Fatty acid metabolic imaging with iodine-123-BMIPP for the diagnosis of coronary artery disease.
Iodine-123-BMIPP kinetics under high glucose levels were examined. The feasibility of 123I-BMIPP imaging after oral glucose loading for the detection of impaired fatty acid metabolism was tested in patients with coronary artery disease.


METHODS
Fatty acid metabolic imaging with 123I-BMIPP was performed on 29 patients in the fasting state and repeated after oral glucose loading. Myocardial SPECT images were obtained 20 min and 4 hr after the injection of 123I-BMIPP. Myocardial uptake of 123I-BMIPP was calculated by a Ishii-Macintyre method and the clearance of 123I-BMIPP from the myocardium was determined as (early counts-delayed counts) x 100/early counts. Regional accumulation of 123I-BMIPP was scored semiquantitatively from 0 (normal) to 4 (no activity), and the sum of regional scores in each patient was defined as a total defect score (TDS).


RESULTS
Total myocardial uptake of 123I-BMIPP was 1.7% +/- 0.4% in the fasting state and 1.6% +/- 0.3% after oral glucose loading (p < 0.05). Iodine-123-BMIPP clearance from the myocardium was faster after glucose loading than in the fasting state (27% +/- 8% versus 11% +/- 6%, p < 0.01). After glucose loading, 123I-BMIPP clearance was faster in the ischemic myocardium (defined as areas perfused by stenosed coronary artery exceeding 90%) than in the nonischemic myocardium (33% +/- 8% versus 25% +/- 9%, p < 0.05). TDS in the ischemic myocardium increased from 1.8 +/- 0.4 in the fasting state to 2.1 +/- 0.4 after glucose loading (p < 0.01). The sensitivity for detecting coronary stenosis exceeding 90% increased from 55% (11/20) in the fasting state to 75% (15/20) after glucose loading without a loss of specificity (78%, 7/9).


CONCLUSIONS
Oral glucose loading enhanced the detection of areas with impaired fatty acid metabolism due to coronary artery narrowing. Iodine-123-BMIPP imaging with oral glucose loading may be a new approach for the noninvasive diagnosis of coronary artery disease.
Fujiwara
S
S
First Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Takeishi
Y
Y
Atsumi
H
H
Takahashi
K
K
Tomoike
H
H
D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000378:metabolism; D005215:Fasting; D005227:Fatty Acids / Q000378:metabolism / Q000493:pharmacokinetics; D005240:Feasibility Studies; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007462:Iodobenzenes / Q000493:pharmacokinetics; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
D005227:Fatty Acids; D007328:Insulin; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; C049338:iodofiltic acid; D017256:Technetium Tc 99m Sestamibi; D005947:Glucose