Hemodynamic and renal effects of atrial natriuretic peptide in congestive heart failure

The hemodynamic and renal effects of anaritide (human atrial natriuretic peptide 102-126), a synthetic analog of atrial natriuretic peptide, were evaluated in 35 patients with chronic New York Heart Association class II to IV heart failure. There were 32 men and 3 women, aged 33 to 75 (mean ± standard error of the mean 56 ± 2) years. In the first phase of the study, right-sided heart catheterization was performed, and anaritide was administered as 1-hour infusions. The rate of the infusion varied among patients from 0.03 to 0.3 μg/kg/min. In response to anaritide, there were decreases in mean systemic arterial (94 ± 2 to 87 ± 2 mm Hg), right atrial (10 ± 1 to 8 ± 1 mm Hg), mean pulmonary arterial (33 ± 2 to 28 ± 2 mm Hg) and pulmonary artery wedge (22 ± 2 to 15 ± 2 mm Hg) pressures (all p < 0.05). Cardiac index increased (2.39 ± 0.15 to 2.62 ± 0.15 liters/min/m², p < 0.05) and heart rate was unchanged. Systemic vascular resistance decreased significantly, but pulmonary vascula resistance was unchanged. There were increases in urine volume (1.6 ± 0.2 to 2.3 ± 0.4 ml/ min), sodium excretion (47 ± 13 to 74 ± 20 μEq/ min) and fractional excretion of sodium (0.41 ± 0.11 to 0.59 ± 0.14%, all p < 0.05), while potassium excretion and creatinine clearance did not change. In the second phase of the study, patients received 2-hour infusions of anaritide (0.03 to 0.6 μg/kg/min) and placebo with noninvasive monitoring. Mean systemic arterial pressure and plasma norepinephrine concentration decreased, while urine volume, sodium excretion and fractional excretion of sodium increased (all p < 0.05) during anaritide infusion, but were unchanged on placebo. Adverse effects, usually related to excessive reduction of systemic arterial pressure, were observed in 6 patients. Short-term infusion of atrial natriuretic peptide produces improvement in hemodynamics and renal function in patients with heart failure.