Prediction of myocardial viability: Tl-201 versus sestamibi versus teboroxime compared with FDG uptake

Several radionuclide imaging agents have been used for assessing the presence of myocardial viability. These include Tl-201 chloride, Tc-99m sestamibi, and Tc-99m teboroxime. Currently, the most reliable indicator is F-18 FDG, which accumulates in severely hypoperfused myocardium, indicating preserved metabolic activity. The presence of chronically ischemic myocardium that has preserved metabolic activity is referred to as "hibernating" myocardium. In this series, the ability of Tl-201, sestamibi, and teboroxime to establish the existence of viable myocardium was compared with that of F-18 FDG. Seventy-seven patients with ischemic cardiomyopathy were referred for determination of myocardial viability. FDG images were compared with representative resting blood-flow images obtained from either: 1) 24 hour Tl-201 reinjection-redistribution images, 2) resting sestamibi blood-flow images, or 3) early images from resting teboroxime washout analysis. Tl-201 was found to underestimate myocardial viability in 41% of patients, Tc-99m sestamibi underestimated viability in 38% of patients, and Tc-99m teboroxime underestimated viability in 26% of patients. There was no significant difference in the prediction of viable myocardium among the three radiopharmaceuticals, as all three underestimated myocardial viability.