Comparing prasugrel to twice daily clopidogrel post percutaneous coronary intervention in a Veterans Affairs population (Reprinted from Journal of Health-System Pharmacy Residents JHPR, vol 1, issue 4, 2013)

Objective. The purpose of this study was to compare various antiplatelet regimens in patients who experienced increased platelet reactivity on clopidogrel therapy with regards to cardiovascular outcomes, including need for revascularization, myocardial infarction (MI), stroke, and cardiovascular (CV) death. Methods. A retrospective chart review was conducted on patients who received percutaneous coronary intervention (PCI) at the Richard L. Roudebush Veterans Affairs Medical Center and were subsequently prescribed either clopidogrel 75 mg twice daily, prasugrel 10 mg daily, or clopidogrel 75 mg daily with high platelet reactivity between October 1, 2009 and November 30, 2010. Correlations between antiplatelet regimens and prevention of cardiovascular outcomes and bleeding events were evaluated. Groups were evaluated statistically as two separate comparisons; the first comparison being clopidogrel twice daily versus prasugrel and the second comparison being clopidogrel twice daily versus clopidogrel daily in those patients with a P2Y(12) test result of less than 50%. Results. A total of 108 patients were included in the study. Eight events occurred in the clopidogrel twice daily group (n = 26), including five revascularizations and three MIs. Seven events occurred in the prasugrel group (n = 64), including two revascularizations, two MIs, two strokes, and one CV death. The difference between these groups was statistically significant (p = 0.031), with patients in the prasugrel group experiencing fewer events. Five events occurred in the clopidogrel daily group (n = 18), including one need for revascularization, two MIs, and two instances of CV death. There were no statistically significant differences in CV events between the clopidogrel twice daily group and clopidogrel daily group (p > 0.999). There were also no statistically significant differences in bleeding incidents for either of the comparisons; p > 0.999 and p = 0.676 respectively for the first and second comparisons. Conclusion. Patients on prasugrel had fewer cardiovascular events as compared to patients on clopidogrel twice daily with no difference in bleeding events. No difference was seen with regards to cardiovascular or bleeding events when comparing clopidogrel twice daily to clopidogrel daily in patients with increased platelet reactivity. Study results suggest that there is no benefit to dosing clopidogrel twice daily when compared to either prasugrel or once daily clopidogrel dosing.