Contrast-induced nephropathy in STEMI patients with and without chronic kidney disease

Introduction: Contrast-induced nephropathy (CIN) following percutaneous coronary intervention (PCI) is associated with adverse outcomes; however, there are scarce data comparing clinical outcomes of post-PCI CIN in ST elevation myocardial infarction (STEMI) patients with and without chronic kidney disease (CKD). We sought to assess the incidence, clinical predictors, and short-term and long-term clinical outcomes of post-PCI CIN in STEMI patients with and without CKD. Methods: We performed a retrospective observational cohort study involving 554 patients who underwent PCI for STEMI from February 2010 to November 2013. CKD was defined as estimated glomerular filtration rate ≤60 mL/min and CIN as creatinine increase by ≥25% or ≥0.5 mg/dL from baseline within 72 hours after catheterization contrast exposure. Results: In the entire population, CIN developed in 89 (16%) patients. The incidence of CIN was 19.7% (27/137) in CKD patients and 11.1% (62/417) in non-CKD patients, P < 0.05. Univariate analysis predictors of CIN were older age (65 vs. 60 years), diabetes (35% vs. 21%), peripheral artery disease (11% vs. 5%), cardiogenic shock (24% vs. 13%), hemodynamic support placement (34% vs. 14%), and Mehran score (9.4 ± 7 vs. 5.4 ± 5.2) with all P < 0.05. The predictors of CIN were the same across the CKD and non-CKD cohort with the exception of diabetes. In multivariate analysis, the strongest predictor of CIN in CKD patients was diabetes (odds ratio, 5.8; CI, 1.8–18.6); however, diabetes was not a predictor in the non-CKD population. In the non-CKD population, each single unit increase in the Mehran score was associated with a 1.1 times greater likelihood of CIN (odds ratio, 1.1; CI, 1.01–1.2). Patients with CIN had higher rates of inpatient mortality (14.6% vs. 2.8%), longer length of hospitalization (8 ± 11 vs. 3.4 ± 4.4 days), need for inpatient dialysis (11.2% vs. 0%), higher 30-day mortality (14.6% vs. 3.0%), and higher incidence of long-term serum creatinine ≫0.5 mg/dL from baseline (16.9% vs. 2.4%) with all P < 0.05. Conclusions: Overall, we found that CKD patients undergoing PCI for STEMI have a higher incidence of CIN than non-CKD patients. CIN confers worse short-term and long-term outcomes irrespective of baseline renal function.