Relationship and Prognostic Value of Modified Coronary Artery Calcium Score, FEV1, and Emphysema in Lung Cancer Screening Population: The MILD Trial

Abstract

To assess the relationship between a modified coronary artery calcium (mCAC) score and both forced expiratory volume in 1 second (FEV1) and pulmonary emphysema and the associations of such factors with all-cause mortality and cardiovascular events (CVEs) in a lung cancer computed tomographic (CT) screening trial. In this institutional review board-approved study, both clinical and low-dose CT data were evaluated in a cohort of heavy smokers consecutively recruited by the Multicentric Italian Lung Detection, or MILD, trial. Low-dose CT images were analyzed by using software that allowed quantification of mCAC, mean lung attenuation (MLA), and total extent of emphysema. The correlations between mCAC, percentage predicted FEV1, MLA, and emphysema extent were tested by using the Pearson correlation coefficient. Adjusted multiple logistic regression models were applied to assess the relationships between mCAC, FEV1, MLA, and emphysema extent and all-cause mortality and CVEs. The final study cohort consisted of 1159 smokers. There were no significant correlations between mCAC score and FEV1 (r=-0.03, P=.4), MLA (r=-0.01, P=.7), or emphysema extent (r=0.02, P=.6). An mCAC score greater than 400 was the only factor that was independently associated with both all-cause mortality (odds ratio [OR]: 3.73; 95% confidence interval [CI]: 1.05, 13.32; P=.04) and CVEs (OR: 2.87; 95% CI: 1.13, 7.27; P=.03). mCAC is a better predictor of CVE and all-cause mortality than FEV1 and emphysema extent and may contribute to the identification of high-risk individuals in a lung cancer screening setting.