Reversibility of Cardiac Wall-Motion Abnormalities Predicted by Positron Tomography

Abstract

Positron emission tomography (PET) can be used with nitrogen-13-ammonia (13NH3) to estimate regional myocardial blood flow, and with fluorine-18-deoxyglucose (18FDG) to measure exogenous glucose uptake by the myocardium. We used PET to predict whether preoperative abnormalities in left ventricular wall motion in 17 patients who underwent coronary-artery bypass surgery were reversible. The abnormalities were quantified by radionuclide or contrast angiography or both, before and after grafting. PET images were obtained preoperatively. Abnormal wall motion in regions in which PET images showed preserved glucose uptake was predicted to be reversible, whereas abnormal motion in regions with depressed glucose uptake was predicted to be irreversible. According to these criteria, abnormal contraction in 35 of 41 segments was correctly predicted to be reversible (85 percent predictive accuracy), and abnormal contraction in 4 of 26 regions was correctly predicted to be irreversible (92 percent predictive accuracy). In contrast, electrocardiograms showing pathological Q waves in the region of asynergy predicted irreversibility in only 43 percent of regions. We conclude that PET imaging with 13NH3 to assess blood flow and 18FDG to assess the metabolic viability of the myocardium is an accurate method of predicting potential reversibility of wall-motion abnormalities after surgical revascularization.

Medical and Cellular Implications of Stunning, Hibernation, and Preconditioning

“…From 7 to 14 days after operation, there was an increase in global ejection fraction from 53% to 71%. Tillisch et al 120 showed with PET that they could identify areas of reduced perfusion that were metabolically active. After surgical revascularization, the majority of these segments recovered function.…”

Positron emission tomography probe demonstrates a striking concentration of ribose salvage in the liver

“…PET is used for imaging and quantifying changes in wholebody metabolism through the use of radiolabeled substrates (13 F]FDG has been extensively used both preclinically and clinically to study glucose metabolism in vivo, including to identify metabolic changes during brain development, to monitor myocardial viability, and to image and identify tumors in vivo (13)(14)(15). We reasoned that a PET probe for measuring and imaging ribose salvage could provide unique and novel information on this understudied pathway in vivo.…”

Characterization of Dysfunctional Myocardium by Positron Emission Tomography and Magnetic Resonance

“…[2][3][4][5][6][7] Up to 83% to 95% [7][8][9] of segments with inotropic reserve on ␤ 1 -adrenergic stimulation recover function after revascularization. Although scintigraphic techniques appear more sensitive for detection of viability, their specificity to predict functional recovery is in general somewhat lower, ranging from 48% to 82%.…”