Background: Early hemodynamic impairment frequently complicates myocardial injury, however, limited data are present regarding its direct association with acute kidney injury (AKI) after ST segment elevation myocardial infarction (STEMI) in patients who undergo primary percutaneous coronary intervention (PCI). We evaluated the effect of acute hemodynamic derangement on the risk of AKI among STEMI patients who undergo primary PCI., Methods: We performed a retrospective analysis of 1656 consecutive patients admitted with the diagnosis of STEMI between January 2008 and December 2014, and treated with primary PCI. Medical records were reviewed for the presence of various clinical parameters of hemodynamic derangement and for the occurrence of AKI., Results: Mean age was 61 ± 13 and 1329 (80%) were men. AKI occurred in 168 patients (10%). Patients with AKI were older, of female sex, with more comorbidities, had longer time to reperfusion, and were more likely to have hemodynamic impairment including critical state, congestive heart failure, life-threatening arrhythmias, and worse left ventricular function (P < 0.001 for all). In a multivariate logistic regression model critical state (odds ratio [OR], 3.33; 95% confidence interval [CI], 1.39-7.8; P = 0.006), reduced left ventricular ejection fraction (OR, 0.95; 95% CI, 0.92-0.99; P = 0.03), congestive heart failure (OR, 2.34; 95% CI, 1.02-5.39; P = 0.04), and a trend for time to coronary reperfusion (OR, 1.01; 95% CI, 1.00-1.01; P = 0.07) emerged as independent predictors of AKI., Conclusions: Among STEMI patients who underwent primary PCI AKI should not be assumed to be solely contrast-induced nephropathy and acute hemodynamic abnormalities should be considered., (Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)