Quantitatively Assessed Emphysema Severity on HRCT Independently Predicts Coronary Artery Disease in COPD: A Retrospective Cohort Study.

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of coronary artery disease (CAD). However, the role of emphysema, which represents an important structural subtype of COPD, in the development of CAD remains insufficiently clarified. This study aimed to evaluate whether quantitatively assessed emphysema on high-resolution computed tomography (HRCT) independently predicts CAD in COPD patients.

Methods: This retrospective cohort study included 392 COPD patients with no prior history of CAD between 2015 and 2020. All participants underwent HRCT for automated emphysema quantification using 3D Slicer software. Emphysema extent was quantified as the percentage of low attenuation areas (LAA%) below -950 Hounsfield units, with severe emphysema defined as LAA% >16.95%. Logistic regression and restricted cubic spline (RCS) analysis were employed to assess the relationship between emphysema index and CAD, including subgroup and interaction analyses. The ability of the emphysema index to predict CAD was evaluated using receiver operating characteristic (ROC) curves.

Results: Severe emphysema was independently associated with a higher risk of CAD in COPD patients (OR = 2.08, 95% CI: 1.30-3.34; p = 0.002). This association remained robust even after adjusting for confounders (adjusted OR= 2.28, p = 0.005). RCS analysis indicates that the risk of CAD increases with the rise of the emphysema (p for nonlinearity =0.031). The area under the ROC curve for the predictive model was 0.81 (95% CI 0.77, 0.86). Additionally, patients with severe emphysema exhibited significantly more complex coronary lesions, reflected by higher SYNTAX scores (median 10.00 vs 16.29; p = 0.013).

Conclusion: Quantitative HRCT-based emphysema independently predicts CAD in COPD and demonstrates additive risk with traditional cardiovascular factors. Integrating emphysema quantification with clinical risk assessment improves CAD risk stratification in COPD patients.