title: Influence of antiplatelet pre-treatment on the risk of intracranial haemorrhage in acute ischaemic stroke after intravenous thrombolysis.
abstract: BACKGROUND
  Pre-treatment with antiplatelet agents (AP) is present amongst 30% of acute stroke patients. Previous studies have shown conflicting results on the effect of these drugs regarding haemorrhagic transformation after thrombolytic therapy. The hypothesis that pre-treatment with AP may increase the risk of cerebral haemorrhage (ICH) after intravenous tissue plasminogen activator (tPA) was assessed.
  
  
  METHODS
  Retrospective study of consecutive prospectively registered patients with acute ischaemic stroke treated with iv tPA (n = 235) in the last 5 years. Baseline characteristics and prior AP therapy were registered on admission. Computed tomography (CT) scan was performed on admission and 24-36 h after tPA. ICH was classified according to the ECASS II criteria into haemorrhagic infarction and parenchymal haematoma (PH). Symptomatic intracerebral haemorrhage (SICH) was defined as a worsening of > or = 4 points in the NIHSS score during the first 36 h in any haemorrhage subtype.
  
  
  RESULTS
  Seventy-two (30.6%) patients were pre-treated with AP (55 aspirin, 14 clopidogrel, 2 aspirin + clopidogrel, 1 triflusal). PH was observed in 33 (14.1%) patients (PH1 13, PH2 12, PHr 8) of whom 16 were symptomatic. Male gender (78.8% vs. 21.2%, P = 0.036), prior AP therapy (54.5% vs. 26.9%, P = 0.001), stroke severity (median NIHSS, 17 vs. 12, P = 0.005) and early CT signs of infarction (12.5% vs. 2.1%, P = 0.004) were associated with PH. The adjusted odds ratios of PH for patients pre-treated with AP therapy was 3.5 (1.5-7.8, P = 0.002) and for SICH 1.9 (0.6-5.9, P = 0.2).
  
  
  CONCLUSIONS
  Pre-treatment with AP is associated with an increased risk of PH after intravenous thrombolysis in patients with acute ischaemic stroke.
authors.affiliation: Stroke Unit, Department of Neurosciences, University Hospital Germans Trias i Pujol, Universitat Autònoma de Barcelona, Badalona, Barcelona, Spain. 36458ldb@comb.cat
authors.forename: L
authors.initials: L
authors.lastname: Dorado
authors.forename: M
authors.initials: M
authors.lastname: Millán
authors.forename: N Pérez
authors.initials: NP
authors.lastname: de la Ossa
authors.forename: C
authors.initials: C
authors.lastname: Guerrero
authors.forename: M
authors.initials: M
authors.lastname: Gomis
authors.forename: E
authors.initials: E
authors.lastname: López-Cancio
authors.forename: A C
authors.initials: AC
authors.lastname: Ricciardi
authors.forename: A
authors.initials: A
authors.lastname: Dávalos
mesh_terms: D000208:Acute Disease; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging; D002545:Brain Ischemia / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D020300:Intracranial Hemorrhages / Q000139:chemically induced* / Q000150:complications / Q000000981:diagnostic imaging; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D011446:Prospective Studies; D011859:Radiography; D012042:Registries; D012189:Retrospective Studies; D012306:Risk; D012307:Risk Factors; D020521:Stroke / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy*; D015912:Thrombolytic Therapy / Q000009:adverse effects / Q000379:methods; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D010959:Tissue Plasminogen Activator