Editor's Choice - Infra-Renal Aortic Diameter and Cardiovascular Risk: Making Better Use of Abdominal Aortic Aneurysm Screening Outcomes

Measuring early vascular aging in youth: an expert consensus document from the Youth Vascular Consortium

Since the conceptualization of early vascular aging (EVA) in 2008, significant efforts have been made to develop and improve its assessment. Initially lead by the investigation of arterial stiffness through pulse wave velocity (PWV), several additional vascular aging biomarkers have gained prominence in recent years. Despite expanding literature addressing methodological concerns associated with these biomarkers in youth, a standardized approach for clinical evaluation of EVA remains elusive, leaving pertinent gaps in understanding the optimal methodology. This article, resulting from international consensus efforts from the Youth Vascular Consortium, aims to provide an updated overview of methods available to measure EVA in youth and to discuss challenges in translating these methods into clinical practice.

Abdominal Noncontrast Computed Tomography Scanning to Screen for Kidney Cancer and Other Abdominal Pathology Within Community-based Computed Tomography Screening for Lung Cancer: Results of the Yorkshire Kidney Screening Trial

BACKGROUND AND OBJECTIVE

The Yorkshire Kidney Screening Trial (YKST) assessed the feasibility of adding abdominal noncontrast computed tomography (NCCT) to lung cancer screening to screen for kidney cancer and other abdominal pathology.

METHODS

A prospective diagnostic study offered abdominal NCCT to 55-80-yr-old ever-smokers attending a UK randomised lung cancer screening trial (May 2021 to October 2022). The exclusion criteria were dementia, frailty, previous kidney/lung cancer, and computed tomography (CT) of the abdomen and thorax within previous 6 and 12 mo, respectively. Six-month follow-up was undertaken.

KEY FINDINGS AND LIMITATIONS

A total of 4438 people attended lung screening, of whom 4309 (97%) were eligible for and 4019 (93%) accepted abdominal NCCT. Only 3.9% respondents regretted participating. The additional time to conduct the YKST processes was 13.3 min. Of the participants, 2586 (64%) had a normal abdominal NCCT, whilst 787 (20%) required an abdominal NCCT imaging review but no further action and 611 (15%) required further evaluation (investigations and/or clinic). Of the participants, 211 (5.3%) had a new serious finding, including 25 (0.62%) with a renal mass/complex cyst, of whom ten (0.25%) had histologically proven kidney cancer; ten (0.25%) with other cancers; and 60 (1.5%) with abdominal aortic aneurysms (AAAs). Twenty-five (0.62%) participants had treatment with curative intent. Of the participants, 1017 (25%) had nonserious findings, most commonly benign renal cysts (727 [18%]), whereas only 259 (6.4%) had nonserious findings requiring further tests. The number needed to screen to detect one serious abdominal finding was 18; it was 93 to detect one suspicious renal lesion and 402 to detect one histologically confirmed renal cancer. Limitations of the cohort were fixed age range and being prior lung cancer screening attendees.

CONCLUSIONS AND CLINICAL IMPLICATIONS

In this first prospective risk-stratified screening study of abdominal NCCT offered alongside CT thorax, uptake and participant satisfaction were high. The prevalence of serious findings, cancers, and AAAs, is in the range of established screening programmes such as bowel cancer. Longer-term outcomes and cost effectiveness should now be evaluated.

Positioning for the use of multivessel clinicalultrasound in vascular risk evaluation: VASUS+protocol. 2024 Recommendations of the Vascular Risk WorkingGroup of The Spanish Society of Internal Medicine (SEMI), Clinical Ultrasound Working Group of the Spanish Society of Internal Medicine (SEMI) and the Spanish Society of Hypertension-Spanish League for the Fight against Arterial Hypertension (SHE-LELHA)

Atherosclerosis is the underlying disease in the entire spectrum of atherosclerotic vascular disease. Point of care ultrasound is a useful tool for its detection. Current guidelines recommend the use of scales such as SCORE 2 and SCORE 2OP in apparently healthy individuals and in those at intermediate-low risk, they recognize the role of the arterial plaque by ultrasound to refine risk stratification and the need for more aggressive preventive strategies. However, the way to evaluate the vascular territories in which there is presence of plaque, the amount or load of plaque is not homogeneous nor is it well protocolized. In this document, 2 protocols are proposed for the evaluation of vascular risk, VASUS and VASUS+, including the presence of ventricular hypertrophy with the objective of homogenizing clinical ultrasound in the assessment of vascular risk in clinical practice.

