Risk factors of contrast-induced nephropathy in patients with acute coronary syndrome.

Background: Patients with acute coronary syndrome (ACS) are at high risk of contrast-induced nephropathy (CIN), which is associated with prolonged hospitalization, higher morbidity and mortality after angiographic procedures. The occurrence of CIN is regarded as a transient and reversible condition. However, the persistence of CIN until hospital discharge in patients with ACS has not been thoroughly analyzed.

Aims: We aimed to analyze CIN persistent until hospital discharge in contemporary ACS population referred to invasive diagnostics and treatment.

Methods: A total of 2638 consecutive patients with ACS were included in a prospective registry. The occurrence of CIN was defined as a 25% increase in serum creatinine from baseline or a 0.5 mg/dl (44 μmol/l) increase in the absolute value.

Results: Criteria of CIN at hospital discharge were met in 10.7% of patients. Immediate percutaneous coronary intervention (PCI) after angiography (67% of patients) was associated with higher rates of CIN compared to patients referred for other treatment strategies (P < 0.001). The logistic regression model showed that anemia at baseline (8.7% of patients) was an independent predictor of CIN, which occurred in 17.9% of anemic patients and 10% of patients without anemia (P < 0.001). Also, ST-segment elevation myocardial infarction (STEMI) presentation and immediate PCI were independent predictors of CIN.

Conclusions: Despite intravenous fluid administration during the hospital stay, CIN persisted until hospital discharge in more than 10% of patients with ACS. Anemia at baseline, STEMI presentation, and immediate PCI strategy were independent predictors of CIN. Thus, preventive actions should be specially aimed at those groups of patients.