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”.