Risk factors for abdominal aortic aneurysms: a 7-year prospective study: the Tromsø Study, 1994-2001

Abdominal Aortic Aneurysm and Liver Fibrosis: Clinical Evidence and Molecular Pathomechanisms

To stimulate further research, this review summarizes studies linking liver fibrosis with the risk of abdominal aortic aneurysms (AAA). AAA is defined as a permanently weakened and dilated abdominal aorta, which develops due to inflammation of the tunica media, activation of the renin-angiotensin-aldosterone system, immune system activation, and coagulation disorders. Typically asymptomatic, AAA is often incidentally detected through imaging done for abdominal symptoms or as part of screening programs. AAA follows a variable course and has a mortality rate strongly dependent on age and sex. Risk factors for AAA include age, male sex, ethnicity, family history of AAA, lifestyle habits, arterial hypertension, dyslipidemia, and comorbid atherosclerotic cardiovascular disease. Conversely, individuals with type 2 diabetes, female sex, and certain ethnicities are at a reduced risk of AAA. Liver fibrosis, resulting from chronic liver diseases owing to varying etiologies, is increasingly recognized as a potential contributor to AAA development. Evidence increasingly indicates that metabolic dysfunction-associated steatotic liver disease (MASLD) and other chronic liver conditions may intensify inflammatory pathways shared with AAA, thereby potentially exacerbating AAA progression. This review specifically examines the epidemiology and risk factors associated with the link between AAA and liver fibrosis. It also highlights potential pathomechanisms, including systemic inflammation, oxidative stress, and extracellular matrix remodeling, which may contribute to both conditions. Although these findings underscore significant overlaps in risk profiles, additional research is needed to clarify whether type 2 diabetes, female sex, and certain ethnicities truly confer protection against AAA or if this association is influenced by other confounding variables. Ultimately, addressing these open questions will help guide targeted therapeutic interventions and the identification of novel biomarkers to predict disease progression.

Association between high-density lipoprotein cholesterol and risk of abdominal aortic aneurysm among males and females aged 60 years and over

OBJECTIVE

Whether high-density lipoprotein cholesterol (HDL-C) has a protective role against abdominal aortic aneurysm (AAA) development in both older males and females remains uncertain. This study aims to assess the sex-specific association between HDL-C and incident AAA in older adults from the UK Biobank.

METHODS

This cohort study included 86,184 males and 95,682 females aged ≥60 years from the UK biobank. Baseline HDL-C was modelled either as a continuous or categorical variable. The primary outcome was incident AAA. Cox proportional hazard models were used for sex-stratified analysis, adjusting for baseline confounders. Restricted cubic splines were plotted to visualize any nonlinear relationship. Harrell's C-index was calculated to assess the added value of HDL-C to the discrimination of model including age and smoking.

RESULTS

Over a mean follow-up of 14.4 years, 1549 and 328 incident AAA were observed in males and females, respectively. Adjusted hazard ratios for AAA with a 1-mmol/L HDL-C increase was 0.26 (95% confidence interval, 0.21- 0.32) and 0.31 (95% confidence interval, 0.21-0.46) in males and females, respectively (both P < .001). Consistent with the results from Cox model modelling HDL-C as a categorical variable showing an inverse and dose-dependent relationship between HDL-C and incident AAA in both sexes, restricted cubic splines confirmed the monotonic, inverse associations. Adding HDL-C to a model including age and smoking significantly improve the model discrimination for AAA in both sexes (C-index +2.1% in males and +1.5% in females; both P < .05).

CONCLUSIONS

This study revealed a significant association between low HDL-C levels and a high risk of incident AAA in both older males and females, suggesting the potential clinical usefulness of HDL-C for AAA risk stratification. Our study was limited by its observational design and the presence of possible residual confounding. Studies using real-world data are warranted to evaluate the practical implications of incorporating HDL-C into AAA screening guidelines and its impact on patient outcomes.

Identifying Circulating Protein Mediators in the Link Between Smoking and Abdominal Aortic Aneurysm: An Integrated Analysis of Human Proteomic and Genomic Data

Background

Smoking is a well-established risk factor for abdominal aortic aneurysm (AAA). However, the molecular pathways underlying this relationship remain poorly understood. This study aimed to identify circulating protein mediators that may explain the association between smoking and AAA.

Methods

We conducted a network Mendelian randomization (MR) study utilizing summary-level data from the largest available genome-wide association studies. Our primary smoking exposure was the lifetime smoking index, with smoking initiation and cigarettes per day included as supplementary traits. The AAA dataset comprised 39,221 cases and 1,086,107 controls. Protein data were sourced from two large cohorts: UKB-PPP, where proteins were measured using the Olink platform in 54,219 individuals, and deCODE, where proteins were measured using the SomaScan platform in 35,559 individuals. Two-sample MR was employed to estimate the association between smoking and AAA (βtotal) and between smoking and circulating protein levels (β1). Summary data-based MR was then used to assess the association between smoking-related proteins and AAA risk (β2). Mediation pathways were identified based on the directionality of effect estimates, and the corresponding mediation effects were quantified.

Results

Genetically predicted smoking traits were consistently associated with an increased risk of AAA. The lifetime smoking index was associated with the levels of 543 out of 5,764 unique circulating proteins, with 470 of these associations replicated in supplementary analyses using additional smoking traits and protein sources. Among the smoking-related proteins, genetically predicted levels of 22 were associated with AAA risk. Eight mediation pathways were identified accounting for 42.7% of the total smoking-AAA association and with mediation effects >4% for ADAMTS15, IL1RN, MMP12, PGF, PCSK9, and UXS1.

Conclusion

This study identified numerous circulating proteins potentially causally linked to smoking, and eight of these proteins were found to mediate the association between smoking and AAA risk.

The Influence of Gender in Open Surgery and Endovascular Repair in the Treatment of Nonruptured Aortoiliac Aneurysms

BACKGROUND

This study aimed to determine the outcomes of survival, endoleaks, reinterventions, and perioperative mortality rate (PMR) in patients with abdominal aortoiliac aneurysms (AAIA) receiving endovascular or open surgical repair with respect to sex, with two groups of patients being evaluated: male and female.

METHODS

This was a prospective, single-centered, consecutive cohort study of patients with AAIA who underwent endovascular treatment or open surgical repair regarding gender. Two groups of patients were evaluated: the male group and the female group.

RESULTS

A total of 160 patients underwent open or endovascular surgery, with two groups as follows: male (128 patients, 80%) and female (32 patients, 20%). The clinical characteristics were similar between the two groups, except for a higher prevalence of diabetes in the male group than in the female group (50.8% vs. 9.4%, P < 0.001) and cardiac disease in the male group than in the female group (23.4% vs. 3.1%, P = 0.004). The PMR was 6.9% in 11 patients, which was higher in the female group (4 patients, 12.5%) than in the male group (7 patients, 5.5%; P = 0.027). The reintervention rates were 13.2% (21 cases) in the total cohort, higher in the female group, seven patients (21.9%) than in the male group (14 patients [11%], P = 0.036). The overall survival in a Kaplan-Meier at 720 days was 89.8% in the male group and 84.4% in the female group, but the difference was not statistically significant among the groups (P = 0.33). The time freedom from reintervention at 720 days was 90.9% in the male group and 76.9% in the female group (P = 0.022).

CONCLUSION

In the present study, female patients had higher rates of reintervention and perioperative mortality than male patients. The main factors associated with death were bowel ischemia, chronic kidney disease, and elevated cardiac risk. Moreover, the main factors related to the reintervention rates were female sex and endoleaks.

Difference in risk factor profile for abdominal aortic aneurysm and thoracic aortic aneurysm

OBJECTIVE

Previous studies suggest partly different risk factor profiles of thoracic aortic aneurysms (TAAs) and abdominal aortic aneurysms (AAAs), but prospective data are scarce. The purpose of this prospective population-based case-control study was to investigate differences in risk factor profile between TAAs and AAAs.

METHODS

Participants in two prospective population-based studies, the Västerbotten Intervention Project (VIP) and the Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA) study, between 1986 and 2010, underwent cardiovascular risk assessments, including blood samples, oral glucose tolerance test, blood pressure readings, and a self-reported health questionnaire. All individuals who were later diagnosed with TAAs or AAAs were identified. Age, sex, and time-matched controls were selected from the same cohorts, aiming at four controls/case. Adjusted odds ratios (aORs) for potential risk factors for later diagnosis of TAAs and AAAs, respectively, were estimated by multivariate conditional logistic regression analyses.

RESULTS

From a total of 96,196 individuals with prospectively collected data in the VIP/MONICA cohort, a total of 236 individuals with AAAs (181 men and 55 women) and 935 matched controls, and 168 individuals with TAAs (115 men and 53 women) and 662 controls were included. The average age at baseline examination was 57.0 ± 5.7 years for AAA cases and controls, and 52.1 ± 8.8 years for TAA cases and controls. Mean time between baseline examination and diagnosis of AAAs/TAAs was 12.1 and 11.7 years, respectively. There was a clear difference in risk factor profile between AAAs and TAAs. Smoking, hypertension, and coronary artery disease were significantly associated with later diagnosis of AAAs, with highest aORs for a history of smoking (aOR, 10.3; 95% confidence interval [CI], 6.3-16.8). For TAAs, hypertension was the only positive risk factor (aOR, 1.7; 95% CI, 1.1-2.7), whereas smoking was not associated. Diabetes was not associated with either AAAs or TAAs; neither was self-reported physical activity.

