Relationship of thallium-201 clearance on exercise stress myocardial scintigraphy to coronary flow reserve in patients with coronary artery disease.
OBJECTIVE
We evaluated thallium-201 (201Th) clearance measurement during exercise myocardial scintigraphy in patients with coronary artery disease, for the assessment of coronary circulatory function and diagnosis.


METHODS
The clearance rate of 201Th was compared with the coronary flow reserve measured by Doppler coronary flow velocimetry.


METHODS
We selected 20 patients who had chronic stable angina with single-vessel coronary artery disease of the left anterior descending artery (LAD) and underwent percutaneous transluminal coronary angioplasty (PTCA). Ten control patients had atypical chest pain but no detectable heart disease. Regional net clearance of 201Th was measured from the early and delayed bull's-eye images of 201Th exercise stress single photon emission tomography (SPECT). Using a Doppler catheter, we also measured coronary flow reserve of the LAD, which was obtained by the intracoronary administration of papaverine.


RESULTS
The net 201Th clearance in the anterior wall myocardium in the patients with coronary artery disease before PTCA was significantly less than that in the controls. At follow-up angiography after successful PTCA, it increased. The coronary flow reserve before PTCA was also lower than that in the controls. It was increased immediately after PTCA, and was more markedly increased at the follow-up angiography. Before PTCA, regional net clearance in the anterior myocardium was correlated with the coronary flow reserve of the LAD. The ratio for the net clearance of the anterior myocardium at follow-up angiography to that before PTCA was also correlated with the ratio for coronary flow reserve.


CONCLUSIONS
In patients with coronary artery disease, the regional 201Th clearance in the ischaemic area measured by exercise 201Th SPECT is correlated with the coronary flow reserve of the affected artery. Moreover, the increase in the clearance rate after PTCA is also correlated with that in the coronary flow reserve. Thus the measurement of regional 201Th clearance might be a useful non-invasive method of estimating of the coronary flow reserve.
Inoue
T
T
Department of Cardiology, Koshigaya Hospital, Dokkyo University School of Medicine, Saitama, Japan.
Fujito
T
T
Hoshi
K
K
Yamaguchi
H
H
Sakai
Y
Y
Takayanagi
K
K
Morooka
S
S
D000704:Analysis of Variance; D015906:Angioplasty, Balloon, Coronary; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000628:therapy; D005080:Exercise Test / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017078:Laser-Doppler Flowmetry / Q000379:methods; D008297:Male; D008875:Middle Aged; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D016277:Ventricular Function, Left
D013794:Thallium Radioisotopes