Relation of aortic wall thickness and distensibility to cardiovascular risk factors (from the Multi-Ethnic Study of Atherosclerosis [MESA])

Assessment of Vascular Indices by Abdominal Aortic Ultrasonography in Preterm Neonates with Bronchopulmonary Dysplasia

Preterm infants with bronchopulmonary dysplasia (BPD) frequently encounter systemic hypertension, yet the underlying cause remains elusive. Given the absence of prior investigations concerning the correlation between systemic hypertension and aortic thickness, we undertook this study to assess and juxtapose diverse vascular indices amidst preterm neonates with BPD, preterm neonates lacking BPD, and healthy neonates, utilizing abdominal aorta ultrasonography. This cross-sectional study encompassed 20 preterm neonates, 20 preterm neonates with BPD, and 20 healthy neonates, meticulously matched for sex and postnatal age. Comprehensive demographic, anthropometric, and clinical evaluation data were documented. The neonates underwent abdominal aortic ultrasonography for comparative evaluation of aortic wall thickness and vasomotor function across the three groups. The study revealed that neonates with BPD exhibited a notably higher average systolic blood pressure than preterm and term neonates (P < 0.05). Conversely, echocardiographic parameters such as input impedance, and arterial wall stiffness index displayed no substantial variance among the three groups (P > 0.05). The mean (SD) aortic intima-media thickness (aIMT) for preterm neonates with BPD, preterm neonates, and term neonates were 814 (193.59) μm, 497.50 (172.19) μm, and 574.00 (113.20) μm, correspondingly (P < 0.05). Furthermore, the mean (SD) pulsatile diameter for preterm neonates with BPD, preterm neonates, and term neonates were 1.52 (0.81) mm, 0.91 (0.55) mm, and 1.34 (0.51) mm, respectively (P < 0.05). Following adjustment for birth weight, sex, and gestational age at birth, the study identified a noteworthy correlation between aIMT and BPD. The investigation concluded that the mean aortic intima-media thickness (aIMT) was significantly elevated in preterm neonates with BPD, signifying a potential early indicator of atherosclerosis and predisposition to future heightened blood pressure and cardiovascular ailments. Consequently, the study postulates that aIMT could be a consistent and well-tolerated marker for identifying BPD patients at risk of developing these health complications.

In-silico investigations of haemodynamic parameters for a blunt thoracic aortic injury case

Accounting for 1.5% of thoracic trauma, blunt thoracic aortic injury (BTAI) is a rare disease with a high mortality rate that nowadays is treated mostly via thoracic endovascular aortic repair (TEVAR). Personalised computational models based on fluid-solid interaction (FSI) principals not only support clinical researchers in studying virtual therapy response, but also are capable of predicting eventual outcomes. The present work studies the variation of key haemodynamic parameters in a clinical case of BTAI after successful TEVAR, using a two-way FSI model. The three-dimensional (3D) patient-specific geometries of the patient were coupled with three-element Windkessel model for both prior and post intervention cases, forcing a correct prediction of blood flow over each section. Results showed significant improvement in velocity and pressure distribution after stenting. High oscillatory, low magnitude shear (HOLMES) regions require careful examination in future follow-ups, since thrombus formation was confirmed in some previously clinically reported cases of BTAI treated with TEVAR. The strength of swirling flows along aorta was also damped after stent deployment. Highlighting the importance of haemodynamic parameters in case-specific therapies. In future studies, compromising motion of aortic wall due to excessive cost of FSI simulations can be considered and should be based on the objectives of studies to achieve a more clinical-friendly patient-specific CFD model.

Magnetic Resonance Imaging and Computed Tomography for the Noninvasive Assessment of Arterial Aging: A Review by the VascAgeNet COST Action

Magnetic resonance imaging and computed tomography allow the characterization of arterial state and function with high confidence and thus play a key role in the understanding of arterial aging and its translation into the clinic. Decades of research into the development of innovative imaging sequences and image analysis techniques have led to the identification of a large number of potential biomarkers, some bringing improvement in basic science, others in clinical practice. Nonetheless, the complexity of some of these biomarkers and the image analysis techniques required for their computation hamper their widespread use. In this narrative review, current biomarkers related to aging of the aorta, their founding principles, the sequence, and postprocessing required, and their predictive values for cardiovascular events are summarized. For each biomarker a summary of reference values and reproducibility studies and limitations is provided. The present review, developed in the COST Action VascAgeNet, aims to guide clinicians and technical researchers in the critical understanding of the possibilities offered by these advanced imaging modalities for studying the state and function of the aorta, and their possible clinically relevant relationships with aging.

Relation of MRI Aortic Wall Area and Plaque to Incident Cardiovascular Events: The Framingham Heart Study

Background Arterial arteriosclerosis and atherosclerosis reflect vascular disease, the subclinical detection of which allows opportunity for cardiovascular disease (CVD) prevention. Larger cohort studies simultaneously quantifying anatomic thoracic and abdominal aortic pathologic abnormalities are lacking in the literature. Purpose To investigate the association of aortic wall area (AWA) and atherosclerotic plaque presence and burden as measured on MRI scans with incident CVD in a community sample. Materials and Methods In this prospective cohort study, participants in the Framingham Heart Study Offspring Cohort without prevalent CVD underwent 1.5-T MRI (between 2002-2005) of the descending thoracic and abdominal aorta with electrocardiogram-gated axial T2-weighted black-blood acquisitions. The wall thickness of the thoracic aorta was measured at the pulmonary bifurcation level and used to calculate the AWA as the difference between cross-sectional vessel area and lumen area. For primary or secondary analyses, multivariable Cox proportional hazards regression models were used to examine the association of aortic MRI measures with risk of first-incident CVD events or stroke and coronary heart disease, respectively. Results In 1513 study participants (mean age, 64 years ± 9 [SD]; 842 women [56%]), 223 CVD events occurred during follow-up (median, 13.1 years), of which 97 were major events (myocardial infarction, ischemic stroke, or CVD death). In multivariable analysis, thoracic AWA and prevalent thoracic plaque were associated with incident CVD (hazard ratio [HR], 1.20 per SD unit [95% CI: 1.05, 1.37] [P = .006] and HR, 1.63 [95% CI: 1.12, 2.35] [P = .01], respectively). AWA and prevalent thoracic plaque were associated with increased hazards: 1.32 (95% CI: 1.07, 1.62; P = .01) and 2.20 (95% CI: 1.28, 3.79; P = .005), for stroke and coronary heart disease, respectively. Conclusion In middle-aged community-dwelling adults, thoracic aortic wall area (AWA), plaque prevalence, and plaque volumes measured with MRI were independently associated with incident cardiovascular disease, with AWA associated in particular with stroke, and plaque associated with coronary heart disease. Clinical trial registration no. NCT00041418 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Peshock in this issue.

Descending Aortic Distensibility and Cardiovascular Outcomes: A Cardiac Magnetic Resonance Imaging Study

Background

Aortic distensibility (AD) is an important determinant of cardiovascular (CV) morbidity and mortality. There is scant data on the association between AD measured within the descending thoracic aorta and CV outcomes.

Objective

We evaluated the association of AD at the descending thoracic aorta (AD _desc) with the primary outcome of all-cause mortality, myocardial infarction (MI), stroke or coronary revascularization in patients referred for a cardiovascular magnetic resonance (CMR) study.

Methods

928 consecutive patients [(mean age 60 ± 17; 33% with prior cardiovascular disease (CVD))] were evaluated. AD _desc was measured at the cross-section of the descending thoracic aorta in the 4-chamber view (via steady-state free precession [SSFP] cine sequences) and was grouped into quintiles (with the 1st quintile corresponding to the least AD, i.e., the stiffest aorta). Cox proportional-hazards regression analysis were performed for the primary outcome.

Results

A total of 315 patients (34%) experienced the primary outcome during a median (25% IQR, 75% IQR) follow-up of 5.0 (0.56, 9.3) years. A decreased AD was significantly associated with hypertension, diabetes, renal disease, and dyslipidemia (p <0.0001). A primary outcome occurred in 43% of patients with AD _desc ≤ median compared to 25% with AD _desc > median, p <0.0001, and in 44% of patients with AD _desc in the 1st quintile compared to 31% with AD _desc in the other quintiles (p = 0.0004). Event free survival was incrementally reduced amongst quintiles (p <0.0001). However, AD _desc ≤ median was not an independent predictor of the primary endpoint after multivariable adjustment in the overall population [adjusted HR 1.09 (95% CI:0.82–1.45), p = 0.518] or in the subgroup analysis of patients with or without prior CVD.

