CHGA and heart failure: In particular, catestatin, which is a neuroendocrine hormone (chromogranin A derivative) also found in enteroendocrine cells, has a close relationship with the regulation of the GM in preclinical models [90] and has been found to correlate with all-cause death and unplanned heart failure hospitalization in patients with heart failure with reduced ejection fraction (HFrEF) [91].