Neutrophil-to-lymphocyte ratio predicts contrast-induced nephropathy in patients undergoing primary percutaneous coronary intervention.

We investigated the relationship between baseline neutrophil-to-lymphocyte ratio (NLR) and contrast-induced nephropathy (CIN) in patients with ST-segment elevation myocardial infarction (STEMI). Consecutive patients diagnosed with STEMI (n = 691) who underwent primary percutaneous coronary intervention (p-PCI) were included in the study. The CIN was defined as an increase in serum creatinine concentration ≥25% over baseline at 48 hours. Both NLR and C-reactive protein levels were significantly higher in the CIN group. There was a stronger correlation in patients with a known history of chronic kidney disease and in patients with a history of diabetes mellitus (DM). Advanced age, DM, low baseline glomerular filtration rate, reduced postprocedural ST resolution, high amount of contrast media, high NLR, and low left ventricular ejection fraction were independent predictors of CIN. The NLR may be used as a simple and reliable indicator of CIN in patients with STEMI who underwent p-PCI.