Comparison of continuous microperfusion and cold storage for pig heart preservation

The aim of this study was to compare two methods of hypothermic heart preservation. Isolated hearts of pigs were preserved in cold cardioplegic solution (St. Thomas Hospital solution) either by simple storage or continuous microperfusion (with a new perfusion device) for 6 hours (group I, n = 12), 12 hours (group II, n = 12) and 24 hours (group III, n = 12). After storage, the myocardial function was studied for 60 minutes under nonworking conditions with an ex vivo functional testing system. Hearts preserved 24 hours by cold storage (group III) showed ventricular compliance and mean spontaneous left ventricular developed pressure significantly lower than hearts preserved by microperfusion (respectively, 63 +/- 47 versus 14 +/- 18 mm Hg and 16.8 +/- 22.0 versus 83 +/- 33 mm Hg). After 12 hours (group II) of preservation, mean left ventricular developed pressure was higher in microperfused hearts compared to immersed hearts (respectively, 133.3 +/- 39.0 versus 83.1 +/- 27.0 mm Hg, p < 0.05), whereas after 6 hours of preservation, no functional difference was observed between the microperfused and the immersed hearts. Hearts were also studied using myocardial biopsy specimens taken at the end of the preservation. The biopsy specimens were analyzed for high-energy phosphates. After 6 hours of preservation, the microperfusion group showed higher levels of adenosine triphosphate and total adenine nucleotides (adenosine triphosphate + adenosine diphosphate + adenosine monophosphate) (respectively, 4.60 +/- 0.5 mumol/gm and 5.98 +/- 0.5 mumol/gm fresh tissue) versus the cold storage group (respectively, 3.10 +/- 0.4 mumol/gm and 3.75 +/- 0.4 mumol/gm).(ABSTRACT TRUNCATED AT 250 WORDS)