Influence of antiplatelet pre-treatment on the risk of symptomatic intracranial haemorrhage after intravenous thrombolysis

Background: The influence of antiplatelet agents (AP) in the development of a symptomatic intracranial haemorrhage (SICH) after intravenous rt-PA is not well known. We assessed the hypothesis that pre-treatment with AP may increase that risk. Methods: We studied data from consecutive patients with ischaemic stroke treated with intravenous rt-PA within the first 3 h after symptom onset. We recorded the antecedent of any AP therapy previous to thrombolysis. A follow-up CT was performed routinely 24-36 h after the infusion of rt-PA. Intracranial bleeding was categorized according to the criteria of the European Cooperative Acute Stroke Study II (ECASS II) into haemorrhagic infarction type 1 and 2 and parenchymal haemorrhage type 1 and 2. SICH was diagnosed if it was of the parenchymal haemorrhage type, occurred within the first 36 h and was associated with neurological deterioration. Results: Of a total of 605 patients, 137 (22.6%) were pre-treated with AP, most of them (n = 106) with aspirin. Any type of intracranial haemorrhage was observed in 119 patients (19.7%), without differences between the AP (18.4%) and the non-AP (20.2%) groups. Parenchymal haemorrhage was observed in 41 patients (8.5%) and SICH in 26 (4.3%). There was a non-significant rise in the frequency of SICH in the AP group compared with the non-AP group (6.6 vs. 3.6% p = 0.10). Conclusions: Pre-treatment with AP non-significantly increases the risk of SICH and therefore this antecedent should not be a contraindication for intravenous thrombolysis. Copyright (C) 2008 S. Karger AG, Basel.