Comparison of adverse cardiovascular events and bleeding complications of loading dose of clopidogrel 300 mg versus 600 mg in stable patients undergoing elective percutaneous intervention (from the CADICE Study)

In large clinical trials enrolling patients with acute coronary syndromes, a high loading dose of clopidogrel (600 mg) has been found to be more effective compared to a low loading dose (300 mg). However, the applicability of these data to stable patients who undergo elective percutaneous coronary intervention is still unclear. A total of 400 patients who underwent elective PCI were prospectively randomized to receive either 600 mg (n = 200) or 300 mg (n = 200) of clopidogrel, followed by a daily maintenance dose of 75 mg. The primary end point was the presence of major adverse cardiovascular events (combined death, myocardial infarction, acute neurologic event, stent thrombosis, and need for percutaneous or surgical revascularization of the target vessel) during hospitalization and at 30 days. The secondary end point was periprocedural vascular complications, major bleeding, and cardiac enzyme elevation. There were no differences in the primary end point among the groups immediately after the procedure (3.5% of patients in the 300-mg group vs 4.5% of those in the 600-mg group, p = 0.799) or at 30 days (6% vs 5%, respectively, p = 0.826). The rates of periprocedural vascular complications (2.5% vs 3%, respectively, p = 1.00), bleeding complications (9% vs 8.5%, respectively, p = 1.00), and cardiac enzyme elevation (11% vs 15.5%, respectively, p = 0.317) were similar between the 2 groups. In conclusion, adverse cardiovascular events and bleeding complications during the initial hospitalization and at 30-day follow-up were similar when a 600-mg loading dose of clopidogrel was used compared to the conventional dose of 300 mg.