An observational study of thrombolysis outcomes in wake-up ischemic stroke patients

Abstract

Background and purpose: 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.

Methods: 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.

Results: 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.

Conclusions: Thrombolysis in selected WUIS patients is feasible and may have potential of benefit.