Hemorrhage in the Interventional Management of Stroke Study

Background and Purpose—The incidence of hemorrhage after combined intravenous (IV) and intra-arterial (IA) recombinant tissue plasminogen activator (rt-PA) was examined in patients entered into the Interventional Management of Stroke (IMS) trial. We also analyzed factors predicting symptomatic and asymptomatic intracerebral hemorrhage (ICH). Methods—The IMS study treated patients within 3 hours of stroke onset with 0.6 mg/kg IV rt-PA followed by up to 22 mg IA rt-PA. Any hemorrhage within 36 hours associated with clinical deterioration was considered symptomatic. Logistic regression analysis was applied to possibly relevant variables selected from the baseline data to test for associations between these factors and symptomatic hemorrhage, asymptomatic hemorrhage, and all hemorrhage. Results—Symptomatic hemorrhage occurred in 6% and asymptomatic hemorrhage in 43% of patients. The rate of symptomatic hemorrhage was similar to the National Institute of Neurological Disorders and Stroke (NINDS) trial with IV rt-PA alone. Asymptomatic hemorrhage was more frequent but consistent with the rate observed in more recent IV and IA thrombolytic trials. The small number of symptomatic hemorrhages precluded meaningful analysis of risk factors. Significant factors associated with ICH in univariate analysis were baseline National Institutes of Health Stroke Scale score (asymptomatic and all ICH), edema or mass effect on initial computed tomography (asymptomatic ICH), atrial fibrillation (all ICH), and location of arterial occlusion (internal carotid artery [ICA] compared with middle cerebral artery [MCA]; asymptomatic and all ICH). In multivariate analysis, ICA versus MCA occlusion remained an independent factor associated with asymptomatic and all hemorrhage, and atrial fibrillation was significantly associated with all hemorrhage. Conclusions—Symptomatic and asymptomatic hemorrhage with combined IV and IA rt-PA occurred at rates similar to previous thrombolytic trials. Site of vascular occlusion and atrial fibrillation may be risk factors for hemorrhagic transformation. (Stroke. 2006;37:847-851.)