Stability of plasma concentrations of N and C terminal atrial natriuretic peptides at room temperature.

Abstract

Plasma concentrations of atrial natriuretic peptide (ANP) are increased in patients with ventricular dysfunction and could have a diagnostic role in heart failure. ANP may be unstable after collection, however, limiting any practical diagnostic role. Blood samples were obtained from 18 patients with various conditions. Aliquots were either processed optimally or kept as blood or plasma at room temperature for 6-72 h before processing. Concentrations of C-terminal ANP were lower in specimens kept as blood for 24 and 72 h (mean difference from control -43% and -76%, respectively, (P < 0.001) but N-terminal ANP (extracted) seemed to be stable under all conditions studied (-2% at 24 h and -7% at 72 h, not significant). N-terminal ANP (extracted) is stable and potentially has a role in the diagnosis of heart failure in routine clinical practice.