摘要：

Seventeen patients with stable congestive heart failure (class II and III New York Heart Association) received intravenous and oral enoximone in a 2-part study. Hemodynamic data were first obtained after intravenous administration of 0.75 mg/kg of enoximone; data were again obtained after 12 weeks of therapy with either oral enoximone (150 mg 3 times daily) or placebo. The efficacy and safety of oral enoximone were also studied in a 12-week, doubleblind randomized format. In the intravenous study, enoximone was delivered over 5 minutes and hemodynamic data were measured for up to 12 hours after. Cardiac index increased 2.76 ± 0.63 to 3.42 ± 0.72 liters/min/m 2), pulmonary wedge pressure decreased (19.5 ± 8.8 to 14.6 ± 8.0 mm Hg) as did mean arterial blood pressure (101 ± 14.8 to 85 ± 13.7 mm Hg) and systemic vascular resistance (1,880 ± 573 to 1,254 ± 383 dynes s cm −5). Heart rate increased slightly (82 ± 17 to 86 ± 14 beats/min). All these changes were maximal 1 to 2 hours after infusion and lasted 8 hours at least. Patients were then randomized double-blind to oral treatment. Baseline values showed that the 7 patients who received placebo had more severe CHF. Therefore, comparison might be biased. Patient overall assessment showed a continuous benefit in both groups. Ejection fraction improved from 30.1 ± 6.8% to 33.9 ± 9.9% in the enoximone group while it remained unchanged with placebo (23.4 ± 6.5% to 23.4 ± 1.5%). Mean exercise time (cycloergometer) increased with enoximone (9.0 ± 3.3 to 10.6 ± 3.7 minutes, p < 0.05) and did not change with placebo (7.1 ± 3.2 to 7.1 ± 4.0 minutes). Minimal side effects were reported. Two patients withdrew from the study, 1 in each group because of increased reversible liver function test values. One patient in the placebo group died. No changes in the electrocardiogram, no aggravation of existing arrhythmias and no appearance of new arrhythmias occurred either during intravenous or oral treatment (initial and final 24-hour Holter recordings). At the end of the 12-week oral treatment patients again received 0.75 mg intravenous enoximone and hemodynamic data were measured. In the patients who were taking oral placebo, compared with the initial intravenous evaluation, the same changes occurred. Patients taking enoximone had a further increase in cardiac index (3.52 ± 0.63 to 4.04 ± 0.83) and decrease in pulmonary capillary wedge pressure (13.3 ± 4.6 to 10.0 ± 2.1 mm Hg), similar changes in mean arterial blood pressure and systemic vascular resistance and a smaller increase in heart rate. Intravenous enoximone produced significant long lasting hemodynamic improvement, which could be reproduced after long-term oral treatment suggesting the absence of tachyphylaxis. Oral 12-week treatment consistently increased exercise time with minor side effects and no arrhythmogenic action.

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