OBJECTIVE: Determine the the normal threshold for an automatically measured left ventricular transient ischemic dilation (TID) ratio in patients undergoing adenosine stress myocardial perfusion SPECT (MPS). Furthermore, to determine the value of integrating TID in detecting severe and extensive coronary artery disease (CAD). METHODS: The normal limit for the TID ratio was obtained from 38 low risk patients undergoing dual-isotope MPS. To determine criteria for abnormality, 179 consecutive patients with an abnormal catheterization within 3 months of adenosine MPS were examined: 41 patients (23%) had severe and extensive CAD, 64 (36%) had no significant CAD, and 74 (41%) had mild or moderate CAD. These high risk criteria were then prospectively validated in a
cohort of 177 patients. A receiver-operating characteristic curve was used to define optimal thresholds. RESULTS: The best threshold to define an abnormal TID ratio was > 1.36, which had a sensitivity of 71% and specificity of 86% compared to extensive CAD by catheterization. In the combined pilot and validation groups, when both perfusion and the TID ratio were normal, the negative predictive value was 99%. When both the TID ratio and perfusion were abnormal, the positive predictive value was 65%. CONCLUSION: The TID ratio both sensitive and specific for the identification of severe and extensive CAD.

COMMENT: when both myocardial perfusion and the TID ratio are normal, the patient almost certainly does not have significant obstructive disease on angiography.


J Nucl Med. 2004 Dec;45(12):1999-2007.

Integration of automatically measured transient ischemic dilation ratio into interpretation of adenosine stress myocardial perfusion SPECT for detection of severe and extensive CAD.

Abidov A, Bax JJ, Hayes SW, Cohen I, Nishina H, Yoda S, Kang X, Aboul-Enein F, Gerlach J, Friedman JD, Hachamovitch R, Germano G, Berman DS.

Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.