Intracranial hemorrhage in association with thrombolytic therapy: incidence and clinical predictive factors.

In a period of 18 months, 2,469 patients with acute myocardial infarction treated with a thrombolytic agent were prospectively registered in 61 hospitals. Most patients (73%) were treated with streptokinase. Intracranial hemorrhage was observed in 24 patients, corresponding to an incidence rate of 1% (95% confidence interval 0.6% to 1.3%). The median time interval between the start of thrombolytic therapy and the first clinical signs of intracranial bleeding was 16 h (range 3 to 36). In total, 16 (66%) of the 24 patients died as a result of cerebral hematoma. To determine clinical predictive factors, a case-control study was conducted. For every patient with intracranial hemorrhage, two control patients who received thrombolytic therapy because of acute infarction in the same hospital and in the same period were selected. Detailed clinical characteristics of 22 of the 24 patients as well as of 7 other patients with documented intracerebral bleeding from the European Cooperative Study Group and of 2 patients who sustained intracranial hemorrhage outside the registry period were compared with 62 control patients. The results of multivariate logistic regression analysis indicate that patients taking an oral anticoagulant before admission, patients with a body weight less than 70 kg and those greater than 65 years old are at higher risk for intracranial hemorrhage during thrombolytic therapy.