NPPB and myocardial infarction: Several pathological conditions have been linked to higher blood NT-proBNP levels in ACS (27, 28), including increased ventricular wall tension from myocardial infarction, which stimulates NT-proBNP synthesis, and hypoxia caused by ACS, which can activate the cardiac endocrine system, resulting in increased NT-proBNP synthesis (29–31).