Combined anti-platelet therapy with aspirin and clopidogrel: risk factor for thrombolysis-related intracerebral hemorrhage in acute ischemic stroke?

Background And Purpose: To date, pre-treatment with anti-platelet agents does not constitute a contraindication for thrombolysis in acute ischemic stroke. We tested the hypothesis that combined pre-treatment with aspirin and clopidogrel is a risk factor for thrombolysis-related symptomatic intracerebral hemorrhage (sICH).

Methods: We retrospectively studied patients with acute ischemic stroke receiving standard i.v. thrombolytic therapy with rt-PA in our institution. Exclusion criteria were thrombolysis initiated later than 3 h from symptom onset or with non-tPA-agents, no follow-up imaging was performed and data on prior medication was missing. We recorded clinical baseline variables including known risk factors for ICH. Our outcome measure was the incidence of ICH defined as parenchymal hematoma type 2 with > or = 4 points deterioration on the National Institute of Health Stroke Scale score. We performed univariate analysis to determine risk factors for sICH.

Results: We identified 102 patients receiving any thrombolysis of which 63 fulfilled the inclusion criteria. Mean age was 69 years, onset-to-treatment-time 138 min, 56% male, median NIHSS score was 10, and 3 patients received additional intra-arterial interventions. A total of 3 patients had received combined aspirin and clopidogrel treatment before thrombolysis. SICH occurred in 3/63 (4.7%) of patients. Out of these, 2 patients had received the combined anti-platelet treatment. In univariate analysis, only combined pre-treatment with aspirin and clopidogrel treatment were associated with the occurrence of sICH.

Conclusion: In our retrospective study, only pre-treatment with aspirin and clopidogrel was associated with thrombolysis-related intracerebral hemorrhage. This finding should be further validated in large prospective databases like the SITS-MOST registry.