CLINICAL RELEVANCE/APPLICATION:
Current smoking is a powerful independent predictor of coronary atherosclerosis in asymptomatic individuals. These results suggest a dose-response relationship between cigarette smoking and subclinical coronary atherosclerosis and reinforce the need for aggressive smoking cessation efforts in asymptomatic individuals.
PURPOSE : The purpose of this study was (a) to investigate the prevalence and plaque characteristics of coronary atherosclerosis in asymptomatic smokers and (b) to assess the dose-response relationship between cigarette smoking and subclinical coronary atherosclerosis using coronary CT angiography (CCTA).
METHOD AND MATERIALS: We consecutively enrolled 7,104 asymptomatic subjects who underwent CCTA as part of a general health evaluation. Current smokers were categorized and according to total pack year (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 smoked per day (CSD) with four grades (A: 1-20, B: 10-20, C: 20-40, D: >40). After adjusting other cardiovascular risk factors using multiple logistic regression, adjusted odds ratios (AORs) for the current smokers regarding never-smokers as control group were estimated in the prevalence of plaque, significant stenosis, and noncalcified plaque (NCP). A p value of < 0.05 indicated a statistical significance.
RESULTS: There were 1,784 current smokers (25.1%), 2,165 ex-smokers (30.5%), and 3,155 never-smokers (44.4%).
According to the each categorization of TPY, SD, and CSD, subclinical atherosclerosis tended to increase as grades increase.
From the TPY categorization, A significant increase appeared: at grades B, C and D (AOR: 1.44, 1.72, and 1.61, respectively) for the prevalence of plaque; at grades C and D (2.15 and 1.95, respectively) for the significant stenosis; and at grades C and D (2.33 and 1.64, respectively) for the NCP.
From the SD categorization, a significant increase appeared: at grades C and D (1.76, and 1.44, respectively) for the prevalence of plaque; at grades C and D (2.14 and 1.77, respectively) for the significant stenosis; and at grades C and D (1.86 and 1.60, respectively) for the NCP.
From the CSD categorization, a significant increase appeared: at grades B, C and D (1.38, 1.63, and 2.12, respectively) for the prevalence of plaque; at grade D (2.04) for the significant stenosis; and at grades C and D (1.8 and 1.96, respectively) for the NCP.
CONCLUSION: Our study suggests dose-response relationship between current smoking and coronary atherosclerosis in asymptomatic individuals.
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