Adenosine single-photon emission computed tomography-derived transient ischemic dilatation and ejection fraction...

Next to myocardial perfusion, single-photon emission computed tomography (SPECT) also allows for the assessment of nonperfusion parameters such as transient ischemic dilatation (TID) and a reduction of ejection fraction (EF) with stress imaging. This study aimed to evaluate the diagnostic value of TID and EF reserve for the detection of significant multivessel coronary artery disease (CAD). A total of 206 patients with suspected stable CAD prospectively underwent gated stress-rest Tc-tetrofosmin SPECT and invasive coronary angiography with routine fractional flow reserve (FFR) measurements, irrespective of imaging results. Left ventricular volumes, TID, and EF reserve were assessed and compared with FFR-defined severity of CAD. According to FFR, 92 (45%) patients had significant CAD, whereas 25 (12%) showed 2-vessel disease (VD) and 22 (11%) showed 3-VD. With an increasing extent of CAD, TID values and EF reserve did not change significantly (P=0.07 and 0.42 for trend, respectively). Conversely, absolute left ventricular volumes and EF differed significantly among groups of CAD severity (P<0.01 for all trends). 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 exerting caution when using these ancillary findings in clinical practice.