CONCLUSIONS

In this prospective, population-based, case-control study, risk factor profile differed between AAAs and TAAs. This suggests a partially different etiology for TAAs and AAAs.

Disruption of PCSK9 Suppresses Inflammation and Attenuates Abdominal Aortic Aneurysm Formation

BACKGROUND

Abdominal aortic aneurysm (AAA) is a chronic vascular inflammatory disease without effective medications. PCSK9 (proprotein convertase subtilisin/kexin 9), a serine protease from the proprotein convertase family, has recently been associated with AAA in human genome-wide association studies. However, its role in AAA is unknown.

METHODS

Transcriptional and histological expression of PCSK9 was examined in AAA tissues and healthy controls. The impact of PCSK9 deletion and inhibition on AAA formation was assessed in mice with hyperlipidemia and Ang II (angiotensin II) overproduction. AAA lesion morphology was assessed by tissue staining. MMP (matrix metalloproteinase) activity was evaluated by gelatin zymography, and leukocyte-vessel wall interaction was monitored by intravital microscopy. RNA sequencing was used to characterize the downstream signaling of PCSK9.

RESULTS

PCSK9 expression was upregulated and colocalized with macrophages in human and mouse AAAs. Pcsk9 deletion attenuated AAA formation, improved survival, and decreased systemic inflammation, without altering circulating cholesterol levels. Pcsk9 deficiency reduced aortic infiltration of macrophages and elastin degradation, without affecting vascular smooth muscle cell apoptosis and proliferation. Mechanistically, PCSK9 was essential in leukocyte-endothelium adhesion and expression of proinflammatory cytokines and MMP9 by macrophages. RNA sequencing of stimulated macrophages revealed that Pcsk9 deficiency upregulated histone deacetylase SIRT1 (sirtuin-1) and suppressed NF-κB (nuclear factor-κB) inflammatory signaling. SIRT1 inhibition attenuated the proinflammatory actions of PCSK9. Furthermore, administration of PCSK9 small interfering RNA or antibody constrained AAA formation/progression and inhibited vascular inflammation.

CONCLUSIONS

PCSK9 critically mediates macrophage inflammation and elastin degradation, promoting AAA formation. PCSK9 inhibitors bear a promise to curtail AAA, beyond being used as cholesterol-lowering drugs.

Risk factors for abdominal aortic aneurysm in patients with diabetes

OBJECTIVE

Although diabetes has been shown to be negatively associated with development of abdominal aortic aneurysm (AAA), patients with diabetes may still develop aneurysms. In this study, we examined risk factors for the development of AAA in patients with diabetes.

METHODS

Adults >50 years of age with diabetes who underwent health screening between 2009 and 2012 were followed for incident AAA until December 31, 2019. Cox proportional hazard regression models were used to calculate multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk factors associated with AAA.

RESULTS

Among 1,913,066 participants (55.3% men), 6996 AAA cases were identified during a mean follow-up of 7.7 years. Increased AAA risk was observed for age ≥65 years (HR, 2.69; 95% CI, 2.55-2.83), men (HR, 1.81; 95% CI, 1.69-1.94), smoking (former smoker ≥20 pack-years [PY]; HR, 1.75; 95% CI, 1.61-1.89; current smoker <20 PY; HR, 1.76; 95% CI, 1.59-1.94; current smoker ≥20 PY; HR, 2.40; 95% CI, 2.23-2.59), abdominal obesity (HR, 1.30; 95% CI, 1.23-1.38), and comorbidities, including hypertension (HR, 1.63; 95% CI, 1.53-1.73), dyslipidemia (HR, 1.35; 95% CI, 1.29-1.42), chronic kidney disease (HR, 1.52; 95% CI, 1.44-1.61), and cardiovascular disease (HR, 1.71; 95% CI, 1.58-1.86). Heavy (HR, 0.67; 95% CI, 0.61-0.74) and mild alcohol consumption (HR, 0.78; 95% CI, 0.74-0.83), overweight (HR, 0.87; 95% CI, 0.81-0.93) and obesity (HR, 0.81; 95% CI, 0.75-0.87), longer diabetes duration (≥5 years: HR, 0.74; 95% CI, 0.70-0.78), and using three or more oral hypoglycemic agents (OHA) (HR, 0.84; 95% CI, 0.79-0.90) were associated with decreased AAA risk, whereas insulin use was associated with a marginally increased risk (HR, 1.09; 95% CI, 1.00-1.18). Among the OHAs, metformin (HR, 0.95; 95% CI, 0.90-1.00), thiazolidinediones (HR, 0.87; 95% CI, 0.79-0.97), and sulfonylureas (HR, 0.88; 95% CI, 0.83-0.93) were associated with a decreased risk of AAA.

CONCLUSIONS

Although diabetes is associated with decreased AAA risk, those with comorbid cardiometabolic diseases, abdominal obesity, and a smoking history should be aware of an increased AAA risk. Further studies are warranted to verify the potential use of OHAs for decreasing AAA risk.

ANK Deficiency-Mediated Cytosolic Citrate Accumulation Promotes Aortic Aneurysm

BACKGROUND

Disturbed metabolism and transport of citrate play significant roles in various pathologies. However, vascular citrate regulation and its potential role in aortic aneurysm (AA) development remain poorly understood.

METHODS

Untargeted metabolomics by mass spectrometry was applied to identify upregulated metabolites of the tricarboxylic acid cycle in AA tissues of mice. To investigate the role of citrate and its transporter ANK (progressive ankylosis protein) in AA development, vascular smooth muscle cell (VSMC)-specific Ank-knockout mice were used in both Ang II (angiotensin II)- and CaPO4-induced AA models.

RESULTS

Citrate was abnormally increased in both human and murine aneurysmal tissues, which was associated with downregulation of ANK, a citrate membrane transporter, in VSMCs. The knockout of Ank in VSMCs promoted AA formation in both Ang II- and CaPO4-induced AA models, while its overexpression inhibited the development of aneurysms. Mechanistically, ANK deficiency in VSMCs caused abnormal cytosolic accumulation of citrate, which was cleaved into acetyl coenzyme A and thus intensified histone acetylation at H3K23, H3K27, and H4K5. Cleavage under target and tagmentation analysis further identified that ANK deficiency-induced histone acetylation activated the transcription of inflammatory genes in VSMCs and thus promoted a citrate-related proinflammatory VSMC phenotype during aneurysm diseases. Accordingly, suppressing citrate cleavage to acetyl coenzyme A downregulated inflammatory gene expression in VSMCs and restricted ANK deficiency-aggravated AA formation.

CONCLUSIONS

Our studies define the pathogenic role of ANK deficiency-induced cytosolic citrate accumulation in AA pathogenesis and an undescribed citrate-related proinflammatory VSMC phenotype. Targeting ANK-mediated citrate transport may emerge as a novel diagnostic and therapeutic strategy in AA.

Polygenic Risk Score Informed Clinical Model for Improving Abdominal Aortic Aneurysm Screening

BACKGROUND

Abdominal aortic aneurysm (AAA) is a complex disease with environmental and genetic risk factors. Polygenic risk scores (PRSs) based on disease-specific risk-associated single nucleotide variants (SNVs) have demonstrated effectiveness in stratifying individual-level disease risk for cardiovascular diseases. This prospective cohort study assessed associations of PRS of AAA (PRSAAA) with risk of incident AAA, analyzed the effectiveness of a combined clinical-genetic risk model, and explored the clinical utility of the model in identifying high-risk individuals for AAA screening.

METHODS

PRSAAA was calculated using 911,440 SNVs and PRS of coronary artery disease was calculated using 2,324,683 SNVs derived from mixed ancestry genome-wide association studies. The UK Biobank was used as the study cohort. All individuals with complete genetic data available and no diagnosis of AAA at the time of recruitment were included in the analysis and followed prospectively to assess for incident AAA. A PRS-informed clinical model, Prob-AAA, was developed using clinically significant variables and PRSAAA.

RESULTS

Four hundred eighty-one thousand one hundred 5 individuals were included in the analysis with 2,668 incident AAA cases. Incident AAA increased from 0.30 to 0.93% between the lowest and highest decile of PRSAAA; similarly, severe AAA, requiring surgery and/or presenting with rupture, increased from 23 to 39% of incident AAA cases across deciles. PRSAAA was a predictor of incident AAA diagnosis (hazard ratio 2.06 [1.70-2.48]) independent of other clinical risk factors including male sex, older age, and smoking history. Prob-AAA was an independent predictor of incident AAA (hazard ratio 1.92 [1.69-2.20]), and identified 9.6% of cases of incident AAA compared to only 4.2% by PRSAAA. Current screening guidelines captured 5.7% of the overall cohort, with an incident AAA rate of approximately 3.2%. Among males not included by current guidelines, Prob-AAA identified an additional cohort, approximately 2% of the overall cohort, with a similar rate of incident AAA.

CONCLUSIONS

Prob-AAA, a PRS-informed clinical model for AAA, improved upon the predictive power of current, clinical risk factor-informed, screening guidelines for AAA.

Genetic evidence for lifestyle and cardiometabolic factors on the risk of aortic aneurysms: A comprehensive Mendelian randomization study

BACKGROUND AND AIMS

Aortic aneurysm (AAs) is a chronic and severe aortic disease, which is extremely life-threatening due to its delayed diagnosis and a high risk of rupture. In current studies, the association between lifestyle and metabolic factors remains controversial given the complexity of pathogenesis and progression in AAs. Consequently, more reliable and robust evidence should be provided.