Positioning for the use of multivessel clinical ultrasound in vascular risk evaluation: VASUS+ protocol. 2024 recommendations of the Vascular Risk Group, clinical ultrasound of the Spanish Society of Internal Medicine and Spanish Society of Hypertension and Vascular Risk

Atherosclerosis is the underlying disease in the entire spectrum of atherosclerotic vascular disease. Point of care ultrasound is a useful tool for its detection. Current guidelines recommend the use of scales such as SCORE 2 and SCORE 2OP in apparently healthy individuals and in those at intermediate-low risk, they recognize the role of the arterial plaque by ultrasound to refine risk stratification and the need for more aggressive preventive strategies. However, the way to evaluate the vascular territories in which there is presence of plaque, the amount or load of plaque is not homogeneous nor is it well protocolized. In this document, 2 protocols are proposed for the evaluation of vascular risk, VASUS and VASUS+, including the presence of ventricular hypertrophy with the objective of homogenizing clinical ultrasound in the assessment of vascular risk in clinical practice.

A feasibility study of the CRISP intervention; a cardiovascular risk reduction intervention in patients with an abdominal aortic aneurysm

Background

Abdominal aortic aneurysm (AAA) screening/surveillance is implemented widely. Those in AAA-surveillance are at high-risk of cardiovascular-events. We developed an intervention, called CRISP, using intervention-mapping, to reduce cardiovascular-risk in AAA-surveillance. This study tested the CRISP intervention in routine clinical-care.

Methods

The CRISP intervention, consisting of a nurse-led cardiovascular risk assessment and subsequent lifestyle change support using a self-care workbook and low-intensity nurse input was delivered in two screening/surveillance programmes. Those consenting to take part were followed-up with cardiovascular-assessments. Fidelity of intervention-delivery was assessed quantitatively/qualitatively.

Results

40 men (mean age 75 ± 7 years) took part over four months and followed-up for a minimum six months. A sub-group of 25 patients and nine Health Care Professionals (HCPs) were interviewed. The median number of risk-factors that patients chose to focus on was two (range 0 to 4), with physical activity (n=17) being the most popular. Participants who had a 'red light' risk factor for stress, low mood, smoking or alcohol intake were offered a referral to appropriate services. Two were offered referral to mental-health services and took it up, three declined referrals to smoking or alcohol support services. The fidelity of intervention-delivery (a score intervention components delivered to each patient based on a score from 0 to 5, with 5 being highest delivery fidelity) was generally low. The highest mean score (on a 0-5 scale) for the nurse assessment was 1.5 for engaging the participant, lowest 0.5 for exploring the importance for selected lifestyle behaviours. In qualitative interviews, the intervention was liked by patients/HCPs. Based on qualitative interviews and observations, the low fidelity of intervention-delivery was due to intervention-training not being detailed.

Conclusions

CRISP can be delivered in AAA-surveillance, but fidelity of delivery is low. The intervention and its training need to be refined/tested before wider implementation.

Registration

ISRCTN9399399518/11/20).

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Improving cardiovascular health in patients with an abdominal aortic aneurysm: development of the cardiovascular risk reduction in patients with aneurysms (CRISP) behaviour change intervention

BACKGROUND

Abdominal aortic aneurysm (AAA) is an important cardiovascular health problem. Ultrasound screening is proven to reduce AAA mortality and programmes have been implemented in some healthcare systems. Those who are identified as having a small AAA in screening enter into a surveillance programme to monitor AAA size. Individuals in AAA surveillance are at elevated risk of cardiovascular events, which is not currently addressed sufficiently. We aimed to develop a simple intervention to reduce cardiovascular risk, which could be embedded in AAA surveillance pathways.

METHODS

Intervention mapping methods were used to co-develop the intervention with individuals with AAA, families/carers, and healthcare staff. We identified "targets for change" by synthesising research evidence and international guidelines and consulting with patients, caregivers and health service providers. We conducted a series of workshops to identify barriers to and facilitators of change and used taxonomies of behaviour change theories and techniques to match intervention strategies to each target. Further stakeholder involvement work helped refine the intervention.

