The diagnostic value for serum-NGAL in discriminating ACS patients, from patients with SA is high (AUC = 0.929) and better than of hs-CRP (AUC = 0.794) and PMN count (AUC = 0.830). If we use as cut-off for serum-NGAL 89.29 ng/mL, we can discriminate an ACS patient from a stable patient with sensitivity and specificity, 89.3% and 81.6%, respectively. The negative predictive value of this cutoff is high (98.65%).