[Diagnostic and prognostic evaluation of unstable angina pectoris using ECG-gated single photon emission computed tomography (SPECT) with 99mTc-tetrofosmin].

Purpose: The purpose of this study is to the diagnostic accuracy and the value as prognostic predictors based on the perfusion and/or functional analysis using the QGS program on 99mTc-tetrofosmin gated SPECT (Tf-QGS-SPECT) in patients with unstable angina pectoris (UAP) who admitted to the CCU.

Methods: Fifty seven consecutive patients (37 males and 20 females, mean age: 62 +/- 7 years) with suspected UAP, who underwent Tf-QGS-SPECT and coronary angiography, were entered into this study. We compared the accuracy for diagnosing UAP in the following 3 analyses: 1. Perfusion analysis alone, 2. Functional analysis alone, 3. Perfusion analysis with functional analysis. In addition, we evaluated the prognostic values of the perfusion and/or functional analysis with Tf-QGS-SPECT.

Results: Thirty-five of 57 patients with suspected UAP had significant coronary stenosis. The highest accuracy was obtained by adequate combination of perfusion and functional analysis (sensitivity 83%, specificity 82%, accuracy 82%). Thirteen of 29 patients with positive findings in this analysis needed emergent or urgent coronary revascularization. Five of 6 patients with false negative findings in this analysis were left circumflex artery lesions, and two of these patients needed emergent coronary revascularization.

Conclusion: Evaluation with perfusion and functional images using Tf-QGS-SPECT is useful to improve the accuracy of diagnosis and to predict the prognosis of patients with UAP who admitted to the CCU.