Clinical Value of F-18-Fluorodeoxyglucose Positron Emission Tomographic Imaging of Myocardial Viability Is Dependent on Adherence to Treatment Strategy Based on Imaging Results.

It has been 30 years since publication of the landmark article in the New England Journal of Medicine, by Tillisch et al, which reported improvement in regional wall motion after revascularization of dysfunctional myocardium that demonstrated viability by positron emission tomographic (PET) imaging. Viability was defined as a mismatch between myocardial blood flow and F-18-fluorodeoxyglucose (FDG) uptake, where resting flow was diminished in areas of enhanced FDG uptake. In contrast, regions of myocardium that showed a match between reduced blood flow and reduced FDG uptake were considered to have poor or no viability. There was no significant reversibility in wall motion abnormalities after revascularization in such nonviable segments. Since that report, a large number of observational studies and one randomized trial, using various noninvasive techniques, have been performed to assess the clinical value of viability imaging for decision making on which patients with ischemic cardiomyopathy would benefit most from revascularization versus medical therapy. Despite these many studies, controversy persists to this day as to whether viability imaging is useful for making such clinical decisions.