Abstract
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Objectives: We have previously shown the feasibility and high sensitivity of imaging exercise-induced myocardial ischemia with 18F-FDG in patients who underwent simultaneous myocardial perfusion and ischemia imaging following the injection of 99mTc-sestamibi and 18F-FDG at peak exercise. This study is designed to address whether enhanced 18F-FDG uptake at exercise would be persistent at 24 hours after exercise.
Methods: Fifteen patients with angiographic coronary artery disease and chronic stable angina were enrolled. None of them had evidence of prior myocardial infarction. Left ventricular wall motion was assessed by echocardiography and no patients had wall motion abnormalities. After overnight fasting, patients underwent simultaneous myocardial perfusion and ischemia imaging after intravenous injection of 99mTc-sestamibi and 18F-FDG at peak exercise using a dual-head SPECT equipped with ultra-high-energy parallel-hole collimators. Rest imaging was performed 24 hours later. Myocardial images were analyzed using a 17-segment model. Myocardial perfusion was scored on a 0 to 4 scale and 18F-FDG uptake was scored on a 0 to 2 scale. The summed 18F-FDG uptake score was obtained by adding 18F-FDG uptake score of each segment.
Results: Coronary angiography demonstrated 1-vessel disease in 2 patients, 2-vessel disease in 7 patients and 3-vessel disease in 6 patients. Exercise-rest 99mTc-sestamibi images were abnormal in 11 patients and normal in 4 patients. All patients showed enhanced 18F-FDG uptake on exercise images. Of them, 8 (53%) patients had no discernible 18F-FDG uptake, 5 (33%) had decreased and only 2 (13%) had persistent 18F-FDG uptake on rest images. The summed 18F-FDG uptake score and the number of segments showing 18F-FDG uptake were significantly lower on rest images compared with exercise images (Table).
Conclusions: Exercise-induced myocardial 18F-FDG uptake significantly decreases 24 hours after an episode of exercise-induced myocardial ischemia in majority of patients with chronic stable angina.
- Society of Nuclear Medicine, Inc.