Long-term oral enoximone therapy in chronic cardiac failure.

Sixty-nine patients with chronic heart failure of moderate to advanced severity were treated with oral enoximone (mean dose 1.8 +/- 0.5 mg/kg every 6 to 8 hours) for an average of 35 weeks (range 1 to 129). Before long-term therapy in 56 patients, oral enoximone was shown to augment cardiac output by more than 30%. In 13 outpatients enoximone was initiated without hemodynamic monitoring. Within 12 weeks of therapy the majority of surviving patients were improved by at least 1 New York Heart Association functional class. In a subset of 30 patients who were able to perform reproducible treadmill exercise before entry, average maximal O2 uptake increased from 14.9 ml/kg/min at baseline to 17.6 ml/kg/min (p less than 0.05) at 2 to 4 weeks and remained increased at 17.4 ml/kg/min (p less than 0.05) at 12 weeks. Adverse gastrointestinal effects occurred in 11 patients and were generally mild. The 12 month survival rate was 44%; etiology of death was cardiogenic shock in 17 patients and 10 patients died suddenly while at home. Thus, improvements in symptoms and maximal VO2 were observed in many patients with moderate to severe heart failure during long-term therapy with enoximone. Controlled trials will be needed to establish the safety and efficacy of this promising new drug.