Enoximone improves selection of candidates for urgent cardiac transplantation

Abstract

Immediate cardiac transplantation, or urgent implantation of devices for mechanical support of the failing heart, has been shown to be effective as life-saving procedures in patients with cardiogenic shock unresponsive to maximal sympathomimetic treatment. The intravenous administration of enoximone in these patients, in addition to previous inotropic support, should permit a ‘buying of time’ strategy, leading to a reduction in the need for complex, invasive and costly techniques, such as artificial hearts. In addition, it should permit improved selection of candidates for cardiac transplantation. A prospective study was started in 1985 to obtain data on the haemodynamic and clinical efficacy of intravenous enoximone in these critically ill patients, and to determine the time gained for evaluation of the need for urgent transplantation. Cardiac index rose from 1.82 ± 0.26 litres/minute/m 2 to 2.67 ± 0.56 litres/minute/m 2 after 30 minutes, while pulmonary capillary wedge pressure decreased from 29.9 ± 7 mm Hg to 18.0 ± 7 mm Hg ( n = 30). This early beneficial effect waned progressively after 6 hours. Prior to the next intravenous infusion at 8 hours, cardiac index was 2.07 ± 0.53 litres/minute/m 2 and pulmonary capillary wedge pressure was 25 ± 8.5 mm Hg. Only four patients could not wait for a biological graft and had to be implanted with a complete artificial heart (3 patients), or a ventricular assist device (1 patient). In all, 30 patients improved and their increased survival allowed a re-evaluation for cardiac transplantation itself; 13 were rapidly (1.7 days; range 0.5–5) confirmed as good candidates. As a whole, this strategy compares favourably with the results of a strategy based on mechanical bridging alone.