Effectiveness of in-laboratory high-dose clopidogrel loading versus routine pre-load in patients undergoing percutaneous coronary intervention: results of the ARMYDA-5 PRELOAD (Antiplatelet therapy for Reduction of MYocardial Damage during Angioplasty) randomized trial.

OBJECTIVES: This study sought to evaluate safety and effectiveness of in-laboratory (in-lab) 600-mg clopidogrel loading pre-percutaneous coronary intervention (PCI) versus routine 6-h pre-load.

BACKGROUND: Clopidogrel pre-treatment significantly improves outcome in patients undergoing PCI; however, efficacy of an in-lab loading strategy before PCI after coronary angiography versus routine pre-load has not been fully characterized.

METHODS: A total of 409 patients (39% with acute coronary syndrome) were randomized to receive a 600-mg clopidogrel loading dose 4 to 8 h before PCI (pre-load group, n = 204) or a 600-mg loading dose given in the catheterization lab after coronary angiography, but prior to PCI (in-lab group, n = 205). Primary end point was 30-day incidence of major adverse cardiac events: cardiac death, myocardial infarction (MI), or unplanned target vessel revascularization.

RESULTS: There was no significant difference in primary end point between the 2 randomization arms (8.8% in-lab vs. 10.3% pre-load; p = 0.72); this was mainly driven by periprocedural MI (8.8% vs. 9.3%, p = 0.99). No increased risk of bleeding or vascular complications was observed in the pre-load arm (5.4% vs. 7.8%; p = 0.42). As determined by the VerifyNow assay (Accumetrics, San Diego, California), patients in the in-lab group showed higher platelet reactivity during PCI and 2 h after intervention versus those in the pre-load arm (p < or = 0.043).

CONCLUSIONS: ARMYDA-5 PRELOAD (Antiplatelet therapy for Reduction of MYocardial Damage during Angioplasty) trial indicates that a strategy of 600-mg in-lab clopidogrel load pre-PCI may have similar clinical outcomes as routine 4- to 8-h pre-load. Thus, when indicated, in-lab clopidogrel administration can be a safe alternative to routine pre-treatment given before knowing patients' coronary anatomy.