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Stroke Research and Treatment
Volume 2017, Article ID 7365684, 13 pages
https://doi.org/10.1155/2017/7365684
Clinical Study

Remote Assessment of Platelet Function in Patients with Acute Stroke or Transient Ischaemic Attack

1Stroke Trials Unit, Division of Clinical Neuroscience, University of Nottingham, City Hospital Campus, Nottingham NG5 1PB, UK
2Stroke, Nottingham University Hospitals NHS Trust, City Hospital Campus, Nottingham NG5 1PB, UK
3Platelet Solutions Ltd., Division of Clinical Neuroscience, University of Nottingham, Queen’s Medical Centre Campus, Nottingham NG7 2UH, UK
4Platelet Research Group/Stroke, Division of Clinical Neuroscience, University of Nottingham, Queen’s Medical Centre Campus, Nottingham NG7 2UH, UK
5Vascular Medicine, Division of Medical Sciences and GEM, School of Medicine, University of Nottingham, Nottingham, UK
6Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Leicester LE3 9QP, UK
7University of Nottingham, Nottingham, UK

Correspondence should be addressed to Philip M. Bath; ku.ca.mahgnitton@htab.pilihp

Received 8 December 2016; Revised 3 March 2017; Accepted 30 March 2017; Published 24 May 2017

Academic Editor: Chelsea Kidwell

Copyright © 2017 Philip M. Bath et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background. The TARDIS trial assessed the safety and efficacy of intensive versus guideline antiplatelet agents given for one month in patients with acute stroke or TIA. The aim of this substudy was to assess the effect of antiplatelet agents taken at baseline on platelet function reactivity and activation. Methods. Platelet function, assessed by remotely measured surface expression of P-selectin, was assessed in patients at their time of randomisation. Data are median fluorescence values. Results. The aspirin P-selectin test demonstrated that platelet expression was lower in 494 patients taking aspirin than in 162 patients not: mean 210 (SD 188) versus 570 (435), difference 360.3 (95% CI 312.2–408.4) (). Aspirin did not suppress P-selectin levels below 500 units in 23 (4.7%) patients. The clopidogrel test showed that platelet reactivity was lower in 97 patients taking clopidogrel than in 585 patients not: 655 (296) versus 969 (315), difference 314.5 (95% CI 247.3–381.7) (). Clopidogrel did not suppress P-selectin level below 860 units in 24 (24.7%) patients. Conclusions. Aspirin and clopidogrel suppress stimulated platelet P-selectin, although one-quarter of patients on clopidogrel have high on-treatment platelet reactivity. Platelet function testing may be performed remotely in the context of a large multicentre trial. Trial registration ISRCTN47823388.