Conclusion

In this real-world cohort of 928 patients referred for CMR, AD _desc is not an independent predictor of CV outcomes.

Fetal and Childhood Exposure to Parental Tobacco Smoking and Arterial Health at Age 10 Years

BACKGROUND

Exposure to parental tobacco smoking during fetal life and childhood is associated with adverse cardiovascular health outcomes. It is not known whether these adverse parental lifestyle exposures are also associated with changes in the structure and function of the carotid arteries in children aged 10 years.

METHODS

In a population-based prospective cohort study among 4,639 healthy children, we examined the associations of fetal exposure to maternal (no, first trimester only, continued), paternal (no, yes), and combined parental tobacco smoking (nonsmoking parents, mother only, father only, both parents smoked) with carotid intima-media thickness and distensibility at 10 years. We also assessed the associations of exposure to any parental tobacco smoking at ages 6 and 10 years with these outcomes.

RESULTS

Compared with no exposure, fetal exposure to continued maternal smoking was not associated with carotid intima-media thickness (-0.04 standard deviation score (SDS); 95% confidence interval (CI): -0.13, 0.05); and distensibility (0 SDS, 95% CI: -0.09, 0.09) at age 10 years. Fetal exposure to two smoking parents was also not associated with carotid intima-media thickness (-0.07 SDS, 95% CI: -0.16, 0.02) and distensibility (0 SDS, 95% CI: -0.09, 0.10) at this age. Exposure to any parental smoking during childhood also was not associated with these outcomes at age 10 years.

CONCLUSIONS

Exposure to parental tobacco smoking during fetal life and childhood was not associated with markers of arterial health in children aged 10 years. Prevention strategies aiming at minimizing smoke exposure later in life are still relevant regarding arterial health.

Reduced arterial elasticity after anabolic-androgenic steroid use in young adult males and mice

High-doses of anabolic-androgenic steroids (AAS) is efficient for building muscle mass, but pose a risk of cardiovascular side effects. Little is known of the effect of AAS on vasculature, but previous findings suggest unfavorable alterations in vessel walls and vasoreactivity. Here, long-term effect of AAS on vascular function and morphology were examined in male weightlifters, and in a mimicking animal model. Arterial elasticity and morphology were tested with ultrasound, pulse wave velocity (PWV) and carotid intima media thickness (cIMT) in 56 current male AAS users, and 67 non-exposed weightlifting controls (WLC). Female mice were treated with testosterone for 14 days and echocardiography were applied to evaluate vascular function and morphology. Male AAS users had higher PWV (p = 0.044), reduced carotid artery compliance (p = 0.0005), and increased cIMT (p = 0.041) compared to WLC. Similar functional changes were found in the ascending aorta of mice after 7- (p = 0.043) and 14 days (p = 0.001) of testosterone treatment. This animal model can be used to map molecular mechanisms responsible for complications related to AAS misuse. Considering the age-independent stiffening of major arteries and the predictive power of an increase in PWV and cIMT, the long-term users of AAS are at increased risk of severe cardiovascular events.

Utility of a Hydrolysate from Overproduced Paralichthys olivaceus for Hypertension Treatment: Correlation between Physical Properties and Potent Anti-Hypertensive Activities

Aquacultured fish are the richest natural source of protein. However, their overproduced biomass is often discarded due to production imbalance, causing considerable losses to the fishery industry. Therefore, it is necessary to utilize surplus fish and add value to overproduced fish. We performed complex enzyme-assisted hydrolysis to determine the correlation between its physical characteristics and anti-hypertensive activity in vitro and in vivo using an SHR model. Protamex-Pepsin assisted hydrolysate from Paralichthys olivaceus (PO_ppH) produced by complex enzyme-assisted hydrolysis contained low-molecular-weight peptides and amino acids with anti-hypertensive activity. PO_ppH regulated blood pressure and serum angiotensin II and angiotensin-I-converting enzyme levels, and histological and ultrasound image analysis revealed substantially reduced thickness and diameter of the carotid aorta in the PO_ppH-administered SHR group. Therefore, we propose to reduce food loss due to overproduction by utilizing the anti-hypertensive activity and physical properties of PO_ppH; the results demonstrate its application as a therapeutic agent.

Machine learning approach to predict acute kidney injury after liver surgery

BACKGROUND

Acute kidney injury (AKI) after surgery appears to increase the risk of death in patients with liver cancer. In recent years, machine learning algorithms have been shown to offer higher discriminative efficiency than classical statistical analysis.

AIM

To develop prediction models for AKI after liver cancer resection using machine learning techniques.

METHODS

We screened a total of 2450 patients who had undergone primary hepatocellular carcinoma resection at Changzheng Hospital, Shanghai City, China, from January 1, 2015 to August 31, 2020. The AKI definition used was consistent with the Kidney Disease: Improving Global Outcomes. We included in our analysis preoperative data such as demographic characteristics, laboratory findings, comorbidities, and medication, as well as perioperative data such as duration of surgery. Computerized algorithms used for model development included logistic regression (LR), support vector machine (SVM), random forest (RF), extreme gradient boosting (XGboost), and decision tree (DT). Feature importance was also ranked according to its contribution to model development.

RESULTS

AKI events occurred in 296 patients (12.1%) within 7 d after surgery. Among the original models based on machine learning techniques, the RF algorithm had optimal discrimination with an area under the curve value of 0.92, compared to 0.87 for XGBoost, 0.90 for DT, 0.90 for SVM, and 0.85 for LR. The RF algorithm also had the highest concordance-index (0.86) and the lowest Brier score (0.076). The variable that contributed the most in the RF algorithm was age, followed by cholesterol, and surgery time.

CONCLUSION

Machine learning algorithms are highly effective in discriminating patients at high risk of developing AKI. The successful application of machine learning models may help guide clinical decisions and help improve the long-term prognosis of patients.

Aortic Stiffness: Epidemiology, Risk Factors, and Relevant Biomarkers

Aortic stiffness (AoS) is a maladaptive response to hemodynamic stress and both modifiable and non-modifiable risk factors, and elevated AoS increases afterload for the heart. AoS is a non-invasive marker of cardiovascular health and metabolic dysfunction. Implementing AoS as a diagnostic tool is challenging as it increases with age and varies amongst races. AoS is associated with lifestyle factors such as alcohol and smoking, as well as hypertension and comorbid conditions including metabolic syndrome and its components. Multiple studies have investigated various biomarkers associated with increased AoS, and this area is of particular interest given that these markers can highlight pathophysiologic pathways and specific therapeutic targets in the future. These biomarkers include those involved in the inflammatory cascade, anti-aging genes, and the renin-angiotensin aldosterone system. In the future, targeting AoS rather than blood pressure itself may be the key to improving vascular health and outcomes. In this review, we will discuss the current understanding of AoS, measurement of AoS and the challenges in interpretation, associated biomarkers, and possible therapeutic avenues for modulation of AoS.

Relationship between Retinal Nerve Fiber Layer Thickness and Aortic Distensibility in Peripheral Arterial Disease Patients

Aim and objective

To evaluate the relationship between aortic distensibility (AD) and aortic stiffness B index (ASBI) with retinal nerve fiber layer (RNFL) thickness measured with HD-OCT in peripheral arterial disease (PAD) patients.

Materials and methods

Twenty-six PAD patients and 22 age-matched healthy control were enrolled. Subjects with PAD were classified into two groups. Patients with diabetes (DM) or hypertension (HT) comprised group I (n = 18) and without DM or HT comprised group II (n = 8). Color Doppler imaging was performed on all patients and PAD was diagnosed by using the ankle-brachial index (ABI). Retinal nerve fiber layer thickness values between control and PAD patients and correlations between RNFL thickness and aortic stiffness parameters (AD and ASBI) were evaluated.

Results

The inferior-nasal and inferior-temporal quadrant were the thickest in healthy subjects and the PAD group. Retinal nerve fiber layer thickness significantly decreased in superior-nasal, temporal, inferior-nasal quadrants in group I than healthy subjects (p < 0.001, p = 0.005, p < 0.001). Temporal and inferior-nasal quadrant thicknesses were statistically significantly thinner in group II than controls (p = 0.02, p < 0.001). The nasal RNFL quadrant was significantly thinner in group I than group II (p = 0.014). The correlation between RNFL thickness and aortic elasticity parameters in each group was not found to be significant.