METHODS

Genome-wide association studies summary statistics were obtained for 25 factors (6 lifestyle factors and 19 cardiometabolic factors) and AAs. Univariable Mendelian randomization (UVMR) and multivariable MR (MVMR) were used to estimate the causal effect of these factors on AAs. Meanwhile, mediation analysis was applied to assess the mediated effect of lifestyle on the association of cardiometabolic factors with AAs.

RESULTS

Several factors were associated with AA risk, among which triglyceride (TG) (OR = 1.32, 95 % CI = [1.18-1.47], p < 0.001) and high-density lipoprotein cholesterol (HDL-C) (OR = 0.70, 95 % CI = [0.61-0.82], p < 0.001) remain consistently associated with AA risk, with an idependent effect on AAs after adjusting for body mass index (BMI). In addition, TG mediated 15.6 % of BMI effects and 3.7 % of smoking effects on AAs, and HDL-C mediated 5.3 % of the effects of cigarette smoking on AAs.

CONCLUSIONS

TG and HDL-C may be the most reliable factors in the risk of AAs. More scientific management of lifestyle and regular monitoring for cardiometabolic traits may serve as a new and effective direction for the prevention and control of the occurrence of AAs.

The cardiovascular pathologist in the aortic team

Aortic diseases require a multidisciplinary management for diagnosis, treatment and follow-up with better outcomes in referral centers using a team-based approach. The setting up of a multi-disciplinary aortic team for the discussion of complex cases has been already proposed; it is also supported by the ACC/AHA. Surgeons and radiologists, more or less other physicians such as cardiologists, geneticists, rheumatologists/internal medicine specialists and pathologists are involved into such a team. The role of the cardiovascular pathologist is to examine the aortic specimens, to diagnose and classify the aortic lesions. Herein, the role of the pathologist in the aortic team is discussed and the pathobiology of aortic diseases is reviewed for reference by pathologists. The aortic specimens are mainly obtained from emergency or elective surgical procedures on the thoracic aorta, less frequently from organ/tissue (including cardiac or heart valve) donors, post-mortem procedures or abdominal aortic surgery. In the last decade, together with the progress of medical sciences, the histological definitions and classifications of the aortic pathology are undergoing thorough revisions that are addressed to an etiopathogenetic approach because of possible clinico-pathological correlations, therapeutic and prognostic impact. Pathologists may also have an important role in research and teaching. Therefore, histological analyses of the aortic specimens require adequate sample processing and pathologist expertise because histology contributes to definite diagnosis, correct management of patients and even (in genetic diseases) families, but also to research in the challenging field of aortopathies.

Aortic aneurysm: pathophysiology and therapeutic options

Aortic aneurysm (AA) is an aortic disease with a high mortality rate, and other than surgery no effective preventive or therapeutic treatment have been developed. The renin-angiotensin system (RAS) is an important endocrine system that regulates vascular health. The ACE2/Ang-(1-7)/MasR axis can antagonize the adverse effects of the activation of the ACE/Ang II/AT1R axis on vascular dysfunction, atherosclerosis, and the development of aneurysms, thus providing an important therapeutic target for the prevention and treatment of AA. However, products targeting the Ang-(1-7)/MasR pathway still lack clinical validation. This review will outline the epidemiology of AA, including thoracic, abdominal, and thoracoabdominal AA, as well as current diagnostic and treatment strategies. Due to the highest incidence and most extensive research on abdominal AA (AAA), we will focus on AAA to explain the role of the RAS in its development, the protective function of Ang-(1-7)/MasR, and the mechanisms involved. We will also describe the roles of agonists and antagonists, suggest improvements in engineering and drug delivery, and provide evidence for Ang-(1-7)/MasR's clinical potential, discussing risks and solutions for clinical use. This study will enhance our understanding of AA and offer new possibilities and promising targets for therapeutic intervention.

Abdominal aortic aneurysm and cardiometabolic traits share strong genetic susceptibility to lipid metabolism and inflammation

Abdominal aortic aneurysm has a high heritability and often co-occurs with other cardiometabolic disorders, suggesting shared genetic susceptibility. We investigate this commonality leveraging recent GWAS studies of abdominal aortic aneurysm and 32 cardiometabolic traits. We find significant genetic correlations between abdominal aortic aneurysm and 21 of the cardiometabolic traits investigated, including causal relationships with coronary artery disease, hypertension, lipid traits, and blood pressure. For each trait pair, we identify shared causal variants, genes, and pathways, revealing that cholesterol metabolism and inflammation are shared most prominently. Additionally, we show the tissue and cell type specificity in the shared signals, with strong enrichment across traits in the liver, arteries, adipose tissues, macrophages, adipocytes, and fibroblasts. Finally, we leverage drug-gene databases to identify several lipid-lowering drugs and antioxidants with high potential to treat abdominal aortic aneurysm with comorbidities. Our study provides insight into the shared genetic mechanism between abdominal aortic aneurysm and cardiometabolic traits, and identifies potential targets for pharmacological intervention.

A prospective longitudinal study of risk factors for abdominal aortic aneurysm

The aim of this study was to identify risk factors for abdominal aortic aneurysm (AAA) from the largest Welsh screening cohort to date. Patients were recruited from 1993 (to 2015) as part of the South East Wales AAA screening programme through general practitioners. Demographic data and risk factors were collected by means of a self-report questionnaire. Statistical tests were performed to determine whether associations could be observed between AAA and potential risk factors. Odds ratios (OR) were also calculated for each of the risk factors identified. A total of 6879 patients were included in the study. Two hundred and seventy-five patients (4.0%) presented with AAA, of which 16% were female and 84% were male. Patients with AAA were older than the (no AAA) control group (p < 0.0001). The following risk factors were identified for AAA: family history of AAA (p < 0.0001); history of vascular surgery (p < 0.0001), cerebrovascular accident (p < 0.0001), coronary heart disease (p < 0.0001), diabetes (p < 0.0001), medication (p = 0.0018), claudication (p < 0.0001), smoking history (p = 0.0001) and chronic obstructive pulmonary disorder (p = 0.0007). AAA is associated with classical vascular risk factors, in addition to other less-well-documented risk factors including previous vascular surgery. These findings have practical implications with the potential to improve future clinical screening of patients in order to reduce AAA mortality.

Ruptured abdominal aortic aneurysm in psoriasis: A case report and review of literature

INTRODUCTION

Psoriasis, a chronic inflammatory skin condition, affects 4 % of the population and is associated with various comorbidities, making it a public health concern.

CASE REPORT

We discuss the case of a 50-year-old man with severe erythrodermic psoriasis who presented with a ruptured saccular abdominal aortic aneurysm (AAA), requiring emergency surgery with good postoperative follow-up. shedding light on the link between psoriasis and cardiovascular complications.

DISCUSSION

Psoriasis severity correlates with cardiovascular risk and shares common development pathways with aortic aneurysms such as systemic and aortic inflammation, and arterial stiffness, emphasizing the importance of managing both skin symptoms and systemic inflammation to reduce vascular comorbidities. Psoriasis patients have a higher risk of AAA, warranting consideration for AAA screening. Controversies exist regarding corticosteroid therapy and choice of surgical intervention for AAA in psoriatic patients.

CONCLUSION

Psoriasis patients face an increased risk of AAA, highlighting the need for vigilant screening and comprehensive management. Further research is essential to understanding the pathophysiological connections between psoriasis and arterial diseases, guiding preventive strategies and optimal medical treatments for these high-risk patients.

Inflammatory Markers and Aortic Aneurysms: Exploring the Role of Hs-CRP and MHR in Ascending Aortic Aneurysm Development

Background

Aortic aneurysms, particularly those affecting the ascending aorta, pose significant health risks due to their potential to cause life-threatening complications such as rupture and dissection. While the etiology of ascending aortic aneurysms has traditionally been associated with non-inflammatory processes, emerging evidence suggests a potential role of inflammation in their development.

Methods

This study investigates the relationship between inflammatory markers and ascending aortic aneurysms, focusing on high-sensitivity C-reactive protein (hs-CRP) and the monocyte-to-HDL ratio (MHR). A total of 135 patients with ascending aortic aneurysms and 40 control subjects underwent comprehensive evaluations, including echocardiography, computed tomography imaging, and serum biomarker measurements.

Results

The results indicate significantly elevated levels of hs-CRP and MHR in patients with ascending aortic aneurysms compared to the control group, suggesting a potential inflammatory component in the pathogenesis of these aneurysms. However, the precise mechanisms underlying this association remain to be elucidated.

Conclusion

Despite limitations such as the cross-sectional study design and relatively small sample size, this study provides valuable insights into the potential involvement of inflammation in ascending aortic aneurysms. Further research, including longitudinal studies and histopathological analysis of aortic tissue, is warranted to confirm these findings and explore the utility of inflammatory markers as diagnostic and prognostic indicators in this patient population.

