Correlation of the Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) with Contrast-Induced Nephropathy in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Interventions.

Introduction Contrast-induced acute nephropathy (CIN) in patients undergoing percutaneous coronary intervention (PCI) in the setting of acute coronary syndromes (ACS) is associated with adverse outcomes, including longer hospitalization and short and long-term mortality. Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) are inflammatory markers that have been validated separately in prior studies as a predictor of CIN in patients with ACS who undergo a left heart catheterization. Our study aims to further investigate the role of NLR and PLR together as markers for predicting CIN in patients with ACS.  Methods A retrospective chart review was performed on a total of 1,577 patients aged 18 - 90 who presented with ACS and underwent PCI between January 2011 to December 2015 at the Florida Hospital Orlando. Cut-off values used for a high PLR and NLR were PLR > 128 and NLR > 2.6. CIN was defined as an increased serum creatinine level by ≥ 0.5 mg/dL, or ≥ 25%, over the baseline value within 72 hours after contrast agent administration. Patients with end-stage renal disease (ESRD) were excluded.  Results Of the 1,577 patients included in the study, 213 (13.51%) patients had CIN. On multivariate logistic regression analysis, high NLR showed an independent association with an elevated risk of CIN (OR 2.03, 95% CI: 1.403 - 3.176, P < 0.001). High PLR did not correlate with CIN (OR 0.831, 95% CI: 0.569 - 1.214, P = 0.339).  Conclusion Elevated NLR is an independent predictor of CIN in patients with acute myocardial infarction (AMI) and may be used to improve on current risk prediction models.