Contrast Volume During Primary Percutaneous Coronary Intervention and Subsequent Contrast-Induced Nephropathy and Mortality

Background: Contrast-induced nephropathy (CIN) frequently occurs in patients with acute ST-segment elevation myocardial infarction (STEMI) who are undergoing primary percutaneous coronary intervention, and CIN is associated with a more complicated clinical course and increased mortality. Objective: To investigate the association between absolute and weight- and creatinine-adjusted contrast volume, CIN incidence, and clinical outcome in the era of mechanical reperfusion of STEMI. Design: Prospective, observational study. Setting: A university cardiology center in Milan, Italy. Patients: 561 consecutive patients with STEMI who were undergoing primary percutaneous coronary intervention. Measurements: For each patient, the maximum contrast dose was calculated, according to the formula (5 X body weight [kg])/serum creatinine, and the contrast ratio, defined as the ratio between the contrast volume administered and the maximum dose calculated, was assessed. An increase in serum creatinine of more than 25% from baseline was defined as CIN. Results: 115 (20.5%) patients developed CIN. In-hospital mortality was higher among patients with CIN than those without CIN (21.4% vs. 0.9%; P < 0.001). The maximum contrast dose was exceeded in 130 (23%) patients. Patients who received more than the maximum contrast dose (contrast ratio >1) had a more complicated in-hospital clinical course and higher mortality rate (13% vs. 2.8%; P < 0.001) than did patients with a contrast ratio less than 1. Development of CIN was associated with both contrast volume and contrast ratio. Limitation: The association between contrast volume and outcomes was observed in a single center and could be due to comorbid conditions, disease severity, or an unknown factor. Conclusion: During primary percutaneous coronary intervention for STEMI, higher contrast volume is associated with higher rates of CIN and mortality; however, further study is needed to determine whether limiting contrast volume would improve patient outcome.