Table of Contents
Thrombosis
Volume 2010 (2010), Article ID 908272, 6 pages
http://dx.doi.org/10.1155/2010/908272
Research Article

The Potential Value of Near Patient Platelet Function Testing in PCI: Randomised Comparison of 600 mg versus 900 mg Clopidogrel Loading Doses

1Cardiac Intervention Unit, Royal Bournemouth Hospital, Castle Lane East, Bournemouth, BH7 7DW, UK
2Wessex Cardiothoracic Unit, Southampton University Hospital, Tremona Road, SO16 6YD, UK
3Southampton University Medical School, Southampton University Hospital, Tremona Road, Southampton, SO16 6YD, UK

Received 4 July 2009; Accepted 14 August 2009

Academic Editor: Karin Przyklenk

Copyright © 2010 Alex R. Hobson 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

Whilst poor response to clopidogrel is associated with adverse outcomes uncertainty exists as to how (a) response should be assessed and (b) poor responders managed. We utilised VerifyNow P2Y12 and short Thrombelastography (TEG) to assess 900 mg doses in (i) initial poor responders to 600 mg and (ii) in a randomised comparison with 600 mg. Blood was taken before and six hours post clopidogrel in (i) 30 volunteers receiving 600 mg (poor responders received 900 mg > two weeks later) and (ii) 60 patients randomized 1 : 1 to 600 mg or 900 mg doses. Poor response was defined as TEG %Clotting Inhibition (%CIn) or VerifyNow Platelet Response Unit (PRU) reduction < 30%. (i) Poor responders to 600 mg had greater PRU reduction (45.0 versus 20.1%, P = 0.03) and greater %CIn (22.9 versus 1 5 . 1 %, P = 0.01) after 900 mg but (ii) there were no significant differences between the patient groups. Near-patient assessment of response to clopidogrel is feasible and clinically useful. Whilst ineffective on a population basis 900 mg doses increase the effect of clopidogrel in initial poor responders.