This study demonstrates that, in the case of diagnostic image quality, contrast-enhanced MDCT permits an accurate identification of coronary plaques and that computed tomography density values measured within plaques reflect echogenity and plaque composition.

Background Hemodynamic load regulates myocardial function and gene expression. We tested the hypothesis that afterload and preload despite similar average load result in different phenotypes. Methods and Results Afterload and preload were compared in mice with transversal aortic constriction (TAC) and aorto-caval shunt (Shunt). When compared to sham mice, six hours after surgery, systolic wall stress (afterload) was increased in TAC (+40%, P<0.05), diastolic wall stress (preload) was increased in Shunt (+277%, P<0.05) and TAC (+74%, P<0.05) and mean total wall stress was similarly increased in TAC (69%) and Shunt (67%) (TAC vs. Shunt: not significant (n.s.), each P<0.05 vs. Sham). At 1 week, left ventricular weight/tibia length was significantly increased by 22% in TAC and 29% in Shunt (n.s. TAC vs. Shunt). After 24 hours and 1 week, calcium/calmodulin dependent protein kinase II (CaMKII) signaling was increased in TAC. This resulted in altered calcium cycling, including increased L-type calcium current, calcium transients, fractional SR release and calcium spark frequency. In Shunt, Akt phosphorylation was increased. TAC was associated with inflammation, fibrosis and cardiomyocyte apoptosis. The latter was significantly reduced in CaMKIIδ-KO TAC mice. 157 mRNAs and 13 microRNAs were differentially regulated in TAC vs. Shunt. After 8 weeks, fractional shortening was lower and mortality higher in TAC Conclusions Afterload results in maladaptive fibrotic hypertrophy with CaMKII-dependent altered calcium cycling and apoptosis. Preload is associated with Akt activation without fibrosis, little apoptosis, better function and lower mortality. This indicates that different loads result in distinct phenotype differences which may require specific pharmacological interventions.

We conclude that 64-slice CT reveals encouraging results to noninvasively detect different types of coronary plaques located in the proximal coronary system. The ability to determine plaque burden currently is hampered by mainly an insufficient reproducibility.

Calcium screening with EBCT is a highly sensitive and moderately specific test to predict stenotic disease. Exclusion of coronary calcium defines a substantial subgroup of patients, albeit symptomatic, with a very low probability of significant stenoses.

Objectives-Pericardial fat as a visceral fat depot may be involved in the pathogenesis of coronary atherosclerosis. To gain evidence for that concept we sought to investigate the relation of pericardial fat volumes to risk factors, serum adiponectin levels, inflammatory biomarkers, and the quantity and morphology of coronary atherosclerosis. PϾ0.001). No association was found between BMI and coronary atherosclerosis. PAT volumes Ͼ300 cm 3 were the strongest independent risk factor for coronary atherosclerosis (odds ratio 4.1; CI 3.63 to 4.33) also significantly stronger compared to the Framingham score. We furthermore demonstrated that elevated PAT volumes are significantly associated with low adiponectin levels, low HDL levels, elevated TNF-␣ levels, and hsCRP. Conclusion-In the present study we demonstrated that elevated PAT volumes are associated with coronary atherosclerosis, hypoadiponectinemia, and inflammation and represent the strongest risk factor for the presence of atherosclerosis and may be important for risk stratification and monitoring. Key Words: cardiac CT Ⅲ pericardial fat Ⅲ obesity Ⅲ adiponectin Ⅲ plaque imaging T here is growing evidence that regional visceral fat distribution may contribute to an unfavorable metabolic and cardiovascular risk profile. 1,2 In patients with obesity, insulin resistance, diabetes, and hyperlipidemia visceral fat hypertrophies and transforms into a multifunctional organ that produces and secretes multiple endocrine and paracrine factors promoting inflammation, neovascularization, and oxidative stress, features that also characterize atherosclerosis. 3 Pericardial fat as a local visceral fat depot with close proximity to coronary arteries may serve as a source of inflammatory cytokines and cells that may locally enhance systemic proatherogenic effects via outside to inside signaling. 4,5 Thus it may be a specific parameter indicating an unfavorable cardio-metabolic state and may be used for risk stratification. To date, however, only little attention has focused on this regional fat depot located around the heart and its relation to cardiovascular risk factors, and the quantity and composition of coronary atherosclerosis is not well studied yet. Methods and Results-UsingMulti-slice CT is a noninvasive tool that allows to reliably assess both obstructive and nonobstructive subclinical coronary artery disease in an earlier stage than invasive angiography. 6 -9 Based on density measurements, plaques can be further characterized in noncalcified, mixed, and calcified plaques. 7 By using the same scan data this tool furthermore allows to quantify the exact pericardial fat volume. 9 We thus sought to assess the relation of pericardial fat volume to cardiovascular risk factors, levels of inflammatory cytokines, adiponectin, and to the extent and the phenotype of coronary atherosclerosis.