Abstract 14880: Neutrophil Gelatinase-Associated Lipocalin Compared to Cystatin C and Estimated Glomerular Filtration Rate in Risk Stratification of Patients with Suspected Acute Coronary Syndrome
Background: Early and adequate risk stratification is essential in patients with suspected acute coronary syndrome (ACS). In these patients renal impairment reflected by estimated glomerular filtration rate (eGFR) or cystatin C is known to be a strong risk predictor. Aim of the present study is to evaluate the prognostic value of urinary neutrophil gelatinase-associated lipocalin (uNGAL) in this context.
Methods: Patients with suspected ACS were consecutively enrolled at three German study centers between 01/2007 and 12/2008. Blood and urine was obtained on admission. Cystatin C, uNGAL (Abbott ARCHITECT) and serum creatinine were measured and eGFR was calculated using the abbreviated Modification of Diet in Renal Disease (MDRD) formula. Follow-up information on the combined endpoint of death or non-fatal myocardial infarction was obtained 6 months after enrollment.
Results: Of 1818 (66.4% male) enrolled patients 413 (22.7%) suffered an acute myocardial infarction whereas in 1165 (64.1%) patients an ACS could be excluded. Follow-Up data was available in 98.1% of the patients, 59 events were registered. Cystatin c was available in 1724 and uNGAL in 1164 patients, eGFR could be calculated in 1809 patients. Cystatin c and eGFR correlated with r=-0.62 (<0.0001), whereas uNGAL showed only a weak correlation with cystatin c (r=0.09, p=0.0026) or eGFR (r=-0.11, p=0.00024). Cox regression analysis revealed predictive information on all three biomarkers with unadjusted hazard ratio (HR) per standard deviation increase of 0.39 for eGFR (p<0.0001), 1.83 for cystatin C (p<0.0001) and 1.83 for uNGAL (p=0.0022). After adjusting for the Global Registry of Acute Coronary Events (GRACE) riskscore variables (excluding creatinine) HR of eGFR was 0.53 (p<0.0001), of cystatin C was 1.65 (p<0.0001) and of uNGAL was 1.57 (p=0.032). A model based on the GRACE risk variables had a c-index of 0.79, addition of eGFR or cystatin C improved the c-index to 0.82, addition of uNGAL yielded a c-index of 0.79.
Conclusion: In patients with suspected ACS uNGAL is moderately correlated with renal function represented by cystatin C or eGFR. Elevated uNGAL is associated with unfavorable mid-term prognosis in chest pain patients and therefore might amend clinical risk stratification.
- © 2011 by American Heart Association, Inc.