Introduction. CZT-SPECT (cadmium-zinc telluride single photon emission tomography) is a novel upgrade of myocardial perfusion scintigraphy. This study aimed to assess the means and effects of treatment of chronic coronary syndrome in patients who have undergone CZT-SPECT and ICA (invasive coronary angiography). Secondly, the authors investigated the phenomenon of multi-focal ischaemia and defined values of perfusion defects for the prediction of revascularization and past myocardial infarction.

Materials and methods. Of 820 consecutive patients tested with CZT-SPECT, 62 with ICA performed within 90 days were chosen. Their symptoms were assessed during hospitalization and after a year in phone call interview. The occurrence of major adverse cardiac events was evaluated. Patient characteristics, data from scintigraphy, ICA and follow-up were subjected to statistical processing.

Results. CZT-SPECT was performed before ICA in 79% of cases. Less often it evaluated residual stenosis. One complication was reported. The intensity of angina and coronary stenosis burden rose with the extent of induced ischaemia. 63% of patients were qualified for revascularization. 80% of patients experienced alleviation of symptoms on follow-up. Five had major adverse events. It was found that the best cut-off of induced ischaemia for revascularization was 14% (AUC 0,798) and 8% (AUC 0,644) of fixed perfusion defect for past myocardial infarction. Multi-focal ischaemia showed bound with false positives, higher values of perfusion defect to start invasive treatment, lower left ventricle ejection fraction and coronary artery bypass-graft history. Fixed perfusion defect predicted no symptom improvement and was associated with lower ejection fraction. In false positive cases left bundle branch block and muscle bridges were frequent.

Conclusions. CZT-SPECT is safe and contributes to lowering the number of ICAs. SPECT-based treatment effect after a year was satisfying. Multi-focal ischaemia and false positive perfusion tests likely had an impact on a higher-than- expected threshold for revascularization. Most of the false positive scintigraphies are explainable. The advantages of CZT-SPECT will ensure a rise in its role in the future.