An Observational Study of Thrombolysis Outcomes in Wake-Up Ischemic Stroke Patients

Abstract

Wake-up ischemic stroke (WUIS) patients are not eligible for thrombolysis; the a priori hypothesis was that thrombolysis of selected WUIS patients who meet clinical and imaging criteria for treatment is associated with better outcomes. The sample consisted of consecutive WUIS patients who fulfilled predefined criteria: (1) were last seen normal >4.5 hours and <12 hours before presentation; (2) National Institute of Health Stroke Scale score ≥ 5; (3) No or early ischemic changes <1/3 middle cerebral artery territory on computed tomography imaging; (4) No absolute contraindications to thrombolysis. The primary outcome measure was the modified Rankin Scale of 0 to 2 at 90 days. Other outcome measures were mortality and symptomatic intracerebral hemorrhage. WUIS patients constituted 10.5% (193/1836) of all stroke admissions. Inclusion criteria were fulfilled by 122 (63%) patients, of whom 68 (56%) were thrombolysed. Thrombolysed and nonthrombolysed patients were comparable for baseline characteristics, but the median baseline National Institute of Health Stroke Scale score was higher in thrombolysed patients (9 versus 11.5; P=0.034). There was no difference in modified Rankin Scale 0 to 2 (25 [37%] versus 14 [26%]; P=0.346), death (10 [15%] versus 14 [26%]; P=0.122), and symptomatic intracerebral hemorrhage (2 versus 0; P=0.204) between thrombolysed and nonthrombolysed patients. After adjusting for age, sex, and baseline National Institute of Health Stroke Scale score thrombolysis was associated with odds ratio of 5.2 (95% confidence interval 1.3-20.3), P=0.017 for modified Rankin Scale 0 to 2 at 90 days and odds ratio of 0.09 (95% confidence interval 0.02-0.44), P=0.003 for death. Thrombolysis in selected WUIS patients is feasible and may have potential of benefit.