Effects of low dose enoximone for chronic congestive heart failure.

To examine the short-term hemodynamic and long-term clinical effects of oral enoximone at low doses, 12 patients with severe, chronic congestive heart failure (CHF) were given 1 mg/kg oral enoximone and followed with serial hemodynamic measurements for 24 hours. Control cardiac index was 1.9 +/- 0.5 liters/min/m2 and it increased significantly by 1 hour, with a peak effect at 2 hours to 2.4 +/- 0.4 liters/min/m2 (p less than 0.05). Similarly, wedge pressure, 22 +/- 8 mm Hg at control, decreased to 16 +/- 10 by 1 hour (p less than 0.05). Six of the 12 patients received 1 mg/kg of enoximone on day 1 and 2 mg/kg on day 2. The higher dose of enoximone caused no further improvement in cardiac performance but prolonged the salutary hemodynamic effect. Subsequently, 79 patients (18 in New York Heart Association class III and 61 in class IV) with CHF (ejection fraction 17 +/- 8%) were followed over a 3 year period; the average enoximone dose was 1.7 +/- 0.7 mg/kg 3 times daily. Improvement of at least 1 functional class occurred in 55 patients (70%) at 1 month, 27 patients (34%) at 6 months and 19 (24%) maintained their improvement for over 1 year. Enoximone was discontinued in 20 patients (25%); in 5 (6%) for adverse effects and in 13 patients because of no clinical benefit. Adverse effects occurred in 14 patients (18%); 6% of all patients required discontinuation of drug. Six month survival was 50%, 42% at 1 year and 30% at 2 years.(ABSTRACT TRUNCATED AT 250 WORDS)