Natriuretic peptides play an important role in the diagnosis and risk stratification of patients with acute and chronic heart failure. Multiple studies have shown that these peptides are liable to the influence of individual factors. For N-terminal-pro-B-type natriuretic peptide (NT-proBNP) some of these confounding factors have been evaluated over the years such as age, gender, New York Heart Association (NYHA) class and body mass index (BMI). The aim of this study was to establish confounding factors of mid-regional pro-atrial natriuretic peptide (MR-proANP) assessment.