Non-contrast head CT-based thrombolysis for wake-up/unknown onset stroke is safe: A single-center study and meta-analysis.

Background: Recent studies have shown that tPA can be safely administered past the standard 4.5 h window with good outcomes when selected with multi-model imaging, which is often lacking outside of comprehensive stroke centers.

Aim: We aim to analyze the safety and outcomes of wake up/unknown onset (WUS/UNK) patients treated based on non-contrast head CT (NCCT) at our institution and in the literature.

Methods: Suspected stroke patients from January 2015 to December 2018 receiving tPA within 4.5 h (standard window-SW) and with WUS/UNK based on NCCT and clinical-imaging mismatch were identified. We compared baseline characteristics, tPA metrics, and outcome data, with primary outcome as symptomatic intracerebral hemorrhage (sICH). A meta-analysis was performed evaluating NCCT-based treatment of WUS/UNK patients.

Results: Of 1827 patients treated at our hub or through telestroke, 93 underwent WUS/UNK-based treatment. There was no statistical difference in sICH between WUS/UNK and SW: 1% vs. 4% (OR 0.3; 95% confidence interval 0.0-1.9). 90-day modified Rankin scale outcomes were similar between SW and WUS/UNK-treated patients. Seven studies encompassing 485 WUS/UNK patients were included in a pooled analysis with a 2.1% incidence of sICH. In our meta-analysis, three studies compared NCCT-based treated WUS/UNK patients with SW patients with no difference in rate of hemorrhage: 2.1% vs 3.4% (OR 1.01; 95% confidence interval 0.45-2.28).

Interpretation: Our single-center analysis and meta-analysis suggest that tPA can be safely administered based on NCCT with comparable rates of sICH for select WUS/UNK stroke patients.