Conclusion and clinical significance

Isolated PAD without DM or HT may lead to localized RNFL loss in temporal and inferior-nasal quadrants. Aortic elasticity parameters did not seem to be correlated with RNFL thickness in PAD.

How to cite this article

Kumova D, Aktas Z, Eyiol A, et al. Relationship between Retinal Nerve Fiber Layer Thickness and Aortic Distensibility in Peripheral Arterial Disease Patients. J Curr Glaucoma Pract 2021;15(2):86–90.

Vascular Ageing and Aerobic Exercise

Impairment of vascular function, in particular endothelial dysfunction and large elastic artery stiffening, represents a major link between ageing and cardiovascular risk. Clinical and experimental studies identified numerous mechanisms responsible for age-related decline of endothelial function and arterial compliance. Since most of these mechanisms are related to oxidative stress or low-grade inflammation, strategies that suppress oxidative stress and inflammation could be effective for preventing age-related changes in arterial function. Indeed, aerobic physical activity, which has been shown to improve intracellular redox balance and mitochondrial health and reduce levels of systemic inflammatory markers, also improves endothelial function and arterial distensibility and reduces risk of cardiovascular diseases. The present paper provides a brief overview of processes underlying age-related changes in arterial function, as well as the mechanisms through which aerobic exercise might prevent or interrupt these processes, and thus attenuate vascular ageing.

Intra-Operative Video-Based Measurement of Biaxial Strains of the Ascending Thoracic Aorta

Local biaxial deformation measurements are essential for the in-depth investigation of tissue properties and remodeling of the ascending thoracic aorta, particularly in aneurysm formation. Current clinical imaging modalities pose limitations around the resolution and tracking of anatomical markers. We evaluated a new intra-operative video-based method to assess local biaxial strains of the ascending thoracic aorta. In 30 patients undergoing open-chest surgery, we obtained repeated biaxial strain measurements, at low- and high-pressure conditions. Precision was very acceptable, with coefficients of variation for biaxial strains remaining below 20%. With our four-marker arrangement, we were able to detect significant local differences in the longitudinal strain as well as in circumferential strain. Overall, the magnitude of strains we obtained (range: 0.02–0.05) was in line with previous reports using other modalities. The proposed method enables the assessment of local aortic biaxial strains and may enable new, clinically informed mechanistic studies using biomechanical modeling as well as mechanobiological profiling.

Atherosclerotic Burden and Remodeling Patterns of the Popliteal Artery as Detected in the Magnetic Resonance Imaging Osteoarthritis Initiative Data Set

Background

An artificial intelligence vessel segmentation tool, Fully Automated and Robust Analysis Technique for Popliteal Artery Evaluation (FRAPPE), was used to analyze a large databank of popliteal arteries imaged through the OAI (Osteoarthritis Initiative) to study the impact of atherosclerosis risk factors on vessel dimensions and characterize remodeling patterns.

Methods and Results

Magnetic resonance images from 4668 subjects contributing 9189 popliteal arteries were analyzed using FRAPPE. Age ranged from 45 to 79 years (median, 61), and 58% were women. Mean lumen diameter, mean outer wall diameter, and mean wall thickness (MWT) were measured per artery. Their median values were 5.8 mm (interquartile range, 5.2–6.5 mm), 7.3 mm (interquartile range, 6.7–8.1 mm), and 0.78 mm (interquartile range, 0.73–0.84 mm) respectively. MWT was associated with multiple cardiovascular risk factors, with age (4.2% increase in MWT per 10‐year increase in age; 95% CI, 3.9%–4.5%) and sex (8.6% higher MWT in men than women; 95% CI, 7.7%–9.3%) being predominant. On average, lumen and outer wall diameters increased with increasing MWT until the thickness was 0.92 mm for men and 0.84 mm for women. After this point, lumen diameter decreased steadily, more rapidly in men than women (−7.9% versus −6.1% per 25% increase in MWT; P<0.001), with little change in outer wall diameter.

Conclusions

FRAPPE has enabled the analysis of the large OAI knee magnetic resonance imaging data set, successfully showing that popliteal atherosclerosis is predominantly associated with age and sex. The average vessel remodeling pattern consisted of an early phase of compensatory enlargement, followed by a negative remodeling, which is more pronounced in men.

Investigation of Aortic Wall Thickness, Stiffness and Flow Reversal in Patients With Cryptogenic Stroke: A 4D Flow MRI Study

BACKGROUND

Stroke etiology is undetermined in approximately one-sixth to one-third of patients. The presence of aortic flow reversal and plaques in the descending aorta (DAo) has been identified as a potential retrograde embolic mechanism.

PURPOSE

To assess the relationships between aortic stiffness, wall thickness, and flow reversal in patients with cryptogenic stroke and healthy controls.

STUDY TYPE

Prospective.

POPULATION

Twenty one patients with cryptogenic stroke and proven DAo plaques (69 ± 9 years, 43% female), 18 age-matched controls (age: 65 ± 8 years, 61% female), and 14 younger controls (36 ± 9 years, 57% female).

FIELD STRENGTH/SEQUENCE

1.5T; 4D flow MRI and 3D dark blood T1 -weighted turbo spin echo MRI of the aorta.

ASSESSMENT

Noncontrast aortic 4D flow MRI to measure 3D flow dynamics and 3D dark blood aortic wall MRI to assess wall thickness. 4D flow MRI analysis included automated quantification of aortic stiffness by pulse wave velocity (PWV) and voxelwise mapping of the flow reversal fraction (FRF).

STATISTICAL TESTS

Analysis of variance (ANOVA) or Kruskal-Wallis tests, Student's unpaired t-tests or Wilcoxon rank-sum tests, regression analysis.

RESULTS

Aortic PWV and FRF were statistically higher in patients (8.9 ± 1.7 m/s, 18.4 ± 7.7%) than younger controls (5.3 ± 0.8 m/s, P < 0.0167; 8.5 ± 2.9%, P < 0.0167), but not age-matched controls (8.2 ± 1.6 m/s, P = 0.22; 15.6 ± 5.8%, P = 0.22). Maximum aortic wall thickness was higher in patients (3.1 ± 0.7 mm) than younger controls (2.2 ± 0.2 mm, P < 0.0167) and age-matched controls (2.7 ± 0.5 mm) (P < 0.0167). For all subjects, positive relationships were found between PWV and age (R2 = 0.71, P < 0.05), aortic wall thickness (R2 = 0.20, P < 0.05), and FRF (R2 = 0.47, P < 0.05). Patients demonstrated relationships between PWV and FRF in the ascending aorta (R2 = 0.32, P < 0.05) and arch (R2 = 0.24, P < 0.05).

DATA CONCLUSION

This study showed the utility of 4D flow MRI for evaluating aortic PWV and voxelwise flow reversal. Positive relationships between aortic PWV, wall thickness, and flow reversal support the hypothesis that aortic stiffness is involved in this retrograde embolic mechanism.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 1.

Methodology for Estimation of Annual Risk of Rupture for Abdominal Aortic Aneurysm

BACKGROUND AND OBJECTIVE

Estimating patient specific annual risk of rupture of abdominal aortic aneurysm (AAA) is currently based only on population. More accurate knowledge based on patient specific data would allow surgical treatment of only those AAAs with significant risk of rupture. This would be beneficial for both patients and health care system.

METHODS

A methodology for estimating annual risk of rupture (EARR) of abdominal aortic aneurysms (AAA) that utilizes Bayesian statistics, mechanics and patient-specific blood pressure monitoring data is proposed. EARR estimation takes into consideration, peak wall stress in AAA computed by patient-specific finite element modeling, the probability distributions of wall thickness, wall strength, systolic blood pressure and the period of time that the patient is known to have already survived with the intact AAA. Initial testing of proposed approach was performed on fifteen patients with intact AAA (mean maximal diameter 51mm±8mm). They were equipped with a pressure holter and their blood pressure was recorded over 24 hours. Then, we calculated EARR values for four possible scenarios - without considering any days of survival prior identification of AAA at computed tomography scans (EARR_0), considering past survival of 30 (EARR_30), 90 (EARR_90) and 180 days (EARR_180). Finally, effect of patient-specific blood pressure variability was analyzed.

