Discordance between accumulation of C-14 deoxyglucose and Tl-201 in reperfused myocardium.

Radiolabeled deoxyglucose (FDG) has been advocated as a marker of viability of reperfused myocardium during acute infarction. However, data for such recommendation are few. We investigated cardiac deposition of C-14 deoxyglucose (C-14 DG) and of Thallium -201 (Tl-201) in rabbits subjected to coronary occlusion (15, 30, 60 or greater than 100 min) and reperfusion (75 min and 24 h). Measured myocardial concentrations of C-14 DG and Tl-201 in macroautoradiograms were quantitatively correlated in a 24 h reperfusion group with presence of myocardial necrosis evaluated by light microscopy. The major finding in this investigation was that with 30 min or 60 min of ischemia followed by reperfusion there were myocardial regions with significant hypoperfusion (Tl-201) and histologic necrosis. However, in the same myocardial areas, the deposition of C-14 DG was not correlated with the extent of necrosis (r = 0.27). Also, the deposition of C-14 DG in acute myocardial infarction was higher than that of Tl-201 (P = 0.05 by paired T test and by nonparametric Wilcoxon's test). It was also demonstrated that when the occlusion time was varied (15-130 min) and early reperfusion was provided for 75 min or omitted altogether, the myocardial accumulation of Tl-201 was variable and that myocardial sequestration of C-14 DG was higher than perfusion in central and peripheral portions of the area-at-risk. These observations do not support a role for the use of radiolabeled deoxyglucose for the detection of myocardial viability in recently infarcted cardiac muscle.