Investigating Neurologic Improvement After IV Thrombolysis
Gabriel Broocks, Lukas Meyer, Matthias Bechstein, Uta Hanning, Helge Kniep, Eckhard Schlemm, Anna A. Kyselyova, Laurens Winkelmeier, Gerhard Schön, Jens Fiehler, André Kemmling
Abstract
BACKGROUND AND OBJECTIVES: Time from stroke onset is associated with clinical response to intravenous thrombolysis (IVT) with alteplase and is therefore used to select patients for treatment. Alternatively, neuroimaging may be used for treatment in the uncertain or extended time window. We hypothesized that the patient-specific imaging indicator of ischemic lesion progression ("tissue clock") using CT perfusion (CTP) or quantitative net water uptake (NWU) is a predictor of early neurologic improvement (ENI) independent of time. METHODS: Observational study of anterior circulation ischemic stroke patients with proximal vessel occlusion and known time from symptom onset triaged by multimodal CT undergoing endovascular treatment. Quantitative NWU using an established threshold (11.5%) or CTP lesion core mismatch (EXTEND criteria) was used to estimate ischemic lesion progression. The treatment effect of IVT depending on lesion progression defined by tissue clock vs time clock was assessed by inverse probability weighting (IPW). End points were binarized ENI and functional independence at day 90. RESULTS: = 0.03), whereas early treatment window did not modify the effect of IVT. DISCUSSION: CT-based measures of the "tissue clock" might identify patients who benefit from IVT more accurately than conventional time windows. Considering the high number of patients with early "tissue clock" (low NWU/CTP mismatch) within an extended time window, considerable benefit from IVT using imaging indicators of the "tissue clock" may be achieved.