RESULTS

The developed intervention focusses on assessment and individually tailored discussion of risk factors, exchanging information, building motivation and action planning, followed by review of progress and problem-solving. Workbooks covering physical activity, diet, stress management, alcohol, smoking, blood pressure and mental health are provided to support behaviour change. The intervention is facilitated by trained healthcare professionals during the patient's AAA screening appointment for the duration that they are in surveillance.

DISCUSSION

The developed intervention will now be tested to assess whether it can be integrated with the current AAA screening programme. The developed intervention is a novel approach to reducing cardiovascular disease in the AAA population, it is also the first intervention which tries to do this in this population.

TRIAL REGISTRATION

International Clinical Trial Registration: ISRCTN93993995.

Assessment of Subclinical Atherosclerosis in Asymptomatic People In Vivo: Measurements Suitable for Biomarker and Mendelian Randomization Studies

BACKGROUND

One strategy to reduce the burden of cardiovascular disease is the early detection and treatment of atherosclerosis. This has led to significant interest in studies of subclinical atherosclerosis, using different phenotypes, not all of which are accurate reflections of the presence of asymptomatic atherosclerotic plaques. The aim of part 2 of this series is to provide a review of the existing literature on purported measures of subclinical disease and recommendations concerning which tests may be appropriate in the prevention of incident cardiovascular disease.

METHODS

We conducted a critical review of measurements used to infer the presence of subclinical atherosclerosis in the major conduit arteries and focused on the predictive value of these tests for future cardiovascular events, independent of conventional cardiovascular risk factors, in asymptomatic people. The emphasis was on studies with >10 000 person-years of follow-up, with meta-analysis of results reporting adjusted hazard ratios (HRs) with 95% CIs. The arterial territories were limited to carotid, coronary, aorta, and lower limb arteries.

RESULTS

In the carotid arteries, the presence of plaque (8 studies) was independently associated with future stroke (pooled HR, 1.89 [1.04-3.44]) and cardiac events (7 studies), with a pooled HR, 1.77 (1.19-2.62). Increased coronary artery calcium (5 studies) was associated with the risk of coronary heart disease events, pooled HR, 1.54 (1.07-2.07) and increasing severity of calcification (by Agaston score) was associated with escalation of risk (13 studies). An ankle/brachial index (ABI) of <0.9, the pooled HR for cardiovascular death from 7 studies was 2.01 (1.43-2.81). There were insufficient studies of either, thoracic or aortic calcium, aortic diameter, or femoral plaque to synthesize the data based on consistent reporting of these measures.

CONCLUSIONS

The presence of carotid plaque, coronary artery calcium, or abnormal ankle pressures seems to be a valid indicator of the presence of subclinical atherosclerosis and may be considered for use in biomarker, Mendelian randomization and similar studies.

Effects of diabetes mellitus and glycemic traits on cardiovascular morpho-functional phenotypes

BACKGROUND

The effects of diabetes on the cardiac and aortic structure and function remain unclear. Detecting and intervening these variations early is crucial for the prevention and management of complications. Cardiovascular magnetic resonance imaging-derived traits are established endophenotypes and serve as precise, early-detection, noninvasive clinical risk biomarkers. We conducted a Mendelian randomization (MR) study to examine the association between two types of diabetes, four glycemic traits, and preclinical endophenotypes of cardiac and aortic structure and function.

METHODS

Independent genetic variants significantly associated with type 1 diabetes, type 2 diabetes, fasting insulin (FIns), fasting glucose (FGlu), 2 h-glucose post-challenge (2hGlu), and glycated hemoglobin (HbA1c) were selected as instrumental variables. The 96 cardiovascular magnetic resonance imaging traits came from six independent genome-wide association studies. These traits serve as preclinical endophenotypes and offer an early indication of the structure and function of the four cardiac chambers and two aortic sections. The primary analysis was performed using MR with the inverse-variance weighted method. Confirmation was achieved through Steiger filtering and testing to determine the causal direction. Sensitivity analyses were conducted using the weighted median, MR-Egger, and MR-PRESSO methods. Additionally, multivariable MR was used to adjust for potential effects associated with body mass index.

RESULTS

Genetic susceptibility to type 1 diabetes was associated with increased ascending aortic distensibility. Conversely, type 2 diabetes showed a correlation with a reduced diameter and areas of the ascending aorta, as well as decreased distensibility of the descending aorta. Genetically predicted higher levels of FGlu and HbA1c were correlated with a decrease in diameter and areas of the ascending aorta. Furthermore, higher 2hGlu levels predominantly showed association with a reduced diameter of both the ascending and descending aorta. Higher FIns levels corresponded to increased regional myocardial-wall thicknesses at end-diastole, global myocardial-wall thickness at end-diastole, and regional peak circumferential strain of the left ventricle.

