Impact of cardiac hybrid SPECT/CT imaging on choice of treatment strategy in coronary artery disease

Objectives Cardiac hybrid imaging by fusing single-photon emission computed tomography (SPECT) myocardial perfusion imaging with coronary computed tomography angiography (CCTA) provides important complementary diagnostic information for coronary artery disease (CAD) assessment. No data exist on the impact of cardiac hybrid imaging on the choice of treatment strategy selection for CAD.

Methods 318 consecutive patients underwent a one day stress/rest 99mTc-tetrofosmin SPECT and a CCTA on a separate scanner for evaluation of CAD. Patients were divided into one of the following three groups according to findings in the hybrid images obtained by fusing SPECT and CCTA: 1) Stenosis by CCTA and matched reversible SPECT defect; 2) Unmatched CCTA and SPECT finding; 3) Normal finding by CCTA and SPECT. Follow-up was confined to the first 60 days after hybrid imaging as this allows best to assess treatment strategy decisions including the revascularization procedure triggered by its findings.

Results Hybrid images revealed matched, unmatched, and normal findings in 51, 74, and 193 patients. The revascularization rate within 60 days was 41%, 11%, and 0% for matched, unmatched, and normal findings (p<0.001 for all inter-group comparisons).

Conclusions Cardiac hybrid imaging with SPECT and CCTA provides an added clinical value for decision making with regard to treatment strategy for CAD