Objective: The added value of coronary artery calcium (CAC) to SPET for identification of multivessel CAD has not been studied yet. The aim of this original study was to investigate CAC as an adjunct to gated single photon emission tomography (GSPET) in the detection of multivessel coronary artery disease (CAD).
Subjects and methods: The study group consisted of 164 prospectively recruited patients without known CAD-123 (75%) men and 60 (37%) women, having diabetes type II, renal insufficiency, left ventricular dilatation and other cardiac problems (arrhythmia, necessity of pharmacological stress test, etc.). The mean age of these patients was 61±12 years (range 34-85 years). All these patients underwent GSPET imaging, CAC score measurement, and coronary angiography. The percentage of ischaemic myocardium, stress and rest left ventricular ejection fraction (LVEF), and transient ischaemic dilation (TID) ratio were measured.
Results: Patients with multivessel CAD had more frequently reversible defects in multiple territories, severe ischaemia ≥10% of the left ventricle, stress worsening of the LVEF ≥5%, TID ratio ≥1.17, and CAC score >1000. In the detection of multivessel CAD, the sensitivity of combined assessment of perfusion, function, and CAC (i.e., multiple and/or ≥10% ischaemia, and/or worsening of the LVEF ≥5%, and/or TID ratio ≥1.17, and/or CAC score >1000) was significantly higher than the sensitivity of perfusion alone or perfusion and function alone (81% vs. 55% and 65%, respectively, P<0.05). Sensitivity of only CAC was low (41%).
Conclusion: Sensitivity of combined assessment of myocardial perfusion, function, and CAC was significantly higher than sensitivity of perfusion alone or perfusion and function alone, suggesting better identification of high-risk patients with CAD.