RESULTS

Consideration of past survival does indeed significantly improve predictions of future risk: EARR_30 (1.04%± 0.87%), EARR_90 (0.67%± 0.56%) and EARR_180 (0.47%± 0.39%) which are unrealistically high otherwise (EARR_0 5.02%± 5.24%). Finally, EARR values were observed to vary by an order as a consequence of blood pressure variability and by factor of two as a consequence of neglected growth.

CONCLUSIONS

Methodology for computing annual risk of rupture of AAA was developed for the first time. Sensitivity analyses showed respecting patient specific blood pressure is important factor and should be included in the AAA rupture risk assessment. Obtained EARR values were generally low and in good agreement with confirmed survival time of investigated patients so proposed method should be further clinically validated.

Aortic Elasticity Evaluated by Pulsed Tissue Doppler Imaging of the Ascending Aorta in Different Diseases: A Systematic Review

Several methods have been applied for the evaluation of aortic elasticity. Pulsed tissue Doppler imaging of the ascending aorta is a noninvasive method applied for the evaluation of aortic elasticity in wide variety of diseases which are reviewed in this study. A comprehensive systematic literature search was carried out in November 2019 using the English databases including PubMed, Scopus, Science Direct, and Embase. All references of eligible articles and published reviews on tissue Doppler imaging were searched for relevant publications. Data were extracted according to predefined criteria (including country of study origin, patient population, number of patients in case and control groups, and results of aortic elasticity evaluation in the specific patient groups compared with controls). Two independent reviewers extracted the data, and the results were checked, compared, and edited by the third reviewer. No formal assessment of the statistics of the primary data was made. The results showed that decreased aortic elasticity is not only present in cardiovascular diseases but also can be identified in diseases of other systems that affect cardiovascular system.

Longitudinal Changes of Input Impedance, Pulse Wave Velocity, and Wave Reflection in a Middle-Aged Population: The Asklepios Study

[Figure: see text].

Aortic Thickness: A Forgotten Paradigm in Risk Stratification of Aortic Disease

BACKGROUND

 This study aimed at risk-stratifying aortic dilatation using aortic wall thickness (AWT) and comparing methods of AWT assessment.

METHODS

 Demographic, epidemiological, and perioperative data on 72 consecutive aortic surgeries (age = 62 years[standard deviation (SD) = 12] years) performed by a single surgeon were collected from hospital database. Aortic thickness was measured on computed tomography scans, as well as intraoperatively in four quadrants, at the level of aortic sinuses, as well as midascending aorta, using calipers. Aortic wall stress was calculated using standard mathematical formulae.

RESULTS

 The ascending aorta was 48.2 (SD = 8) mm and the mean thickness at ascending aorta level was 1.9 (SD = 0.3) mm. There was congruence between imaging and intraoperative measurements of thickness, as well as between the radiologist and surgeon. Preoperatively, 16 patients had multiple imaging studies showing an average rate of growth of 1.2 mm per year without significant difference in thickness. The wider the aorta, the thinner was the lateral or convex wall. Aortic stenosis (p = 0.01), lateral to medial wall thickness ratio (p = 0.04), and history of hypertension (p = 0.00), all had protective effect on aortic root stress. The ascending aortic stress was directly affected by age (p = 0.03) and inversely related to lateral to medial wall thickness ratio (p = 0.03).

CONCLUSION

 Aortic thickness can be measured preoperatively and easily confirmed intraoperatively. Risk stratification based on both aortic thickness and diameter (stress calculations) would better predict acute aortic events in dilated aortas and define aortic resection criteria more objectively.

Renin Angiotensin System Inhibitors Reduce Aortic Stiffness and Flow Reversal After a Cryptogenic Stroke

BACKGROUND

Blood flow reversal is a possible mechanism for retrograde embolism in the setting of high-risk atherosclerotic plaques in the descending aorta (DAo). Evidence suggests that pulse wave velocity (PWV) is a determinant of blood flow reversal and can be reduced by the destiffening effect of renin-angiotensin system inhibitors (RASI).

PURPOSE

To evaluate the impact of antihypertensive therapy on in vivo changes in PWV and flow reversal in patients with cryptogenic stroke.

STUDY TYPE

Prospective.

POPULATION

Sixteen patients (69 ± 9 years; 10 males) included after cryptogenic stroke.

FIELD STRENGTH/SEQUENCE

3T. 4D flow sequence (temporal resolution = 19.6 msec) ASSESSMENT: Patients underwent aortic MRI at baseline and at 6-month follow-up. Patients received standard-of-care antihypertensive therapy that were classified as RASI vs. non-RASI medications (ie, destiffening vs. nondestiffening).We compared aortic PWV, flow reversal fraction (FRF), aortic measurements, cardiac function, and other aortic and cardiac measurements in the antihypertensive therapy groups.

STATISTICAL TESTS

Two-tailed paired or unpaired Student's t-tests (normal distributions) or Wilcoxon tests (nonnormal distribution). Univariate correlations using Pearson correlation coefficients.

RESULTS

There was a significant decrease in PWV in the RASI (n = 10) group (9.4 ± 1.6 m/s vs. 8.3 ± 1.9 m/s; P < 0.05), as well as FRF (18.6% ± 4.1% vs. 16.3% ± 4.0%; P < 0.05) between baseline and the 6-month MRI studies. There were no changes in PWV or FRF in the non-RASI (n = 6) group (P = 0.146 and P = 0.32). A decrease in FRF was significantly correlated with a decrease in PWV (r = 0.53; P < 0.05).

DATA CONCLUSION

The findings of our study suggest that RASI therapy after cryptogenic stroke resulted in a decrease of blood flow reversal and aortic stiffness.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY STAGE: 4.

Prediction of post-stenting biomechanics in coarcted aortas: A pilot finite element study

Endovascular stenting has recently become a standard treatment for native coarctation of the aorta (CoA) in children and young adults, given the efficacy in relieving vessel obstruction with a low incidence of adverse events. Yet, despite the short-term success of the technique, late hypertension remains an endemic risk. To assess the impact of the percutaneous procedure on the aortic wall biomechanics, we designed a novel finite element (FE) protocol for the simulation of endovascular stenting in three patient-specific CoA anatomies, developing a remeshing procedure that allows for coping with different CoA severities. Our FE protocol was able to yield numerical results on stent distortions and stresses, as well as on changes in aortic wall stresses and distensibility. These results were consistent with intraprocedural in-vivo evidences and with previous findings from the literature, and they suggest that our numerical approach could be used to understand the role of patient specific anatomical features (CoA severity and arch type) on the post-stenting aortic biomechanics. If soundly validated on a vast cohort of patients, our approach could support patient selection for the procedure.

Rice Intake, Arsenic Exposure, and Subclinical Cardiovascular Disease Among US Adults in MESA

Background Arsenic-related cardiovascular effects at exposure levels below the US Environmental Protection Agency's standard of 10 μg/L are unclear. For these populations, food, especially rice, is a major source of exposure. We investigated associations of rice intake, a marker of arsenic exposure, with subclinical cardiovascular disease (CVD) markers in a multiethnic population. Methods and Results Between 2000 and 2002, MESA (Multi-Ethnic Study of Atherosclerosis) enrolled 6814 adults without clinical CVD. We included 5050 participants with baseline data on rice intake and markers of 3 CVD domains: inflammation (hsCRP [high-sensitivity C-reactive protein], interleukin-6, and fibrinogen), vascular function (aortic distensibility, carotid distensibility, and brachial flow-mediated dilation), and subclinical atherosclerosis at 3 vascular sites (carotid intima-media thickness, coronary artery calcification, and ankle-brachial index). We also evaluated endothelial-related biomarkers previously associated with arsenic. Rice intake was assessed by food frequency questionnaire. Urinary arsenic was measured in 310 participants. A total of 13% of participants consumed ≥1 serving of rice/day. Compared with individuals consuming <1 serving of rice/week, ≥1 serving of rice/day was not associated with subclinical markers after demographic, lifestyle, and CVD risk factor adjustment (eg, geometric mean ratio [95% CI] for hsCRP, 0.98 [0.86-1.11]; aortic distensibility, 0.99 [0.91-1.07]; and carotid intima-media thickness, 0.98 [0.91-1.06]). Associations with urinary arsenic were similar to those for rice intake. Conclusions Rice intake was not associated with subclinical CVD markers in a multiethnic US population. Research using urinary arsenic is needed to assess potential CVD effects of low-level arsenic exposure. Understanding the role of low-level arsenic as it relates to subclinical CVD may contribute to CVD prevention and control.

