Mid-regional pro-adrenomedullin in the early evaluation of acute chest pain patients

Background: The purpose of this study was to investigate the utility of mid-regional pro-adrenomedullin (MR-proADM) in the early diagnosis and risk stratification of patients with acute chest pain in comparison with established and novel biomarkers and risk scores. Methods: In this prospective, observational, international, multi-center trial (APACE), MR-proADM was determined in 1179 unselected patients with acute chest pain. Patients were followed for 24 months. Results: MR-proADMconcentrations at presentationwere higher in patientswith AMI (median: 0.78 nmol/l, IQR 0.60-1.13) than in patients with other diagnoses (0.64 nmol/l, IQR 0.49-0.86 nmol/l; p<0.001). The diagnostic accuracy of MR-proADM for AMI as quantified by the area under the receiver operating characteristic curve (AUC) was 0.66. Adding MR-proADM to hs-cTnT could not improve its diagnostic accuracy for AMI (p= 0.431). Seventy-six percent of all deaths occurred in the fourth quartile of MR-proADM (>0.90 nmol/l). Adding MR-proADMto the TIMI-score (AUC 0.87) predicted 1-year mortalitymore accurately than the TIMI-score alone (AUC 0.82; p<0.001). Net reclassification improvement (TIMI vs. additionally MR-proADM) amounted to 0.137 (p=0.012). MR-proADM had higher prognostic accuracy as compared to hs-cTnT in patients with AMI (p= 0.015) and in those without AMI (p=0.003). MR-proADM at presentation was tantamount to GRACE score and BNP as to its prognostic accuracy for mortality. The AUC for the prediction of cardiovascular events amounted to 0.63. Conclusions: While MR-proADM does not have clinical utility in the early diagnosis of AMI or predicting cardiovascular events in patients with acute chest pain, it may provide prognostic value for all-cause mortality.