Benefit of Clopidogrel Therapy in Patients With Myocardial Infarction and Chronic Kidney Disease—A Danish Nation‐Wide Cohort Study

BACKGROUND: The aim of the present study was to evaluate clopidogrel treatment after incident myocardial infarction (MI) in patients with and without chronic kidney disease (CKD). METHODS AND RESULTS: By linking nation‐wide registries, information about patients admitted with incident MI was found. Primary endpoints were all‐cause and cardiovascular (CV) mortality, a composite of all‐cause mortality and recurrent MI, and a composite of fatal and nonfatal bleedings. Effect of clopidogrel use versus clopidogrel nonuse was estimated using an adjusted Cox's regression model stratified according to percutaneous coronary intervention (PCI) treatment. A total of 69 082 incident MI patients in the period 2002–2011 were included. Clopidogrel treatment was associated with hazard ratios (HRs) for the combined endpoint of all‐cause mortality and recurrent MI in PCI‐treated patients of 0.90 (95% confidence interval [CI], 0.47 to 1.72) in renal replacement therapy (RRT) patients, 0.59 (95% CI: 0.40 to 0.88) in non‐end‐stage CKD patients and 0.69 (95% CI, 0.61 to 0.77) in patients without kidney disease (P for interaction=0.60). In patients not treated with PCI, HRs were 0.90 (95% CI, 0.68 to 1.21) in RRT patients, 0.86 (95% CI, 0.75 to 0.99) in non‐end‐stage CKD patients, and 0.91 (95% CI, 0.87 to 0.95) in patients without kidney disease (P for interaction=0.74). An increase in bleeding events (not significant) was noted for clopidogrel‐treated patients not undergoing PCI and for non‐end‐stage CKD patients undergoing PCI, whereas clopidogrel was associated with less bleedings in PCI‐treated RRT patients and patients without kidney disease. CONCLUSIONS: During a 1‐year follow‐up, after MI, clopidogrel was associated with improved outcomes in patients with non‐end‐stage CKD. Even though no effect difference, compared to patients without CKD, was observed, the benefit associated with the use of clopidogrel after MI in patients requiring RRT is less clear.