Presurgical identification of hibernating myocardium by combined use of technetium-99m hexakis 2-methoxyisobutylisonitrile single photon emission tomography and fluorine-18 fluoro-2-deoxy-d-glucose positron emission tomography in patients with coronary artery disease

We tested the possibility of identifying areas of hibernating myocardium by the combined assessment of perfusion and metabolism using single photon emission tomography (SPET) with technetium-99m hexakis 2-methoxyisobutylisonitrile (^99mTc-MIBI) and positron emission tomography (PET) with fluorine-18 fluoro-2-deoxy-d-glucose (¹⁸F-FDG). Segmental wall motion, perfusion and ¹⁸F-FDG uptake were scored in 5 segments in 14 patients with coronary artery disease (CAD), for a total number of 70 segments. Each subject underwent the following studies prior to and following coronary arterybypass grafting (CABG): first-pass radionuclide angiography, electrocardiography gated planar perfusion scintigraphy and SPET perfusion scintigraphy with ^99mTc-MIBI and, after 16 h fasting, ¹⁸F-FDG/PET metabolic scintigraphy. Wall motion impairment was either decreased or completely reversed by CABG in 95% of the asynergic segments which exhibited ¹⁸F-FDG uptake, whereas it was unmodified in 80% of the asynergic segments with no ¹⁸-FDG uptake. A stepwise multiple logistic analysis was carried out on the asynergic segments to estimate the postoperative probability of wall motion improvement on the basis of the preoperative regional perfusion and metabolic scores. The segments with the highest probability (96%) of functional recovery from preoperative asynergy after revascularization were those with a marked ¹⁸F-FDG uptake prior to CABG. High probabilities of functional recovery were also estimated for the segments presenting with moderate and low ¹⁸F-FDG uptake (92% and 79%, respectively). A low probability of functional recovery (13 %) was estimated in the segments with no ¹⁸F-FDG uptake. Despite the potential limitations due to the semiquantitative analysis of the images, the method appears to provide reliable information for the diagnostic and prognostic evaluation of patients with CAD undergoing CABG and confirms that the identification of hibernating myocardium with ¹⁸F-FDG is of paramount importance in the diagnosis of patients undergoing CABG.