Clopidogrel-naive patients subjected to coronary angiography may be candidates for percutaneous coronary intervention (PCI). Clopidogrel loading with 600 mg at least 2 hours before the procedure is advised for such patients. However, there is no direct evidence that delaying PCI for 2 hours after clopidogrel loading is superior to ad hoc PCI.

After coronary angiography, clopidogrel-naive patients (N = 199) with stable or unstable angina, candidates for PCI, were loaded with 900 mg of clopidogrel and then randomized to ad hoc PCI (ad hoc group, n = 103) or delayed PCI 2 hours after loading (delayed group, n = 96). Combined primary end point was death/periprocedural myocardial infarction (MI)/stroke/reintervention within 30 days post-PCI. Secondary end points were periprocedural MI; periprocedural creatine kinase-MB elevation >3 × upper limit of normal; any periprocedural increase of creatine kinase-MB, troponin-I, or myoglobin above upper limit of normal; Thrombolysis in Myocardial Infarction flow <3 after PCI; thrombocytopenia with platelet count of <70,000/mL; major bleeding defined according to the Thrombolysis in Myocardial Infarction criteria; and elevation of high-sensitivity C-reactive protein and soluble P selectin.

Primary end point occurred in 12.6% ad hoc group versus 15.6% delayed group patients (P = .34). High-sensitivity C-reactive protein increased in both groups post-PCI (analysis of variance P < .0001) without difference between groups (P = .5). Major bleeding occurred in 2.9% ad hoc group versus 3.1% delayed group patients (P = .9). No significant difference was observed in any other secondary end point.

In clopidogrel-naive patients, a strategy of delaying PCI for 2 hours after high-dose clopidogrel loading does not seem to confer any benefit compared to ad hoc PCI.