Hemorrhagic transformation in acute ischemic stroke. Potential contributing factors in the European Cooperative Acute Stroke Study.

BACKGROUND AND PURPOSE: Recent studies suggest that thrombolytic therapy may be of benefit to patients with acute ischemic stroke. However, the treatment also carries a significant risk of hemorrhagic transformation (HT). The purpose of this study was to select potential contributors to HT.

METHODS: We provide an explanatory analysis of the European Cooperative Acute Stroke Study (ECASS) data. ECASS was a multicenter, placebo-controlled, randomized trial of recombinant tissue plasminogen activator in ischemic stroke, within 6 hours of symptom onset, which enrolled 620 patients. HTs were classified into either hemorrhagic infarction or parenchymal hemorrhage according to their CT scan appearance. We used logistic regression analysis to select potential contributing factors to each type of HT.

RESULTS: The severity of initial clinical deficit (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.6 to 4.0) and the presence of early ischemic changes on CT scan (OR, 3.5; 95% CI, 2.3 to 5.3) were associated with increased risk of hemorrhagic infarction. Increasing age (in decades; OR, 1.3; 95% CI, 1.0 to 1.7) and treatment with recombinant tissue plasminogen activator (OR, 3.6; 95% CI, 2.1 to 6.1) were related to the risk of parenchymal hemorrhage.

CONCLUSIONS: Since all potential contributing factors are readily discernible upon hospital admission, they should be used to improve selection of patients into future studies.