A recent study in the Journal of the American College of Cardiology (JACC) investigated the efficacy, safety and antiplatelet effect of prasugrel as compared with clopidogrel in patients with high on-treatment platelet reactivity (HTPR) after elective percutaneous coronary intervention (PCI).

The “Percutaneous Coronary Intervention With Implantation of Drug-Eluting Stents: Results of the TRIGGER-PCI (Testing Platelet Reactivity In Patients Undergoing Elective Stent Placement on Clopidogrel to Guide Alternative Therapy With Prasugrel) Study,” randomly assigned coronary artery disease (CAD) patients with HTPR after elective PCI with at least one drug-eluting stent to daily doses of either 10 mg of prasugrel or 75 mg of clopidogrel. Platelet reactivity of the patients on the study drug was reassessed at three and six months. The study was stopped prematurely for ineffectiveness because of a lower than expected incidence of the primary endpoint.

In 212 patients assigned to prasugrel, PRU decreased from 245 at baseline to 80 at three months, whereas in 211 patients assigned to clopidogrel, PRU decreased from 249 to 241, according to the study. The primary efficacy endpoint of cardiac death or myocardial infarction at six months occurred in no patient on prasugrel compared to a patient on clopidogrel. The primary safety endpoint of non–coronary artery bypass graft thrombolysis in myocardial infarction major bleeding at six months occurred in three patients (1.4%) on prasugrel versus one (0.5%) on clopidogrel, according to the study.

Study authors concluded switching from clopidogrel to prasugrel in patients with HTPR afforded effective platelet inhibition, but given the low rate of adverse ischemic events after PCI with contemporary drug-eluding stents in stable coronary artery disease (CAD), the clinical utility of this strategy could not be demonstrated.

They noted how future randomized trials are warranted to examine the risk–benefit ratio of allocating higher-risk patients with stable CAD and high on clopidogrel platelet reactivity to more potent platelet inhibition before and after PCI.

For more information about this and other studies, visit http://content.onlinejacc.org/ . A CardioSource journal scan is also available on the topic, as well as a TRIGGER-PCI clinical trial summary .

Also watch the latest Cardiology Countdown, which includes a segment about TRIGGER-PCI , or a Heart Minute on the trial .

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