Radiologic Patterns of Intracranial Hemorrhage and Clinical Outcome after Endovascular Treatment in Acute Ischemic Stroke: Results from the ESCAPE-NA1 Trial

Background Intracranial hemorrhage is a known complication after endovascular treatment in patients with acute ischemic stroke due to large vessel occlusion, but the association between radiologic hemorrhage severity and outcome is controversial. Purpose To investigate the prevalence and impact on outcome of intracranial hemorrhage and hemorrhage severity after endovascular stroke treatment. Materials and Methods The Efficacy and Safety of Nerinetide for the Treatment of Acute Ischemic Stroke (ESCAPE-NA1) trial enrolled participants with acute large vessel occlusion stroke who underwent endovascular treatment from March 1, 2017, to August 12, 2019. Evidence of any intracranial hemorrhage, hemorrhage multiplicity, and radiologic severity, according to the Heidelberg classification (hemorrhagic infarction type 1 [HI1], hemorrhagic infarction type 2 [HI2], parenchymal hematoma type 1 [PH1], and parenchymal hematoma type 2 [PH2]) was assessed at CT or MRI 24 hours after endovascular treatment. Good functional outcome, defined as a modified Rankin score of 0-2 at 90 days, was compared between participants with intracranial hemorrhage and those without intracranial hemorrhage at follow-up imaging and between hemorrhage subtypes. Poisson regression was performed to obtain adjusted effect size estimates for the presence of any intracranial hemorrhage and hemorrhage subtypes at good functional outcome. Results Of 1097 evaluated participants (mean age, 69 years ± 14 [standard deviation]; 551 men), any degree of intracranial hemorrhage was observed in 372 (34%). Good outcomes were less often achieved among participants with hemorrhage than among those without hemorrhage at follow-up imaging (164 of 372 participants [44%] vs 500 of 720 [69%], respectively; P < .01). After adjusting for baseline variables and infarct volume, intracranial hemorrhage was not associated with decreased chances of good outcome (adjusted risk ratio [RR] = 0.91 [95% CI: 0.82, 1.02], P = .10), but there was a graded relationship of radiologic hemorrhage severity and outcomes, whereby PH1 (RR = 0.77 [95% CI: 0.61, 0.97], P = .03) and PH2 (RR = 0.41 [95% CI: 0.21, 0.81], P = .01) were associated with decreased chances of good outcome. Conclusion Any degree of intracranial hemorrhage after endovascular treatment was seen in one-third of participants. A graded association existed between radiologic hemorrhage severity and outcome. Hemorrhagic infarction was not associated with outcome, whereas parenchymal hematoma was strongly associated with poor outcome, independent of infarct volume. © RSNA, 2021 Clinical trial registration no. NCT01778335 Online supplemental material is available for this article.