Mid-regional pro-adrenomedullin in patients with acute dyspnea: Data from the Akershus Cardiac Examination (ACE) 2 Study.

BACKGROUND: Mid-regional pro-adrenomedullin (MR-proADM) is a surrogate marker for adrenomedullin; a hormone that attenuates myocardial remodeling. Accordingly, we hypothesized that MR-proADM could provide diagnostic and prognostic information in patients with acute dyspnea.

METHODS AND RESULTS: We measured MR-proADM by a commercial ELISA on hospital admission in 311 patients with acute dyspnea and compared the utility of MR-proADM with N-terminal pro-B-type natriuretic peptide (NT-proBNP). Blood samples were also available after 24h (n=232) and before discharge (n=94). The principal diagnosis of the index hospitalization was determined by an adjudication committee. MR-proADM concentrations on hospital admission were higher in patients with acute heart failure (HF; n=143) vs. patients hospitalized with non-HF-related dyspnea (n=168): 1.31 (Q1-3 0.97-1.89) vs. 0.85 (0.59-1.15) nmol/L; p<0.001. The receiver-operating characteristics area under the curve (ROC-AUC) for MR-proADM to diagnose HF was 0.77 (95% CI 0.72-0.82) and 0.86 (0.82-0.90) for NT-proBNP. During a median follow-up of 816days, 66/143 patients (46%) with acute HF and 35/84 patients (42%) with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) died; p=0.58 between groups. In multivariate Cox regression analyses, admission MR-proADM concentrations were associated with mortality in patients with acute HF (HR 5.90 [3.43-10.13], p<0.001), but not in patients with AECOPD. Admission MR-proADM concentrations also improved risk stratification in acute HF as assessed by the net reclassification index. MR-proADM concentrations decreased from admission to later time points.

CONCLUSION: Admission MR-proADM concentrations provide strong prognostic information in patients with acute HF, but modest diagnostic information in patients with acute dyspnea.