To evaluate the ability to detect
coronary artery disease (CAD) with a new
iodine-123 labeled branched
fatty acid analog, iodophenyl-9-methyl
pentadecanoic acid (
9MPA), we performed
9MPA,
iodine-123 BMIPP and
thallium-201 SPECT in patients with CAD. Twenty-four patients (11 with effort angina and 13 with
myocardial infarction) were studied. In all patients,
9MPA SPECT was obtained at 15 min after injection. Twenty-three patients underwent stress-redistribution 201Tl SPECT and 9 patients also underwent
BMIPP myocardial
fatty acid imaging. The regional uptakes of
9MPA,
BMIPP and 201Tl were scored semiquantitatively and the segmental agreements were compared among them. In the segment-to-segment comparison,
9MPA showed reduced activity in comparison to stress-redistribution 201Tl imaging. The defect score of
9MPA was significantly greater than that of redistribution 201Tl images (p < 0.001). In addition, segmental
9MPA uptake was lower than
BMIPP and its defect score was significantly greater than that of
BMIPP (p < 0.05). When coronary angiography was used as the criterion,
9MPA showed higher sensitivity and lower specificity than stress-redistribution 201Tl (p < 0.01). In conclusion,
fatty acid metabolic imaging with
9MPA is a sensitive but nonspecific detector of CAD.