Background: The purpose of this study was to investigate whether the combined positive inotropic and vasodilating properties of enoximone have a short-term benefit when used in patients who underwent open heart surgery.
Methods: From 7/1994 to 1/1995 twenty-six patients with severe myocardial dysfunction (ejection fraction < 35%) were enrolled into a prospective trial before undergoing coronary artery bypass graft. They were randomly selected into two study groups: the first treated with enoximone (group E) and the other one with dopamine (group D). Anaesthesia was the same for both groups using high-dose fentanyl. Buckberg cardioplegia was used. All patients were followed by: conventional monitoring, Swan-Ganz catheter and transesophageal echocardiography. measurements (hemodynamic parameters, end-systolic and diastolic area and left ventricular wall motion) were recorded: after induction of anesthesia, after loading-dose and an intensive care unit. Enoximone- and dopamine infusions were started during weaning from cardiopulmonary bypass and tailored to hemodynamic parameters (cardiac index > 2.8 l/min, wedge pressure < 16 mmHg, mixed venous blood saturation > 65%). Major events were defined as: endotracheal intubation > 36 h, using intraortic balloon pump or centrifugal pump, intensive care timer > 48 h, in hospital cardiac death. Prices, were established by DRG-tables (diagnosis related groups). Statistical analysis were performed by X and "t" Student tests.
Results: Cardiac index increased more significantly in group E (CI 1.9-->3.9 vs 2.3-->3.3; p 0.05) thanks to a higher reduction of vascular systemic (SVRI 2889-->1447 vs 2536 -->1565; p 0.005) and pulmonary resistances (PVRI 271-->193 vs 288-->218; p 0.05). Fewer major cumulative events and intensive care costs were observed in group E rather than group D.
Conclusions: Enoximone administer immediately after open heart surgery had more beneficial hemodynamic and clinical effects than dopamine in patients with severe left ventricular dysfunction.