Orthotopic
heart transplantation is contraindicated in patients with
pulmonary hypertension and an elevated pulmonary vascular resistance. In an attempt to make otherwise unacceptable patients possible candidates for
heart transplantation,
amrinone was administered intravenously to 27 individuals with a transpulmonary gradient and pulmonary vascular resistance in the abnormal range. Twenty-four of 27 patients (89%) responded positively. Twenty-one of 27 (78%) went on to
transplantation and 20 of 21 (95%) survived the procedure. A second study compared
amrinone therapy with conventional
therapy in 38 potential transplant candidates with
pulmonary hypertension.
Amrinone was more effective in reducing
pulmonary hypertension than conventional
therapy with high-dose
diuretics, digitalis, and
captopril (86% v 63%). Survival rate of those awaiting
transplantation was also significantly higher in the
amrinone group (91% v 63%). Although the protocol for comparing the two regimens does not allow for extrapolation of the results (
amrinone was administered in-hospital under close monitoring, whereas conventional
therapy was self-administered at home), the findings confirm the clinical impression that
amrinone seems more effective and safer than conventional
therapy in the treatment of potential heart transplant patients with
pulmonary hypertension.