A case-controlled comparison of thrombolysis outcomes between wake-up and known time of onset ischemic stroke patients

Wake-up ischemic stroke (WUIS) patients are not thrombolysed even if they meet other criteria for treatment. We hypothesized that patients with WUIS showing no or early ischemic changes on brain imaging will have thrombolysis outcomes comparable with those with known time of symptom onset.

Consecutive sampling of a prospective registry of patients with stroke between January 2009 and December 2010 identified 394 thrombolysed patients meeting predefined inclusion criteria, 326 presenting within 0 to 4.5 hours of symptom onset (Reference Group) and 68 WUIS patients. Inclusion criteria were last seen normal<12 hours or >4.5 hours (WUIS) or presented <4.5 hours (Reference Group), had National Institutes of Health Stroke Scale score ≥5, and no or early ischemic changes on imaging at presentation. The primary outcome measure was the modified Rankin Scale of 0 to 2 at 90 days measured by trained assessors blinded to patient grouping. Other outcome measures were symptomatic intracerebral hemorrhage, modified Rankin Scale 0 to 1, and mortality at 90 days.

The groups were comparable for mean age (72.8 versus 73.9 years; P=0.58) and baseline median National Institutes of Health Stroke Scale score (median 13 versus 12; P=0.34). The proportions of patients with modified Rankin Scale 0 to 2 (38% versus 37%; P=0.89) and modified Rankin Scale 0 to 1 (24% versus 16%; P=0.18) at 90 days, any ICH (20% versus 22%; P=0.42) and symptomatic intracerebral hemorrhage (3.4% versus 2.9%; P=1.0) were comparable after adjusting for age, stroke severity, and imaging changes. Only 9/394 (2%) patients were lost to follow-up.

Thrombolysis in selected patients with WUIS is feasible, and its outcomes are comparable with those thrombolysed with 0 to 4.5 hours.