HEMODYNAMIC, RENAL, AND HORMONAL RESPONSES TO BRAIN NATRIURETIC PEPTIDE INFUSION IN PATIENTS WITH CONGESTIVE-HEART-FAILURE

Background. This study was designed to examine the hemodynamic, renal, and hormonal effects of brain natriuretic peptide (BNP) infusion in patients with congestive heart failure (CHF) and in control subjects. Methods and Results. We infused synthetic human BNP at a rate of 0.1-mu-g/kg/min. BNP infusion decreased pulmonary capillary wedge pressure (control, from 5 +/- 1 to 2 +/- 1 mm Hg, p < 0.01; CHF, from 21 +/- 3 to 14 +/- 4 mm Hg, p < 0.05) and systemic vascular resistance (control, from 1,264 +/- 75 to 934 +/- 52 dyne.sec.cm-5; CHF, from 2,485 +/- 379 to 1,771 +/- 195 dyne.sec.cm-5; p < 0.01, respectively) and increased stroke volume index (control, from 49.9 +/- 2.7 to 51.5 +/- 2.3 ml/m2, p = NS; CHF, from 25.6 +/- 3.8 to 32.0 +/- 3.9 ml/m2, p < 0.01). BNP infusion significantly increased urine volume (control, from 2.3 +/- 0.7 to 7.5 +/- 1.9 ml/min; CHF, from 0.8 +/- 0.2 to 5.3 +/- 1.0 ml/min; p < 0.01, respectively), excretion of sodium (control, from 79.2 +/- 21.6 to 332.8 +/- 70.9-mu-Eq/min; CHF, from 77.4 +/- 20.8 to 753.5 +/- 108.0-mu-Eq/min; p < 0.01, respectively), and excretion of chloride (control, from 72.5 +/- 18.4 to 256.0 +/- 43.3-mu-Eq/min; CHF, from 74.0 +/- 19.6 to 708.8 +/- 103.3-mu-Eq/min; p < 0.01, respectively). Urinary excretion of sodium and of chloride in response to BNP infusion was higher in patients with CHF than in control subjects (p < 0.01, respectively). BNP infusion increased the levels of plasma atrial natriuretic peptide (control, from 65 +/- 11 to 84 +/- 14 pg/ml; CHF, from 262 +/- 65 to 301 +/- 62 pg/ml; p < 0.05, respectively) and decreased plasma aldosterone concentrations in both groups (control, from 43.3 +/- 12.1 to 27.3 +/- 7.1 pg/ml; CHF, from 91.1 +/- 34.3 to 66.3 +/- 27.2 pg/ml; p < 0.05, respectively). Conclusions. We conclude that BNP infusion improves left ventricular function in patients with CHF by vasodilation and prominent natriuretic action.