Epicardial adipose tissue (EAT) plays an important role in the pathogenesis of coronary artery disease (CAD). The association between EAT and obstructive CAD or myocardial ischemia has been established, but its relationship with CAD phenotypes based on anatomical and functional imaging remains unclear. A total of 495 suspected CAD patients who underwent both single-photon emission computed tomography/computed tomography myocardial perfusion imaging (SPECT/CT MPI) and coronary angiography (CAG/CTA) were enrolled in this retrospective study. Epicardial fat volume (EFV) and epicardial fat volume indexed to body surface (EFVi) were measured on non-contrast CT. CAD phenotypes were categorized into 4 groups based on the presence or absence of obstructive CAD (any epicardial coronary diameter stenosis ≥ 50% by CAG/CTA) and myocardial ischemia (diagnosed by MPI): Group1 (non-obstructive CAD without ischemia, n = 165), Group2 (ischemia with non-obstructive CAD, INOCA, n = 69), Group3 (obstructive CAD without ischemia, n = 149), Group4 (obstructive CAD with ischemia, n = 112). Both EFV and EFVi had an increasing trend across 4 groups [EFVi: median (interquartile range), cm3/m2: 80.54 (68.10-102.37) vs. 84.44 (73.57-100.93) vs. 89.63 (75.39-103.15) vs. 91.67 (76.48-111.66), p = 0.007, p for trend 134.47cm3 for INOCA, OR = 1.94, 95%CI:0.97–3.88, p = 0.058, EFVi: EFVi >80.67cm3/m2 for INOCA, OR = 2.53, 95%CI:1.25–5.12, p = 0.010). Net reclassification improvement (NRI) showed that EFVi was more effective than EFV in diabetes subgroup to differentiate CAD phenotypes over traditional cardiovascular risk factors. EFVi was correlated with the severity of CAD phenotype levels based on anatomical and functional imaging. EFVi had the strongest correlation with CAD phenotypes levels in diabetes subgroup. Notably, EFVi rather than EFV exhibits a distinct linkage with INOCA. EFVi was more effective to provide incremental value of differentiating CAD phenotypes over traditional cardiovascular risk factors than EFV in diabetes subgroup.
Wang et al. (Wed,) studied this question.