Longitudinal Effects of Cigarette Smoking and Smoking Cessation on Aortic Wave Reflections, Pulse Wave Velocity, and Carotid Artery Distensibility

Background We evaluated the effects of smoking and smoking cessation on aortic wave reflections (augmentation index), aortic pulse wave velocity, and carotid artery distensibility and stiffness (distensibility coefficient, Young's elastic modulus). Methods and Results Current smokers underwent carotid, radial, and femoral artery tonometry and carotid ultrasound at baseline and 3 years after a quit attempt. Baseline associations of smoking heaviness markers (exhaled carbon monoxide and cigarettes smoked/d) and effects of smoking cessation at year 3 on changes in arterial measures were assessed using multivariable linear regression models. The 1417 smokers (54% female) were mean (SD) 49.3 (11.6) years old and smoked 17.2 (8.3) cigarettes/d (exhaled carbon monoxide 14.7 [8.2] parts per million). Arterial measures were associated more strongly with age, blood pressure (BP), and waist circumference than with smoking heaviness markers. Augmentation index was associated independently with carbon monoxide (P=0.004). Pulse wave velocity, distensibility coefficient, and Young's elastic modulus had small, inconsistent associations with smoking heaviness markers. At year 3, augmentation index improved with smoking cessation (P=0.006) despite more weight gain (2.54 vs 0.36 kg, P<0.001) and insulin resistance (P=0.001) among abstainers, but distensibility coefficient decreased (P=0.004). Changes in arterial measures were related more strongly to changes in BP than smoking cessation. Conclusions Arterial wave reflection and stiffness measures were associated more strongly with age, BP, and waist circumference than smoking heaviness. Smoking cessation was associated with weight gain and increased insulin resistance. Changes in arterial measures were predicted by changes in BP, highlighting the need to address weight gain and BP changes during a quit attempt.

Clinical Correlates of Aortic Stiffness and Wave Amplitude in Black Men and Women in the Community

Background

Black individuals have greater risk for cardiovascular disease (CVD) than whites. Identifying CVD risk factors associated with abnormal aortic hemodynamics in blacks may optimize CVD prevention and treatment strategies.

Methods and Results

Jackson Heart Study participants underwent applanation tonometry (2011–2016) with assessment of carotid‐femoral pulse wave velocity (CFPWV) and forward wave amplitude (FWA). CVD risk factors were assessed during examination 3 (2009–2012). We examined the association of risk factors with binary and continuous CFPWV and FWA in multivariable stepwise models. We evaluated for effect modification by sex to determine differential associations of risk factors with aortic hemodynamics in men and women. We examined 1322 individuals (mean age 66±11 years, 66% women). Age was strongly associated with elevated CFPWV (odds ratio, 4.76; 95% confidence interval, 3.84–5.89 [P<0.0001]) and FWA (odds ratio, 2.30; 95% CI, 1.98–2.69 [P<0.0001]). Men had greater odds of elevated CFPWV compared with women (odds ratio, 1.54; 95% confidence interval, 1.11–2.13 [P=0.009]). Heart rate, mean arterial pressure, and use of antihypertensive medications were associated with elevated CFPWV and FWA (all P≤0.02). Additionally, total/high‐density lipoprotein cholesterol and fasting glucose were associated with elevated CFPWV (both P≤0.002) and use of diabetes mellitus medications was associated with elevated FWA (P≤0.0001). We observed a steeper association of age and mean arterial pressure with unfavorable aortic hemodynamics in women than men.

Conclusions

In blacks in the community, differential CVD risk factors are associated with aortic stiffness and FWA. Future work may determine the impact of risk factor modification on abnormal central aortic hemodynamics and CVD outcomes.

Natural History of Atherosclerosis and Abdominal Aortic Intima-Media Thickness: Rationale, Evidence, and Best Practice for Detection of Atherosclerosis in the Young

Atherosclerosis underlies most myocardial infarctions and ischemic strokes. The timing of onset and the rate of progression of atherosclerosis differ between individuals and among arterial sites. Physical manifestations of atherosclerosis may begin in early life, particularly in the abdominal aorta. Measurement of the abdominal aortic intima-media thickness by external ultrasound is a non-invasive methodology for quantifying the extent and severity of early atherosclerosis in children, adolescents, and young adults. This review provides an evidence-based rationale for the assessment of abdominal aortic intima-media thickness-particularly as an age-appropriate methodology for studying the natural history of atherosclerosis in the young in comparison to other methodologies-establishes best practice methods for assessing abdominal aortic intima-media thickness, and identifies key gaps in the literature, including those that will identify the clinical relevance of this measure.

Association of aortic vascular uptake of 18FDG by PET/CT and aortic wall thickness by MRI in psoriasis: a prospective observational study

BACKGROUND

The contribution of inflammation to the incidence of cardiovascular disease (CVD) has been increasingly recognized in recent years. We investigated the relationship of aortic vascular uptake of 18F-FDG by PET/CT and aortic wall thickness (AWT) by MRI in psoriasis, a chronic inflammatory disease with increased incidence of CVD. One hundred sixty-five patients with plaque psoriasis participated in an ongoing longitudinal cohort study. Subclinical atherosclerosis was assessed as aortic uptake of 18F-FDG by PET/CT reported as target-to-background ratio (TBR) and AWT by MRI reported as maximal thickness.

RESULTS

Patients with psoriasis were middle aged, predominantly male, and had mild CV risk by traditional risk factors. Psoriasis severity as measured by PASI score was a notable determinant of AWT (ρ = 0.20, p = 0.01). Moreover, aortic vascular uptake of 18F-FDG associated with AWT by MRI at baseline in unadjusted analysis (β = 0.27 p = 0.001) and following adjustment for traditional cardiovascular risk factors, waist-to-hip ratio, and statin use (β = 0.21 p = 0.01). Finally, following 1 year of psoriasis treatment, a decrease in aortic vascular uptake of 18F-FDG was associated with a reduction in AWT in fully adjusted models (β = 0.33, p = 0.02).

CONCLUSION

In conclusion, we demonstrate that psoriasis severity and aortic vascular uptake of 18F-FDG in the aorta were associated with AWT. Following treatment of psoriasis, a decrease in aortic vascular uptake of 18F-FDG was associated with a reduction in AWT at 1 year. These findings suggest that aortic vascular uptake of 18F-FDG is associated with early evidence of vascular disease assessed by aortic wall thickness. Prospective studies in larger populations including other inflammatory diseases are warranted.

Applying the ordinal model of atherosclerosis to imaging science: a brief review

Atherogenesis has been well demonstrated to proceed in an ordinal fashion. Imaging technologies have advanced substantially in recent decades, enabling early detection of atherosclerosis. Some modalities, such as coronary CT, have seen broad clinical adaptation. In contrast, others, such as flow-mediated dilatation, remain predominantly research-based. Optimal and appropriate usage of these technologies remains an area of active investigation. We hypothesise that investigators ought to consider which stage of atherosclerosis is under investigation when choosing imaging modalities. Additionally, when assessing the efficacy of a particular treatment, some imaging modalities may be more appropriate than others. We review the most important available imaging modalities and suggest stages at which each may or may not be well used. Conceptual application of the classic stages of atherosclerosis model to the variety of modern imaging modalities available will result in more effective investigation and treatment of cardiovascular disease.

Relation of Sex Hormone Levels With Prevalent and 10-Year Change in Aortic Distensibility Assessed by MRI: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Women experience a steeper decline in aortic elasticity related to aging compared to men. We examined whether sex hormone levels were associated with ascending aortic distensibility (AAD) in the Multi-Ethnic Study of Atherosclerosis.

