Fluorochemical emulsion APE-LM substantially improves cardiac preservation.

Abstract

We determined the efficacy of a novel fluorochemical emulsion for long-term hypothermic preservation of hearts. Rat hearts were preserved for 12 h at 12 degrees C with use of continuous low-pressure coronary perfusion with one of three oxygenated media (n = 6 hearts/groups): an "extracellular" crystalloid solution; APE-LM, a novel fluorochemical emulsion of perfluoroperhydrophenanthrene in egg yolk phospholipid; and FC-43, the Fluosol-43 (Oxypherol) fluorochemical emulsion of perfluorotributylamine in Pluronic F68. The emulsion media contained the same components as the crystalloid medium. All three media contained 0.5% albumin. An isolated working heart perfusion system was used to quantify the function of preserved hearts and controls (fresh hearts, n = 6). The APE-LM-preserved hearts were not significantly different from control hearts in contractile function, output, and energetics during a 4-h 37 degrees C reperfusion period. The control and APE-LM-preserved hearts had significantly better performance than crystalloid- and FC-43-preserved hearts. All preserved hearts gained fluid during preservation. The edema of APE-LM-preserved hearts, but not that of the other two preserved groups, was reversed during 37 degrees C reperfusion. These data provide the first evidence that a unique fluorochemical emulsion improves long-term preservation of cardiac tissue and produces significantly better recovery of cardiac function after preservation. This salutary effect was specifically associated with APE-LM emulsion and may result from its high O2 capacity, its biologically compatible emulsifier, and its superior physical properties, which include very small emulsion particle size (0.1-0.15 micron), low viscosity, and minimal toxicity.