Assessing the causal relationship between circulating immune cells and abdominal aortic aneurysm by bi-directional Mendelian randomization analysis

Although there is an association between abdominal aortic aneurysm (AAA) and circulating immune cell phenotypes, the exact causal relationship remains unclear. This study aimed to explore the causal relationships between immune cell phenotypes and AAA risk using a bidirectional two-sample Mendelian randomization approach. Data from genome-wide association studies pertaining to 731 immune cell traits and AAA were systematically analyzed. Using strict selection criteria, we identified 339 immune traits that are associated with at least 3 single nucleotide polymorphisms. A comprehensive MR analysis was conducted using several methods including Inverse Variance Weighted, Weighted Median Estimator, MR-Egger regression, Weighted Mode, and Simple Median methods. CD24 on switched memory cells (OR = 0.922, 95% CI 0.914-0.929, P = 2.62e-79) at the median fluorescence intensities level, and SSC-A on HLA-DR + natural killer cells (OR = 0.873, 95% CI 0.861-0.885, P = 8.96e-81) at the morphological parameter level, exhibited the strongest causal associations with AAA. In the reverse analysis, no significant causal effects of AAA on immune traits were found. The study elucidates the causal involvement of multiple circulating immune cell phenotypes in AAA development, signifying their potential as diagnostic markers or therapeutic targets. These identified immune traits may be crucial in modulating AAA-related inflammatory pathways.

Increased diameter and stiffness of elastic but not muscular arteries in men with abdominal aortic aneurysm

It has been proposed that formation of abdominal aortic aneurysm (AAA) is part of a systemic arterial dilatative disease. However, arteries in the upper extremities are scarcely studied and it remains unclear whether both muscular and elastic arteries are affected by the proposed systemic arterial dilatation. The aim of this study was to investigate the diameter and stiffness of muscular and elastic arteries in arterial branches originating from the aortic arch. Twenty-six men with AAA (69 ± 4 yr) and 57 men without AAA (70 ± 5 yr) were included in the study. Ultrasound was used to examine the distal and proximal brachial artery, axillary artery, and common carotid artery (CCA), and measurement of diameter and diameter change was performed with wall-tracking software. Blood pressure measurements were used to calculate local arterial wall stiffness indices. The AAA cohort presented larger arterial diameters in the CCA and axillary artery after adjustment for body surface area (P = 0.002, respectively), whereas the brachial artery diameters were unchanged. Indices of increased stiffness in CCA (e.g., lower distensibility, P = 0.003) were seen in subjects with AAA after adjustments for body mass index and mean arterial blood pressure. This study supports the theory of a systemic arterial dilating diathesis in peripheral elastic, but not in muscular, arteries. Peripheral elastic arteries also exhibited increased stiffness, in analogy with findings in the aorta in AAA.NEW & NOTEWORTHY We present data partially supporting the notion of abdominal aortic aneurysm being a systemic vascular disease with focal manifestation in the abdominal aorta, from two well-defined groups recruited from a regional screening program. We show that elastic arteries distal from the aorta exhibit vascular alterations without aneurysmal formation in subjects with AAA compared with controls while muscular arteries seem unaffected.

The causal relationship between smoking and thoracic aortic aneurysm: Evidence from Mendelian randomization analysis

The potential role of smoking as a risk factor for thoracic aortic aneurysm is still a subject of debate. Therefore, it is important to systematically investigate the causal relationship between smoking and thoracic aortic aneurysm using Mendelian randomization methods. Genetic data were obtained from genome-wide association studies using the inverse variance weighting method as the primary approach. A thorough sensitivity analysis was conducted to ensure the reliability of the findings. Instrumental variables were assessed using the F statistic, and meta-analysis was employed to assess the average genetic predictive effect between smoking and thoracic aortic aneurysm. Our Mendelian randomization study found a positive association between smoking and thoracic aortic aneurysm. The odds ratios (OR) in the inverse variance weighting method were OR = 1.23 (95% confidence interval [CI] = 1.00-1.51; P = .053) and OR = 2.07 (95% CI = 1.10-3.91; P = .024). Furthermore, meta-analyses consistently demonstrated a positive causal relationship between ferritin and myocardial infarction, although statistical significance was not observed. The analysis results did not indicate any horizontal pleiotropy. Despite the presence of heterogeneity, the Mendelian randomization analysis still yielded significant results. This study employed Mendelian randomization to establish a positive association between smoking levels and the risk of thoracic aortic aneurysm. The genetic evidence reveals a causal relationship between the two, offering new insights for future interventions targeting thoracic aortic aneurysms.

Implicit screening of abdominal aortic aneurysms among veterans using lumbar spine MRI

BACKGROUND

Early detection of abdominal aortic aneurysms (AAAs) is critical given the high morbidity and mortality of a ruptured aneurysm. Screening ultrasound is recommended for men 65 and 75 years of age with a smoking history. However, studies have shown that the rate of ultrasound screening is low and that implicit AAA screening by abdominal imaging studies that were not originally intended for AAA screening can play a major role in AAA detection.

OBJECTIVE

The main objective was to evaluate the role of lumbar spine MRIs as an implicit AAA screening study by assessing the detection rate of AAAs in a broader cohort of veterans that included screening and non-screening populations.

METHODS

4085 consecutive lumbar spine MRIs from our institution between 2/2020 and 9/2023 were retrospectively reviewed. Each study was labeled AAA present, AAA not present, or indeterminate by radiologists. The correlation between the presence of AAAs and cardiovascular risk factors was assessed using multinomial logistic regression.

RESULTS

AAAs were present in 89 studies (2.2 %) from 80 patients (mean age 75.8 (56-93), M:F 10:0) and absent in 3935 cases (96.3 %) from 3310 patients (mean age 61.7 (19-100), M:F 9:1). Indeterminate cases (n = 61, 1.5 %) were mainly due to incomplete visualization (70.5 %). Mean AAA size was 3.6 cm with most AAAs (n = 43) smaller than 3.5 cm. Sixteen AAAs were 3.5-3.9 cm, 16 between 4 and 4.9cm, and 6 between 5 and 5.9 cm. Artifact precluded measurements in 8 cases. Among the AAA-positive cases, 20 had no prior documentation of AAA. Twenty-one patients with AAAs would not have met the criteria for the routine AAA screening ultrasound. Higher rates of hypertension, hyperlipidemia, and smoking were observed for the AAA cohort at 78.8 % (OR 2.037, CI 1.160-3.576, P = .013), 82.5 % (2.808, 1.543-5.110, P < .001), and 75 % (3.340, 1.979-5.638, P < .001), respectively, compared to the matched no-AAA cohort (58.2 %, 57.6 %, and 50.8 %; n = 2055).

CONCLUSION

Lumbar spine MRI is a valid modality for implicit screening of AAAs.

CLINICAL IMPACT

Those interpreting lumbar spine MRIs should be vigilant about assessing for AAAs, especially in men with a history of hypertension, hyperlipidemia, or tobacco smoking.

Spatiotemporal trends in the burden of aortic aneurysms caused by high sodium intake from 1990 to 2019: A global, regional, and national analysis

BACKGROUND AND AIMS

This study, drawing on Global Burden of Disease (GBD) data, examines spatiotemporal trends in mortality and disability-adjusted life years (DALYs) linked to aortic aneurysm (AA) from high sodium intake. The aim is a comprehensive analysis globally, regionally, and nationally spanning 1990 to 2019.

METHODS AND RESULTS

Quantifying AA deaths and DALYs due to high sodium intake, incorporating age-standardized mortality rate (ASMR) and age-standardized DALYs rate (ASDR), revealed a global surge. Deaths rose by 86.09 %, DALYs by 74.02 % from 1990 to 2019. EAPC for ASMR and ASDR displayed negative trends (-0.72 and -0.77). High/middle-high Socio-demographic Index (SDI) regions bore higher burdens than lower SDI regions. Males consistently had higher burdens across SDI regions, with both genders showing a slight downward trend. Age-wise, AA deaths and DALYs rose with age, followed by decline. A positive correlation existed between SDI and global burden, inversely related to EAPC for ASMR and ASDR.

CONCLUSION

AA burden from high sodium intake is pronounced in high SDI regions, necessitating targeted interventions. The global data highlights a significant increase in AA deaths and DALYs due to high sodium intake, urging prompt and effective control measures.

Machine learning-based prediction of abdominal aortic aneurysms for individualized patient care

OBJECTIVE

The United States Preventative Services Task Force guidelines for screening for abdominal aortic aneurysms (AAA) are broad and exclude many at risk groups. We analyzed a large AAA screening database to examine the utility of a novel machine learning (ML) model for predicting individual risk of AAA.

METHODS

We created a ML model to predict the presence of AAAs (>3 cm) from the database of a national nonprofit screening organization (AAAneurysm Outreach). Participants self-reported demographics and comorbidities. The model is a two-layered feed-forward shallow network. The ML model then generated AAA probability based on patient characteristics. We evaluated graphs to determine significant factors, and then compared those graphs with a traditional logistic regression model.

RESULTS

We analyzed a cohort of 10,033 patients with an AAA prevalence of 2.74%. Consistent with logistic regression analysis, the ML model identified the following predictors of AAA: Caucasian race, male gender, advancing age, and recent or past smoker with recent smoker having a more profound affect (P < .05). Interestingly, the ML model showed body mass index (BMI) was associated with likelihood of AAAs, especially for younger females. The ML model also identified a higher than predicted risk of AAA in several groups, including female nonsmokers with cardiac disease, female diabetics, those with a family history of AAA, and those with hypertension or hyperlipidemia at older ages. An elevated BMI conveyed a higher than expected risk in male smokers and all females. The ML model also identified a complex relationship of both diabetes mellitus and hyperlipidemia with gender. Family history of AAA was a more important risk factor in the ML model for both men and women too.

