Prognostic and diagnostic significance of mid-regional pro-atrial natriuretic peptide in acute exacerbation of chronic obstructive pulmonary disease and acute heart failure: data from the ACE 2 Study.

Purpose: To compare the diagnostic and prognostic value of mid-regional pro-ANP (MR-proANP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with acute dyspnea. Methods: MR-proANP and NT-proBNP were measured with commercial immunoassays at hospital admission (n = 313), on day 2 (n = 234), and before discharge (n=91) and compared for diagnosing acute heart failure (HF; n = 143) and to predict mortality among patients with acute HF and acute exacerbation of chronic obstructive pulmonary disease (AECOPD; n = 84) separately. Results: The correlation coefficient between MR-proANP and NT-proBNP was 0.89 (p < 0.001) and the receiver-operating area under the curve (AUC) was 0.85 (95% CI 0.81-0.89) for MR-proANP and 0.86 (0.82-0.90) for NT-proBNP to diagnose acute HF. During a median follow-up of 816 days, mortality rates were 46% in acute HF patients and 42% in AECOPD patients. After adjustment for other risk variables by multivariate Cox regression analysis, MR-proANP and NT-proBNP concentrations were associated with mortality in patients with acute HF, but only MR-proANP were associated with mortality among patients with AECOPD: hazard ratio (lnMR-proANP) 1.98 (95% CI 1.17-3.34). Conclusion: MR-proANP and NT-proBNP concentrations provide similar diagnostic and prognostic information in patients with acute HF. In contrast to NT-proBNP, MR-proANP measurements also provided independent prognostic information in AECOPD patients.