Relationship between amount of cigarette smoking and coronary atherosclerosis on coronary CTA in asymptomatic individuals.

Current smoking is a powerful independent predictor of coronary atherosclerosis in asymptomatic individuals. Many researchers have suggested a cigarette dose-response relationship between smoking and subclinical coronary atherosclerosis. Our study purposes were (a) to investigate the prevalence and plaque characteristics of coronary atherosclerosis in asymptomatic smokers and (b) to assess the cigarette dose-response relationship between smoking and subclinical coronary atherosclerosis using coronary CT angiography (CTA). We consecutively enrolled 7,104 self-referred asymptomatic subjects who underwent coronary CTA as part of a general health evaluation. Current smokers (n = 1,784) were categorized according to total pack years (TPY) with four grades (A, 0.1-10; B, 10-20; C, 20-30; D, >30), smoking duration (SD, years) with four grades (A, 0.1-10; B, 10-20; C, 20-30; D, >30), and number of cigarettes per day (CPD) with four grades (A, 1-20; B, 10-20; C, 20-40; D, >40). After adjusting for other cardiovascular risk factors, adjusted odds ratios for current smokers versus never-smokers as a control group were estimated for the presence of plaques, significant stenosis, and non-calcified plaques (NCP). Current smokers had a statistically significant higher prevalence of any plaque, significant stenosis, NCP, and coronary artery calcium score >100 than never-smokers. According to each categorization of TPY, SD, and CPD, the subclinical coronary atherosclerosis risk increased as grades increased in asymptomatic current smokers relative to never-smokers after adjusting for variable clinical and chemical risk factors. Our study suggests a cigarette dose-response relationship between current smoking and coronary atherosclerosis in asymptomatic individuals.