BACKGROUND Heart failure has been associated with an increased risk for ischemic stroke. This study estimated the risk of stroke and thromboembolism for patients with congestive heart failure (CHF) in the context of the general population, especially compared to those with atrial fibrillation (AF).

METHODS Data of patients discharged alive from 2003 to 2012 were extracted from the National Health Insurance Corporation sample cohort. Subjects were classified into control (n=90,277), CHF (n=4533), AF (n=1187), and CHF plus AF (n=1213) groups.

RESULTS CHF was associated with an increased risk for ischemic stroke, which was significant after various adjustment models. Annualized stroke risk was 0.54 (0.52-0.57) per 100 person-years for the control group, 2.00 (1.79-2.21) for the CHF group, 2.27 (1.84-2.69) for the AF group, and 2.87 (2.38-3.36) for the CHF plus AF group. The CHA₂DS₂-VASc scoring schema had a moderate discriminatory value for stroke risk in patients with CHF as well as in AF. The risk of stroke for the CHF group was comparable to that of the AF group when stratified according to the CHA₂DS₂-VASc scores. Those with CHA₂DS₂-VASc score of 0 or 1 were at low risk for stroke for both CHF and AF.

CONCLUSION Patients with CHF are at increased risk for ischemic stroke and thromboembolism. This study showed that the CHA₂DS₂-VASc schema can help stratify stroke risk for individual CHF patients. Stroke is a frequent complication among patients with CHF; therefore, safe and effective strategies to prevent stroke are needed.