Infusion of Atrial Natriuretic Peptide to Patients with Congestive Heart Failure

Abstract

Summary

Atrial natriuretic peptides (ANP) exert vasodilating and natriuretic actions. The present study was undertaken to test the effect of low dose infusions of synthetic ANP on hemodynamic and humoral variables of patients with severe heart failure. Eight patients, aged 26 to 71 years, with severe congestive heart failure due to ischemic heart disease or idiopathic dilated cardiomyopathy were included in the study. Synthetic human (3–28) ANP was infused at doses ranging from 0.5 to 2 μg/min for up to 3 h. Pulmonary capillary wedge pressure fell from 24 ± 1 to 16 ± 2 mm Hg (mean ± SEM) (p < 0.01) and cardiac index tended to rise from 2 ± 0.2 to 2.3 ± 0.2 L/min/m2 (NS), while blood pressure and heart rate did not change. One patient experienced a marked drop in pulmonary capillary wedge and arterial blood pressure that necessitated the administration of saline. ANP infusion did not alter plasma renin activity or plasma aldosterone, norepinephrine, or vasopressin levels. It decreased plasma epinephrine levels from 0.472 ± 0.077 to 0.267 ± 0.024 nmol/L (p < 0.05). Plasma ANP levels were markedly elevated in all patients before initiating the infusion. They had no predictive value for the hemodynamic response to exogenous ANP. No correlation was observed between the hemodynamic effects of ANP and those induced by the subsequently administered converting enzyme inhibitor captopril, which seemed to improve cardiac function more consistently. These preliminary results suggest that even if ANP can exert some beneficial hemodynamic effects in patients with severe congestive heart failure, its usefulness may be limited by the potential of side effects possibly related to excessive doses, and by its moderate efficacy at doses that do not induce untoward effects.