[Comparison between CHADS2 score and CHA2DS2-VASc score on assessing the risk of ischemic stroke in patients with nonvalvular atrial fibrillation].

OBJECTIVE: To compare the value between CHADS2 score and CHA2DS2-VASc score on assessing the risk of ischemic stroke in patients with nonvalvular atrial fibrillation.

METHODS: In this retrospective study, nonvalvular atrial fibrillation patients with acute ischemic stroke hospitalized from January 2004 to March 2013 in our department were included. CHADS2 score (range, 0-6) and CHA2DS2-VASc score (range, 0-9) before acute ischemic stroke was calculated. For both schemes, patients were also classified with scores of 0, 1 and ≥ 2 in low-risk, intermediated-risk and high-risk categories, respectively, the difference between the two risk stratification schemes was evaluated by each category.

RESULTS: A total of 599 patients [320 men, mean age (75.4 ± 9.1) years] were collected. According to CHADS2 score, 30 (5.0%), 132 (22.0%) and 437 (73.0%) patients were classified in the low-risk, intermediated-risk and high-risk categories, respectively. The corresponding classification by CHA2DS2-VASc score was 6(1.0%), 25(4.2%) and 568 (94.8%) cases. The number of low-risk category patients (5.0% vs. 1.0%, χ(2) = 22.04, P < 0.001) and in intermediate-risk category patients (22.0% vs. 4.2%, χ(2) = 84.81, P < 0.001, Kappa = 0.075) was significantly higher in CHADS2 score group than in CHA2DS2-VASc score group, and the consistence between the two scores was poor (Kappa = 0.322). There were less patients classified in the high-risk group by CHADS2 score compared to CHA2DS2-VASc score (73.0% vs. 94.8%,χ(2) = 131.00, P < 0.001, Kappa = 0.257).

CONCLUSION: Compared with CHADS2 score, CHA2DS2-VASc score is more valuable in predicting ischemic stroke for patients with nonvalvular atrial fibrillation.