Cardiovascular Mortality in Chest Pain Patients: Comparison of Natriuretic Peptides With Novel Biomarkers of Cardiovascular Stress

BACKGROUND: Natriuretic peptides are the standard biomarker for risk stratification in cardiovascular disease. Novel biomarkers of cardiovascular stress might allow refinement in risk stratification for patients with acute coronary syndrome (ACS). We tested the performance of these novel biomarkers for cardiovascular risk stratification in patients who presented with ACS.

METHODS: In the AtheroGene study, 873 patients presented with ACS in the emergency department. Biomarkers measured were: B-type natriuretic peptide (BNP), N-terminal pro BNP (NT-proBNP), midregional proatrial natriuretic peptide, midregional proadrenomedullin (MR-proADM), copeptin, and troponin I. The median follow-up time was 4 years and during this time 50 patients died from cardiac causes.

RESULTS: Cox regression analysis for the continuous variables NT-proBNP and BNP showed a hazard ratio (HR) of 1.9 and 1.8, respectively, for 1 SD increase (P < 0.001 and P = 0.003) in the fully adjusted model. Novel biomarkers with MR-proADM had an HR of 3.2, followed by midregional proatrial natriuretic peptide with an HR of 1.9 (both P < 0.001), and copeptin with an HR of 1.6 (P < 0.001). C-index revealed MR-proADM as the best discriminator for identifying patients with the outcome with a C-index = 0.8, and C-index was 0.72 for NT-proBNP (P for comparison = 0.017). Integrated discrimination improvement for MR-proADM was 0.059 compared with NT-proBNP (P = 0.016), thus providing background that MR-proADM was better to identify persons with the outcome. Troponin I levels at the time of admission were not significant for risk stratification.

CONCLUSIONS: In patients who present with ACS the novel biomarker, MR-proADM was the best predictor for outcome. MR-proADM adds modest information and is useful for risk prediction in ACS patients.