Visual scoring of coronary artery calcification in lung cancer screening computed tomography: association with all-cause and cardiovascular mortality risk

Objective Current and former smokers are at an increased risk for lung cancer and cardiovascular disease (CVD). We investigated two methods of visual scoring of coronary artery calcium on lung cancer screening computed tomography (CT) to predict cardiovascular and all-cause mortality. Participants and methods Cases were 1000 participants, age 55-74 years, enrolled in the National Lung Screening Trial CT arm who died during the study. An equal number of participants alive at the end of the study (controls) were matched in terms of sex, CT scanner vendor, and model, and 5-year age and smoking pack-years group. Coronary calcium was measured visually by three readers using two semiquantitative scoring schemes. Conditional logistic regression was used to analyze the association between the presence and the extent of coronary calcium and allcause and cardiovascular mortality, stratified on matching criteria. Results Cases and controls were well matched for age (64 +/- 6 vs. 64 +/- 5, P = 0.95) and mean pack-years smoking (61 +/- 24 vs. 62 +/- 24, P = 1.0). Cases were significantly more likely to have coronary calcium than controls (85 vs. 77%, P < 0.001). Having any calcium was associated with an increased risk for CVD mortality using either visual scoring method (odds ratio 3.4, 95% confidence interval 2.0-5.6, P < 0.001, and odds ratio 3.3, 95% confidence interval 2.0-5.6, P < 0.001). Conclusion Visual scoring of coronary calcium predicts all-cause and CVD mortality in National Lung Screening Trial participants, independent of current versus former smoking status. Visual coronary calcium scoring in low-dose CT scans helps identify individuals at high risk for mortality who may benefit from further CVD prevention. Coron Artery Dis 26: 157-162 Copyright (C) 2015 Wolters Kluwer Health, Inc. All rights reserved.