Reduction of Cerebral Infarct Size by Dronedarone

Purpose In the ATHENA trial, dronedarone reduced the incidence of stroke in patients with atrial fibrillation. Since smaller cerebral infarcts are sometimes asymptomatic, the reduced incidence of stroke might reflect reduction of infarct size (IS) by dronedarone. However, no data on this effect of dronedarone are available. Methods In 60 rats, the middle cerebral artery was occluded (MCAO) for 1 h followed by reperfusion. IS was assessed at day 7. Animals were examined using a neurological 5 points score. Twelve animals served as controls (group A), 12 animals received 30 mg/kg (group B) and 100 mg/kg (group C) dronedarone daily starting 3 days before MCAO; 12 animals received 30 mg/kg (group D) starting 2 h after MCAO. In all groups treatment was maintained until day 7. In 12 additional animals (6 controls, 6 pretreated animals) fractional anisotropy (FA) was assessed using magnetic resonance imaging (MRI). Results IS in group A was 151 ± 45 mm 3 versus 94 ± 42 mm 3 in group B, 79 ± 29 mm 3 in group C, and 127 ± 51 mm 3 in group D, respectively (B,C,D P