Long-Term Enoximone Therapy in Unstable Chronic Heart Failure

Long-term safety and efficacy of oral enoximone were evaluated in 32 patients with unstable chronic heart failure despite digitalis, diuretics, and vasodilator therapy. Oral enoximone. 75–150 mg t.i.d. was given for an average of 32 weeks. At baseline. 21 patients were in NYHA functional class IV. 10 patients in class III. and 1 patient in class II. Within 12 weeks. 14 of 20 patients surviving for more than 26 weeks had improved by at least one functional class. Hemodynamic data showed an 18% increase of cardiac index and a 34% decrease of diastolic pulmonary artery pressure. Echocardiographic recordings revealed an increase of fractional shortening from 13.9 ± 7 to 15.6 ± 5% after 12 weeks and 20.3 ± 5% after 26 weeks. The 1-year survival rate was 40% Sudden death occurred in three patients and pump failure in 11 patients. No serious side effects were reported. Holter monitoring did not show a significant proarrhythmic drug effect. Thus, long-term enoximone therapy is safe and produces sustained clinical and functional improvement in unstable chronic heart failure. However, overall survival appears not to be influenced in this patient group