Point-of-care platelet reactivity determination with VerifyNow-P2Y12 following administration of Clopidogrel or Prasugrel

Abstract

Objectives: To describe VerifyNow-P2Y12 (VN-P2Y12, Accumetrics, San Diego, CA) results from patients treated with either clopidogrel or prasugrel who were seeking care in a hospital setting. Background: VN-P2Y12 is a point-of-care device that measures platelet reactivity to adenosine diphosphate. Past assessments of thienopyridine therapy utilizing VN-P2Y12 have largely come from clinical trial settings. There are limited data from real-world settings. Methods: Electronic medical record data from Huntsville Hospital (Huntsville, AL) for those who underwent VN-P2Y12 testing for clopidogrel or prasugrel between January 1, 2009 and October 31, 2010 were analyzed. The VN-P2Y12 data included P2Y12 reaction units (PRUs) and device-reported percentage of inhibition. Descriptive analyses were conducted with t tests, and a logistic regression model was estimated to assess the association between patient characteristics and the likelihood of platelet nonresponse. Results: In total, 2882 tests (2476 with clopidogrel and 406 with prasugrel) were analyzed. For clopidogrel and prasugrel, respectively, mean PRU standard deviation (SD) was 206 (90) and 107 (93; P < 0.0001) and mean % inhibition (SD) was 31% (26%) and 63% (31%; P < 0.0001). Treatment with clopidogrel alone (odds ratio [OR] = 5.25; P < 0.0001), being non-Caucasian (OR = 1.48; P = 0.0440), obese (OR = 1.49; P = 0.0010), anemic (OR = 3.29; P < 0.0001), diabetic (OR = 1.75; P < 0.0001), and having a history of myocardial infarction (OR = 1.57; P < 0.0001) were significant predictors of having PRU ? 235. Conclusion: This real-world data analysis shows results that are consistent with clinical trial results, namely that compared with clopidogrel, prasugrel is associated with significantly lower PRU and greater percentage of inhibition, regardless of age, race, gender, diabetes, obesity, or proton pump inhibitor use.