Abstract 4449: Impact of High Loading and Maintenance Dose of Clopidogrel within the First 15 Days after Percutaneous Coronary Intervention on Early Patient Outcome
An increase in clopidogrel dose results in an improved inhibition of platelet aggregation. However, whether an increase in clopidogrel dose may improve patient outcome is still debated. The aim of this study was to analyse the impact on patient outcome of an increase in clopidogrel loading and maintenance doses within the first 15 days after percutaneous coronary intervention (PCI). Between May 2003 and February 2007, we included 2954 consecutive patients who underwent PCI. We compared 2 historical groups. In the “low-dose” group (2003–2005, n=1984), patients were pre-treated with a 300mg clopidogrel loading dose followed by 75mg per day after PCI. In the “high-dose” group (2006 –2007, n=970), patients were pre-treated with a 600mg clopidogrel loading dose followed by 150mg per day within the first 15 days and 75mg per day thereafter. At 2 months, the composite primary endpoint (Death - Myocardial Infarction (MI) - Stent Thrombosis (ST)) and bleedings were systematically indexed. Clinical and angiographic characteristics were similar between the 2 groups. The incidence of the composite primary endpoint Death-MI-ST was 7.6% in the whole population, 8.2% in the “low-dose” group and 6.3% in the “high-dose” group (p=0.04). By multivariate analysis, “high-dose” of clopidogrel was associated with a decrease in the composite primary endpoint (HR=0.69, p =0.046). The other independent predictors are shown in the table⇓ below. Bleedings were similar in the “low-dose” and “high-dose” groups, 2.8% versus 3.4% (p=0.379), respectively. Our results show that a 600mg loading dose followed by a 150mg maintenance dose of clopidogrel within the first 15 days after PCI is independently associated with a decrease in the composite criteria Death-MI-ST at 2 months without increase in hemorrhagic complications.