA risk stratification schemes were 1049 (17.9%), 860 (14.7%), and 3280 (56.0%), respectively. During follow-up, the low-risk category using CHADS 2 , CHA 2 DS 2 -VASc, and ATRIA scores was retained in 811 (13.9%), 667 (11.4%), and 2729 (46.6%) patients, respectively. Rates of ischemic stroke (100 person-years) in the low risk categories of CHADS 2 , CHA 2 DS 2 -VASc, and ATRIA scores were 0.42, 0.26, and 1.43, respectively. CHA 2 DS 2 -VASc had the best sensitivity (98.8% versus 85.7% in CHADS 2 and 74.8% in ATRIA) and negative predictive value (98.8% versus 95.3% for CHADS 2 and 93.7% for ATRIA) for the prediction of stroke incidence and was best for the prediction of the absence of ischemic stroke during 5 years of follow-up (odds ratio, 16.4 95% confidence interval, 8.8–30.8). Conclusions— The CHA 2 DS 2 -VASc score shows good performance in defining truly low-risk Asian patients with atrial fibrillation for stroke compared with CHADS 2 and ATRIA scores.
Kim et al. (Sat,) studied this question.