Objective
Next to myocardial perfusion, single-photon emission computed tomography (SPECT) also allows for assessment of non-perfusion parameters such as transient ischemic dilatation (TID) and a reduction of ejection fraction (EF) with stress imaging. The present study aimed to evaluate the diagnostic value of TID and EF reserve for the detection of significant multivessel coronary artery disease (CAD).
Methods
A total of 206 patients with suspected stable coronary artery disease prospectively underwent gated stress-rest 99mTc-tetrofosmin SPECT and invasive coronary angiography with routine fractional flow reserve (FFR) measurements, regardless of imaging results. Left ventricular (LV) volumes, TID and EF reserve were assessed and compared with FFR defined severity of CAD.
Results
According to FFR, 92 (45%) patients had significant CAD, whereas 25 (12%) showed two vessel disease and 22 (11%) showed three vessel disease (3-VD). With an increasing extent of CAD, TID values and EF reserve did not significantly change (p = 0.07 and p = 0.42 for trend, respectively). Conversely, absolute LV volumes and EF differed significantly among groups of CAD severity (p < 0.01 for all trends).
Conclusion
SPECT derived TID and EF reserve did not differ between patients with high risk CAD (3-VD) and low risk or no significant CAD. Therefore the present results advocate exert caution when using these ancillary findings in clinical practice.