title: Platelet aggregates detected by a conventional hematology analyzer method is a risk factor for stroke or a predictive factor in patients with chronic-stage cerebral infarction.
abstract: Assessment of platelet activation and/or function is important for primary and secondary prevention of vascular events. To test the hypothesis that determination of platelet aggregation in patients with chronic-stage cerebral infarction (CI) provides a simple measure of risk for ischemic stroke, we used a conventional hematology analyzer to detect aggregates and to assess the efficacy of antiplatelet agents in preventing spontaneous aggregate formation. Platelet aggregates were measured in citrated blood from 142 magnetic resonance imaging confirmed CI patients and 97 controls without CI (nonstroke). Aggregates were detected in 1 of 36 (2.8%) nonstroke subjects without risk factors, but in 24 of 52 (46.2%) nonstroke subjects with risk factors (odds ratio [OR], 3.32; 95% confidence interval [CI], 1.10-10.00), in 21 of 35 (60.0%) nonstroke subjects with a predictive factor (carotid artery intima-media thickness [IMT] >1.1 mm) (OR, 9.13; 95% CI, 2.70-30.48), and in 31 of 63 (49.2%) CI patients who had not received antiplatelet therapy (OR, 2.16; 95% CI, 1.12-4.17). After adjusting for other risk factors, the appearance of platelet aggregates was correlated only with IMT ≥1.1 mm. The rate of appearance of platelet aggregates was 0.33-fold lower in patients on antiplatelet therapy compared with those not on antiplatelet therapy (24.1%; 19 of 79 CI patients). Patients with platelet aggregates in the blood are considered at high risk for ischemic stroke, because the appearance of aggregates is associated with increased IMT. Our method is suitable for screening platelet function in high-risk patients and for examining the efficacy of antiplatelet agents.
authors.affiliation: Department of Neurology, Tokai University School of Medicine, Isehara, Kanagawa, Japan. mie@is.icc.u-tokai.ac.jp
authors.forename: Mie
authors.initials: M
authors.lastname: Shimizu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Shunya
authors.initials: S
authors.lastname: Takizawa
authors.forename: Saori
authors.initials: S
authors.lastname: Kohara
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Takagi
authors.forename: Yukito
authors.initials: Y
authors.lastname: Shinohara
mesh_terms: D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D002340:Carotid Artery Diseases / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D016022:Case-Control Studies; D002544:Cerebral Infarction / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D002908:Chronic Disease; D016903:Drug Monitoring / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007564:Japan; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D010979:Platelet Function Tests / Q000295:instrumentation*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000209:etiology* / Q000517:prevention & control; D016896:Treatment Outcome; D017539:Tunica Intima / Q000000981:diagnostic imaging; D017540:Tunica Media / Q000000981:diagnostic imaging; D014463:Ultrasonography
chemical_list: D010975:Platelet Aggregation Inhibitors