CONCLUSIONS

This study provides evidence that diabetes and glycemic traits have a causal relationship with cardiac and aortic structural and functional remodeling, highlighting the importance of intensive glucose-lowering for primary prevention of cardiovascular diseases.

Protective Role for Smooth Muscle Cell Hepcidin in Abdominal Aortic Aneurysm

BACKGROUND

Hepcidin is a liver-derived hormone that controls systemic iron homeostasis, by inhibiting the iron exporter ferroportin in the gut and spleen, respective sites of iron absorption and recycling. Hepcidin is also expressed ectopically in the context of cardiovascular disease. However, the precise role of ectopic hepcidin in underlying pathophysiology is unknown. In patients with abdominal aortic aneurysm (AAA), hepcidin is markedly induced in smooth muscle cells (SMCs) of the aneurysm wall and inversely correlated with the expression of LCN2 (lipocalin-2), a protein implicated in AAA pathology. In addition, plasma hepcidin levels were inversely correlated with aneurysm growth, suggesting hepcidin has a potential disease-modifying role.

METHODS

To probe the role of SMC-derived hepcidin in the setting of AAA, we applied AngII (Angiotensin-II)-induced AAA model to mice harbouring an inducible, SMC-specific deletion of hepcidin. To determine whether SMC-derived hepcidin acted cell-autonomously, we also used mice harboring an inducible SMC-specific knock-in of hepcidin-resistant ferroportinC326Y. The involvement of LCN2 was established using a LCN2-neutralizing antibody.

RESULTS

Mice with SMC-specific deletion of hepcidin or knock-in of hepcidin-resistant ferroportinC326Y had a heightened AAA phenotype compared with controls. In both models, SMCs exhibited raised ferroportin expression and reduced iron retention, accompanied by failure to suppress LCN2, impaired autophagy in SMCs, and greater aortic neutrophil infiltration. Pretreatment with LCN2-neutralizing antibody restored autophagy, reduced neutrophil infiltration, and prevented the heightened AAA phenotype. Finally, plasma hepcidin levels were consistently lower in mice with SMC-specific deletion of hepcidin than in controls, indicating that SMC-derived hepcidin contributes to the circulating pool in AAA.

CONCLUSIONS

Hepcidin elevation in SMCs plays a protective role in the setting of AAA. These findings are the first demonstration of a protective rather than deleterious role for hepcidin in cardiovascular disease. They highlight the need to further explore the prognostic and therapeutic value of hepcidin outside disorders of iron homeostasis.

The predictive value of four serum biomarkers for major adverse events in patients with small abdominal aortic aneurysm

BACKGROUND

The primary aim of this study was to test which of a group of four inflammation and thrombosis biomarkers were independently predictive of major adverse cardiovascular events (MACE) in patients with small abdominal aortic aneurysm (AAA).

METHODS

A total of 471 participants with a 30- to 54-mm AAA had serum C-reactive protein (CRP), fibrinogen, neutrophil-lymphocyte ratio (NLR), and homocysteine measured. The primary outcome was MACE, which was defined as the first occurrence of myocardial infarction, stroke, or cardiovascular death. The association of biomarkers with events was assessed using Kaplan-Meier and Cox proportional hazard analyses. The net improvement in risk of event categorization with addition of a biomarker to clinical risk factors alone was assessed using net reclassification index.

RESULTS

Participants were followed for a median of 2.4 years (interquartile range, 0.8-5.4 years), and 102 (21.7%) had a MACE. The incidence of MACE was 13.2% in participants with CRP >3.0 mg/L, compared with 10.1% in those with CRP ≤3.0 mg/L at 2.5 years (P = .047). After adjusting for other risk factors, higher CRP was associated with a significantly higher risk of MACE (hazard ratio, 1.19; 95% confidence interval, 1.05-1.35). None of the other biomarkers were associated with the risk of MACE. According to the net reclassification index, CRP significantly improved the risk classification of MACE compared with clinical risk factors alone.

CONCLUSIONS

CRP can assist in classification of risk of MACE for patients with small AAA.

