Prediction of ischemic stroke by the CHA2DS2 -VA score in an Asian population: A report from the prospective nationwide COOL-AF registry.

Background: The CHA2DS2-VA score, derived by the removal of female sex from the CHA2DS2-VASc score, has recently been recommended for the prediction of ischemic stroke/systemic embolism (SSE) in patients with atrial fibrillation (AF).

Objective: Given the limited data in non-Western cohorts, the objective was to compare the performance of CHA2DS2-VASc and CHA2DS2-VA score for the prediction of SSE in an Asian population.

Methods: AF patients from the prospective multicentre COOL-AF registry were studied. Patients were followed-up every 6 months for 3 years. The primary outcome was SSE. C-statistics were used to compare the performance of CHA2DS2-VASc and CHA2DS2-VA scores for SSE risk prediction. The pattern of OAC use is according to the practicing physicians.

Results: A total of 3405 patients were studied (mean age 67.8±11.3 years, 41.8% female). The incidence rate of SSE was 1.51 (1.26-1.78) per 100 person-years. The risk ratio for SSE for females was higher than males at CHA2DS2-VA scores ≥2 [1.72 (1.19-2.50), p = 0.004], similar for patients with and without OAC use. The C-statistics for SSE was not statistically significantly different between CHA2DS2-VASc and CHA2DS2-VA scores [0.655 (0.639-0.671) and 0.647 (0.631-0.663), p=0.258]. Females had a greater risk of SSE compared to males at age above 70 years (p-valueinteraction 0.007).

Conclusions: Female patients with AF have an increased SSE risk compared to male patients with a higher CHA2DS2-VA scores and at age above 70 years. The CHA2DS2-VA scores had a numerical but non-statistically significant difference to CHA2DS2-VASc score for SSE risk prediction.