Aims: To compare the accuracy of the N-terminal fragment of its pro-hormone (Nt-proBNP) and N-terminal pro-atrial natriuretic peptide (Nt-proANP) in the prediction of the 2 year mortality and to investigate whether additional measurement of Nt-proANP to troponin I (TnI) could improve risk assessment in the subgroups of patients with unstable coronary artery disease (UCAD) and normal Nt-proBNP.
Methods and results: Plasma levels of the TnI, Nt-proANP, and Nt-proBNP were determined in 120 consecutive patients with UCAD without ST-segment elevations and normal left ventricular function. In multivariable logistic regression analysis, TnI and Nt-proBNP were independent predictors of mortality (P=0.01 and P=0.02, respectively). However, in the group of patients with normal Nt-proBNP levels, only Nt-proANP and TnI were independently associated with mortality (P=0.007 and P=0.03, respectively). Accordingly, patients with elevated Nt-proANP levels in this group of patients had significantly higher mortality rate than patients with normal Nt-proANP levels (P=0.003).
Conclusion: Our results suggest that determination of Nt-proANP might improve risk assessment in patients with UCAD, especially when Nt-proBNP is in the normal range.