METHODS

We studied 1,345 postmenopausal women and 1,532 men aged 45-84 years, who had serum sex hormone levels, AAD measured by phase-contrast cardiac magnetic resonance imaging, and ejection fraction>50% at baseline. Among these participants, 457 women and 548 men returned for follow-up magnetic resonance imaging 10-years later. Stratified by sex, and using mixed effects linear regression methods, we examined associations of sex hormones (as tertiles) with baseline and annual change in log-transformed AAD (mm Hg-110-3), adjusting for demographics, body size, lifestyle factors, mean arterial pressure, heart rate, hypertensive medication use (and in women, for hormone therapy use and years since menopause).

RESULTS

The mean (SD) age was 65 (9) for women and 62 (10) years for men. AAD was lower in women than men (P < 0.001). In adjusted cross-sectional analysis, the highest tertile of free testosterone (compared to lowest) in women was significantly associated with lower AAD [-0.10 (-0.19, -0.01)] and the highest tertile of estradiol in men was associated with greater AAD [0.12 (0.04, 0.20)]. There were no associations of sex hormones with change in AAD over 10 years, albeit in a smaller sample size.

CONCLUSIONS

Lower free testosterone in women and higher estradiol in men were associated with greater aortic distensibility at baseline, but not longitudinally. Sex hormone levels may account for differences in AAD between women and men.

Imaging Insights on the Aorta in Aging

The aorta has 2 main functions, conduit and cushion, and is designed to transmit blood to the periphery and buffer pulsatile stress from ventricular contraction. In the interaction between the structural and functional changes of the aorta, aging and disease processes impact on aortic material properties and hemodynamics. For a comprehensive assessment of changes in aortic structure and function associated with aging and disease, noninvasive cardiovascular imaging techniques, especially magnetic resonance imaging, have recently been developed. Magnetic resonance imaging allows for direct and accurate measurement of different aortic characteristics including structural measures such as aortic area or volume, aortic length, curvature, and aortic wall thickness and functional measures such as aortic strain, distensibility, and pulse wave velocity. Excellent reproducibility of magnetic resonance imaging methods allows us to assess the response of the whole aorta to both pharmacological and nonpharmacological therapies. Aortic flow and functional assessment could be added to clinical routine cardiac magnetic resonance as a comprehensive imaging modality primarily performed for the noninvasive evaluation of left ventricular function, left ventricular load, and vascular/ventricular coupling. New techniques such as 4-dimensional flow could provide and further elucidate the combined age-related effects of altered aortic geometry and function. This following review will describe the pathophysiological aspects of the aorta and the ability, value, and prospects of cardiovascular imaging, especially magnetic resonance imaging, to study age-related changes in aortic structure and function and assess the relationship between these alterations and cardiovascular disease.

A competitive strategy for atrial and aortic tract segmentation based on deformable models

Multiple strategies have previously been described for atrial region (i.e. atrial bodies and aortic tract) segmentation. Although these techniques have proven their accuracy, inadequate results in the mid atrial walls are common, restricting their application for specific cardiac interventions. In this work, we introduce a novel competitive strategy to perform atrial region segmentation with correct delineation of the thin mid walls, and integrated it into the B-spline Explicit Active Surfaces framework. A double-stage segmentation process is used, which starts with a fast contour growing followed by a refinement stage with local descriptors. Independent functions are used to define each region, being afterward combined to compete for the optimal boundary. The competition locally constrains the surface evolution, prevents overlaps and allows refinement to the walls. Three different scenarios were used to demonstrate the advantages of the proposed approach, through the evaluation of its segmentation accuracy, and its performance for heterogeneous mid walls. Both computed tomography and magnetic resonance imaging datasets were used, presenting results similar to the state-of-the-art methods for both atria and aorta. The competitive strategy showed its superior performance with statistically significant differences against the traditional free-evolution approach in cases with bad image quality or missed atrial/aortic walls. Moreover, only the competitive approach was able to accurately segment the atrial/aortic wall. Overall, the proposed strategy showed to be suitable for atrial region segmentation with a correct segmentation of the mid thin walls, demonstrating its added value with respect to the traditional techniques.

Racial Differences in Arterial Stiffness are Mainly Determined by Blood Pressure Levels: Results From the ELSA-Brasil Study

Background

Black people have a higher risk of developing hypertension and presenting higher vascular stiffening. Our aim was to investigate whether the association between race and aortic stiffness could be explained by differences in the primary risk factors.

Methods and Results

We analyzed data from 11 472 adults (mean age, 51.9±8.9; 53.8% female) self‐reported as white (n=6173), brown (n=3364), or black (n=1935). Their carotid‐to‐femoral pulse wave velocity (cf‐PWV) as well as clinical and anthropometric parameters were measured. cf‐PWV was higher in blacks than in whites or browns (men: white, 9.63±1.81; brown, 9.63±1.88; black, 9.98±1.99; women: white, 8.84±1.64; brown, 9.02±1.68; black, 9.34±1.91; P<0.05). However, this difference disappeared after adjustments for age, mean arterial pressure, heart rate, waist circumference, fasting glucose, and glomerular filtration rate (men: white, 9.68±1.54; brown, 9.68±1.50; black, 9.73±1.52; women: white, 8.93±1.32; brown, 8.98±1.29; black, 9.02±1.32; P>0.05). The association between race and arterial stiffness was significant for brown and black women in the highest cf‐PWV quartile, even after controlling for covariates. There were no differences in the age‐related increase in cf‐PWV among the racial groups after adjustment, confirming the strong effect of age and mean arterial pressure on cf‐PWV revealed by the multiple linear regression.

Conclusions

Racial differences in cf‐PWV were mainly attributed to differences in mean arterial pressure and age, although they cannot fully explain the association between race and cf‐PWV in women in the highest cf‐PWV values. This suggests that therapeutic approaches to overcome the effects of aging on the vascular system should focus on blood pressure control, especially in the black population.

Sex, body mass index, and blood pressure are related to aortic characteristics in healthy, young adults using magnetic resonance vessel wall imaging: the AMBITYON study

Objectives

More detailed evaluation of atherosclerosis and its key determinants in young individuals is warranted to improve knowledge on the pathophysiology of its development and progression. This study evaluated associations of magnetic resonance imaging (MRI)-derived aortic wall area, wall thickness, and pulse wave velocity (PWV) with cardiovascular risk factors in asymptomatic, young adults.

Materials and methods

In 124 adults (age: 25–35 years) from the general population-based Atherosclerosis Monitoring and Biomarker Measurements in the Young study, demography, anthropometry, and blood samples were collected. The studied MRI-parameters were measured using a 3.0T MRI system. Relations between cardiovascular risk factors and aortic characteristics were assessed using multivariable linear regression analyses.

Results

Mean age was 31.8 years, 47.6% was male. Aortic wall area was positively associated with age [β = 0.01, (95% confidence interval (CI) 2.00 × 10⁻³, 0.02), p = 0.01] and BMI [β = 0.01, (0.01, 0.02), p = 0.003] and negatively associated with sex (reference: men) [β = −0.06, (−0.11, −0.01), p = 0.02]. Natural logarithm transformed (ln) aortic wall thickness was positively associated with BMI [β = 0.01, (1.00 × 10⁻³, 0.02), p = 0.02]. Ln aortic PWV was positively associated with 10 mmHg increment of SBP [β = 0.06, (0.03, 0.09), p < 0.001] and DBP [β = 0.06, (0.02, 0.09), p = 0.006]. No relations were observed for smoking and lipids.

Conclusions

Already in early adulthood, aortic wall geometry and stiffness vary by age, sex, BMI, and blood pressure.

Pulmonary artery stiffness in chronic obstructive pulmonary disease (COPD) and emphysema: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study

PURPOSE

Chronic obstructive pulmonary disease (COPD) and particularly emphysema are characterized by stiffness of the aorta, due in part to accelerated elastin degradation in the lungs and aorta. Stiffness of the pulmonary arteries (PAs) may also be increased in COPD and emphysema, but data are lacking. We assessed PA stiffness using MRI in patients with COPD and related these measurements to COPD severity and percent emphysema.

MATERIALS AND METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study recruited 290 participants, age 50-79 years with 10 or more packyears and free of clinical cardiovascular disease. COPD severity were defined on postbronchodilator spirometry by ATS/ERS criteria. Percent emphysema was defined as the percentage of regions of the lung < -950 Hounsfield units on full-lung computed tomography (CT). PA stain was defined by the percent change in cross-sectional PA area between systole and diastole on MRI. Blood flow across the tricuspid and mitral valves was assessed by phase-contrast MRI for determination of the ventricular diastolic dysfunction (E/A ratio).