CONCLUSIONS

We successfully developed an ML model based on an AAA screening database that unveils a complex relationship between AAA prevalence and many risk factors, including BMI. The model also highlights the need to expand AAA screening efforts in women. Using ML models in the clinical setting has the potential to deliver precise, individualized screening recommendations.

Terazosin attenuates abdominal aortic aneurysm formation by downregulating Peg3 expression to inhibit vascular smooth muscle cell apoptosis and senescence

Abdominal aortic aneurysm (AAA), a vascular degenerative disease, is a potentially life-threatening condition characterised by the loss of vascular smooth muscle cells (VSMCs), degradation of extracellular matrix (ECM), inflammation, and oxidative stress. Despite the severity of AAA, effective drugs for treatment are scarce. At low doses, terazosin (TZ) exerts antiapoptotic and anti-inflammatory effects in several diseases, but its potential to protect against AAA remains unexplored. Herein, we investigated the effects of TZ in two AAA animal models: Angiotensin II (Ang II) infusion in Apoe-/- mice and calcium chloride application in C57BL/6J mice. Mice were orally administered with TZ (100 or 1000 μg/kg/day). The in vivo results indicated that low-dose TZ alleviated AAA formation in both models. Low-dose TZ significantly reduced aortic pulse wave velocity without exerting an apparent antihypertensive effect in the Ang II-induced AAA model. Paternally expressed gene 3 (Peg3) was identified via RNA sequencing as a novel TZ target. PEG3 expression was significantly elevated in both mouse and human AAA tissues. TZ suppressed PEG3 expression and reduced the abundance of matrix metalloproteinases (MMP2/MMP9) in the tunica media. Functional experiments and molecular analyses revealed that TZ (10 nM) treatment and Peg3 knockdown effectively prevented Ang II-induced VSMC senescence and apoptosis in vitro. Thus, Peg3, a novel target of TZ, mediates inflammation-induced VSMC apoptosis and senescence. Low-dose TZ downregulates Peg3 expression to attenuate AAA formation and ECM degradation, suggesting a promising therapeutic strategy for AAA.

CT-derived body composition: Differential association with disease, age and inflammation in a retrospective cohort study

BACKGROUND

Low skeletal muscle mass and density, as assessed by CT-body composition (CT-BC), are recognised to have prognostic value in non-cancer and cancer patients. The aim of the present study was to compare CT-BC parameters between non-cancer (abdominal aortic aneurysm, AAA) and cancer (colorectal cancer, CRC) patients.

METHODS

Two retrospective multicentre cohorts were compared. Thresholds of visceral fat area (VFA, Doyle), skeletal fat index (SFI, Ebadi), skeletal muscle index (SMI, Martin), and skeletal muscle density (SMD, Martin) were applied to these cohorts and compared. The systemic inflammatory response (SIR) was measured by the systemic inflammatory grade (SIG).

RESULTS

1695 patients were included; 759 patients with AAA and 936 patients with CRC. Low SMD (33% vs. 66%, p <0.001) was more prevalent in the CRC cohort. Low SMI prevalence was similar in both cohorts (51% vs. 51%, p = 0.80). Compared with the AAA cohort, the CRC cohort had a higher prevalence of raised SIG (p <0.001). Increasing age (OR 1.54, 95% CI 1.38-1.72, p < 0.001) and elevated SIG (OR 1.23, 95% CI 1.09-1.40, p = 0.001) were independently associated with increased odds of low SMI. Increasing age (OR 1.90, 95% CI 1.66-2.17, p < 0.001) CRC diagnosis (OR 5.89, 95% CI 4.55-7.62, p < 0.001), ASA > 2 (OR 1.37, 95% CI 1.08-1.73, p = 0.01), and elevated SIG (OR 1.19, 95% CI 1.03-1.37, p = 0.02) were independently associated with increased odds of low SMD.

CONCLUSIONS

Increasing age and systemic inflammation appear to be important determinants of loss of skeletal muscle mass and quality irrespective of disease.

Association between the non-HDL-cholesterol to HDL- cholesterol ratio and abdominal aortic aneurysm from a Chinese screening program

BACKGROUND

Abdominal aortic aneurysms (AAAs) can result in high mortality upon rupture but are usually undiagnosed because of the absence of symptoms in the early stage. Ultrasound screening is regarded as an impactful way to prevent the AAA-related death but cannot be performed efficiently; therefore, a target population, especially in Asia, for this procedure is lacking. Additionally, although dyslipidaemia and atherosclerosis are associated with AAA. However, it remains undetermined whether the non-high-density lipoprotein-cholesterol to high-density lipoprotein-cholesterol ratio (NHHR) is associated with AAA. Therefore, this study was aimed at examining whether NHHR is associated with AAA.

METHOD

A total of 9559 participants who underwent AAA screening at Guangdong Provincial People's Hospital and through screening in two communities in Dongguan, from June 2019 to June 2021 joined in this screening program. The diagnosis of AAA was confirmed by the ultrasound examination of the abdominal aorta rather than any known or suspected AAA. Clinical and laboratory data of participants were collected. The participants were separated into a normal group and an AAA group according to the abdominal aortic status. To eliminate confounding factors, a propensity score matching (PSM) approach was utilized. The independent relationship between NHHR and AAA was assessed through the utilization of multivariable logistic regression analysis. In addition, internal consistency was evaluated through subgroup analysis, which controlled for significant risk factors.

RESULTS

Of all the participants, 219 (2.29%) participants were diagnosed with AAA. A significant elevation in NHHR was identified in the AAA group when contrasted with that in the normal group (P < 0.001). As demonstrated by the results of the multivariable logistic regression analysis, AAA was independently associated with NHHR before (odds ratio [OR], 1.440, P < 0.001) and after PSM (OR, 1.515, P < 0.001). Significant extension was observed in the areas under the receiver operating characteristic curves (AUROCs) of NHHR compared to those of single lipid parameters before and after PSM. An accordant association between NHHR and AAA in different subgroups was demonstrated by subgroup analysis.

CONCLUSION

In the Chinese population, there is an independent association between NHHR and AAA. NHHR might be propitious to distinguish individuals with high risk of AAA.

Precocious Rupture of Abdominal Aortic Aneurysms Below Size Criteria for Repair: Risk Factors and Outcomes

BACKGROUND

Practice guidelines recommend elective repair for abdominal aortic aneurysms (AAAs) ≥ 5.5 cm in men and ≥ 5 cm in women to prevent rupture; however, some rupture at smaller diameters. We identify risk factors for rupture AAA (rAAA) below this threshold and compare outcomes following rAAA repair above/below size criteria.

METHODS

The Vascular Quality Initiative (2013-2019) was queried for patients undergoing repair for rAAA and stratified based on diameter into small and large cohorts [Small: < 5.5 cm (men), < 5.0 cm (women)]. Univariate analysis was performed, and Kaplan-Meier analysis compared overall survival, aneurysm-related mortality, and reintervention at 12 months.

RESULTS

Five thousand one hundred sixty two rAAA were identified. Small rAAA patients [n = 588] were more likely to have hypertension (81.3% vs. 77.0%, P < 0.02), diabetes (18.2% vs. 14.9%, P < 0.04), and end-stage renal disease (2.9% vs. 0.9%, P < 0.01) and be on optimal medical therapy (32.1% vs. 26.8%, P < 0.01). Women were more likely to rupture at smaller diameters compared to men (P < 0.01). Small rAAA patients were more likely to undergo endovascular aortic repair (EVAR) (70.2% vs. 56.0%, P < 0.01) and had lower in-hospital mortality (17.7% vs. 27.7%, P < 0.01) and fewer perioperative complications across all categories. At 12 months, small rAAA patients had better overall survival, freedom from aneurysm-related mortality, and freedom from reintervention, largely driven by EVAR approach.

CONCLUSIONS

More than 11% of patients presenting with ruptured AAA were below the recommended size threshold for repair, and they tended to be younger, non-White, and have hypertension, diabetes, and/or renal failure. Patients with small rAAA experienced lower in-hospital morbidity and mortality and improved 1-year survival, and EVAR was associated with better outcomes than open repair. However, women more frequently rupture at smaller diameters compared to men. Given contemporary elective outcomes for women, a randomized controlled trial for EVAR versus surveillance at a sex-specific size threshold is needed.

Genome-wide association meta-analysis identifies risk loci for abdominal aortic aneurysm and highlights PCSK9 as a therapeutic target

Abdominal aortic aneurysm (AAA) is a common disease with substantial heritability. In this study, we performed a genome-wide association meta-analysis from 14 discovery cohorts and uncovered 141 independent associations, including 97 previously unreported loci. A polygenic risk score derived from meta-analysis explained AAA risk beyond clinical risk factors. Genes at AAA risk loci indicate involvement of lipid metabolism, vascular development and remodeling, extracellular matrix dysregulation and inflammation as key mechanisms in AAA pathogenesis. These genes also indicate overlap between the development of AAA and other monogenic aortopathies, particularly via transforming growth factor β signaling. Motivated by the strong evidence for the role of lipid metabolism in AAA, we used Mendelian randomization to establish the central role of nonhigh-density lipoprotein cholesterol in AAA and identified the opportunity for repurposing of proprotein convertase, subtilisin/kexin-type 9 (PCSK9) inhibitors. This was supported by a study demonstrating that PCSK9 loss of function prevented the development of AAA in a preclinical mouse model.

