Comparison of higher clopidogrel loading and maintenance dose to standard dose on platelet function and outcomes after percutaneous coronary intervention using drug-eluting stents

Abstract

Adequate antiplatelet therapy is paramount for good clinical outcomes in patients undergoing percutaneous coronary intervention (PCI). The purpose of this study was to determine whether a high-dose regimen of clopidogrel in patients undergoing PCI is superior to standard dosing. A total of 119 patients undergoing PCI were blindly randomized in 2:1 fashion to receive clopidogrel loading 600 mg on the table immediately before PCI and 75 mg 2 times/day for 1 month (high-dose group) versus standard dosing (300 mg loading and 75 mg/day; low-dose group). Platelet aggregation was measured using light transmission aggregometry at baseline, 4 hours, and 30 days. The composite of cardiovascular death, myocardial infarction, and target vessel revascularization was studied at 30 days in addition to major and minor bleeding. Baseline characteristics and baseline platelet aggregation were similar in the 2 groups. Percent inhibitions of platelet activity were 41% and 27% in the high-dose group versus 19% and 10% in the low-dose group at 4 hours and 30 days (p = 0.046 and 0.047, respectively). Composite clinical end points were 10.3% in the high-dose group and 23.8% in the low-dose group (p = 0.04). No difference was noted in major or minor bleeding. In conclusion, a higher loading and maintenance dose of clopidogrel in patients undergoing PCI results in superior platelet inhibition and decreased cardiovascular events without increasing bleeding complications.