title: Correlation between frequency of microembolic signals and efficacy of antiplatelet therapy in symptomatic carotid disease.
abstract: OBJECTIVE
  The detection of microembolic signals in transcranial-Doppler monitoring is associated with a higher stroke risk. We investigated the correlation between the frequency of microembolic signals and the efficacy of the antiplatelet therapy in patients with a recent symptomatic carotid-artery stenosis.
  
  
  METHODS
  Thirty-two patients (mean age: 70 years, 22 men) with a recent symptomatic carotid-artery stenosis underwent 30-minute TCD-monitoring. Twenty-three patients received acetylsalicylic-acid and 9 patients clopidogrel as antiplatelet-therapy. At the same day, the antiplatelet effect was measured with multiple-electrode-impedance aggregometry.
  
  
  RESULTS
  In 20 cases, the qualifying event was a stroke and in 12 cases, a TIA. Twenty-six of the patients had a >50% degree of stenosis. More than one microembolic signals were detected in 13 (40.6%) of the subjects, while multiple-electrode-impedance aggregometry revealed eight low responders (6 acetylsalicylic-acid, 2 clopidogrel). More than one microembolic signals were detected in 6 of the 8 (75.0%) patients with low response, but in only 7 of the 24 subjects (29.2%) with an effective antiplatelet treatment (sensitivity 75%, specificity 70.8%; Fisher's exact test: P = .038).
  
  
  CONCLUSIONS
  Our study suggests that in patients with recent symptomatic carotid-artery stenosis the detection of more than one microembolic signals might serve as a useful marker for the effectiveness of the antiplatelet treatment.
authors: Department of Neurology, Ruhr University, St. Josef-Hospital, Bochum, Germany.
authors: Antonios
authors: A
authors: Kerasnoudis
authors: Saskia H
authors: SH
authors: Meves
authors: Ralf
authors: R
authors: Gold
authors: Christos
authors: C
authors: Krogias
mesh_terms: D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*
chemical_list: D010975:Platelet Aggregation Inhibitors
keywords: Ischemic stroke; antiplatelet therapy; carotid artery disease; embolic stroke; stenosis; stroke; ultrasound