Differential Association of COPD Subtypes With Cardiovascular Events and COPD Exacerbations

Abstract

Background: The coronary artery calcium score (CACS) and ratio of the pulmonary artery to aorta diameters (PA:A ratio) measured from chest CT scans have been established as predictors of cardiovascular events and COPD exacerbations, respectively. However, little is known about the reciprocal relationship between these predictors and outcomes. Furthermore, the prognostic implications of COPD subtypes on clinical outcomes remain insufficiently characterized.

Research question: How can these two chest CT scan-derived parameters predict subsequent cardiovascular events and COPD exacerbations in different COPD subtypes?

Study design and methods: Using COPDGene study data, we assessed prospective cardiovascular disease (CVD) and COPD exacerbation risk in participants with COPD (Global Initiative for Chronic Obstructive Lung Disease spirometric grades 2-4), focusing on CACS and PA:A ratio at study enrollment, with logistic regression models. These outcomes were analyzed in three COPD subtypes: 1,042 participants with non-emphysema-predominant COPD (NEPD; low attenuation area at -950 Hounsfield units [LAA-950] < 5%), 1,324 participants with emphysema-predominant COPD (EPD; LAA-950 ≥ 10%), and 465 participants with intermediate emphysema COPD (IE; 5% ≤ LAA-950 < 10%).

Results: Our study indicated significantly higher overall risk for cardiovascular events in participants with higher CACS (≥ median; OR, 1.61; 95% CI, 1.30-2.00) and increased COPD exacerbations in those with higher PA:A ratios (≥ 1; OR, 1.80; 95% CI, 1.46-2.23). Notably, participants with NEPD showed a stronger association between these indicators and clinical events compared to EPD (with CACS/CVD, NEPD vs EPD: OR, 2.02 vs 1.41; with PA:A ratio/COPD exacerbation, NEPD vs EPD: OR, 2.50 vs 1.65); the difference in ORs between COPD subtypes was statistically significant for CACS/CVD.

Interpretation: Two chest CT scan parameters, CACS and PA:A ratio, hold distinct predictive values for cardiovascular events and COPD exacerbations that are influenced by specific COPD subtypes.

Trial registration: ClinicalTrials.gov; No.: NCT00608764; URL: www.

Clinicaltrials: gov.

Keywords: COPD; COPD exacerbations; COPD subtypes; cardiovascular events; coronary artery calcification.