title: Clinical Implications of Changes in Individual Platelet Reactivity to Aspirin Over Time in Acute Ischemic Stroke.
abstract: OBJECTIVE
  Time-dependent changes in individual platelet reactivity have been detected in patients with coronary artery disease. Therefore, we sought to evaluate the time-dependent changes in platelet reactivity to aspirin during the acute stage after ischemic stroke and the clinical implications of variable patient responses to aspirin in acute ischemic stroke.
  
  
  METHODS
  We conducted a single-center, prospective, observational study. The acute aspirin reaction unit (ARU) was measured after 3 hours of aspirin loading, with higher values indicating increased platelet reactivity despite aspirin therapy. The follow-up ARU was measured on the fifth day of consecutive aspirin intake. The numeric difference between the follow-up ARU and the acute ARU was defined as ΔARU and was stratified into quartiles. Early neurological deterioration was regarded as an early clinical outcome.
  
  
  RESULTS
  Both the acute ARU (476±69 IU) and the follow-up ARU (451±68 IU) were measured in 349 patients in this study. Early neurological deterioration was observed in 72 patients (20.6%). Changes in aspirin platelet reactivity over time showed an approximately Gaussian distribution. The highest ΔARU quartile was independently associated with early neurological deterioration (odds ratio, 3.19; 95% confidence interval, 1.43-7.10; P=0.005) by multivariate logistic regression analysis.
  
  
  CONCLUSIONS
  The results of our study showed that the increase in platelet reactivity to aspirin over time is independently associated with early neurological deterioration in patients with acute ischemic stroke. In addition, during the acute stage of ischemic stroke, serial platelet reactivity assays may be more useful than a single assay for identifying the clinical implications of aspirin platelet reactivity after ischemic stroke.
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.). alldelight2@jnu.ac.kr.
authors.forename: Joon-Tae
authors.initials: JT
authors.lastname: Kim
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Suk-Hee
authors.initials: SH
authors.lastname: Heo
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Kang-Ho
authors.initials: KH
authors.lastname: Choi
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Tai-Seung
authors.initials: TS
authors.lastname: Nam
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Seong-Min
authors.initials: SM
authors.lastname: Choi
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Seung-Han
authors.initials: SH
authors.lastname: Lee
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Man-Seok
authors.initials: MS
authors.lastname: Park
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Byeong C
authors.initials: BC
authors.lastname: Kim
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Myeong-Kyu
authors.initials: MK
authors.lastname: Kim
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Saver
authors.affiliation: From the Department of Neurology, Chonnam National University Hospital, Gwangju, Korea (J.-T.K., K.-H.C., T.-S.N., S.-M.C., S.-H.L., M.-S.P., B.C.K., M.-K.K., K.-H.C.); Department of Radiology, Chonnam National University Hwasun Hospital, Hwasun, Korea (S.-H.H.); and Stroke Center and Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles (J.L.S.).
authors.forename: Ki-Hyun
authors.initials: KH
authors.lastname: Cho
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001241:Aspirin / Q000008:administration & dosage / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects*; D002545:Brain Ischemia / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007206:Individuality; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D010979:Platelet Function Tests; D020521:Stroke / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin
keywords: aspirin; platelet function tests; stroke