Intravascular ultrasound measures of coronary atherosclerosis are associated with the Framingham risk score: an analysis from a global IVUS registry.

AIMS: In addition to an adjunctive imaging platform during coronary angiography, intravascular ultrasound (IVUS) with Virtual Histology (VH) is increasingly being used to quantify coronary atherosclerosis. The relationship between VH-IVUS measures of coronary atherosclerosis and traditional cardiovascular risk factors has not been completely described. The objective of this study was to determine if an association exists between VH-IVUS measures of coronary atherosclerosis and the Framingham risk score in a prospective, multinational registry. METHODS AND RESULTS: Patients enrolled from 2004-2006 at 37 multinational centres in the prospective VHIVUS Global Registry were analysed. All subjects underwent diagnostic coronary angiography followed by IVUS. A Framingham risk score (FRS) was calculated for each subject, then stratified into three exclusive estimates (<10%, 10-19%, or >or= 20%) for future coronary heart disease (CHD) event risk over 10 years. Among 531 patients, plaque volume of the most diseased 10 mm segment increased with increasing FRS (P=0.006, adjusted for multiple comparisons). Patients with higher FRS estimates of CHD risk had a higher proportion of plaque classified as thin cap fibroatheroma compared with patients in the middle and lower risk score categories (21.4% vs 15.2% and 11.3%, respectively, P=0.008, adjusted for multiple comparisons). CONCLUSIONS: Using data from a large, multinational VH-IVUS registry we describe an association between the Framingham risk score and VH-IVUS measures of atherosclerosis within the most diseased 10 mm segment, namely plaque volume and the proportion of thin cap fibroatheroma.

Low adiponectin levels are associated with atherogenic dyslipidemia and lipid-rich plaque in nondiabetic coronary arteries.

OBJECTIVE: The purpose of this study was to determine whether an association exists between adiponectin and plaque composition in human coronary arteries. RESEARCH DESIGN AND METHODS: Adiponectin is an adipocyte-derived protein with antiatherogenic and insulin-sensitizing properties. To date, the relationship between adiponectin and plaque composition is unknown. Fasting blood samples were collected from 185 patients undergoing coronary angiography and intravascular ultrasound (IVUS). Plaque composition was categorized as fibrous, fibrofatty, necrotic core, or dense calcium and further classified as IVUS-derived adaptive or pathological intimal thickening, fibroatheroma, fibrocalcific, or thin cap fibroatheroma. RESULTS: Adiponectin correlated with normalized plaque volume (r = -0.16, P = 0.025) and atheroma lipid content as measured by normalized fibrofatty volume (r = -0.19, P = 0.009). Low adiponectin levels were associated with IVUS-derived pathological intimal thickening (r = -0.18, P = 0.01). With increasing quartiles (Q) of adiponectin, the normalized volume of fibrofatty plaque decreased (P = 0.03), which was driven by reductions in the nondiabetic cohort (Q1 44.2 mm(3); Q2 28.2 mm(3); Q3 24.7 mm(3); and Q4 23.4 mm(3); P = 0.01). No similar association was present in diabetic patients. Low adiponectin levels were also associated with IVUS-derived pathological intimal thickening in nondiabetic (r = -0.20, P = 0.03) but not diabetic patients. CONCLUSIONS: Low adiponectin levels are associated with atherogenic lipoproteins (elevated triglycerides, small dense LDL cholesterol, and low HDL cholesterol), increased plaque volume, lipid-rich plaque, and IVUS-derived pathological intimal thickening in the total cohort that was driven by the nondiabetic population, suggesting an antiatherogenic role in the early stages of lesion development.

Intravascular ultrasound radiofrequency analysis of coronary atherosclerosis: an emerging technology for the assessment of vulnerable plaque.

Evaluation of atherosclerotic plaque composition and morphometry may yield insight into plaque biology and the mechanisms of plaque-associated thrombosis. Analysis of intravascular ultrasound radiofrequency (IVUS-RF) backscatter signal is one technology that provides in vivo assessment of both atherosclerotic plaque composition and morphometry. We summarize three different approaches to IVUS-RF and critique the studies using this technology. In addition, we address the potential application of IVUS-RF to assess vulnerable plaque.