NPPB and congestive heart failure: ET-1 is a powerful vasoconstrictor predominantly produced by the endothelial cell, with inflammatory action (promote IL-6 release from small airway epithelial cells).[36,37] On the other hand, the presence of inflammatory mediators stimulates the ET-1 secretion.[38,39] Recent studies also showed a positive correlation between ET-1 and other inflammatory mediators including CRP and TNF-alfa, as well as NT-proBNP concentrations in patients with chronic heart failure.[40,41]