Worsening of left ventricular ejection fraction induced by dipyridamole on Tl-201 gated myocardial perfusion imaging predicts significant coronary artery disease.
BACKGROUND
Vasodilator stress on myocardial perfusion imaging has been found to induce ischemic stunning, which may present as transient worsening of left ventricular ejection fraction (LVEF) or regional wall motion abnormality. This study aimed to evaluate the significance of stress-induced worsening of LVEF in the diagnosis of coronary artery disease (CAD) on dipyridamole thallium 201 gated single photon emission computed tomography (SPECT).


RESULTS
The study included 126 patients who underwent dipyridamole Tl-201 gated SPECT and coronary angiography within 3 months. Poststress and 4-hour rest images were obtained, and LVEF was calculated by use of automated software (QGS 3.0). A decrease in LVEF of 6% or greater from rest to poststress was considered significant, and this threshold was determined by the serial reproducibility assessment of Tl-201 gated SPECT. If worsening of LVEF was used as the criterion for detecting significant CAD (> or = 70% coronary stenoses in > or = 1 vessel), the sensitivity, specificity, positive predictive value, and negative predictive value were 35%, 93%, 90%, and 44%, respectively.


CONCLUSIONS
Dipyridamole-induced worsening of LVEF, as shown by Tl-201 gated SPECT, is a valuable nonperfusion marker of significant CAD. Although the sensitivity of LVEF worsening in detecting significant CAD is only 35%, the specificity is as high as 93%.
Department of Nuclear Medicine, Changhua Christian Hospital, Changhua, Taiwan.
Guang-Uei
GU
Hung
Kung-Wei
KW
Lee
Ching-Pei
CP
Chen
Kuang-Tao
KT
Yang
Wan-Yu
WY
Lin
D000368:Aged; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D005080:Exercise Test / Q000379:methods*; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000187:drug effects; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D066298:In Vitro Techniques; D008297:Male; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000187:drug effects*; D013793:Thallium; D014665:Vasodilator Agents; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology
D019275:Radiopharmaceuticals; D014665:Vasodilator Agents; C027549:thallium chloride; D004176:Dipyridamole; D013793:Thallium