Why Is BNP a Stronger Prognostic Indicator Than ANP and N-ANP?
Various mechanisms may contribute to the different prognostic merits of circulating ANP, N-ANP, and BNP after AMI. First, the site of synthesis and release may differ for ANP and BNP. Northern blot hybridization analysis and selective catheterization studies both suggest that circulating BNP is derived predominantly from ventricular tissue and that ANP is derived predominantly from atrial tissue in subjects without cardiac disease. [13,21,43] In patients with LV dysfunction, circulating ANP probably is derived from ventricular tissue as well. [13,21,43] Interestingly, recent data suggest that the secretion of BNP but not ANP is significantly greater from the infarcted region than from the noninfarcted region of the left ventricle. [44] Consequently, in contrast to ANP (and N-ANP), plasma BNP secretion may more accurately reflect regional wall stress in the infarcted region of the ventricle. Increased regional wall stress is believed to be associated with adverse ventricular remodeling
