Prognostic value of normal exercise 99mTc-sestamibi myocardial tomography in patients with angiographic coronary artery disease

BACKGROUND AND AIM: Previous studies have documented the prognostic value of normal exercise Tl myocardial perfusion imaging in patients with angiographic coronary artery disease (CAD). However, data on exercise Tc-sestamibi myocardial single photon emission computed tomography (SPECT) are scant. Accordingly, the purpose of this study was to investigate the prognostic value of normal exercise Tc-sestamibi SPECT in patients with angiographic CAD. METHODS: We retrospectively investigated 90 consecutive patients who had a normal exercise Tc-sestamibi myocardial SPECT but angiographic CAD. A group of 69 consecutive patients with both normal exercise Tc-sestamibi myocardial SPECT and coronary arteries were included as control. RESULTS: During a mean follow-up of 50+/-19 months, a total of three hard cardiac events (non-fatal myocardial infarction) and seven soft cardiac events (late revascularization) were observed. The annual hard cardiac event rate between the two groups was not significantly different (0.6% vs. 0.3%, chi=0.47, P=NS), nevertheless the annual soft cardiac event rate was higher in patients with angiographic CAD (1.9% vs. 0, chi=5.74, P=0.02). Moreover, the annual hard cardiac events rate in patients with angiographic CAD who were treated medically was also not significantly different from that of the control group (0.8% vs. 0.3%, chi=0.77, P=NS). Among patients with angiographic CAD, the annual hard cardiac event rate was not statistically different between those treated medically and those who underwent revascularization (0.8% vs. 0, chi=0.53, P=NS). CONCLUSIONS: Our data demonstrate that normal exercise Tc-sestamibi myocardial SPECT despite angiographic CAD suggests a low rate of cardiac death or non-fatal myocardial infarction but a relatively high rate of late revascularization during an intermediate term of follow-up.