When assessing patients with ischemic stroke for endovascular therapy or tPA, the ratio of hypoperfused to nonviable ischemic tissue is determined. From previous studies, appropriate candidates for endovascular intervention have a ratio of 1.8 or greater between critically hypoperfused and ischemic core, and a volume of ischemic core of 70 mL or less. This study assessed the benefits of treating patients with baseline ischemic cores of up to 150 mL.

Data were reviewed from a prospectively collected large vessel occlusion stroke database for patients with intracranial internal carotid artery and/or proximal middle cerebral artery occlusion on CT angiography, with a time from last known normal of less than 12 hours, baseline ischemic cores of greater than 50 mL and an absolute mismatch volume of 40 mL-150 mL. Patients undergoing endovascular treatment were compared with matched controls who did not receive this treatment.

Data were included from 28 patients in the intervention group and 41 in the control group. Endovascular therapy was significantly associated with a favorable shift in the 90 day modified Rankin scores [mRS (P＝0.04)], with good outcomes in 0% of the controls and in 25% of the intervention group (P＝0.04). The final infarct volumes were smaller in the intervention group (87 ml) than in the control group (242 ml). For the subgroup with ischemic volumes of greater than 70 ml, a significant improvement in final infarct volume was noted in the intervention group (P<0.001) with an insignificant trend towards better mRS in the treatment group. The 90 day mortality was numerically but not statistically lower in the treatment group.

This study of patients with ischemic stroke found that for properly selected patients, endovascular therapy may benefit those with a large ischemic core and large mismatch profiles.