Postprocedure Subarachnoid Hemorrhage after Endovascular Treatment for Acute Ischemic Stroke.

BACKGROUND: The rate of occurrence and associated outcomes of subarachnoid hemorrhage (SAH) in acute ischemic stroke patients following endovascular treatment is not well studied.

METHODS: We analyzed data from subjects treated with intravenous recombinant tissue plasminogen activator followed by endovascular treatment in the Interventional Management of Stroke III trial. The baseline and 24 (±6) hours postrandomization computed tomographic scans were interpreted centrally for presence, type, and location of intracranial hemorrhages (ICHs) including SAH. The primary outcome assessment was by modified Rankin scale (mRS) score at 3 months.

RESULTS: Of these 323 subjects who underwent endovascular treatment, the patterns of postprocedure ICHs were as follows: none (n = 168), isolated SAH (type 1, n = 9), SAH with intraparenchymal hemorrhage (IPH) or other ICHs (type 2, n = 33), and IPH or other ICHs without SAH (n = 113). At 3 months, the rates of independent functional outcome (mRS 0-2) were lower among subjects with type 2 SAHs (odds ratio [OR] .2; 95% confidence interval [CI] .1-.8; P = .016), and IPH or other ICHs without SAH (OR .5; 95% CI .3-.9; P = .022) but not in subjects with type 1 SAH (OR .8; 95% CI .2-3.5; P = .810), after adjusting for age, baseline serum glucose levels, National Institutes of Health Stroke Scale score strata, and procedure related complications.

CONCLUSIONS: The rates of independent functional outcome were lower among subjects with postprocedure type 2 SAHs but not in subjects with type 1 SAH.