Aachi RV, et al. - Herein, researchers studied the laboratory characteristics of ischemic stroke (IS) patients with atrial fibrillation (AF) on or off therapeutic warfarin. In comparison with others, higher average serum creatinine and blood urea nitrogen, and lower glomerular filtration rates were observed in AF patients who presented with IS on therapeutic warfarin. Findings also suggested a probable contribution of impaired renal function to occurrence of IS in AF patients despite adequate anticoagulation.