Increases in cerebral atherosclerosis according to CHADS₂ scores in patients with stroke with nonvalvular atrial fibrillation

Background and Purpose- The CHADS₂ score is used for risk stratification of ischemic stroke in patients with nonvalvular atrial fibrillation and high CHADS₂ scores are associated with increased risk of stroke. Most components of the CHADS₂ score are also risk factors for atherosclerosis. Therefore, high CHADS₂ scores can be associated with concomitant cerebral atherosclerosis and subsequently atherothrombotic stroke. The aim of this study was to determine whether there are differences in the presence and burden of concomitant cerebral atherosclerosis according to CHADS₂ scores in patients with stroke with nonvalvular atrial fibrillation. Methods- We included 780 consecutive patients with nonvalvular atrial fibrillation who had undergone angiographic studies at index stroke between August 1994 and March 2010 in the present study. We investigated the relationships between the CHADS₂ score and the presence, severity, and pattern of cerebral atherosclerosis and stroke mechanism. Results- Of the 780 patients, concomitant arterial stenosis (50%) was found in 231 patients (29.6%). The number of arteries with atherosclerosis increased as the CHADS₂ score increased (P<0.001) as did the proportion of combined extracranial and intracranial atherosclerosis (P<0.001). Multivariate analyses showed that high risk based on the CHADS₂ score was an independent predictor of concomitant cerebral atherosclerosis (OR, 3.121; 95% CI, 1.770 to 5.504) and the presence of proximal stenosis at the symptomatic artery (OR, 3.043; 95% CI, 1.458 to 6.350). Conclusions- The CHADS₂ score can predict the presence of concomitant cerebral artery atherosclerosis. Increased risk of stroke in patients with high CHADS₂ scores may be partly explained by increased frequency and burden of cerebral atherosclerosis.