Association between smoking status and subclinical coronary atherosclerosis in asymptomatic Korean individuals

OBJECTIVES: In this study, we sought to evaluate the association between smoking status and subclinical coronary atherosclerosis, as detected by coronary computed tomography angiography (CCTA), in asymptomatic individuals. METHODS: We retrospectively analyzed 9,285 asymptomatic participants (mean age, 53.7 ± 8.0 years; n = 6,017, 64.8% male) with no history of coronary artery disease (CAD) who had undergone self-referred CCTA. Of these participants, 4,333 (46.7%) were considered never smokers, 2,885 (31.1%) former smokers, and 2,067 (22.3%) current smokers. We assessed the degree and characteristics of subclinical coronary atherosclerosis using CCTA, with obstructive CAD defined as a diameter stenosis of at least 50%. RESULTS: Compared with never-smokers, former smokers exhibited no significant differences in the probabilities of obstructive CAD, any coronary plaque, calcified plaque, or mixed plaque, as determined using adjusted odds ratios (aORs; p > 0.05 for all). However, the risk of non-calcified plaque was significantly higher in former smokers (aOR, 1.34; 95% confidence interval [CI], 1.00 to 1.78; p = 0.048). Current smokers had significantly higher rates of obstructive CAD (aOR, 1.46; 95% CI, 1.10 to 1.96; p = 0.010), any coronary plaque (aOR, 1.41; 95% CI, 1.20 to 1.65; p < 0.001), calcified plaque (aOR, 1.32; 95% CI, 1.13 to 1.55; p = 0.001), non-calcified plaque (aOR, 1.72; 95% CI, 1.28 to 2.32; p < 0.001), and mixed plaque (aOR, 2.00; 95% CI, 1.39 to 2.86; p < 0.001) compared to never smokers. CONCLUSIONS: This cross-sectional study revealed a significant association between current smoking and subclinical coronary atherosclerosis, as detected on CCTA. Additionally, former smoking demonstrated an association with non-calcified plaque, indicating elevated cardiovascular risk.