title: Antiplatelet therapy as a modulator of stroke aetiology: a meta-analysis.
abstract: OBJECTIVE
  Antiplatelet therapy reduces the incidence of ischaemic stroke. Platelet-mediated thrombosis contributes variably to the major subtypes of stroke as defined by the TOAST criteria: large artery atherosclerosis (LAA), cardioembolic (CE) and small vessel occlusion (SVO). The effect of antiplatelet therapy on the incidence of each subtype is unknown and is the subject of this meta-analysis.
  
  
  METHODS
  Electronic databases were searched for articles comparing the effect of antiplatelet therapy on the incidence of stroke according to aetiological subtype. Studies containing subjects prescribed anticoagulant therapy or solely investigating subjects with atrial fibrillation were excluded. Pooled odds ratios (ORs) were calculated using a fixed effects model.
  
  
  RESULTS
  Nine studies were included (n = 5739). In patients who had an ischaemic stroke, pre-event antiplatelet therapy was associated with significantly decreased incidence of LAA (OR 0.88, 95% CI 0.79, 0.99; P = 0.026), increased incidence of CE (OR 1.23, 95% CI 1.08, 1.41; P = 0.002) and no effect on SVO (OR 0.99, 95% CI 0.88, 1.11; P = 0.806). Concordant non-significant trends were observed in primary prevention populations (n = 751): LAA (OR 0.81, 95% CI 0.57, 1.15; P = 0.240), CE (OR 1.29, 95% CI 0.89, 1.87; P = 0.179) and SVO (OR 0.99, 95% CI 0.73, 1.36; P = 0.970). Subgroup analysis of aspirin monotherapy (n = 3786) demonstrated a significant reduction in LAA (OR 0.87, 95% CI 0.76, 1.00; P = 0.046), but non-significant effects on the incidence of CE (OR 1.17, 95% CI 0.99, 1.39; P = 0.068) and SVO (OR 1.04, 95% CI 0.91, 1.20; P = 0.570). Probability of publication bias was low (P > 0.05).
  
  
  CONCLUSIONS
  Antiplatelet therapy preferentially reduces the incidence of LAA stroke compared with CE and SVO subtypes.
authors.affiliation: Department of Clinical Pharmacology, Cardiovascular Division, British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Rajkumar
authors.affiliation: Department of Clinical Pharmacology, Cardiovascular Division, British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom.
authors.forename: Christopher N
authors.initials: CN
authors.lastname: Floyd
authors.affiliation: Department of Clinical Pharmacology, Cardiovascular Division, British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom.
authors.forename: Albert
authors.initials: A
authors.lastname: Ferro
mesh_terms: D050197:Atherosclerosis / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology; D016208:Databases, Factual; D057286:Electronic Health Records; D006801:Humans; D015994:Incidence; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D011322:Primary Prevention; D055502:Secondary Prevention; D020521:Stroke / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control*; D013923:Thromboembolism / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology; D020246:Venous Thrombosis / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology
chemical_list: D010975:Platelet Aggregation Inhibitors
keywords: antiplatelet; cerebral infarction; stroke classification