Hemodynamic evaluation during exercise test after acute and chronic ibopamine treatment in patients with congestive heart failure

The hemodynamic effects of ibopamine (SB-7505), the orally active 3,4-diisobutyryl ester of N-methyldopamine, were studied in 12 patients with congestive heart failure (CHF) after acute dosing, after 20 days of maintenance therapy and after 20 days of drug discontinuation. Acute ibopamine administration increased at rest cardiac index (CI p <0.05) and stroke work index (SWI p <0.05), and reduced pulmonary capillary wedge pressure (PCWP), mean pulmonary arterial pressure (P̄ĀP̄), total systemic (SVR p <0.05) and pulmonary vascular resistance (PVR). These beneficial hemodynamic effects were maintained during supine bicycle exercise: CI and SWI increased more markedly (p <0.05) and PCWP increased at a lower extent (p <0.05) after ibopamine than on control conditions. PVR exhibited a more pronounced decrease (p <0.02), while SVR showed superimposable reductions before and after ibopamine. After chronic therapy with the drug, hemodynamics and left ventricular function again improved during exercise, while withdrawal of ibopamine resulted in hemodynamic deterioration. Heart rate and systemic arterial pressure did not change significantly after the drug. This study demonstrates that ibopamine is able to improve cardiac performance during exercise in CHF patients after both acute and chronic administration.