title: Neutrophil to lymphocyte ratio might help prediction of acute myocardial infarction in patients with elevated serum creatinine.
abstract: OBJECTIVE
  Diagnostic performance of troponin assays is affected by renal insufficiency. Neutrophil to lymphocyte ratio(NLR) is an independent predictor of acute coronary syndrome. Our objective was to evaluate performance of NLR in diagnosing acute myocardial infarction (AMI) among patients with elevated serum creatinine.
  
  
  METHODS
  Patients with elevated creatinine levels evaluated for coronary artery disease were included (n=284). Patients were divided into two groups according to having AMI or non-specific chest pain. AMI diagnosis was made based on clinical and laboratory data, including serial EKG and cardiac enzymes, ECHO and coronary angiography.
  
  
  RESULTS
  Troponin, neutrophil, and NLR were found to be higher in patients with AMI, compared to patients without AMI (P= 0.001, P= 0.001 and P=0.028, respectively). ROC curve analysis for NLR in diagnosing AMI was significant (AUC: 0.607; P=0.003). Sensitivity, specificity, LR +, LR-, PPV and NPV for NLR>7.4 were found as 42.3%, 74.7%, 1.68%, 0.77%, 77% and 40%, respectively. Logistic regression analysis revealed that patients whose NLR>7.4 were 2.18 times as likely to have AMI.
  
  
  CONCLUSIONS
  NLR can be used as an independent predictor of AMI in patients with renal insufficiency. This seems to get more important in the era of high sensitivity troponin assays. Our results might also help in early diagnosis of AMI in this high risk population while serial cardiac enzyme results are pending.
authors.affiliation: Dr. Ahmet Nalbant, Internal Medicine Consultant, Department of Internal Medicine, Sakarya University School of Medicine, Sakarya, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Nalbant
authors.affiliation: Dr. Hakan Cinemre, Associate Professor, Department of Internal Medicine, Sakarya University School of Medicine, Sakarya, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Cinemre
authors.affiliation: Dr. Tezcan Kaya, Assistant Professor, Department of Internal Medicine, Sakarya University School of Medicine, Sakarya, Turkey.
authors.forename: Tezcan
authors.initials: T
authors.lastname: Kaya
authors.affiliation: Dr. Ceyhun Varim, Assistant Professor, Department of Internal Medicine, Sakarya University School of Medicine, Sakarya, Turkey.
authors.forename: Ceyhun
authors.initials: C
authors.lastname: Varim
authors.affiliation: Dr. Perihan Varim, Cardiology Consultant, Dept. of Cardiology, Sakarya University School of Medicine, Sakarya, Turkey.
authors.forename: Perihan
authors.initials: P
authors.lastname: Varim
authors.affiliation: Prof. Dr. Ali Tamer, Department of Internal Medicine, Sakarya University School of Medicine, Sakarya, Turkey.
authors.forename: Ali
authors.initials: A
authors.lastname: Tamer
keywords: Acute myocardial infarction; Neutrophil to lymphocyte ratio; Renal insufficiency