LOW-DOSE ENOXIMONE THERAPY IN PRETRANSPLA NT PATIENTS - HEMODYNAMIC, ECHOCARDIOGRAPHIC, AND NEUROHUMORAL FINDINGS

Keeping pre-transplant patients alive while waiting for a suitable don or to be found is still a major challenge. New pharmacological agents which can provide improved hemodynamics are urgently needed in patient s with severe heart failure who are on the waiting list for cardiac tr ansplantation. Intravenous enoximone therapy (an initial 0.5 mg/kg bol us, then 1.25 - 5.0 mcg/kg/min infusion) was administered to 18 transp lant candidates with heart failure progression despite optimal drug re gimen including digoxin, diuretics, and ACE-inhibitors. Complete hemod ynamic, echocardiographic, and neurohumoral studies were performed bef ore and 24 h after intravenous enoximone infusion. Enoximone infusion increased cardiac index (1.78 +/- 0.45 l/min/qm vs. 3.04 +/- 0.83 l/mi n/qm; p < 0.001) and stroke volume index (22.33 +/- 9.45 ml/qm vs. 32. 28 +/- 7.29 ml/qm; p < 0.05) and decreased wedge pressure (24.1 +/- 11 .98 mmHg vs. 17.78 +/- 8.76 mmHg; p < 0.05) and systemic vascular resi stance (1700.8 +/- 555.8 dyn x s x cm(-5) vs. 952.8 +/- 384.0 dyn x s x cm(-5); p < 0.001). Heart rate and mean arterial pressure were uncha nged. Left ventricular ejection time (225.1 +/- 26.9 ms vs. 242.2 +/- 25.8 ms; p < 0.05) was increased, whereas other echocardiographic para meters were unchanged (left ventricular end-diastolic dimension, left ventricular end-systolic dimension, fractional shortening, early diast olic relaxation parameter Te). Plasma neurohumoral parameters did not change (aldosterone, epinephrine, renin, atrial natriuretic factor) ex cept for a significant drop of norepinephrine (936.7 +/- 443.2 pg/ml v s. 522.4 +/- 287.6 pg/ml; p < 0.05). In our study of pre-transplant pa tients refractory to conventional medical therapy including digoxin, d iuretics, and ACE-inhibitors, clinical improvement due to low-dose eno ximone infusion was associated with improvements in hemodynamic, echoc ardiographic, and neurohumoral status. Low-dose enoximone therapy may be a useful adjunct to stabilize decompensated heart failure.