Added value of hybrid myocardial perfusion SPECT and CT coronary angiography in the diagnosis of coronary artery disease

• Published in: European heart journal cardiovascular imaging Vol. 15; no. 11; pp. 1281 - 1288
• Main Authors: Schaap, Jeroen, de Groot, Joris A H, Nieman, Koen, Meijboom, W Bob, Boekholdt, S Matthijs, Kauling, Robert M, Post, Martijn C, Van der Heyden, Jan A, de Kroon, Thom L, Rensing, Benno J W M, Moons, Karel G M, Verzijlbergen, J Fred
• Format: Journal Article
• Language: English
• Published: England 01-11-2014
• Subjects: Coronary Angiography; Coronary Artery Disease - diagnostic imaging; Cross-Sectional Studies; Electrocardiography; Exercise Test; Female; Fractional Flow Reserve, Myocardial; Humans; Male; Middle Aged; Multimodal Imaging; Netherlands; Prospective Studies; Radiopharmaceuticals; Risk Factors; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Myocardial perfusion SPECT; Hybrid imaging; Added value; Coronary computed tomography angiography
• ISSN: 2047-2404; 2047-2412
• DOI: 10.1093/ehjci/jeu135

Hybrid single photon emission computed tomography (SPECT)/coronary computed tomography angiography (CCTA) has only been evaluated for its diagnostic accuracy as a single test in patients suspected of significant coronary artery disease (CAD). Added value of hybrid SPECT/CCTA beyond usual clinical work-up, or use of each of these tests separately, remains unclear. We evaluated the added value of hybrid myocardial perfusion SPECT (SPECT) and CCTA, beyond pre-test likelihood and exercise stress ECG (X-ECG), in the diagnosis of CAD.
Two hundred and five patients with stable angina pectoris and intermediate-to-high pre-test likelihood were prospectively included. All patients underwent clinical history and examination, X-ECG, stress and rest SPECT, coronary calcium scoring (CCS) and CCTA. Fractional flow reserve measurement <0.80 or a lesion >50% on coronary angiography (CA) served as reference standard for significant CAD. Multiple imputation was used to correct for missing test results (17-20%). Added value of hybrid SPECT/CCTA to the basic model of pre-test likelihood plus X-ECG was quantified using logistic regression analysis. Model differences were then assessed using differences in C-index and in net reclassification improvement (NRI). The basic model had a C-index of 0.73 (95%CI 0.66-0.80). This significantly increased to 0.85 (95%CI 0.80-0.91) by addition of only SPECT, to 0.90 (95%CI 0.85-0.94) when adding only CCTA, and to 0.96 (95%CI 0.92-0.99) when adding hybrid SPECT/CCTA. The accompanying NRIs were 0.82 (95%CI 0.62-1.02), 0.86 (95%CI 0.66-1.06) and 1.57 (95%CI 1.11-1.59) respectively.
Current analysis resembles clinical routine of layered testing and shows that hybrid SPECT/CCTA imaging has a substantially higher yield than standalone SPECT or CCTA in the diagnostic workup of patients suspected of significant CAD.