RESUMO
In addition to the classical actions of hemodynamic regulation, natriuretic peptides (NPs) interact with various neurohumoral factors that are deeply involved in the pathophysiology of cardiovascular diseases. However, their effects on the hypothalamic-pituitary-adrenal (HPA) axis, which is activated under acute high-stress conditions in acute coronary syndrome (ACS), remain largely unknown. We investigated the impact of plasma B-type NP (BNP) on plasma adrenocorticotropic hormone (ACTH)-cortisol levels during the acute phase of ACS ischemic attacks. The study population included 436 consecutive patients with ACS for whom data were collected during emergency cardiac catheterization. Among them, biochemical data after acute-phase treatment were available in 320 cases, defined as the ACS-remission phase (ACS-rem). Multiple regression analyses revealed that plasma BNP levels were significantly negatively associated with plasma ACTH levels only during ACS attacks (P < 0.001), but not in ACS-rem, whereas plasma BNP levels were not significantly associated with plasma cortisol levels at any point. Accordingly, covariance structure analyses were performed to clarify the direct contribution of BNP to ACTH by excluding other confounding factors, confirming that BNP level was negatively correlated with ACTH level only during ACS attacks (ß = -0.152, P = 0.002), whereas BNP did not significantly affect ACTH in ACS-rem. In conclusion, despite the lack of a significant direct association with cortisol levels, BNP negatively regulated ACTH levels during the acute phase of an ACS attack in which the HPA axis ought to be activated. NP may alleviate the acute stress response induced by severe ischemic attacks in patients with ACS.NEW & NOTEWORTHY BNP negatively regulates ACTH during a severe ischemic attack of ACS in which hypothalamic-pituitary-adrenal axis ought to be activated, indicating an important role of natriuretic peptides as a mechanism of adaptation to acute critical stress conditions in humans.