Contrast medium induced nephropathy in patients undergoing percutaneous coronary intervention for acute coronary syndrome: differences in STEMI and NSTEMI

The aim of this study was to assess the incidence, clinical predictors, and outcome of patients developing contrast medium induced nephropathy (CIN) after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). CIN is associated with significant higher morbidity and mortality after coronary intervention. Recently it was shown, that patients undergoing percutaneous coronary intervention for acute myocardial infarction have a significant higher risk of developing CIN. Non-ST-elevating myocardial infarction (NSTEMI) patients (pts) might be at an even higher risk developing CIN than patients with ST-elevating myocardial infarction (STEMI), because of presenting older and more often with diabetes. In 392 consecutive ACS patients developing myocardial infarction and therefore undergoing emergent coronary angiography between October 2004 and March 2007, we measured serum creatinine concentration (Cr) at baseline and each day of the following 3 days. Contrast medium induced nephropathy was defined as an increase in Cr > 0.5 mg/dl. ACS was defined according to the guidelines of the German Society of Cardiology. Overall, 392 pts were included: 203 (51.8%) with STEMI and 189 (48.2%) with NSTEMI. Patients with STEMI developed more often a cardiogenic shock (18 vs. 6%; P < 0.001) whereas patients with NSTEMI were older (67 vs. 61 years; P < 0.001) and presenting with a higher co-morbidity. Forty-five (11.5%) pts developed CIN; 22 (10.8%) in the STEMI group and 23(12.2%) in the NSTEMI group (P = 0.75). Patients developing CIN presented a more complicated clinical course and a significantly longer hospital stay (14 vs. 10 days; P < 0.001). The mortality rate was also significantly higher (16 vs. 6%; P < 0.05). This prospective study showed no differences in the incidence of developing CIN in patients undergoing PCI for STEMI or NSTEMI, but the predisposing factors, however, differed significantly. Although STEMI patients needed significantly more contrast medium for revascularisation, they did not develop CIN more often. CIN was associated with higher in-hospital complication rate and mortality. Thus, better preventive strategies according to the different predisposing factors leading to CIN are needed to reduce morbidity and mortality, especially in high risk patients.