Attenuation of Compensation of Endogenous Cardiac Natriuretic Peptide System in Chronic Heart Failure

Abstract

Background Patients with congestive heart failure (CHF) have high plasma levels of atrial natriuretic peptide (ANP), mainly from the atrium, and brain natriuretic peptide (BNP), mainly from the ventricle. We examined the prognostic role of plasma BNP in chronic CHF patients in comparison with plasma ANP and other variables previously known to be associated with high mortality. We also evaluated the relationship between mortality and plasma cGMP, a biological marker of ANP and BNP. Methods and Results The study subjects were 85 patients with chronic CHF (left ventricular ejection fraction <0.45) who were followed for 2 years. The plasma levels of ANP, BNP, cGMP, and norepinephrine increased with the severity of CHF. Among plasma levels of ANP, BNP, cGMP, and norepinephrine and clinical and hemodynamic parameters, only high levels of plasma BNP ( P <.0001) and pulmonary capillary wedge pressure ( P =.003) were significant independent predictors of the mortality in patients with CHF by Cox proportional hazard analysis. Although plasma levels of ANP and BNP were threefold or fivefold higher in nonsurvivors than in survivors, there was no difference in plasma cGMP level between nonsurvivors and survivors. Conclusions These findings indicate that plasma BNP is more useful than ANP for assessing the mortality in patients with chronic CHF and that the plasma levels of BNP provide prognostic information independent of other variables previously associated with a poor prognosis. Our findings also suggest that the compensatory activity of the cardiac natriuretic peptide system is attenuated as mortality increases in chronic CHF patients with high plasma levels of ANP and BNP.