Evidence on the need for early identification of asymptomatic true abdominal aortic aneurysm in pregnancy: A case report

Pregnant women are more likely to face cardiovascular disease than non-pregnant women. However, abdominal aortic aneurysm is an extremely rare complication of pregnancy. Abdominal aortic aneurysms in pregnancy are difficult to identify in the early stage and are often diagnosed only when the symptoms have manifested. We report the case of a multiparous 35-year-old patient with a history of abnormal ascending aorta and ruled-out Marfan syndrome by genetic testing. After a multidisciplinary medical team evaluation, she delivered a live baby by cesarean section at 37 weeks of gestation, and the abdominal aortic aneurysm was repaired simultaneously. This case offers evidence-based recommendations for obstetricians to carry out preventive imaging examination for pregnant women with similar risk factors and provide successful experience in prenatal examination for similar diseases.

The contribution of matrix metalloproteinases and their inhibitors to the development, progression, and rupture of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) account for up to 8% of deaths in men aged 65 years and over and 2.2% of women. Patients with AAAs often have atherosclerosis, and intimal atherosclerosis is generally present in AAAs. Accordingly, AAAs are considered a form of atherosclerosis and are frequently referred to as atherosclerotic aneurysms. Pathological observations advocate inflammatory cell infiltration alongside adverse extracellular matrix degradation as key contributing factors to the formation of human atherosclerotic AAAs. Therefore, macrophage production of proteolytic enzymes is deemed responsible for the damaging loss of ECM proteins, especially elastin and fibrillar collagens, which characterise AAA progression and rupture. Matrix metalloproteinases (MMPs) and their regulation by tissue inhibitors metalloproteinases (TIMPs) can orchestrate not only ECM remodelling, but also moderate the proliferation, migration, and apoptosis of resident aortic cells, alongside the recruitment and subsequent behaviour of inflammatory cells. Accordingly, MMPs are thought to play a central regulatory role in the development, progression, and eventual rupture of abdominal aortic aneurysms (AAAs). Together, clinical and animal studies have shed light on the complex and often diverse effects MMPs and TIMPs impart during the development of AAAs. This dichotomy is underlined from evidence utilising broad-spectrum MMP inhibition in animal models and clinical trials which have failed to provide consistent protection from AAA progression, although more encouraging results have been observed through deployment of selective inhibitors. This review provides a summary of the supporting evidence connecting the contribution of individual MMPs to AAA development, progression, and eventual rupture. Topics discussed include structural, functional, and cell-specific diversity of MMP members; evidence from animal models of AAA and comparisons with findings in humans; the dual role of MMPs and the requirement to selectively target individual MMPs; and the advances in identifying aberrant MMP activity. As evidenced, our developing understanding of the multifaceted roles individual MMPs perform during the progression and rupture of AAAs, should motivate clinical trials assessing the therapeutic potential of selective MMP inhibitors, which could restrict AAA-related morbidity and mortality worldwide.

The circular RNA Ataxia Telangiectasia Mutated regulates oxidative stress in smooth muscle cells in expanding abdominal aortic aneurysms

An abdominal aortic aneurysm (AAA) is a pathological widening of the aortic wall characterized by loss of smooth muscle cells (SMCs), extracellular matrix degradation, and local inflammation. This condition is often asymptomatic until rupture occurs, leading to high morbidity and mortality rates. Diagnosis is mostly accidental and the only currently available treatment option remains surgical intervention. Circular RNAs (circRNAs) represent a novel class of regulatory non-coding RNAs that originate from backsplicing. Their highly stable loop structure, combined with a remarkable enrichment in body fluids, make circRNAs promising disease biomarkers. We investigated the contribution of circRNAs to AAA pathogenesis and their potential application to improve AAA diagnostics. Gene expression analysis revealed the presence of deregulated circular transcripts stemming from AAA-relevant gene loci. Among these, the circRNA to the Ataxia Telangiectasia Mutated gene (cATM) was upregulated in human AAA specimens, in AAA-derived SMCs, and serum samples collected from aneurysm patients. In primary aortic SMCs, cATM increased upon angiotensin II and doxorubicin stimulation, while its silencing triggered apoptosis. Higher cATM levels made AAA-derived SMCs less vulnerable to oxidative stress, compared with control SMCs. These data suggest that cATM contributes to elicit an adaptive oxidative-stress response in SMCs and provides a reliable AAA disease signature.

Status of diagnosis and therapy of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are characterized by localized dilation of the abdominal aorta. They are associated with several serious consequences, including compression of adjacent abdominal organs, pain, treatment-related financial expenditure. The main complication of AAA is aortic rupture, which is responsible for about 200,000 deaths per year worldwide. An increasing number of researchers are dedicating their efforts to study AAA, resulting in significant progress in this field. Despite the commendable progress made thus far, there remains a lack of established methods to effectively decelerate the dilation of aneurysms. Therefore, further studies are imperative to expand our understanding and enhance our knowledge concerning AAAs. Although numerous factors are known to be associated with the occurrence and progression of AAA, the exact pathway of development remains unclear. While asymptomatic at most times, AAA features a highly unpredictable disease course, which could culminate in the highly deadly rupture of the aneurysmal aorta. Current guidelines recommend watchful waiting and lifestyle adjustment for smaller, slow-growing aneurysms, while elective/prophylactic surgical repairs including open repair and endovascular aneurysm repair are recommended for larger aneurysms that have grown beyond certain thresholds (55 mm for males and 50 mm for females). The latter is a minimally invasive procedure and is widely believed to be suited for patients with a poor general condition. However, several concerns have recently been raised regarding the postoperative complications and possible loss of associated survival benefits on it. In this review, we aimed to highlight the current status of diagnosis and treatment of AAA by an in-depth analysis of the findings from literatures.

Multi-omics in thoracic aortic aneurysm: the complex road to the simplification

BACKGROUND

Thoracic aortic aneurysm (TAA) is a serious condition that affects the aorta, characterized by the dilation of its first segment. The causes of TAA (e.g., age, hypertension, genetic syndromes) are heterogeneous and contribute to the weakening of the aortic wall. This complexity makes treating this life-threatening aortopathy challenging, as there are currently no etiological therapy available, and pharmacological strategies, aimed at avoiding surgical aortic replacement, are merely palliative. Recent studies on novel therapies for TAA have focused on identifying biological targets and etiological mechanisms of the disease by using advanced -omics techniques, including epigenomics, transcriptomics, proteomics, and metabolomics approaches.

METHODS

This review presents the latest findings from -omics approaches and underscores the importance of integrating multi-omics data to gain more comprehensive understanding of TAA.

RESULTS

Literature suggests that the alterations in TAA mediators frequently involve members of pro-fibrotic process (i.e., TGF-β signaling pathways) or proteins associated with cell/extracellular structures (e.g., aggrecans). Further analyses often reported the importance in TAA of processes as inflammation (PCR, CD3, leukotriene compounds), oxidative stress (chromatin OXPHOS, fatty acids), mitochondrial respiration and glycolysis/gluconeogenesis (e.g., PPARs and HIF1a). Of note, more recent metabolomics studies added novel molecular markers to the list of TAA-specific detrimental mediators (proteoglycans).

CONCLUSION

It is increasingly clear that integrating data from different -omics branches, along with clinical data, is essential as well as complicated both to reveal hidden relevant information and to address complex diseases such as TAA. Importantly, recent progresses in metabolomics highlighted novel potential and unprecedented marks in TAA diagnosis and therapy.

An Epidemiologic Study of the Incidence and Mortality of Abdominal Aortic Aneurysms in Koreans Aged ≥50 Years from 2009 to 2018 Based on a National Database

Large-scale population studies of the incidence of and mortality from abdominal aortic aneurysm (AAA) are needed to develop healthcare policies and priorities. The aim of this study was to estimate the incidence of AAA and the all-cause mortality from it among Koreans aged ≥50 years from 2009 to 2018 using data from the Korean National Health Insurance System Database. The crude and standardized incidence and all-cause mortality of the disease among patients with unruptured AAA were calculated. A total of 73,933 AAA patients were identified. The overall incidence of AAA in adults ≥50 years during the study period was 37.5 per 100,000 population (49.7 per 100,000 in men and 26.8 per 100,000 in women), with an increase from 32.33 per 100,000 persons in 2009 to 46.85 per 100,000 in 2018. The crude all-cause mortality rate of patients with untreated AAA was 21.26/100 person-years in 2009 and 8.87/100 person-years in 2018, with decreasing trends observed both in men and women. This nationwide study showed that the incidence of AAA in Koreans aged ≥50 years in 2018 was 63.40 per 100,000 in men and 32.07 per 100,000 in women. The overall rates were 0.06% and 0.03%, respectively, with an increasing trend. Mortality has decreased in both treated and untreated patients. The observed increase in incidence suggests a rising burden of AAA in the Korean population, particularly among men. The decreasing mortality rates may indicate improvements in the management and treatment of AAA over the study period.

