Myocardial stiffness is an important determinant of the plasma brain natriuretic peptide concentration in patients with both diastolic and systolic heart failure

Aims Plasma brain natriuretic peptide (BNP) concentration increases in proportion to heart failure (HF) severity. Although plasma BNP decreases to a certain level by optimal treatment, there is significant heterogeneity in the baseline value among individuals. The underlying mechanism of the steady-state plasma BNP levels remains still controversial. We investigated the hypothesis that myocardial stiffness ( K m) is a major determinant of the plasma BNP level. Methods and results In 19 patients with diastolic HF [DHF; left ventricular ejection fraction (LVEF)≥45%], 18 with systolic HF (SHF; LVEF