Prostaglandin E1--bridge to cardiac transplantation. Technique, dosage, results.

BACKGROUND: Heart transplantation candidates who remain severely symptomatic despite therapy are normally hospitalized. Continuous infusion of intravenous drugs from a portable pump may allow such patients to live a fairly active life until a donor heart is found.

AIM: To investigate in an open pilot study if heart transplantation can be safely accomplished if these patients are continuously bridged with various regimens including inotropic support with low-dose dobutamine in conjunction with dopamine and prostaglandin E1.

METHODS: We report on 5 years' experience with prostaglandin E1, a potent vasodilator with proven efficacy in severe heart failure when coupled with catecholamines. From 1990 to 1995 54 heart transplantation candidates were bridged with prostaglandin E1 in addition to dobutamine 5 micrograms.kg-1. min-1 and dopamine 3 micrograms.kg-1 min-1 (group A; n = 32) or in addition to 3 micrograms.kg-1 min-1 dopamine alone (group B; n = 22), and 11 heart transplantation candidates were bridged with dobutamine 5 micrograms.kg-1. min-1 and dopamine 3 micrograms.kg-1 min-1 only (group C; n = 11). In an initial dose-ranging test, prostaglandin E1 was uptitrated to side effect limit (29 +/- 1 ng.kg-1.min-1). Haemodynamics, except for stroke volume index, were similar in all patients at baseline and a sufficient haemodynamic response (20% increase in stroke volume) was observed during the acute study. Fifty percent of the peak dose was used for initiating chronic therapy; the dose of prostaglandin E1 was further reduced if side effects recurred.

RESULTS: Twenty-nine (54%) patients in groups A and B and six in group C could be discharged home with chronic therapy via a Hickman catheter connected to a portable pump. After 4 weeks in six patients in group A and in 13 patients in group B, when prostaglandin E1 had been reduced from 15 +/- 2 ng.kg-1.min-1 to 8 +/- 1 ng.kg-1 min-1 increases in cardiac index and decreases in systemic vascular resistance were sustained, and a permanent decrease in pulmonary vascular resistance index was observed in group B. Intravenous therapy was changed in nine patients (3/1/5) because of side effects and worsening heart failure. Prostaglandin E1 was withdrawn in three of these patients because of an increase in serum creatinine (3 mg.100 ml-1), and in one because of noncompliance. In total, there were 17 cardiac deaths (9/6/2), 42 heart transplants (22/14/6) and six (1/2/3) weaned survivors (including one non-cardiac death) in this study. Overall outcome was similar in groups A and B, but distribution after 2 months appeared to be different (P < 0.05) based on more transplantations in group A.

CONCLUSION: We concluded that chronic infusions with prostaglandin E1 at reduced dosages is a feasible and safe therapeutic adjunct to bridge end-stage heart failure patients and may yield desirable effects in a subset of patients in the absence of inotropic support by dobutamine.