The Safety of Intravenous Thrombolysis for Ischemic Stroke in Patients With Pre-Existing Cerebral Aneurysms

Abstract

Unruptured cerebral aneurysms are currently considered a contraindication to intravenous tissue-type plasminogen activator for acute ischemic stroke. This is due to a theoretical increase in the risk of hemorrhage from aneurysm rupture, although it is unknown whether this risk is a significant one. We sought to determine the safety of intravenous tissue-type plasminogen activator administration in a cohort of patients with pre-existing aneurysms. We reviewed the medical records of patients treated for acute ischemic stroke with intravenous tissue-type plasminogen activator during an 11-year period at 2 academic medical centers. We identified a subset of patients with unruptured cerebral aneurysms present on prethrombolysis vascular imaging. Our outcomes of interest were any intracranial hemorrhage, symptomatic intracranial hemorrhage, and subarachnoid hemorrhage. Fisher exact test was used to compare the rates of hemorrhage among patients with and without aneurysms. We identified 236 eligible patients, of whom 22 had unruptured cerebral aneurysms. The rate of intracranial hemorrhage among patients with aneurysms (14%; 95% CI, 3%-35%) did not significantly differ from the rate among patients without aneurysms (19%; 95% CI, 14%-25%). None of the patients with aneurysms developed symptomatic intracranial hemorrhage (0%; 95% CI, 0%-15%) compared with 10 of 214 patients without aneurysms (5%; 95% CI, 2%-8%). Similar proportions of patients developed subarachnoid hemorrhage (5%; 95% CI, 0%-23% versus 6%; 95% CI, 3%-10%). Our findings suggest that intravenous tissue-type plasminogen activator for acute ischemic stroke is safe to administer in patients with pre-existing cerebral aneurysms because the risk of aneurysm rupture and symptomatic intracranial hemorrhage is low.