Sm. Martin et al., PERFLUOROCHEMICAL REPERFUSION YIELDS IMPROVED MYOCARDIAL RECOVERY AFTER GLOBAL-ISCHEMIA, The Annals of thoracic surgery, 55(4), 1993, pp. 954-960
Reperfusion injury remains a limiting factor in extending ischemic sto
rage time for human heart transplantation. In this study, initial myoc
ardial reperfusion with an oxygenated perfluorochemical (Fluosol) was
investigated as a means of limiting such injury. Neonatal piglet heart
s were arrested with crystalloid cardioplegia, excised, and stored for
12 hours in saline solution at 0-degrees-C. Initial reperfusion (10 m
inutes) was either with whole blood (n = 6), unmodified perfluorochemi
cal (n = 8), or aspartate/glutamate-enriched perfluorochemical cardiop
legia (n = 6), and was followed by an additional 40 minutes of whole b
lood perfusion. Functional evaluation was then completed, and left ven
tricular biopsy specimens were taken. A control group (n = 7) was eval
uated without an intervening period of ischemia. At a left ventricular
end-diastolic pressure of 9 mm Hg, hearts stored in whole blood cardi
oplegia developed a left-ventricular stroke work index of 3.8 +/- 2.3
x 10(3) erg/g (mean +/- standard error of the mean). Under the same co
nditions, perfluorochemical-reperfused hearts achieved a stroke work i
ndex of 14.6 +/- 1.3 x 10(3) erg/g, significantly greater than that of
the whole blood group (p < 0.001). Stroke work index for hearts reper
fused with aspartate/glutamate-enriched perfluorochemical cardioplegia
was 19.8 +/- 1.6 x 10(3) erg/g, significantly increased over that of
the nonenriched perfluorochemical group (p < 0.01) and not different f
rom values obtained in controls (19.2 +/- 0.8 x 10(3) erg/g). In addit
ion, perfluorochemical-reperfused hearts demonstrated superior mainten
ance (p < 0.05) of adenosine triphosphate (2.08 +/- 0.16 mumol/g) comp
ared with the whole blood group (1.50 +/- 0.19 mumol/g), whereas prese
rvation of adenosine triphosphate in the enriched perfluorochemical gr
oup (2.99 +/- 0.12 mumol/g) was significantly increased over that of t
he nonenriched perfluorochemical group (p < 0.001 mumol/g) and not sig
nificantly different from that in controls (2.68 +/- 0.17 mumol/g). El
ectron microscopy revealed notably improved preservation of ultrastruc
tural architecture in perfluorochemical-treated hearts (with or withou
t aspartate/glutamate) compared with the whole blood group. We conclud
e that initial reperfusion of the postischemic myocardium with oxygena
ted perfluorochemical ameliorates the deleterious effects of whole blo
od reperfusion. In addition, amino acid enrichment, buffer supplementa
tion, and chemical cardioplegia enhance this effect, allowing for comp
lete functional recovery of the piglet myocardium after 12 hours of hy
pothermic ischemia.