Objectives: Cigarette smoking is associated with atherosclerosis and is an important risk factor for cardiovascular disease. We evaluated the impact of cigarette smoking on coronary plaque composition using integrated backscatter intravascular ultrasound (IB-IVUS).
Methods: A total of 143 consecutive patients undergoing percutaneous coronary intervention were enrolled. A history of illness, as well as smoking habits, was obtained by interview. Participants were asked to report whether they were current smokers, had quit smoking, or had never smoked. According to interview results, patients were divided into the following three groups: current, former, and never smokers. Conventional and IB-IVUS tissue characterization analyses were carried out. Three-dimensional analyses were carried out to determine plaque volume and the volume of each plaque component (lipid, fibrous, and calcified).
Results: IB-IVUS analysis indicated that the patients in the current smoker group had significantly increased percent lipid volume and significantly decreased percent fibrous volume (P=0.01 and 0.03). Logistic regression analysis showed that the current smoking state (odds ratio 3.51, 95% confidence interval 1.02-12.10, P=0.04) was independently associated with the presence of lipid-rich plaques, which was defined as the upper 75th percentile of the study population.
Conclusion: Smoking is independently associated with lipid-rich plaques, contributing to the increasing risk for plaque vulnerability.