Plasma Lipidomics Analysis Reveals the Potential Role of Lysophosphatidylcholines in Abdominal Aortic Aneurysm Progression and Formation

Abdominal aortic aneurysm (AAA) is hallmarked by irreversible dilation of the infrarenal aorta. Lipid deposition in the aortic wall and the potential importance of a lipid disorder in AAA etiology highlight the need to explore lipid variation during AAA development. This study aimed to systematically characterize the lipidomics associated with AAA size and progression. Plasma lipids from 106 subjects (36 non-AAA controls and 70 AAA patients) were comprehensively analyzed using untargeted lipidomics. An AAA animal model was established by embedding angiotensin-II pump in ApoE^-/- mice for four weeks and blood was collected at 0, 2 and 4 weeks for lipidomic analysis. Using a false-discovery rate (FDR) < 0.05, a group of lysophosphatidylcholines (lysoPCs) were specifically decreased in AAA patients and mice. LysoPCs were principally lower in the AAA patients with larger diameter (diameter > 50 mm) than those with a smaller size (30 mm < diameter < 50 mm), and levels of lysoPCs were also found to be decreased with modelling time and aneurysm formation in AAA mice. Correlation matrices between lipids and clinical characteristics identified that the positive correlation between lysoPCs and HDL-c was reduced and negative correlations between lysoPCs and CAD rate, lysoPCs and hsCRP were converted to positive correlations in AAA compared to control. Weakened positive correlations between plasma lysoPCs and circulating HDL-c in AAA suggested that HDL-lysoPCs may elicit instinctive physiological effects in AAA. This study provides evidence that reduced lysoPCs essentially underlie the pathogenesis of AAA and that lysoPCs are promising biomarkers for AAA development.

Targeting long non-coding RNA NUDT6 enhances smooth muscle cell survival and limits vascular disease progression

Long non-coding RNAs (lncRNAs) orchestrate various biological processes and regulate the development of cardiovascular diseases. Their potential therapeutic benefit to tackle disease progression has recently been extensively explored. Our study investigates the role of lncRNA Nudix Hydrolase 6 (NUDT6) and its antisense target fibroblast growth factor 2 (FGF2) in two vascular pathologies: abdominal aortic aneurysms (AAA) and carotid artery disease. Using tissue samples from both diseases, we detected a substantial increase of NUDT6, whereas FGF2 was downregulated. Targeting Nudt6 in vivo with antisense oligonucleotides in three murine and one porcine animal model of carotid artery disease and AAA limited disease progression. Restoration of FGF2 upon Nudt6 knockdown improved vessel wall morphology and fibrous cap stability. Overexpression of NUDT6 in vitro impaired smooth muscle cell (SMC) migration, while limiting their proliferation and augmenting apoptosis. By employing RNA pulldown followed by mass spectrometry as well as RNA immunoprecipitation, we identified Cysteine and Glycine Rich Protein 1 (CSRP1) as another direct NUDT6 interaction partner, regulating cell motility and SMC differentiation. Overall, the present study identifies NUDT6 as a well-conserved antisense transcript of FGF2. NUDT6 silencing triggers SMC survival and migration and could serve as a novel RNA-based therapeutic strategy in vascular diseases.

Abdominal Aortic Aneurysm Detection in Bioelectrical Impedance Cardiovascular Screenings-A Pilot Study

Screening and diagnosing abdominal aortic aneurysms (AAA) are currently dependent on imaging studies such as ultrasound or computed tomography angiography. All imaging studies offer distinct advantages but also suffer from inherent limitations such as examiner dependency or ionizing radiation. Bioelectrical impedance analysis has previously been investigated with respect to its use in the detection of several cardiovascular and renal pathologies. The present pilot study assessed the feasibility of AAA detection based on bioimpedance analysis. In this single-center exploratory pilot study, measurements were conducted among three different cohorts: patients with AAA, end-stage renal disease patients without AAA, and healthy controls. The device used in the study, CombynECG, is an open-market accessible device for segmental bioelectrical impedance analysis. The data was preprocessed and used to train four different machine learning models on a randomized training sample (80% of the full dataset). Each model was then evaluated on a test set (20% of the full dataset). The total sample included 22 patients with AAA, 16 chronic kidney disease patients, and 23 healthy controls. All four models showed strong predictive performance in the test partitions. Specificity ranged from 71.4 to 100%, while sensitivity ranged from 66.7 to 100%. The best-performing model had 100% accuracy for classification when applied to the test sample. Additionally, an exploratory analysis to approximate the maximum AAA diameter was conducted. An association analysis revealed several impedance parameters that might possess predictive ability with respect to aneurysm size. AAA detection via bioelectrical impedance analysis is technically feasible and appears to be a promising technology for large-scale clinical studies and routine clinical screening assessments.

Genetic Association between the Levels of Plasma Lipids and the Risk of Aortic Aneurysm and Aortic Dissection: A Two-Sample Mendelian Randomization Study

Although a growing number of studies have attempted to uncover the relationship between plasma lipids and the risk of aortic aneurysm (AA), it remains controversial. Meanwhile, the relationship between plasma lipids and the risk of aortic dissection (AD) has not been reported on. We conducted a two-sample Mendelian randomization (MR) analysis to evaluate the potential relationship between genetically predicted plasma levels of lipids and the risk of AA and AD. Summary data on the relationship between genetic variants and plasma lipids were obtained from the UK Biobank and Global Lipids Genetics Consortium studies, and data on the association between genetic variants and AA or AD were taken from the FinnGen consortium study. Inverse-variance weighted (IVW) and four other MR analysis methods were used to evaluate effect estimates. Results showed that genetically predicted plasma levels of low-density lipoprotein cholesterol, total cholesterol, or triglycerides were positively correlated with the risk of AA, and plasma levels of high-density lipoprotein cholesterol were negatively correlated with the risk of AA. However, no causal relationship was found between elevated lipid levels and the risk of AD. Our study revealed a causal relationship between plasma lipids and the risk of AA, while plasma lipids had no effect on the risk of AD.

Ruptured abdominal aortic aneurysm, what does the interventional radiologist and vascular surgeon need from our report?

Abdominal aortic aneurysm is defined as a dilatation of the abdominal aorta greater than 3cm. Its prevalence is between 1 and 1.5 cases per 100 people, constituting an important cause of morbidity and mortality. Rare in women, its frequency increases with age and its most frequent location is between the renal arteries and the aorto-iliac bifurcation. Approximately 5% of cases will involve the visceral branches. It is a silent pathological process whose natural evolution is rupture, which often has a fatal outcome and whose diagnosis is part of the pathology that we will find in emergency radiology. The involvement of the radiologist and the preparation of an accurate diagnostic report, as soon as possible, is essential for decision-making by the team in charge of the patient's surgery.

The mechanism and therapy of aortic aneurysms

Aortic aneurysm is a chronic aortic disease affected by many factors. Although it is generally asymptomatic, it poses a significant threat to human life due to a high risk of rupture. Because of its strong concealment, it is difficult to diagnose the disease in the early stage. At present, there are no effective drugs for the treatment of aneurysms. Surgical intervention and endovascular treatment are the only therapies. Although current studies have discovered that inflammatory responses as well as the production and activation of various proteases promote aortic aneurysm, the specific mechanisms remain unclear. Researchers are further exploring the pathogenesis of aneurysms to find new targets for diagnosis and treatment. To better understand aortic aneurysm, this review elaborates on the discovery history of aortic aneurysm, main classification and clinical manifestations, related molecular mechanisms, clinical cohort studies and animal models, with the ultimate goal of providing insights into the treatment of this devastating disease. The underlying problem with aneurysm disease is weakening of the aortic wall, leading to progressive dilation. If not treated in time, the aortic aneurysm eventually ruptures. An aortic aneurysm is a local enlargement of an artery caused by a weakening of the aortic wall. The disease is usually asymptomatic but leads to high mortality due to the risk of artery rupture.

Distribution, Determinants and Normal Reference Values of Aortic Arch Width: Thoracic Aortic Geometry in the Framingham Heart Study

Study Objective

Aortic arch geometry changes with age, including an increase in aortic arch width (AAW). High AAW is a predictor of incident adverse cardiovascular disease (CVD) events, but its distribution and determinants are unknown. We hypothesized that traditional CVD risk factors, in addition to age, are associated with increased AAW in community-dwelling adults.

Study Design

Framingham Offspring and Third Generation cohort participants (N=3026, 52% Men) underwent thoracic multidetector computed tomography (MDCT). A referent group (733M, 738W) free of clinical CVD, hypertension, dyslipidemia, smoking, and diabetes was used to generate sex and 10-year age-group specific upper 90th percentile (P90) cut-points for AAW. AAW was measured as the distance between the cross-sectional centroids of the ascending and descending thoracic aorta. Multivariable logistic regression models were used to identify clinical correlates of high AAW (≥referent P90) in the overall study group.

Results

Among referent participants, AAW increased with greater age-group, p for trend <0.0001 in each sex. Overall and within each age group, AAW was greater in men than women, p<0.0001 all comparisons. Across all participants, high AAW was associated with greater age (odds ratio, OR=1.34/10y; 95% confidence interval 1.20 - 1.50), body surface area (OR=1.97/SD; 1.62 - 2.40), diastolic blood pressure (OR=1.59/10mmHg; 1.40 - 1.81), pack-years smoked (OR=1.07; 1.02 - 1.13), and prevalent CVD (OR=1.64; 1.08 - 2.49).

Conclusion

AAW increases with greater age, body size, diastolic blood pressure and burden of smoking. High AAW (≥referent P90) is also associated with prevalent (clinically apparent) CVD. AAW is often seen on and easily measured from tomographic thoracic images and has prognostic value.

