Contrast-induced nephropathy after primary angioplasty for acute myocardial infarction

Introduction: The prevention of contrast-induced nephropathy (CIN) is difficult in emergency situations, making it essential to study CIN in patients submitted to urgent angioplasty. Objective: To determine the incidence and associated factors to CIN in patients with myocardial infarction (MI) submitted to primary angioplasty in the first 12 hours after onset of symptoms. Methods: We studied 201 consecutive cases of MI with ST-segment elevation with less than 12 hours of evolution. All patients were submitted to the same angioplasty protocol. CIN was defined as an absolute increase of creatinine of at least 0.5 mg/dL and/or a relative increase of creatinine of 25% in relation to baseline in a period between 48 and 72 hours after contrast administration. The variables that differed between patients with and without CIN in univariate analysis were analyzed by logistic regression. Results: The sample was formed by 135 (67.2%) men and 66 (32.8%) women, with mean age of 66.6 ± 11.7 years. The incidence of CIN was 23.8%. In univariate analysis the patients with CIN were older and had higher frequency of left ventricular ejection fraction ≤ 40% and Killip classification ≥ 2. In multivariate analysis, we did not find independent predictors of CIN. Conclusion: CIN occurred in ¼ of the patients with MI submitted to angioplasty without predictor variables. This finding highlights the need for CIN preventive measures after contrast use in emergency angioplasty.