Relationship Between Cardiovascular Risk Factors and Atherosclerotic Disease Burden Measured by Intravascular Ultrasound

Objectives: The goal of this study was to determine the relationship between established cardiovascular risk factors and the extent of coronary atherosclerotic plaque. Background: Few data exist correlating cardiovascular risk factors with volumetric measurements of coronary atheroma burden in patients with coronary artery disease. Methods: Clinical characteristics, quantitative coronary angiography, and intravascular ultrasound (IVUS) were evaluated in subjects enrolled in a study comparing atorvastatin and pravastatin. Plaque areas were measured at 1-mm intervals to compute atheroma volume. The percent of cross sections with an abnormal intimal thickness (>0.5 mm) was determined. Data on cardiovascular risk factors were collected. Results: In 654 subjects, atheroma volume averaged 174.5 mm³ and percent atheroma volume 38.9%. Atherosclerosis was present in 81.2% of 25,897 cross sections. In univariate analysis, there was a strong association between diabetes, male gender, and a history of either prior revascularization or stroke with percent atheroma volume. Hypertension or prior myocardial infarction was also predictive of more severe disease. Low-density lipoprotein and C-reactive protein were not significant predictors of greater disease burden. In multivariate analysis, diabetes, male gender, and a history of a prior interventional procedure remained strong predictors of increased atheroma volume. History of stroke, non-Caucasian race, and smoking status remained significant. Although multiple measures of IVUS disease burden were worse in subjects with diabetes, angiographic stenosis severity was not different. Conclusions: Male gender, diabetes, and a history of prior revascularization are strong independent predictors of atherosclerotic burden in coronary disease patients. Many risk factors did not predict angiographic disease severity, suggesting different mechanisms drive stenosis development and atheroma accumulation.