Randomized Comparison of Different Thienopyridine Loading Strategies in Patients Undergoing Elective Coronary...

This randomized trial investigated to what extent loading with prasugrel can provide a more rapid peri-interventional antiplatelet effect than clopidogrel 600 mg.

Effective platelet inhibition at the start of a percutaneous coronary intervention (PCI) reduces the risk of ischemic complications. With clopidogrel administered immediately before a PCI, effective platelet inhibition is delayed by 2 h. Prasugrel has the potential of shortening this period.

We randomly assigned 300 P2Y12 receptor blocker-naive patients undergoing an elective PCI to loading with clopidogrel 600 mg, prasugrel 30 mg, or prasugrel 60 mg immediately before the PCI. Platelet function was assessed serially by impedance aggregometry. The primary endpoint was the proportion of patients with high on-treatment platelet reactivity at 60 min after loading defined as ≥468 aggregation units × minute (Multiplate Analyzer, Roche Diagnostics, Mannheim, Germany).

The 3 groups were well balanced with respect to clinical and angiographic characteristics. At 60 min, 33% of the patients assigned to prasugrel 60 mg, 37% of patients assigned to prasugrel 30 mg, but 55% of those assigned to clopidogrel had high on-treatment platelet reactivity (p < 0.001). At any time point starting from 30 min, prasugrel 60 mg achieved significantly lower platelet reactivity than clopidogrel. Platelet reactivity at 60 min after prasugrel was not significantly different from that at 120 min after clopidogrel (p = 0.18). Prasugrel 30 mg had an intermediate effect. The 30-day incidence of bleeding events was not different among the 3 groups.

From 30 min onward, prasugrel 60 mg achieved a stronger platelet inhibition than clopidogrel loading in stable patients undergoing a PCI. Compared with clopidogrel, prasugrel 60 mg was associated with a twice as fast onset of platelet inhibition. (Impact of Extent of Clopidogrel-Induced Platelet Inhibition during Elective Stent Implantation on Clinical Event Rate-Advanced Loading Strategies [ExcelsiorLOAD]; DRKS00006102).