RESULTS

PA strain was reduced in COPD compared with controls (P = 0.002) and was inversely correlated with COPD severity (P = 0.004). PA strain was inversely associated to percent emphysema (P = 0.01). PA strain was also markedly correlated with right ventricular diastolic dysfunction measured by E/A ratios in the fully adjusted mix models (P = 0.02).

CONCLUSION

PA strain is reduced in COPD, related in part to percent emphysema on CT scan, which may have implications for pulmonary small vessel flow and right ventricular function.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:262-271.

The importance of accurate measurement of aortic stiffness in patients with chronic kidney disease and end-stage renal disease

Cardiovascular (CV) disease is the leading cause of death in chronic kidney disease (CKD) and end-stage renal disease (ESRD). A key driver in this pathology is increased aortic stiffness, which is a strong, independent predictor of CV mortality in this population. Aortic stiffening is a potentially modifiable biomarker of CV dysfunction and in risk stratification for patients with CKD and ESRD. Previous work has suggested that therapeutic modification of aortic stiffness may ameliorate CV mortality. Nevertheless, future clinical implementation relies on the ability to accurately and reliably quantify stiffness in renal disease. Pulse wave velocity (PWV) is an indirect measure of stiffness and is the accepted standard for non-invasive assessment of aortic stiffness. It has typically been measured using techniques such as applanation tonometry, which is easy to use but hindered by issues such as the inability to visualize the aorta. Advances in cardiac magnetic resonance imaging now allow direct measurement of stiffness, using aortic distensibility, in addition to PWV. These techniques allow measurement of aortic stiffness locally and are obtainable as part of a comprehensive, multiparametric CV assessment. The evidence cannot yet provide a definitive answer regarding which technique or parameter can be considered superior. This review discusses the advantages and limitations of non-invasive methods that have been used to assess aortic stiffness, the key studies that have assessed aortic stiffness in patients with renal disease and why these tools should be standardized for use in clinical trial work.

Comparing Arterial Function Parameters for the Prediction of Coronary Heart Disease Events: The Multi-Ethnic Study of Atherosclerosis (MESA)

Arterial dysfunction has been linked to decline in cardiac function and increased risk of cardiovascular disease events. We calculated the value of arterial function, measured at baseline (2000-2002), in predicting time to first coronary heart disease (CHD) event (median follow-up, 10.2 years) among participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Measures included the following: C₁ and C₂, derived from diastolic pulse contour analysis from the radial artery blood pressure waveform obtained by tonometry (n = 6,336); carotid distensibility and Young's elastic modulus at the carotid artery, derived from carotid artery ultrasonography (n = 6,531 and 6,528); and aortic distensibility, measured using cardiac magnetic resonance imaging (n = 3,677). After adjustment, the hazard ratio for a CHD event per standard-deviation increment in arterial function was 0.97 (95% confidence interval (CI): 0.86, 1.10) for C₁, 0.73 (95% CI: 0.63, 0.86) for C₂, 0.98 (95% CI: 0.86, 1.11) for carotid distensibility, 0.99 (95% CI: 0.90, 1.09) for Young's modulus, and 0.90 (95% CI: 0.74, 1.10) for aortic distensibility. We examined the area under the receiver operating characteristic curve for the model with full adjustment plus the addition of each measure individually. C₂ provided additional discrimination for the prediction of CHD (area under the curve = 0.736 vs. 0.743; P = 0.04). Lower C₂ was associated with a higher risk of future CHD events.

Multi-component model of intramural hematoma

A novel multi-component model is introduced for studying interaction between blood flow and deforming aortic wall with intramural hematoma (IMH). The aortic wall is simulated by a composite structure submodel representing material properties of the three main wall layers. The IMH is described by a poroelasticity submodel which takes into account both the pressure inside hematoma and its deformation. The submodel of the hematoma is fully coupled with the aortic submodel as well as with the submodel of the pulsatile blood flow. Model simulations are used to investigate the relation between the peak wall stress, hematoma thickness and permeability in patients of different age. The results indicate that an increase in hematoma thickness leads to larger wall stress, which is in agreement with clinical data. Further simulations demonstrate that a hematoma with smaller permeability results in larger wall stress, suggesting that blood coagulation in hematoma might increase its mechanical stability. This is in agreement with previous experimental observations of coagulation having a beneficial effect on the condition of a patient with the IMH.

Smoking Behaviors and Arterial Stiffness Measured by Pulse Wave Velocity in Older Adults: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Though smoking is strongly associated with peripheral vascular disease and arteriosclerosis, smoking's association with arterial stiffness has been inconsistent and mostly limited to a single arterial segment. We examined the relationship between smoking behaviors with arterial stiffness in multiple arterial segments among community dwelling older adults.

METHODS

The cross-sectional relationship between smoking behavior with carotid-femoral (cfPWV) and femoral-ankle pulse wave velocity (faPWV) was examined in 5,002 men and women, separately, of the Atherosclerosis Risk in Communities (ARIC) cohort study. Brachial-ankle PWV was also assessed and presented in Supplementary Material. Heckman selection models were used to control for selective attrition and death in the ARIC cohort.

RESULTS

In women, faPWV was lower in current smokers compared to never smokers (-66.0cm/s; 95% confidence interval (95% CI): -94.6, -37.4), and was 1.0cm/s lower (95% CI: -1.8, -0.2) for every additional year a woman smoked, after adjustment for confounders. Among women, cfPWV was not associated with smoking status or cigarette pack-years. Additionally, no associations of smoking status and cigarette pack-years with PWV were observed among men. Years since smoking cessation was not associated with PWV in either gender.

CONCLUSION

Both smoking status and cumulative smoking exposure were associated with lower peripheral arterial stiffness among women, but not among men. We did not observe an association between central arterial stiffness and smoking status in either gender. The profound and well-documented adverse effects of cigarette smoking on the vasculature may not include a sustained stiffening of the arteries measured at older age.

Development of a Patient-Specific Multi-Scale Model to Understand Atherosclerosis and Calcification Locations: Comparison with In vivo Data in an Aortic Dissection

Vascular calcification results in stiffening of the aorta and is associated with hypertension and atherosclerosis. Atherogenesis is a complex, multifactorial, and systemic process; the result of a number of factors, each operating simultaneously at several spatial and temporal scales. The ability to predict sites of atherogenesis would be of great use to clinicians in order to improve diagnostic and treatment planning. In this paper, we present a mathematical model as a tool to understand why atherosclerotic plaque and calcifications occur in specific locations. This model is then used to analyze vascular calcification and atherosclerotic areas in an aortic dissection patient using a mechanistic, multi-scale modeling approach, coupling patient-specific, fluid-structure interaction simulations with a model of endothelial mechanotransduction. A number of hemodynamic factors based on state-of-the-art literature are used as inputs to the endothelial permeability model, in order to investigate plaque and calcification distributions, which are compared with clinical imaging data. A significantly improved correlation between elevated hydraulic conductivity or volume flux and the presence of calcification and plaques was achieved by using a shear index comprising both mean and oscillatory shear components (HOLMES) and a non-Newtonian viscosity model as inputs, as compared to widely used hemodynamic indicators. The proposed approach shows promise as a predictive tool. The improvements obtained using the combined biomechanical/biochemical modeling approach highlight the benefits of mechanistic modeling as a powerful tool to understand complex phenomena and provides insight into the relative importance of key hemodynamic parameters.

Subclinical Vascular Disease and Subsequent Erectile Dysfunction: The Multiethnic Study of Atherosclerosis (MESA)

BACKGROUND

The association between subclinical cardiovascular disease and subsequent development of erectile dysfunction (ED) remains poorly described.

HYPOTHESIS

Among multiple subclinical atherosclerosis and vascular dysfunction measurements, coronary artery calcium (CAC) score best predicts ED.

METHODS

After excluding participants taking ED medications at baseline, we studied 1862 men age 45 to 84 years free of known cardiovascular disease from the Multi-Ethnic Study of Atherosclerosis (MESA) with comprehensive baseline subclinical vascular disease phenotyping and ED status assessed at MESA visit 5 (9.4 ± 0.5 years after baseline) using a standardized question on ED symptoms. Multivariable logistic regression was used to assess the associations between baseline measures of vascular disease (atherosclerosis domain: CAC, carotid intima-media thickness, carotid plaque, ankle-brachial index; vascular stiffness/function domain: aortic stiffness, carotid stiffness, brachial flow-mediated dilation) and ED symptoms at follow-up.

