EFFECT OF ENOXIMONE ALONE AND IN COMBINATION WITH METOPROLOL ON MYOCARDIAL-FUNCTION AND ENERGETICS IN SEVERE CONGESTIVE-HEART-FAILURE - IMPROVEMENT IN HEMODYNAMIC AND METABOLIC PROFILE

The hemodynamic and myocardial metabolic effects of enoximone (phospho diesterase III inhibitor), alone or in combination with metoprolol (be ta-adrenergic blocker), were studied in patients with congestive heart failure. Ten patients (New York Heart Association Class III-IV) under went right heart and coronary sinus catheterization, and parameters we re assessed at basal condition, at peak enoximone response (mean intra venous loading dose = 2.2 mg/kg), and after the combination with metop rolol (mean intravenous dose = 8.5 mg). Heart rate tended to increase during enoximone administration (from 102 +/- 16 to 107 +/- 16 min-1, ns) and was reduced during enoximone plus metoprolol (to 88 +/- 15 min -1, p < 0.05 vs. basal). Cardiac index was increased during enoximone (from 2.2 +/- 0.2 to 3.8 +/- 0.5 1/min/m2, p < 0.05) and decreased dur ing enoximone plus metoprolol (to 2.8 +/- 0.5 1/min/m2, p < 0.05 vs. e noximone). Mean pulmonary wedge pressure fell during enoximone and rem ained reduced during enoximone plus metoprolol (from 27 +/- 9 to 9 +/- 3 and to 13 +/- 4 mmHg, respectively, both p < 0.05). Myocardial oxyg en consumption did not change during enoximone (from 27 +/- 8 to 25 +/ - 13 ml/min, ns) and was reduced during enoximone plus metoprolol (to 19 +/- 8 ml/min, p < 0.05 vs. basal). Myocardial lactate extraction te nded to be lower during enoximone and during enoximone plus metoprolol conditions (from 38 +/- 17% to 26 +/- 20% and to 29 +/- 24%, respecti vely), but no statistical significance was found. Myocardial efficienc y was increased during enoximone and during enoximone plus metoprolol (from 9 +/- 3% to 15 +/- 6% and to 14 +/- 6%, respectively, both p < 0 .05). Thus in patients with congestive heart failure enoximone improve s hemodynamics and, in most cases, it does not influence energetics. T he addition of metoprolol to enoximone reduces heart rate, cardiac ind ex, and myocardial oxygen consumption without any other major changes, producing a more physiologic hemodynamic and metabolic profile.