Determination of myocardial viability with ECG-gated fluorodeoxyglucose F-18 positron emission tomography

Objective: We hypothesize that ECG-gated positron emission tomography (PET) using Fluorodeoxyglucose F-18 (FDG) alone can determine myocardial viability by identifying dysfunctional myocardium with preserved glucose metabolism. We compared the contraction-metabolism pattern of gated FDG PET with the perfusion-metabolism pattern of conventional PET using N-13 ammonia (NH₃) as a perfusion agent and FDG as a glucose metabolism agent in 21 consecutive patients with chronic coronary artery disease with left ventricular dysfunction (mean ejection fraction 23.6 ± 7.7%). Methods: The left ventricle was divided into 17 segments. Uptakes of NH₃ and FDG were scored from absent (0) to normal (4), and wall motion was scored from dyskinesia (-1) to normal (3). Scores were determined by the visual interpretation of the majority of 3 blinded expert readers. Viable myocardium was defined by normal or mildly reduced uptakes of both NH₃ and FDG, perfusion-metabolism mismatch on NH₃-FDG PET, or normal to mildly reduced uptake of FDG with regional dysfunction on gated FDG PET. Results: Gated FDG PET identified 184 segments as viable, all of which were determined as viable by NH₃-FDG PET. Among 125 segments identified as nonviable by NH₃-FDG PET, 76 segments were determined as nonviable by NH₃-FDG PET. The results provided a positive and negative predictive value of gated FDG PET for the determination of myocardial viability to be 100% and 60.8%, respectively. Conclusions: Gated FDG PET has a high positive predictive value (100%) for the identification of viable myocardium.