ATRIAL-NATRIURETIC-FACTOR AND BRAIN NATRI URETIC PEPTIDE - VARIATIONSIN ELDERLY SUBJECTS WITH HEART-FAILURE

Atrial natriuretic factor (ANF) is a peptide hormone secreted by the a tria in response to increased transmural pressure. This peptide is the first of a series of natriuretic hormones which also includes brain n atriuretic peptide (BNP). It is destroyed mainly by an ubiquitous enzy me, neutral endopeptidase (NEP). Its main actions are vasodilatation a nd natriuresis. It is the main physiological agonist of the renin/angi otensin/aldosterone system. In elderly subjects free of cardiovascular disease, baseline concentrations are higher than in younger subjects. In patients with congestive heart disease (CHD), the level of ANF ris es due to permanent increased filling pressures. Both atrial and ventr icular secretion increase ANF levels which loose their day/night rhyth m. ANF is a risk factor independent of mortality, rhythm disorders and acute heart failure in patients with heart failure. BNP is also raise d in CHD. There is an inverse correlation between concentration and se verity of left ventricule dysfunction. There has been little work on A NF in elderly subjects with CHD. ANF is elevated in these patients and is an independent risk factor for cardiac decompensation. In addition , in very elderly subjects where the diagnosis of CHD is difficult and echocardiography not always possible, assay of BNP could be an intere sting diagnostic teal. Currently work on therapeutic possibilities (ad ministration of exogenous ANF, combinations with NEP inhibitor / conve rsion enzyme inhibitor, ANF / diuretics) have revealed certain problem s (short half life of ANF, transient effects, non-specific activity of NEP). The usefulness of ANF and BNP in heart failure in elderly subje cts will undoubtly lie in its capacity to mark disease severity and as a diagnostic tool, particuarly in case of acute dyspnoea.