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The Scientific World Journal
Volume 2013, Article ID 313492, 8 pages
Research Article

Von Willebrand Factor Antigen Predicts Response to Double Dose of Aspirin and Clopidogrel by PFA-100 in Patients Undergoing Primary Angioplasty for St Elevation Myocardial Infarction

Operative Unit of Cardiology, Fondazione Gabriele Monasterio, Ospedale del Cuore “G. Pasquinucci”, Via Aurelia Sud, 54100 Massa, Italy

Received 7 August 2013; Accepted 8 October 2013

Academic Editors: H. Kitabata and E. Skalidis

Copyright © 2013 Jacopo Gianetti 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.


Von Willebrand factor (VWF) is an emerging risk factor in acute coronary syndromes. Platelet Function Analyzer (PFA-100) with Collagen/Epinephrine (CEPI) is sensitive to functional alterations of VWF and also identifies patients with high on-treatment platelet reactivity (HPR). The objective of this study was to verify the effect of double dose (DD) of aspirin and clopidogrel on HPR detected by PFA-100 and its relation to VWF and to its regulatory metalloprotease ADAMTS-13. Between 2009 and 2011 we enrolled 116 consecutive patients with ST elevation myocardial infarction undergoing primary PCI with HPR at day 5 after PCI. Patients recruited were then randomized between a standard dose (SD, ) or DD of aspirin and clopidogrel (DD, ), maintained for 6 months follow-up. Blood samples for PFA-100, light transmittance aggregometry, and VWF/ADAMTS-13 analysis were collected after 5, 30, and 180 days (Times 0, 1, and 2). At Times 1 and 2 we observed a significantly higher CEPI closure times (CT) in DD as compared to SD ( ). Delta of CEPI-CT was significantly related to VWF ( ) and inversely related to ADAMTS-13 (0.01). Responders had a significantly higher level of VWF at . Finally, in a multivariate model analysis, VWF and ADAMTS-13 in resulted significant predictors of CEPI-CT response ( ). HRP detected by PFA-100 in acute myocardial infarction is reversible by DD of aspirin and clopidogrel; the response is predicted by basal levels of VWF and ADAMTS-13. PFA-100 may be a useful tool to risk stratification in acute coronary syndromes given its sensitivity to VWF.