EFFECTS OF PERFLUOROCARBON EXCHANGE-TRANSFUSION ON REDUCING MYOCARDIAL INFARCT SIZE IN A PRIMATE MODEL OF ISCHEMIA-REPERFUSION INJURY - A PROSPECTIVE, RANDOMIZED STUDY

Background. This study was undertaken to test the hypothesis that perf luorocarbons were able to reduce myocardial infarct size in a baboon m odel of ischemia-reperfusion injury. Exchange transfusion of perfluoro carbons has been shown to reduce myocardial infarct size in the dog, w ho, unlike the baboon, has an extensive collateral circulation. Method s. After 15 minutes of occlusion of the left anterior descending coron ary artery, 14 baboons were bled to attain a hematocrit of 24% to 26% and were simultaneously transfused six with Fluosol-DA 20% emulsion an d eight with FC-43 emulsion. After 2 hours of ligation, the coronary a rteries were reperfused. Baboons were killed 24 hours after ligation, and the hearts were excised. Microvascular dye was infused into the co ronary artery to delineate its perfusion bed. Ratios of the mean volum e of infarct to the mean volume of perfusion bed were calculated and c ompared by use of planimetry. A similar protocol was followed in two o ther groups of baboons except that lactated Ringer's solution was infu sed into six of then, whereas eight had no exchange transfusions. Resu lts. The ratios of the mean volume of infarct to the mean volume of pe rfusion bed of the four groups were as follows. Fluosol-DA, 38.1% +/- 7.5%; FC-43, 37.7% +/- 8.3%; lactated Ringer's, 46.9% +/- 10.5%; contr ols, 65.6% +/- 6.9%. Statistical significance was reached when compari ng both perfluorocarbon-treated groups with the controls (p < 0.05 for both groups) but not significant when comparing them with the Ringer' s lactate-treated group. Conclusions. Results suggest that the benefic ial effects of exchange transfusion with the perfluorocarbons may be p rimarily due to hemodilution.