Excess Mortality for Abdominal Aortic Aneurysms and the Potential of Strict Implementation of Cardiovascular Risk Management: A Multifaceted Study Integrating Meta-Analysis, National Registry, and PHAST and TEDY Trial Data

OBJECTIVE

Previous studies imply a profound residual mortality risk following successful abdominal aorta aneurysm (AAA) repair. This excess mortality is generally attributed to increased cardiovascular risk. The aim of this study was (1) to quantify the excess residual mortality for patients with AAA, (2) to evaluate the cross sectional level of cardiovascular risk management, and (3) to estimate the potential of optimised cardiovascular risk management to reduce the excess mortality in these patients.

METHODS

Excess mortality was estimated through a systematic review and meta-analysis, and through data from the Swedish National Health Registry. Cardiovascular risk profiles were individually assessed during eligibility screening of patients with AAA for two multicentre pharmaceutical AAA stabilisation trials. The potential of full implementation of cardiovascular risk management was estimated through the validated Second Manifestations of ARTerial disease (SMART) risk scores algorithm.

RESULTS

The meta-analysis showed a similarly impaired survival for patients who received early repair (small AAA) or regular repair (≥ 55 mm), and a further impaired survival for patients under surveillance for a small AAA. Excess mortality was further quantified using Swedish population data. The data revealed a more than quadrupled and doubled five year mortality rate for women and men who had their AAA repaired, respectively. Evaluation of the level of risk management of 358 patients under surveillance in 16 Dutch hospitals showed that the majority of patients with AAA did not meet therapeutic targets set for risk management in high risk populations, and indicated a more pronounced prevention gap in women. Application of the SMART risk score algorithm predicted that optimal implementation of risk management guidelines would reduce the 10 year risk of major adverse cardiovascular events from 43% to 14%.

CONCLUSION

Independent of the rupture risk, AAA is associated with a worryingly compromised life expectancy with a particularly poor prognosis for women. Optimal implementation of cardiovascular risk prevention guidelines is predicted to profoundly reduce cardiovascular risk.

Anticoagulants and reduced thrombus load in abdominal aortic aneurysms assessed with three-dimensional contrast-enhanced ultrasound examination

OBJECTIVE

The relationship between intraluminal thrombus (ILT) and abdominal aortic aneurysm (AAA) growth and rupture risk remains ambiguous. Studies have shown a limited effect of antiplatelet therapy on ILT size, whereas the impact of anticoagulant therapy on ILT is unresolved. This study aims to evaluate an association between antithrombotic therapy and ILT size assessed with three-dimensional contrast-enhanced ultrasound (3D-CEUS) examination in a cohort of patients with AAA.

METHODS

In a cross-sectional study, 309 patients with small AAAs were examined with 3D-CEUS. Patients were divided into three groups based on prescribed antithrombotic therapy: anticoagulant (n = 36), antiplatelet (n = 222), and no antithrombotic therapy (n = 51). Patient ILT size was calculated in volume and thickness and compared between the three groups.

RESULTS

Patients on anticoagulants had a significantly lower estimated marginal mean ILT volume of 16 mL (standard error [SE], ±3.2) compared with 28 mL (SE, ±2.7) in the no antithrombotic group and 30 mL (SE, ±1.3) in the antiplatelet group when adjusting for AAA volume (P < .001) and comorbidities (P < .001). In addition, patients on anticoagulant therapy had significantly lower estimated marginal mean ILT thickness of 10 mm (SE, ±1.1) compared with 13 mm (SE, ±0.9) in the no antithrombotic group of and 13mm (SE, ±0.4) in the antiplatelet group when adjusting for AAA diameter (P = .03) and comorbidities (P = .035).

CONCLUSIONS

A 3D-CEUS examination is applicable for ILT assessment and demonstrates that patients with AAA on anticoagulant therapy have lower ILT thickness and volume than patients with AAA on antiplatelet therapy and those without antithrombotic therapy. Causality between anticoagulants and ILT size, and extrapolation to AAA growth and rupture risk, is unknown and merits further investigations, to further nuance US-based AAA surveillance strategy.

Antithrombotic Therapy for Aortic Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVES

The role of antithrombotic therapy in the management of aortic and peripheral aneurysms is unclear. This systematic review and meta-analysis aimed to assess the impact of antithrombotics on clinical outcomes for aortic and peripheral aneurysms.

METHODS

Medline, Embase, and CENTRAL databases were searched. Randomised controlled trials and observational studies investigating the effect of antithrombotic therapy on clinical outcomes for patients with any aortic or peripheral artery aneurysm were included.

