Incremental value of 18F-FDG cardiac PET imaging over dobutamine stress echocardiography in predicting myocardial ischemia in patients with suspected coronary artery disease

Background. To assess the incremental value of 18F-fluorodeoxyglucose (FDG) cardiac positron emission tomography (PET) over dobutamine stress echocardiography (DSE) in predicting myocardial ischemia in patients with suspected coronary artery disease (CAD). Methods. Forty-one patients with suspected CAD underwent within 7 days apart rest-stress cardiac PET with 82Rb and DSE followed by cardiac 18F-FDG PET imaging. 18F-FDG images were scored on a 0 (no discernible uptake) to 2 (intense uptake) scale. Logistic regression analysis was performed to identify predictors of stress-induced ischemia. The incremental value of 18F-FDG PET over DSE in detecting ischemia at 82Rb PET cardiac imaging was assessed by the likelihood ratio chi-square and net reclassification index. Results. On 82Rb-PET imaging, myocardial ischemia (ischemic total perfusion defect > 5%) was detected in 20 (49%) patients. Inducible ischemia was found in 22 (54%) patients on DSE (biphasic or worsening response pattern in > 1 segment) and in 21 (51%) patients on 18FFDG PET (uptake score of 2 in ‡ 1 segment). 18F-FDG PET resulted as statistically significant predictor of ischemia on 82Rb-PET. The addition of 18F-FDG PET to DSE increased the likelihood of ischemia on 82Rb-PET (P < .05). 18F-FDG PET was able to reclassify the probability of stress-induced myocardial ischemia on both patient and vessel analyses. Conclusion. 18F-FDG PET performed after dobutamine stress test may provide incremental value to DSE in the evaluation of myocardial ischemia. These results suggest that stress induced myocardial ischemia can be imaged directly using 18F-FDG PET after dobutamine stress test.