[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.