RESULTS

Mean baseline age was 59.5 ± 9 years, and 839 participants (45%) reported ED symptoms at follow-up. Compared with symptom-free individuals, participants with ED had higher baseline prevalence of CAC score >100 (36.4% vs 17.2%), carotid intima-media thickness Z score >75th percentile (35.3% vs 16.6%), carotid plaque score ≥2 (39% vs 21.1%), carotid distensibility <25th percentile (34.6% vs 17.1%), aortic distensibility <25th percentile (34.2% vs 18.7%), and brachial flow-mediated dilation <25th percentile (28.4% vs 21.3%); all P < 0.01. Only CAC >100 (odds ratio: 1.43, 95% confidence interval: 1.09-1.88) and carotid plaque score ≥2 (odds ratio: 1.33, 95% confidence interval: 1.02-1.73) were significantly associated with ED.

CONCLUSIONS

Subclinical vascular disease is common in men who later self-report ED. Early detection of subclinical atherosclerosis, particularly advanced CAC and carotid plaque, may provide opportunities for predicting the onset of subsequent vascular ED.

High levels of thyroid-stimulating hormone are associated with aortic wall thickness in the general population

OBJECTIVES

Our aim was to investigate the association of thyroid function defined by serum concentrations of thyroid-stimulating hormone (TSH) with thoracic aortic wall thickness (AWT) as a marker of atherosclerotic processes.

METHODS

We pooled data of 2,679 individuals from two independent population-based surveys of the Study of Health in Pomerania. Aortic diameter and AWT measurements were performed on a 1.5-T MRI scanner at the concentration of the right pulmonary artery displaying the ascending and the descending aorta.

RESULTS

TSH, treated as continuous variable, was significantly associated with descending AWT (β = 0.11; 95 % confidence interval (CI) 0.02-0.21), while the association with ascending AWT was not statistically significant (β = 0.20; 95 % CI -0.01-0.21). High TSH (>3.29 mIU/L) was significantly associated with ascending (β = 0.12; 95 % CI 0.02-0.23) but not with descending AWT (β = 0.06; 95 % CI -0.04-0.16). There was no consistent association between TSH and aortic diameters.

CONCLUSIONS

Our study demonstrated that AWT values increase with increasing serum TSH concentrations. Thus, a hypothyroid state may be indicative for aortic atherosclerosis. These results fit very well to the findings of previous studies pointing towards increased atherosclerotic risk in the hypothyroid state.

KEY POINTS

• Serum TSH concentrations are positively associated with aortic wall thickness. • Serum TSH concentrations are not associated with the aortic diameters. • Serum 3,5-diiodothyronine concentrations may be positively associated with aortic wall thickness.

Carotid artery distensibility and hormone therapy and menopause: the Los Angeles Atherosclerosis Study

OBJECTIVE

Observational studies have suggested that arterial distensibility decreases during menopause; however, its relationship with hormone therapy use remains controversial. We prospectively studied distensibility and hormone therapy use at different menopause stages.

METHODS

One hundred sixty-one women (aged between 42 and 61 y) without cardiovascular disease underwent carotid artery measurements by ultrasound to calculate distensibility index at baseline and 3 years later. Menopause stage was classified at each visit as premenopausal, perimenopausal, and postmenopausal. Across 3 years of prospective observation, women were classified as remaining premenopausal, remaining postmenopausal, or transitioning (defined as change from premenopausal to perimenopausal, from premenopausal to postmenopausal, from perimenopausal to perimenopausal, or from perimenopausal to postmenopausal).

RESULTS

Distensibility declined across time at all menopause stages (P < 0.0001). Compared with postmenopausal women, premenopausal and transitioning/no hormone therapy women had more than twice the decline in distensibility index (P = 0.06 and P = 0.016, respectively), whereas transitioning/hormone therapy women did not differ in distensibility decline (P = 0.28). In a multivariate model, change in systolic blood pressure (P < 0.0001) and change in pulse pressure (P = 0.004) were independent predictors of distensibility index change and served as effect modulators. In an adjusted model, women in the premenopausal and transitioning/no hormone therapy groups had a significantly faster decline in distensibility index (P = 0.002 and P = 0.001, respectively) compared with postmenopausal women, whereas the transitioning/hormone therapy group did not (P = 0.21).

CONCLUSIONS

These findings confirm that the menopausal transition is associated with reduced vascular compliance. Hormone therapy is associated with better arterial distensibility only during the menopausal transition. Additional prospective studies are needed to confirm these findings and to determine whether hormone therapy use beyond the menopausal transition is related to distensibility.

Ten-year longitudinal change in aortic stiffness assessed by cardiac MRI in the second half of the human lifespan: the multi-ethnic study of atherosclerosis

AIMS

Longitudinal determinants of aortic stiffness (AS) measured by magnetic resonance imaging (MRI) have not been assessed in a large community-based population. Our aim was to examine the determinants of change in thoracic AS over 10 years of follow-up in a multi-ethnic population of individuals 45 years of age and older measured by MRI.

METHODS AND RESULTS

We studied 1160 participants (mean age = 60 ± 9 years at baseline, 45% male) with aortic MRI at both the MESA Year 0 and Year 10 examinations. Ascending and descending aorta distensibility (AAD/DAD) and aortic arch pulse-wave velocity (PWV) were measured using MRI. Determinants of the change in AS parameters over 10 years were assessed using linear regression adjusted for baseline values, demographic variables, baseline risk factors and change in risk factors, and chronic risk exposure. AAD and DAD decreased slightly (5% decrease in median for AAD: 1.33-1.26 mmHg(-1) · 10(-3), P = 0.008; 5% decrease in median for DAD: 1.73-1.64 mmHg(-1) · 10(-3), P < 0.001), and PWV increased over 10 years (18% increase in median: 6.8-8.0 m/s P < 0.001). Baseline age was related to a reduction in AAD and DAD and an increase in PWV throughout the follow-up period. Baseline and change in mean blood pressure and continued smoking were associated with a reduction in AAD and an increase in PWV. Furthermore, baseline heart rate was also related to a reduction in AAD and DAD. Blood pressure normalization was related to less aortic stiffening throughout the follow-up period.

CONCLUSIONS

In our longitudinal, community-based cohort study of adult individuals aged 45 years or greater, greater mean blood pressure and a history of smoking history were associated with increased aortic stiffening over 10 years as assessed by MRI.

Effects of Anxiety and Depression on Arterial Elasticity of Subjects With Suboptimal Physical Health

BACKGROUND

The authors investigated the effects of suboptimal health status (SHS; high-normal blood pressure, blood glucose, and blood lipids) on arterial elasticity in subjects with or without anxiety or depression.

HYPOTHESIS

Suboptimal physical health status and anxiety or depression increase the risk of cardiovascular diseases.

METHODS

This was a cross-sectional, observational, multicenter study. Among 1520 subjects who underwent physical examination between May 2009 and December 2012 in Beijing and Chongqing, China, 955 were included. All subjects completed anxiety and depression questionnaires. Systemic vascular compliance (SVC), systemic vascular resistance, and brachial artery distensibility (BAD) were measured during arterial elasticity evaluation.

RESULTS

Of 955 participants, 633 were classified as having SHS and 322 were classified as healthy. Systemic vascular compliance and BAD were worse in SHS subjects than in healthy subjects (SVC: 1.23 ± 0.22 vs 1.29 ± 0.25 mL/mm Hg; BAD: 6.26 ± 1.32 vs 6.61 ± 1.24%/mm Hg, respectively; both P < 0.05). Of 955 subjects, 37.7% and 43.9% had anxiety and depression, respectively. Systemic vascular compliance and BAD in SHS subjects with concomitant anxiety or depression were significantly lower than in SHS subjects without anxiety or depression (SVC: 1.22 ± 0.23 vs 1.23 ± 0.20 mL/mm Hg; BAD: 6.10 ± 1.36 vs 6.33 ± 1.20 %/mm Hg, respectively; both P < 0.05) and even lower than in healthy subjects.

CONCLUSIONS

Though anxiety and depression had less impact on arterial elasticity in a healthy population, they may be involved in pathogenesis of vascular damage in the population with SHS.