RESULTS

Fifty-nine studies (28 with antiplatelet agents, 12 anticoagulants, two intra-operative heparin, and 16 any antithrombotic agent) involving 122 102 patients were included. Abdominal aortic aneurysm (AAA) growth rate was not significantly associated with the use of antiplatelet therapy (SMD -0.36 mm/year; 95% CI -0.75 - 0.02; p = .060; GRADE certainty: very low). Antithrombotics were associated with increased 30 day mortality for patients with AAAs undergoing intervention (OR 2.30; 95% CI 1.51 - 3.51; p < .001; GRADE certainty: low). Following intervention, antiplatelet therapy was associated with reduced long term all cause mortality (HR 0.84; 95% CI 0.76 - 0.92; p < .001; GRADE certainty: moderate), whilst anticoagulants were associated with increased all cause mortality (HR 1.64; 95% CI 1.14 - 2.37; p = .008; GRADE certainty: very low), endoleak within three years (OR 1.99; 95% CI 1.10 - 3.60; p = .020; I² = 60%; GRADE certainty: very low), and an increased re-intervention rate at one year (OR 3.25; 95% CI 1.82 - 5.82; p < .001; I² = 35%; GRADE certainty: moderate). Five studies examined antithrombotic therapy for popliteal aneurysms. Meta-analysis was not possible due to heterogeneity.

CONCLUSIONS

There was a lack of high quality data examining antithrombotic therapy for patients with aneurysms. Antiplatelet therapy was associated with a reduction in post-intervention all cause mortality for AAA, whilst anticoagulants were associated with an increased risk of all cause mortality, endoleak, and re-intervention. Large, well designed trials are still required to determine the therapeutic benefits of antithrombotic agents in this setting.

Editor's Choice - Systematic Review and Meta-Analysis of Normal Infrarenal Aortic Diameter in the General Worldwide Population and Changes in Recent Decades

OBJECTIVE

To analyse the characteristics of normal infrarenal aortic diameter (AD) in the general worldwide population, to examine changes over time, and to investigate geographical differences.

DATA SOURCES

PubMed, Cochrane Library, and Web of Science.

REVIEW METHODS

This was a systematic review and meta-analysis of studies published up to October 2020 describing infrarenal AD measured by ultrasound in the general adult population. The study was conducted in accordance with the PRISMA statement and placed no restrictions on geographical location or year of publication. Studies of individuals pre-selected for certain diseases or risk factors and opportunistic screening were excluded. A random effects model was used to estimate pooled mean AD, and meta-regression analysis was used to study the effects of determinants of AD.

RESULTS

Thirty-two studies were included, reporting data for 941 144 individuals (98% were men). The pooled mean AD was 19.4 mm (95% confidence interval [CI] 18.8 - 20.1), being 20.1 mm (95% CI 19.4 - 20.8) in men and 17.8 mm (95% CI 16.5 - 19.1) in women (p < .001). Outer edge to outer edge (OTO) caliper placement method (p = .015) and body surface area (BSA; p = .010) were significantly associated with larger AD. In men, the largest mean AD was observed in Oceania (p < .001) and the smallest in Asia (p < .020). As none of the studies collected data between 2002 and 2007, the studies were divided into two periods: 2001 and before, and 2008 and after. All recent studies were European, with the diameters being significantly smaller (p = .003) in the latter period (18.3 mm [95% CI 17.5 - 19.1] vs. 20.7 mm [95% CI 19.1 - 22.3]). In the meta-regression models, the reduction in AD over time remained significant after adjustment for potential effect modifiers such as sex, age, geographical area, body size, cardiovascular risk factors, and ultrasound method.

CONCLUSION

Mean infrarenal AD in older European adults has decreased significantly in recent decades. Male sex, BSA, and OTO ultrasound measurement method are associated with larger AD, and geographical differences were observed in men.

Introducing multi-component cardiovascular health screening into existing Abdominal Aortic Aneurysm (AAA) screening programmes in the UK: a qualitative study of programme staff views

BACKGROUND

Cardiovascular disease is a major contributor to poor health in the UK and the leading cause of death in England. Peripheral arterial disease and high blood pressure are conditions that identify individuals at high cardiovascular disease risk, likely to benefit from cardiovascular risk management. Both conditions remain considerably underdiagnosed and untreated. The National Health Service abdominal aortic aneurysm (AAA) screening programmes represent an opportunity to screen for these conditions with potentially minimal additional effort or cost. We explored AAA screening programme staff views on the proposed introduction of such additional screening within AAA screening.

