[18F]Fluorodeoxyglucose as a memory marker of transient myocardial ischaemia.
BACKGROUND
Experimental data have shown that glucose utilization increases during acute myocardial ischaemia, and may persist for up to 24 h. Whether fluorodeoxyglucose (FDG) uptake can be imaged as a memory marker of ischaemia in humans is unknown.


METHODS
Patients with mild-to-moderate ischaemia on exercise single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) underwent repeat exercise testing within 1-2 weeks. Positron emission tomography (PET) was performed after injection of FDG 60 min post-exercise. SPECT and PET images were assessed visually, aided by circumferential profile-based analysis modified for 'hot-spot' imaging.


RESULTS
Twelve men with stress SPECT ischaemia (mean age, 69 years; nine with known coronary artery disease) were studied. The mean rate-pressure products for the first (SPECT) and second (FDG PET) exercise tests were similar (22,841+/-7321 vs. 22,680+/-7393 mmHg x bpm, P=NS). Overall, six of 12 patients studied had evidence of FDG uptake. The extent of ischaemia on SPECT was similar in FDG positive and FDG negative patients (summed difference score 10.6+/-6.9 vs. 8.0+/-1.6, P=NS). All patients with a positive FDG scan had uptake in either an ischaemic SPECT region or in a territory with known CAD by angiography.


CONCLUSIONS
Regional myocardial uptake of FDG is enhanced even when injected 1 h post-exercise stress in a subset of patients with ischaemia on exercise SPECT MPI. The ability to image FDG uptake injected 1 h after an ischaemic episode suggests the potential utility of FDG as a memory marker of transient ischaemia.
Abbott
Brian G
BG
Division of Cardiology, Brown Medical School, Rhode Island Cardiology Center, Providence, Rhode Island, USA.
Liu
Yi-Hwa
YH
Arrighi
James A
JA
D000368:Aged; D000792:Angiography / Q000379:methods; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D017202:Myocardial Ischemia / Q000188:drug therapy*; D009206:Myocardium / Q000473:pathology; D010477:Perfusion; D049268:Positron-Emission Tomography / Q000379:methods*; D011312:Pressure; D015203:Reproducibility of Results; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D019788:Fluorodeoxyglucose F18