Enhanced regional washout of technetium-99m-sestamibi in patients with coronary spastic angina.
BACKGROUND
Reverse redistribution and rapid washout of 99mTc-sestamibi are observed in patients with acute myocardial infarction and may indicate viable myocardium. However, the clinical significance of this phenomenon has not been rigorously examined in other cardiac diseases. Thus, we investigated whether reverse redistribution and washout of 99mTc-sestamibi could be used in the diagnosis and follow-up of patients with coronary spastic angina.


METHODS
Thirty patients diagnosed as coronary spastic angina were examined. During coronary arteriography, spasm was induced by provocation test with ergonovine, and only total or subtotal occlusion was considered positive. Myocardial perfusion tomography was obtained 45 min (early) and 3 hr (delayed) after 99mTc-sestamibi injection. Segmental defect score was visually graded from 0 (normal) to 4 (defect), and a total defect score was determined as the sum of defect scores for all segments. Washout rate of 99mTc-sestamibi from the myocardium was calculated for each segment. After medical treatment with calcium antagonists and nitrates for 3 months, 99mTc-sestamibi imaging was repeated.


RESULTS
Out of 30 patients, on the early images 17 (57%) patients demonstrated decreased 99mTc-sestamibi uptake in spastic segments; on the other hand, 24 (80%) patients did decreased 99mTc-sestamibi uptake in spastic segments on delayed images. Total defect scores in delayed images were higher than those in early images (6.9 +/- 0.3 vs. 3.6 +/- 0.4, p < 0.01). Reverse redistribution of 99mTc-sestamibi was observed in 17 out of 30 patients (57%) with coronary spastic angina. Washout rate of 99mTc-sestamibi from spastic segments was higher than that from non-spastic segments (16 +/- 2% vs. 11 +/- 5%, p < 0.01). After medical treatment, washout rate from spastic segments was decreased to 10 +/- 4 (p < 0.01), and left ventricular ejection fraction was increased from 63 +/- 8% to 73 +/- 4% (p < 0.01).


CONCLUSIONS
Rapid washout of 99mTc-sestamibi was observed in patients with coronary spastic angina and might indicate that the ability of myocyte to retain the tracer was impaired due to repetitive brief ischemia by coronary spasm. The early and delayed 99mTc-sestamibi imaging provides useful information for the diagnosis and responses to the treatment in patients with coronary spastic angina.
Ono
Souichi
S
Department of Radiology and Cardiology, Yamagata Prefectural Shinjo Hospital, Japan.
Takeishi
Yasuchika
Y
Yamaguchi
Hiroyuki
H
Abe
Shigeru
S
Tachibana
Hidetada
H
Sato
Takayuki
T
Kubota
Isao
I
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D003329:Coronary Vasospasm / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism*; D004874:Ergonovine; D005260:Female; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009566:Nitrates / Q000627:therapeutic use; D011865:Radioisotope Dilution Technique; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics*
D002121:Calcium Channel Blockers; D009566:Nitrates; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D004874:Ergonovine