METHODS

Nine focus groups and seven follow-on interviews were undertaken with 38 AAA screening staff. Our study methods were oriented broadly towards a grounded theory methodology, and data were analysed using thematic analysis.

RESULTS

Three themes were identified: (i) 'Perceptions of patient experience and health-related outcomes', (ii) 'Opportunities and challenges for programme staff', and (iii) 'Maintaining and improving programme standards'. Staff talked about the high uptake of AAA screening, staff experience and skills in their role, and the programme's high quality standards as both opportunities and potential challenges linked to the proposed additions to AAA screening. While positive about the potential to improve patients' health outcomes, participants had questions about the practicalities of incorporating additional procedures within their time- and resource-constrained context, and how this may reconfigure work processes, roles and relationships.

CONCLUSIONS

The proposed additions to the programme require taking staff's views into account. Key areas that need to be addressed relate to ensuring follow-up support for patients, clarity around staff responsibilities, and availability of sufficient resources for the programme.

Aortic Area as an Indicator of Subclinical Cardiovascular Disease

Aim:

Outward arterial remodeling occurs early in cardiovascular disease (CVD) and, as such, measuring arterial dimension may be an early indicator of subclinical disease.

Objective:

The objective of our study was to measure area at three aortic locations: The ascending thoracic (ASC), the descending thoracic (DSC), and the abdominal (ABD), and to test for association with traditional CVD risk factors and subclinical CVD throughout the body.

Methods:

We measured ASC, DSC, and ABD using computed tomography (CT) in 408 African ancestry men aged 50-89 years. We assessed prevalent CVD risk factors via participant interview and clinical exam, and subclinical CVD, including carotid atherosclerosis through B-mode carotid ultrasound, vascular calcification via chest and abdominal CT, and arterial stiffness via pulse-wave velocity (PWV).

Results:

As expected, all aortic areas were in correlation with each other (r=0.39-0.63, all p<0.0001) and associated with greater age, greater body size, and hypertension (p≤0.01 for all). After adjustment for traditional CVD risk factors, ASC was positively associated with carotid atherosclerosis (p<0.01). A greater area at each location was associated with greater PWV (p<0.03 for all), with the DSC region showing the most significant association.

Conclusion:

This is the first study to test the association of aortic area measured at multiple points with subclinical CVD. We found that combined CT assessment of ascending and descending aortic area may indicate a high risk of prevalent subclinical CVD elsewhere in the body independent of age, body size, and blood pressure.

Abdominal aortic diameter and cardiovascular status in patients with idiopathic retroperitoneal fibrosis

Although much debated, an exaggerated inflammatory response to advanced atherosclerosis has been implicated in the pathogenesis of idiopathic retroperitoneal fibrosis (RPF). Clinical presentation, infrarenal abdominal aortic diameter and RPF mass thickness were retrospectively analyzed in 166 patients with idiopathic RPF seen at our referral center between April 1998 and December 2019. Patients were stratified to their infrarenal abdominal aortic diameter at presentation (i.e., non-ectatic [< 25 mm]; ectatic [25-29 mm]; and aneurysmal [≥ 30 mm]) to compare characteristics across groups with an undilated or dilated aorta. Ectatic or aneurysmal aortic dilatation was present in 34% of patients. Most clinical characteristics did not differ across abdominal aortic diameter stratified groups, but RPF mass thickness was greater in patients presenting with aortic aneurysmal dilatation compared to that in patients with an undilated aorta (49.0 mm [IQR 34.0-62.0] vs 32.5 mm [IQR 25.3-47.8]; P < 0.001). A positive linear association was found between aortic diameter on a continuous scale and RPF mass thickness (β 0.32 [95% CI 0.34-0.96]; P < 0.001). This association remained significant after adjusting for age, sex and acute-phase reactant levels (β 0.28 [95% CI 0.15-0.95]; P < 0.01). Treatment success across aortic diameter stratified groups did not differ (P = 0.98). Treatment induced RPF mass regression was not associated with an increase in aortic expansion rate (P = 0.44). Aortic dilatation was prevalent among patients. Infrarenal abdominal aortic diameter was independently associated with RPF mass thickness. Findings support the concept that at least in a subset of patients, RPF may be secondary to advanced atherosclerosis.