Abstract 2828: Impact Of Higher Clopidogrel Loading And Maintenance Dose On Platelet Function And Outcome After PCI Using Drug-Eluting Stents
Background: Adequate anitplatelet therapy is paramount for good clinical outcomes in patients undergoing PCI. The purpose of this study is to determine whether a high dose regimen of clopidogrel in patients undergoing PCI is superior to standard dosing.
Methods: A total of 123 patients ( 70% ACS) undergoing PCI were randomized in 2:1 fashion to receive 600 mg clopidogrel loading on the table immediately before PCI and 75 mg twice daily maintenance for 1 month (group A) vs. standard dosing (group B). PIatelet aggregation (PA) was measured using Light Transmission Aggrgometry (LTA, 20 uM ADP) at baseline, 4 hours, and 30 days. Percent inhibition of platelet activity (%IPA) was also determined. The composite of death, myocardial infarction and revascularisation was studied at 30 days, along with major and minor bleeding.
Results: Baseline characteristics were similar in both groups. Baseline platelet aggregation was 52% in both groups. Percent IPA 41% in group A c/t 18% in Group B at 4 hours (p=0.038), and 27% vs. 0% at 1 month respectively (p=0.047). Half of the patients in each group were clopidogrel naive. Clopidogrel naive patients randomized to Group A had more reduction in PA at 4 hours and 30 days compared to those randomized to Group B. Patients on chronic clopidogrel therapy had similar reduction in PA at 4 hours (15%) in both groups. The composite incidence of Death, myocardial infarction, and target vessel revascularization was 11% in Group A vs. 23% in Group B (P=0.038). No difference was noted in major or minor bleeding in hospital or at follow up between the 2 groups.
Conclusions: A higher loading and maintenance dose of clopidogrel in patients undergoing PCI results in more effective platelet inhibition, reduced cardiovascular events without increasing bleeding complications.