Magnetic resonance imaging of atherosclerosis : studies in visceral obesity

The aim of this thesis was to explore the relation between visceral obesity and the accompanying metabolic disturbances, systemic inflammation and the atherosclerotic process. A newly developed magnetic resonance vessel wall imaging technique was implemented in phenotyping patients and as a therapeutic endpoint in a randomised controlled setting. A three step approach was chosen for this purpose. First, the magnetic resonance black blood vessel wall imaging technique at the magnetic field strength of 3 Tesla was developed and validated. Secondly, phenotyping of viscerally obese subjects was performed with special attention for the role of systemic inflammation and atherosclerosis. Finally, in the setting of a randomised controlled trial, the impact of reducing visceral obesity and systemic inflammation with lifestyle intervention and rosiglitazone treatment (PPARg agonist) on the progression of atherosclerosis was assessed.UBL - phd migration 201

Assessment of Aortic Pulse Wave Velocity and Cardiac Diastolic Function in Subjects With and Without the Metabolic Syndrome: HDL cholesterol is independently associated with cardiovascular function

OBJECTIVE—To evaluate the influence of lipid and glucose metabolism in the metabolic syndrome on aortic pulse wave velocity (PWV) and left ventricular (LV) diastolic function using magnetic resonance imaging (MRI)

Echocardiography in takotsubo cardiomyopathy; a useful approach?

Cardiac Dysfunction and Arrhythmia

Inflammation increases plasma angiopoietin-like protein 4 in patients with the metabolic syndrome and type 2 diabetes

Contains fulltext : 138901.pdf (publisher's version ) (Open Access)BACKGROUND: Angiopoietin-like protein 4 (ANGPTL4) inhibits lipoprotein lipase and associates with dyslipidemia. The expression of ANGPTL4 is regulated by free fatty acids (FFA) that activate lipid-sensing peroxisome proliferator-activated receptors (PPARs), but FFA can also activate pattern recognition receptors including Toll-like receptor 4 (TLR4) in macrophages. OBJECTIVE: To assess whether systemic low-grade inflammation is a determinant for plasma ANGPTL4 levels in patients with the metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM). DESIGN: We studied 335 male participants: healthy controls (Controls), patients with the MetS without inflammation (MetS-I) and with low-grade inflammation (MetS+I), and patients with T2DM. All patients without diabetes included in the present study were initially matched for waist circumference. In plasma, ANGPTL4, C reactive protein (CRP) and metabolic parameters were determined. Underlying mechanisms were examined using human macrophages in vitro. RESULTS: As compared with Controls, plasma ANGPTL4 levels were increased in patients with MetS-I, MetS+I, and T2DM. Furthermore, ANGPTL4 was increased in T2DM compared with MetS-I. In fact, plasma CRP correlated positively with plasma ANGPTL4. In vitro studies showed that TLR 3/4 activation largely increased the expression and release of ANGPTL4 by macrophages. CONCLUSIONS: Plasma ANGPTL4 levels in humans are predicted by CRP, a marker of inflammation, and ANGPTL4 expression by macrophages is increased by inflammatory stimuli

Impact of left atrial box surface ratio on the recurrence after ablation for persistent atrial fibrillation

Background The posterior wall of the left atrium (LA) is a well-known substrate for atrial fibrillation (AF) maintenance. Isolation of the posterior wall between the pulmonary veins (box lesion) may improve ablation success. Box lesion surface area size varies depending on the individual anatomy. This retrospective study evaluates the influence of box lesion surface area as a ratio of total LA surface area (box surface ratio) on arrhythmia recurrence. Methods Seventy consecutive patients with persistent AF (63 +/- 11 years, 53 men) undergoing computed tomography (CT) imaging and ablation procedure consisting of a first box lesion were included in this study. Box lesion surface area was measured on electroanatomical maps and total LA surface area was derived from CT. Patients were followed with 24-h electrocardiography and exercise tests at 3, 6, and 12 months after AF ablation. Arrhythmia recurrence was defined as any AF/atrial tachycardia (AT) beyond 3 months without antiarrhythmic drugs. Results During a median follow-up of 13 (interquartile range = 10-17) months, 42 (60%) patients had AF/AT recurrence. Multivariate Cox proportional regression analysis showed that a larger box surface ratio protected against recurrence (hazard ratio [HR] = 0.81; 95% confidence interval [CI] = 0.690-0.955; P = 0.012). Left atrial volume index (HR = 1.01 [0.990-1.024, P = 0.427] and a history of mitral valve surgery (HR = 2.90; 95% CI = 0.970-8.693; P = 0.057) were not associated with AF recurrence in multivariate analysis. Conclusion A larger box lesion surface area as a ratio of total LA surface area is protective for AF/AT recurrence after ablation for persistent AF.Cardiolog

Assessment of the carotid artery by MRI at 3T: a study on reproducibility

PURPOSE: To examine the reproducibility of carotid artery dimension measurements using 3T MRI. MATERIALS AND METHODS: Ten healthy volunteers underwent three scans on two occasions for assessment of total vessel wall area (TVWA), total luminal area (TLA), and minimum (MinT) and maximum (MaxT) vessel wall thickness. A double inversion-recovery (IR) fast gradient-echo (FGRE) sequence was used on a commercial 3T system. During the first visit the subjects were scanned twice. The third scan was performed at least four days later. One observer traced all scans, and a second observer retraced the first scan series. RESULTS: For TVWA an interclass correlation (ICC) of 0.994 was calculated with all three scans taken into account. The interobserver ICC was 0.984. The agreement between the scans for TLA showed an ICC of 0.982 with an interobserver ICC of 0.998. For MinT and MaxT an ICC of 0.843 and 0.935 were calculated, with interobserver ICCs of 0.860 and 0.726, respectively. CONCLUSION: With the use of a commercial 3T MR system, TVWA, TLA, and wall thickness measurements of the carotid artery can be assessed with good reproducibility