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Background COPD is associated with cardiovascular disease (CVD), and coronary artery calcification (CAC) provides incremental prognostic information. CAC is measured using Agatston scores on electrocardiographically gated CT scans. With increasing use of non-gated CT scans in clinical practice, we hypothesized that a simple visual Weston score would perform as well in predicting prevalent coronary artery disease (CAD) and incident CVD in COPD. Methods Current and former smokers (45-80 years) enrolled in the COPDGene study and followed for 5 years. At baseline, significant CAC was defined as Agatston >400 and Weston >7; incident CVD recorded as one/more of incident acute coronary event, stroke, peripheral arterial disease and coronary intervention. Results 1913 subjects were included; 813 with and 1100 without airflow obstruction. CAD was reported by 140(7.3%) subjects at baseline. 439(22.9%) and 748(39.1%) had significant CAC by Weston and Agatston respectively; the two methods correlated significantly (r=0.51;p 7 identified more patients with undiagnosed CAD who developed incident CVD (6.3% vs. 10.2%;p=0.01) than Agatston >400 (6.9% vs. 7.2%;p = 0.77). Conclusions A simple visual score for CAC performs well in predicting prevalent CAD and incident CVD in smokers with and without COPD.

Many patients with chronic obstructive pulmonary disease (COPD) have marked discordance between forced expiratory volume in 1 second (FEV1) and degree of emphysema on computed tomography (CT). Biomechanical differences between these patients have not been studied. We aimed to identify reasons for the discordance between CT and spirometry in some patients with COPD.Subjects with Global initiative for chronic Obstructive Lung Disease stages I-IV from a large multicenter study (The Genetic Epidemiology of COPD) were arranged by percentiles of %predicted FEV1 and emphysema on CT. Three categories were created using differences in percentiles: Catspir with predominant airflow obstruction/minimal emphysema, CatCT with predominant emphysema/minimal airflow obstruction, and Catmatched with matched FEV1 and emphysema. Image registration was used to derive Jacobian determinants, a measure of lung elasticity, anisotropy, and strain tensors, to assess biomechanical differences between groups. Regression models were created with the previously mentioned categories as outcome variable, adjusting for demographics, scanner type, quantitative CT-derived emphysema, gas trapping, and airway thickness (model 1), and after adding biomechanical CT metrics (model 2).Jacobian determinants, anisotropy, and strain tensors were strongly associated with FEV1. With Catmatched as control, model 2 predicted Catspir and CatCT better than model 1 (Akaike information criterion 255.8 vs. 320.8). In addition to demographics, the strongest independent predictors of FEV1 were Jacobian mean (β = 1.60,95%confidence intervals [CI] = 1.16 to 1.98; P 0.001), coefficient of variation (CV) of Jacobian (β = 1.45,95%CI = 0.86 to 2.03; P 0.001), and CV of strain (β = 1.82,95%CI = 0.68 to 2.95; P = 0.001). CVs of Jacobian and strain are both potential markers of biomechanical lung heterogeneity.CT-derived measures of lung mechanics improve the link between quantitative CT and spirometry, offering the potential for new insights into the linkage between regional parenchymal destruction and global decrement in lung function in patients with COPD.