R. Bonini

Acute enoximone effect on systemic and renal hemodynamics in patients with heart failure

SummaryPatients with heart failure generally show improvement in their clinical condition after enoximone infusion over the period of treatment; this effect cannot be ascribed only to the known hemodynamic action of this drug. Thirty-six patients (age range 44–82 years) with heart failure (NYHA class II–IV) underwent 48-hour enoximone infusion to study whether this prolonged improvement might depend on changes in systemic or renal hemodynamics or in neurohormonal balance. All patients underwent Swan-Ganz hemodynamic monitoring; renal plasma flow, glomerular filtration rate, plasma atrial natriuretic factor (ANF), and plasma renin activity (PRA) were all measured at baseline, at the peak of the enoximone action, and 48 hours after drug discontinuation. The main hemodynamic parameters were significantly improved during enoximone infusion and after drug discontinuation. The cardiac index basal value of 2.2±0.1 l/min/m2 increased to 3.1±0.1 l/min/m2 after 24-hour therapy (p<0.01); similarly, pulmonary wedge pressure, mean pulmonary arterial pressure, and right atrial pressure decreased markedly (p<0.01). Beneficial effects were also observed in renal hemodynamics; indeed, renal plasma flow (basal value 485±39 ml/min) increased significantly after 24-hour enoximone infusion (575±35 ml/min; p<0.01), and this tendecy was also observed 48 hours after drug discontinuation. No significant modifications were observed in plasma hormone data; however, the PRA plasma level had a tendency to decrease. We conclude that in patients with heart failure, enoximone infusion has a less marked effect on renal hemodynamics, but this is more lasting than systemic hemodynamic effects. The tendency of PRA to decrease (although not statistically significant), still detectable 2 days after treatment in the presence of steady high plasma ANF concentrations, may also contribute to the paradoxical longlasting benefit despite the short-lived improvement in systemic hemodynamles after brief cycles of enoximone infusion.

Acute Enoximone Effect on Systemic Hemodynamics, Renal Function, and Hormonal Activation in Patients with Heart Failure

Several lines of evidence suggest that activation of the renin angiotensin system, with consequent peripheral vasoconstriction and sodium retention, plays an important role in the progression of heart failure. Pharmacologic agents that block this activation exert a positive effect on symptoms and survival. This study was designed to examine the hemodynamic, hormonal, and renal effects of enoximone infusion for 48 hr in 15 patients with heart failure (NYHA class III). All patients underwent Swan-Ganz hemodynamic monitoring. Renal plasma flow, glomerular filtration rate, and plasma renin activity were measured at baseline, at peak enoximone action, and 72 hr after withdrawal of the drug. Our data suggest that in patients with heart failure, enoximone exerts favorable effects on renal function, hemodynamics, and neurohormonal activation for a period outlasting drug suspension.