Objectives: We sought to assess the effects of combined oral positive inotropic and beta-blocker therapy in patients with severe heart failure.
Background: Patients with severe, class IV heart failure who receive standard medical therapy exhibit a 1-year mortality rate >50%. Moreover, such patients generally do not tolerate beta-blockade, a promising new therapy for chronic heart failure. Positive inotropes, including phosphodiesterase inhibitors, are associated with increased mortality when administered over the long term in these patients. The addition of a beta-blocker to positive inotropic therapy might attenuate this adverse effect, although long-term oral inotropic therapy might serve as a bridge to beta-blockade.
Methods: Thirty patients with severe heart failure (left ventricular ejection fraction [LVEF] 17.2+/-1.2%, cardiac index 1.6+/-0.1 liter/min per m2) were treated with the combination of oral enoximone (a phosphodiesterase inhibitor) and oral metoprolol at two institutions. Enoximone was given at a dose of < or = 1 mg/kg body weight three times a day. After clinical stabilization, metoprolol was initiated at 6.25 mg twice a day and slowly titrated up to a target dose of 100 to 200 mg/day.
Results: Ninety-six percent of the patients tolerated enoximone, whereas 80% tolerated the addition of metoprolol. The mean duration of combination therapy was 9.4+/-1.8 months. The mean length of follow-up was 20.9+/-3.9 months. Of the 23 patients receiving the combination therapy, 48% were weaned off enoximone over the long term. The LVEF increased significantly, from 17.7+/-1.6% to 27.6+/-3.4% (p=0.01), whereas the New York Heart Association functional class improved from 4+/-0 to 2.8+/-0.1 (p=0.0001). The number of hospital admissions tended to decrease during therapy (p=0.06). The estimated probability of survival at 1 year was 81+/-9%. Heart transplantation was performed successfully in nine patients (30%).
Conclusions: Combination therapy with a positive inotrope and a beta-blocker appears to be useful in the treatment of severe, class IV heart failure. It may be used as a palliative measure when transplantation is not an option or as a bridge to heart transplantation. Further study of this form of combined therapy is warranted.