Myocardial 18F-FDG uptake after exercise-induced myocardial ischemia in patients with coronary artery disease.
We have recently demonstrated the potential of (18)F-FDG as an imaging marker of myocardial ischemia if injected at peak exercise. However, how long increased (18)F-FDG uptake can be observed after an episode of exercise-induced myocardial ischemia is not known. We performed the current study to determine whether increased regional myocardial (18)F-FDG uptake at exercise in patients with coronary artery disease (CAD) persists on rest imaging (24 h later), after an episode of exercise-induced myocardial ischemia.


METHODS
Twenty-four patients with suspected CAD underwent exercise (99m)Tc-sestamibi and (18)F-FDG imaging. Repeated (18)F-FDG imaging was performed 24 h after exercise imaging, after an injection of a second dose of (18)F-FDG at rest in 20 patients. Perfusion imaging with (99m)Tc-sestamibi was simultaneously performed with (18)F-FDG imaging. All patients underwent coronary angiography.


RESULTS
Eighteen patients had greater than or equal to 70% luminal narrowing of 1 or more coronary vessels. Fifteen patients (83%) showed increased regional (18)F-FDG uptake on exercise imaging, but only 11 patients (61%) had perfusion abnormalities. Of these 15 patients with increased regional (18)F-FDG uptake on exercise imaging, 8 (53%) had no discernible (18)F-FDG uptake, 5 (33%) had decreased (18)F-FDG uptake, and only 2 (13%) had persistent (18)F-FDG uptake on rest (18)F-FDG images. The summed (18)F-FDG uptake score significantly decreased, from 14.4 +/- 10.3 at exercise to 6.7 +/- 9.2 at rest (P = 0.01). Patients with persistent (18)F-FDG uptake at rest had more (18)F-FDG uptake and lower peak rate-pressure product at exercise, compared with patients with no residual (18)F-FDG uptake at rest.


CONCLUSIONS
Exercise-induced regional myocardial (18)F-FDG uptake is highly specific and sensitive for exercise-induced myocardial ischemia. Regional myocardial (18)F-FDG uptake may persist 24 h after an episode of exercise-induced myocardial ischemia in some patients.
Dou
Ke-Fei
KF
Department of Cardiology, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Yang
Min-Fu
MF
Yang
Yue-Jin
YJ
Jain
Diwakar
D
He
Zuo-Xiang
ZX
D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism*; D005080:Exercise Test; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism*; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18