Severe Hemorrhagic Transformation after Thrombolysis for Acute Ischemic Stroke Prevents Early Neurological Improvement

Background: Intravenous thrombolysis can improve neurological outcomes after acute ischemic stroke (AIS), but hemorrhagic transformation (HT) of the infarct remains a risk. Current definitions for symptomatic intracerebral hemorrhage (ICH) all entail that there be some degree of associated neurological deterioration. However, early deleterious effects of secondary ICH might also be manifested as reduced neurological improvement. This study aims to investigate whether there are any independent associations between different radiological subtypes of HT and the degree of neurological improvement 24 hours after thrombolysis. Methods: This study is a retrospective analysis of a single-center database of consecutive thrombolysis cases for AIS. Multivariate regression analysis was undertaken to explore the relationship between different subtypes of HT with changes in National Institutes of Health Stroke Scale (NIHSS) score 24 hours after thrombolysis, after adjusting for potential confounders. Results: As compared to cases with no HT, occurrence of the parenchymal hematoma 2 (PH2) subtype of secondary ICH was independently associated with reduced improvement or worsening in the NIHSS score, with an average effect size of 7 points (95% confidence interval -10 to -4, P < .001). In the absence of PH2, thrombolysis for AIS was generally associated with an improvement in the neurological status at 24 hours. Conclusions: The PH2 subtype of HT is associated with reduced neurological improvement or deterioration 24 hours after thrombolysis for AIS.