Silvain J, et al. - This inquiry was set up to examine the association of contrast-induced acute kidney injury (CI-AKI), using four definitions, on inhospital mortality, mortality or haemodialysis requirement over 1-year follow-up, in patients with ST elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). Findings demonstrated that STEMI treated by pPCI was frequently complicated with CI-AKI, which represents a serious complication. For the recognition of patients with CI-AKI at high risk of mortality or haemodialysis, the Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) definition was recognized as the most accurate definition.