Arterial stiffness, but not endothelium-dependent vasodilation, is related to a low Ankle-Brachial index. The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS)

Background: Arterial compliance and endothelium‐dependent vasodilation are two characteristics of the vessel wall. In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study we studied the relationships between arterial compliance and endothelium‐dependent vasodilation versus the Ankle‐Brachial index (ABI), a clinically used index of peripheral artery disease. Methods: In the population‐based PIVUS study (all aged 70), arterial compliance was determined by ultrasound as the distensibility of the carotid artery and the stroke volume to pulse pressure (SV/PP) ratio by echocardiography, while endothelium‐dependent vasodilation was assessed by the invasive forearm technique with acetylcholine (EDV) and brachial artery ultrasound (FMD) in 519 subjects in whom the Ankle‐Brachial index was investigated. Results: After adjustments for gender and Framingham risk score, distensibility in the carotid artery and the SV/PP ratio were significantly reduced in subjects with a reduced ABI (<0·9) in both legs (n = 15, P = 0·0006 and P = 0·0003, respectively). Endothelium‐dependent vasodilation was not significantly related to a reduced ABI. Conclusion: A reduced arterial compliance, but not endothelium‐dependent vasodilation, was related to a low ABI in both legs after adjustment for major risk factors, suggesting that atherosclerosis in the leg arteries is associated with arterial compliance also in other parts of the vasculature.     

Arterial compliance and endothelium-dependent vasodilation are independently related to coronary risk in the elderly: the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study

Background: Measurements of both arterial compliance and endothelium‐dependent vasodilation have previously been related to coronary risk factors, but not in the same study. In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, we studied the interplay between arterial compliance and endothelium‐dependent vasodilation on coronary risk. Methods: In the population‐based PIVUS study (1016 subjects aged 70 years), arterial compliance was determined by ultrasound in the carotid artery, by pulse wave analysis (augmentation index) and the stroke volume to pulse pressure ratio by echocardiography, while endothelium‐dependent vasodilation (EDV) was assessed by the invasive forearm technique with acetylcholine , brachial artery ultrasound [flow‐mediated dilatation (FMD)] and pulse wave analysis with terbutaline provocation [change in reflection index (RI)]. Results: Factor analysis disclosed three major factors. The first factor was reflecting the three arterial compliance methods, the second factor was reflecting EDV and the change in RI, while the third factor mainly was reflecting FMD. All these three factors were independently related to the Framingham risk score in multiple regression analysis (P<0·0001, P = 0·0002 and P = 0·0046, respectively). Conclusions: In conclusion, both arterial compliance and endothelium‐dependent vasodilation were independently related to the Framingham risk score, suggesting that it is worthwhile to evaluate the parallel use of these two vascular characteristics in a prospective fashion.     

颈动脉三维对比增强磁共振血管成像技术规范化探讨

目的探讨颈动脉三维对比增强磁共振血管成像(3D CE-MRA)技术的规范。方法回顾性分析20例患者颈动脉3D CE-MRA的参数设置、实际操作和图像质量。结果不同对比剂注射方法、扫描方式、对比剂速率,以及是否使用生理盐水对图像质量的影响有显著差异。结论运用高压注射器注射对比剂、采用透视触发技术(主动脉弓显影至最亮时启动扫描)、维持对比剂速率2.0~3.0 mL/s、使用生理盐水维持团注,可提高3D CE-MRA的图像质量。     

Gadolinium susceptibility artifact causing false positive stenosis isolated to the proximal common carotid artery in 3D dynamic contrast medium enhanced MR angiography of the thorax--a brief review of causes and prevention

Due to the close proximity of arteries and veins in the superior mediastinum and upper extremities, T2* shortening effects of the gadolinium within the central veins may cause artifactual vascular stenosis (susceptibility artifact) on arterial-phase MR angiographic images of the major branches of the aortic arch. We report a case of artifactual stenosis isolated to the origin of the left common carotid artery on arterial-phase MR angiography, secondary to susceptibility artifact from non-diluted gadolinium in the adjacent brachiocephalic vein. The cause of the artifact, its identification and prevention is reviewed.     

The echogenicity of the intima–media complex in the common carotid artery is related to insulin resistance measured by the hyperinsulinemic clamp in elderly men

The echogenicity of the intima–media complex (IM‐GSM) has recently been shown to be related to the echogenicity in carotid artery plaque and to predict cardiovascular (CV) mortality. The present study aims to evaluate the relationship between metabolic CV risk factors, with special emphasis on insulin resistance, and IM‐GSM in the carotid artery. Carotid artery ultrasound with grey‐scale median analysis of the intima–media complex, IM‐GSM, was performed in a population sample of 480 men aged 75 years. In these subjects, a euglycemic hyperinsulinemic clamp to investigate insulin resistance was performed together with measurements of conventional CV risk factors at the age of 70. The metabolic syndrome (MetS) was defined by the NCEP/ATPIII‐criteria. In univariate analysis, IM‐GSM in the common carotid artery was inversely correlated with the intima–media thickness (IMT), body mass index (BMI), waist/hip ratio, fasting glucose, serum triglycerides, low HDL cholesterol and insulin resistance at the clamp (r = ?0·24, P<0·001). In multiple regression analysis, only insulin resistance at the clamp and BMI were independently related to IM‐GSM. Subjects with the MetS (22%) showed a reduced IM‐GSM when compared to those without (64 ± 20 SD versus 68 ± 19, P<0·05). Because the echogenicity of the intima–media complex in the carotid artery is related to obesity and insulin resistance at clamp independently of IMT, this new vascular characteristic would serve as a marker of vascular alterations induced by insulin resistance and the MetS and has the advantage to be obtainable in almost all subjects.     

Cost evaluation of cardiovascular magnetic resonance versus coronary angiography for the diagnostic work-up of coronary artery disease: Application of the European Cardiovascular Magnetic Resonance registry data to the German,United Kingdom,Swiss, and United States health care systems

Background

Cardiovascular magnetic resonance (CMR) has favorable characteristics for diagnostic evaluation and risk stratification of patients with known or suspected CAD. CMR utilization in CAD detection is growing fast. However, data on its cost-effectiveness are scarce. The goal of this study is to compare the costs of two strategies for detection of significant coronary artery stenoses in patients with suspected coronary artery disease (CAD): 1) Performing CMR first to assess myocardial ischemia and/or infarct scar before referring positive patients (defined as presence of ischemia and/or infarct scar to coronary angiography (CXA) versus 2) a hypothetical CXA performed in all patients as a single test to detect CAD.

Methods

A subgroup of the European CMR pilot registry was used including 2,717 consecutive patients who underwent stress-CMR. From these patients, 21% were positive for CAD (ischemia and/or infarct scar), 73% negative, and 6% uncertain and underwent additional testing. The diagnostic costs were evaluated using invoicing costs of each test performed. Costs analysis was performed from a health care payer perspective in German, United Kingdom, Swiss, and United States health care settings.

Results

In the public sectors of the German, United Kingdom, and Swiss health care systems, cost savings from the CMR-driven strategy were 50%, 25% and 23%, respectively, versus outpatient CXA. If CXA was carried out as an inpatient procedure, cost savings were 46%, 50% and 48%, respectively. In the United States context, cost savings were 51% when compared with inpatient CXA, but higher for CMR by 8% versus outpatient CXA.

Conclusion

This analysis suggests that from an economic perspective, the use of CMR should be encouraged as a management option for patients with suspected CAD.