Application of Epicardial Fat Volume for Identifying Hemodynamically Significant Coronary Artery Disease: A Retrospective Study

Background: With the widespread application of coronary computed tomography angiography (CCTA), exploring novel biomarkers in imaging data to optimize the risk stratification of hemodynamically significant coronary artery disease (HS-CAD) has become a research hotspot. HS-CAD was defined as ≥ 50% stenosis on CCTA with a corresponding reversible perfusion defect on single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). Although coronary artery calcium score (CACS) is routinely used, it is difficult to fully reflect the biological activity and functional impact of plaques. This single-center retrospective study aimed to investigate the association between epicardial fat volume (EFV) and HS-CAD, and to evaluate its incremental diagnostic value over clinical risk factors and the CACS. Methods: A single-center retrospective study included 140 patients who underwent both CCTA and SPECT-MPI. EFV and CACS were quantitatively assessed. Univariable and multivariable logistic regression analyses were performed to identify independent predictors. Results: Among the included patients, 50 (35.7%) had HS-CAD. The HS-CAD group had a higher prevalence of smoking and significantly greater EFV and CACS (all P< 0.05). Multivariable analysis identified smoking history (OR=5.79;95% CI:2.14– 15.66; indicating that smokers had nearly 6-fold higher odds of HS-CAD), CACS (OR=1.91 per 100-unit increase;95% CI:1.35– 2.70), and EFV (OR=1.04 per cm 3 increase;95% CI:1.02– 1.07) as independent predictors (all P< 0.01). The optimal EFV cutoff for predicting HS-CAD was 91.98 cm 3 , with a sensitivity of 0.53 (95% CI: 0.42– 0.63) and specificity of 0.96 (95% CI: 0.91– 1.00). The area under the curve (AUC) for identifying HS-CAD was 0.78 for EFV alone and 0.79 for CACS alone. The combination of smoking history and CACS yielded an AUC of 0.84, which significantly improved to 0.90 after adding EFV. The combined model also showed good calibration and provided a net clinical benefit. Conclusion: EFV is independently associated with HS-CAD and provides incremental diagnostic value over clinical risk factors and CACS in this single-center retrospective study. These findings suggest that EFV may serve as a valuable biomarker for improving non-invasive risk stratification, warranting prospective validation in multicenter studies.