Ability of 201Tl and 123I-BMIPP mismatch to diagnose myocardial ischemia in patients with suspected coronary artery disease.
OBJECTIVE
A mismatch defect between (201)TL and (123)I-BMIPP dual isotope SPECT (d-SPECT) is useful to detect myocardial ischemia in patients with acute coronary syndrome. However, whether mismatched d-SPECT findings reflect actual myocardial ischemia in stable patients with suspected, but unknown ischemic heart disease is unclear. The present study assesses the significance of a d-SPECT mismatch among such patients.


METHODS
Forty-nine patients with suspected stable coronary heart disease who had been referred for chest pain, ECG abnormalities or multiple risk factors (66 +/- 11 years old, 34 males) with a d-SPECT mismatch participated in this study. All of them underwent coronary angiography (CAG) to assess coronary artery disease. The entire myocardial area on d-SPECT images was divided into 17 segments, each of which was scored from 0 (normal) to 4 (defect). The d-SPECT mismatch score (MS) was defined as the summed BMIPP defect score (BM-TDS) minus the summed defect score (TL-TDS). The inclusion criterion was MS >or= 1, and the mismatch was defined as true positive if the mismatched area was concordant with the territories supplied by significant coronary stenotic arteries by CAG.


RESULTS
Ischemic heart disease was judged by coronary angiography in 31 (63%) patients (IHD group), of which 24 (49.0%) were true positives. Of the remaining 18 (37%) patients without no significant coronary stenosis (non-IHD group), 12 (24%) had some types of organic heart disease. If MS >or= 4 was defined as the threshold for an ischemic positive mismatch, then the sensitivity and specificity were 80% and 63%, respectively. However, mismatch scores did not significantly differ between the groups with true positive-IHD and organic heart disease in non-IHD group (6.6 +/- 4.4 vs. 6.4 +/- 3.7).


CONCLUSIONS
A d-SPECT mismatch score of >or=4 was an appropriate cutoff at which diagnosis of myocardial ischemia in patients who were screened for ischemic heart disease. However, since patients with non-ischemic but organic heart disease can also present with abnormal mismatch findings, coronary angiography or CT might be warranted to differentiate IHD from non-IHD.
Department of Cardiology, Tokyo Women's Medical University, Tokyo, Japan.
Ayako
A
Nakamura
Mitsuru
M
Momose
Chisato
C
Kondo
Takatomo
T
Nakajima
Kiyoko
K
Kusakabe
Nobuhisa
N
Hagiwara
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003324:Coronary Artery Disease / Q000150:complications*; D005189:False Positive Reactions; D005227:Fatty Acids; D005260:Female; D006801:Humans; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications* / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
D005227:Fatty Acids; D007462:Iodobenzenes; D013794:Thallium Radioisotopes; C049338:iodofiltic acid