The CHADS2 score predicts ischemic stroke in chronic heart failure patients without atrial fibrillation: comparison to other stroke risk scores.

The CHADS2 score is useful in stratifying the risk of ischemic stroke or transient ischemic attack (TIA) in patients with non-valvular atrial fibrillation (AF). However, it remains unclear whether the CHADS2 score could predict stroke or TIA in chronic heart failure (CHF) patients without AF. Recently, the new stroke risk score was proposed from 2 contemporary heart failure trials. We evaluated the prognostic power of the CHADS2 score for stroke or TIA in CHF patients without AF in comparison to the "stroke risk score". We retrospectively studied 127 CHF patients [left ventricular ejection fraction (LVEF) <40 %] without AF, who had been enrolled in our previous prospective cohort study. The primary endpoint was the incidence of stroke or TIA. The mean baseline CHADS2 score was 2.1 ± 1.0. During the follow-up period of 8.4 ± 5.1 years, stroke or TIA occurred in 21 of 127 patients. At multivariate Cox analysis, CHADS2 score (C-index 0.794), but not "stroke risk score" (C-index 0.625), was significantly and independently associated with stroke or TIA. The incidence of stroke or TIA appeared to increase in relation to the CHADS2 score [low (=1), 0 per 100 person-years; intermediate (=2), 1.6 per 100 person-years; high (≥3), 4.7 per 100 person-years; p = 0.04]. CHADS2 score could stratify the risk of ischemic stroke in CHF patients with the absence of AF, with greater prognostic power than the "stroke risk score".