Thienopyridine reloading in clopidogrel-loaded patients undergoing percutaneous coronary interventions: The PRAISE study.

OBJECTIVE: The impact of thienopyridine reloading on clinical outcomes, and residual high platelet reactivity (HPR) is unclear. We sought to compare the HRP-related effect of prasugrel and clopidogrel reloading in the already clopidogrel-loaded patients undergoing percutaneous coronary intervention (PCI).

MATERIALS AND METHODS: In this prospective, two-center, randomized, open-label study, patients with HPR who had undergone PCI after a clopidogrel (300-600mg) loading dose (LD) were enrolled. Among screened (n=153), HPR was determined in seventy-six patients, who were randomized to either repeated clopidogrel (300mg LD, followed by 75mg MD daily) or prasugrel (20mg LD, followed by 5mg MD daily). The primary endpoint was HPR at 24h after PCI, as determined by the VerifyNow assay. The rates of sustained high and low platelet reactivity, periprocedural myocardial injury (PMI) and 30-day clinical outcomes were also assessed.

RESULTS: Higher inhibition of platelet reactive units (PRU) was observed in the prasugrel group than after clopidogrel reloading (Pre-PCI: 284.4±32.0 vs 279.5±32.5, p=0.504; Post-PCI: 100.0±67.0 vs 202.9±65.8, p<0.001; 30days: 170.8±69.8 vs 215.1±62.4, p=0.007). There were less HRP post-PCI after prasugrel compared with the clopidogrel group (2.7 vs 36.1%, p<0.001). However, reloading with prasugrel did not reduce PMI compared to clopidogrel (36.8% vs 39.5%, p=0.813).

CONCLUSION: Prasugrel reloading led to a greater reduction in HPR, but similar with clopidogrel PMI in post-PCI patients. Larger randomized evidence is needed for optimization of loading strategies with thienopyridines.

CLINICAL TRIAL REGISTRATION INFORMATION: NCT01609647.