Abstract 1633: Active Smoking Has an Impact on the Morphological Distribution of Coronary Arterial Plaque Visualized by Intravascular Ultrasound- Virtual Histology
Background: Smoking is known to be one of the risk factors for coronary artery disease. However, the effect of smoking on histological composition of coronary plaque has not been well documented in vivo. Recently, spectral analysis of intravascular ultrasound (IVUS) radiofrequency (Virtual Histology [VH]) data demonstrated a potential to provide detailed quantitative information on plaque composition. We assessed the hypothesis that active smoking was associated with coronary plaque instability verified by IVUS-VH in humans.
Methods and Results: Consecutive 18 stable effort angina (SEA) patients with smoking habit and 65 SEA patients without smoking habit, matched for age, blood pressure, hemoglobin A1c and low-density lipoprotein cholesterol (LDL-C) levels of SEA patients with smoking habit were included in this study. Preintervention IVUS-VH using a continuous pullback (0.5 mm/s) was performed prospectively in 83 culprit lesions with coronary stenosis ≥90% in 83 patients. External elastic membrane area (15.5±5.2 vs 14.5±5.1 mm2, P=0.450) and plaque area (11.5±5.0 vs 10.1±4.8 mm2, P=0.280) were not different between active smoking and non-smoking groups. However, fibrous area and %fibrous tissue were decreased and necrotic core area and %necrotic core tissue were increased in active smoking group compared with non-smoking group (Table⇓). A multiple regression analysis including all clinical variables revealed that active smoking was an independent determinant of %necrotic core tissue (β=10.01, 95% CI: 3.30 –16.71, P=0.004).
Conclusions: The morphological distribution of coronary arterial plaque demonstrating decremental fibrous tissue and incremental necrotic core tissue may be regulated by active smoking irrespective of coronary risk factors such as age, blood pressure, hemoglobin A1c and LDL-C levels. The IVUS-VH may help to explain missing link between active smoking and coronary plaque instability which is liable to acute coronary syndrome.