Impact of clopidogrel loading dose in patients with chronic kidney disease undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction

The optimal loading dose of clopidogrel in patients with chronic kidney disease who undergo primary percutaneous coronary intervention for ST-segment elevation myocardial infarction has not been investigated. The aim of this study was to assess the impact of clopidogrel loading dose on clinical outcomes in this setting. A total of 1,457 patients with CKD (estimated glomerular filtration rate <60 ml/min/1.73 m²) were evaluated according to clopidogrel loading dose: 600 mg (n = 861) versus 300 mg (n = 596). In-hospital complications, including major bleeding and clinical outcomes at 1 and 12 months, were compared between the 2 groups. The in-hospital major bleeding rate was similar (0.8% vs 0.2%, p = 0.09). Also, there were no differences in major adverse cardiac event rates, including death, recurrent myocardial infarction, target lesion revascularization, and stent thrombosis, at 1 month (15.6% vs 16.4%, p = 0.70) and 12 months (19.0% vs 21.3%, p = 0.32). On multivariate analysis, a 600-mg loading dose of clopidogrel was not an independent predictor of 1-month (odds ratio 1.13, 95% confidence interval 0.49 to 2.57, p = 0.78) and 12-month (odds ratio 0.89, 95% confidence interval 0.52 to 1.51, p = 0.66) major adverse cardiac events. After propensity score-matched analysis, these results were unchanged. In conclusion, a 600-mg loading dose of clopidogrel was not effective in reducing 1- and 12-month major adverse cardiac events in patients with chronic kidney disease who underwent primary percutaneous coronary intervention for ST-segment elevation myocardial infarction, but this dose did not increase the in-hospital major bleeding rate.