Distinct Mechanisms of β-Arrestin-Biased Agonist and Blocker of AT1R in Preventing Aortic Aneurysm and Associated Mortality

BACKGROUND

Aortic aneurysm (AA) is a "silent killer" human disease with no effective treatment. Although the therapeutic potential of various pharmacological agents have been evaluated, there are no reports of β-arrestin-biased AT1R (angiotensin-II type-1 receptor) agonist (TRV027) used to prevent the progression of AA.

METHODS

We tested the hypothesis that TRV027 infusion in AngII (angiotensin II)-induced mouse model of AA prevents AA. High-fat-diet-fed ApoE (apolipoprotein E gene)-null mice were infused with AngII to induce AA and co-infused with TRV027 and a clinically used AT1R blocker Olmesartan to prevent AA. Aortas explanted from different ligand infusion groups were compared with assess different grades of AA or lack of AA.

RESULTS

AngII produced AA in ≈67% male mice with significant mortality associated with AA rupture. We observed ≈13% mortality due to aortic arch dissection without aneurysm in male mice. AngII-induced AA and mortality was prevented by co-infusion of TRV027 or Olmesartan, but through different mechanisms. In TRV027 co-infused mice aortic wall thickness, elastin content, new DNA, and protein synthesis were higher than untreated and Olmesartan co-infused mice. Co-infusion with both TRV027 and Olmesartan prevented endoplasmic reticulum stress, fibrosis, and vasomotor hyper responsiveness.

CONCLUSIONS

TRV027-engaged AT1R prevented AA and associated mortality by distinct molecular mechanisms compared with the AT1R blocker, Olmesartan. Developing novel β-arrestin-biased AT1R ligands may yield promising drugs to combat AA.

Stage II Pancreatic Adenocarcinoma after Endovascular Repair of Abdominal Aortic Aneurysm: A Case Report and Literature Review

BACKGROUNDS

Concomitant abdominal aortic aneurysms (AAA) and gastrointestinal malignancies are uncommon. Endovascular repair (EVAR) is widely used to treat AAA. However, no consensus exists on the optimal strategy for treating AAA when associated with pancreatic adenocarcinoma. In addition, only few reports of pancreaticoduodenectomy (PD) after EVAR exist.

PRESENTATION OF CASE

A pancreatic tumor was detected during follow-up after EVAR for AAA in an 83-year-old female patient. The diagnosis was high-grade intraepithelial neoplasia. Modified pylorus-preserving pancreaticoduodenectomy was safely performed. The patient recovered moderately and was discharged two weeks after surgery. The pathological diagnosis was middle-grade pancreatic ductal adenocarcinoma. The patient survived for 24 months with no recurrence or cardiovascular complications.

CONCLUSIONS

Conducting periodic follow-ups after AAA surgery is helpful for the early discovery of gastrointestinal tumors. EVAR surgery is safe and feasible and thus recommended for AAA patients with pancreatic cancer, although it may increase the risk of cancer. The stage of malignancy and post-EVAR medical history can be valuable in evaluating the benefits of pancreatic surgery for such cases.

Elective Endovascular vs Open Repair for Elective Abdominal Aortic Aneurysm in Patients ≥80 years of Age: A Systematic Review and Meta-Analysis

OBJECTIVE

To provide updated, pooled evidence on clinical outcomes among octogenarians (aged ≥80 years) with abdominal aortic aneurysm (AAA) managed by elective endovascular repair, compared to conventional open repair.

METHODS

PubMed, Embase, and Scopus databases were systematically searched. Studies that were either observational or randomized controlled trials were considered for the review. Included studies were conducted in elderly subjects (≥80 years) with AAA, and clinical and mortality outcomes were compared between endovascular and open surgical repair. Those reporting on outcomes of patients with urgent repair were excluded. The primary outcomes of interest were mortality and risk of complications. The pooled effect sizes were reported as odds ratio (OR) for categorical outcomes and weighted mean difference (WMD) for continuous outcomes. STATA software was used for statistical analysis.

RESULTS

The meta-analysis included 15 studies. Compared to those undergoing open repair, patients receiving endovascular repair had significantly reduced risk of immediate post-operative mortality (OR .23, 95% CI: .20, .27), overall complication (OR .30, 95% CI: .20, .44), cardiac (OR .23, 95% CI: .16, .35), renal (OR .29, 95% CI: .18, .46), pulmonary (OR .14, 95% CI: .09, .21) and bleeding related (OR .59, 95% CI: .42, .83) complications. The risk of mortality at latest follow up (at 36 months and 60 months) was similar in the two groups. The total blood loss (ml) (WMD -1126.47, 95% CI: -1497.81, -755.13), operative time (min) (WMD -29.40, 95% CI: -56.19, -2.62), length of intensive care unit stay (days) (WMD -2.27, 95% CI: -3.43, -2.12) and overall hospital stay (days) (WMD -6.64, 95% CI: -7.60, -5.68) was significantly lower in those undergoing endovascular repair.

CONCLUSIONS

Endovascular repair appears to be better than open repair of AAA in this high-risk, frail population, with respect to short term outcomes. The benefits of reduced risk of short term mortality, complications, and better peri and post-operative outcomes may be considered when making a choice between these two surgical approaches. Randomized controlled trials are needed to provide reliable evidence on the effect of EVAR on long term survival.

Abdominal aortic aneurysm and exfoliation syndrome in Utah

PURPOSE

A pilot study of electronic medical records (EMR) in Utah was undertaken to investigate exfoliation syndrome and exfoliation glaucoma (XFS/XFG) in abdominal aortic aneurysm (AAA) patients. In a subsequent retrospective cohort study of Utah XFS/XFG patients and population controls, the risk of AAA was examined.

METHODS

EMR of a statewide healthcare population were obtained from the Utah Population Database (UPDB) which links decades of medical records with Utah demographic and vital records data. In a pilot study, 7167 patients ages ≥40 years identified with AAA diagnosed from 1996 to 2015, based on International Classification of Diseases (ICD) version 9/10 codes, were included. A univariable hazards model was used to determine the risk of XFS/XFG in AAA patients. An XFS/XFG outcome based on ICD 9/10 codes in AAA patients and in 5:1 sex- and age-matched non-AAA controls was determined. A retrospective cohort of 3412 XFS/XFG patients ages ≥50 years diagnosed from 1996 to 2020 and 10 227 3:1 sex- and age-matched controls who underwent ≥1 dilated eye examination(s) were recently identified and updated diagnoses of AAA were obtained. Multivariable logistic regression was used to estimate AAA risk in XFS/XFG patients compared with controls. In a subset of XFS/XFG patients, chart reviews were conducted to confirm clinically diagnosed AAA.

RESULTS

In the AAA pilot, 20 patients (0.3%) and 118 controls (0.3%) developed XFS/XFG, respectively. We observed no increased risk of XFS/XFG in AAA patients compared with non-AAA-matched controls (HR = 0.99, 95% CI 0.6-1.6). Among XFS/XFG study patients and controls, 122 patients (3.6%) and 376 controls (3.7%) had an AAA diagnosis. We likewise observed no increased risk of AAA in XFS/XFG patients (OR = 0.97, 95% CI 0.8-1.2). In 14 XFS/XFG patients with an ICD 9/10 diagnosis of AAA who underwent chart review, a clinical diagnosis of AAA was confirmed in 9 patients (64.3%).

CONCLUSION

Our findings do not support an association between AAA and XFS/XFG.

Linking single nucleotide polymorphisms to signaling blueprints in abdominal aortic aneurysms

Abdominal aortic aneurysms (AAA) is a multifactorial complex disease with life-threatening consequences. While Genome-wide association studies (GWAS) have revealed several single nucleotide polymorphisms (SNPs) located in the genome of individuals with AAA, the link between SNPs with the associated pathological signals, the influence of risk factors on their distribution and their combined analysis is not fully understood. We integrated 86 AAA SNPs from GWAS and clinical cohorts from the literature to determine their phenotypical vulnerabilities and association with AAA risk factors. The SNPs were annotated using snpXplorer AnnotateMe tool to identify their chromosomal position, minor allele frequency, CADD (Combined Annotation Dependent Depletion), annotation-based pathogenicity score, variant consequence, and their associated gene. Gene enrichment analysis was performed using Gene Ontology and clustered using REVIGO. The plug-in GeneMANIA in Cytoscape was applied to identify network integration with associated genes and functions. 15 SNPs affecting 20 genes with a CADD score above ten were identified. AAA SNPs were predominantly located on chromosome 3 and 9. Stop-gained rs5516 SNP obtained high frequency in AAA and associated with proinflammatory and vascular remodeling phenotypes. SNPs presence positively correlated with hypertension, dyslipidemia and smoking history. GO showed that AAA SNPs and their associated genes could regulate lipid metabolism, extracellular matrix organization, smooth muscle cell proliferation, and oxidative stress, suggesting that part of these AAA traits could stem from genetic abnormalities. We show a library of inborn SNPs and associated genes that manifest in AAA. We uncover their pathological signaling trajectories that likely fuel AAA development.

Fibromuscular Dysplasia and Abdominal Aortic Aneurysms Are Dimorphic Sex-Specific Diseases With Shared Complex Genetic Architecture

BACKGROUND

The risk of arterial diseases may be elevated among family members of individuals having multifocal fibromuscular dysplasia (FMD). We sought to investigate the risk of arterial diseases in families of individuals with FMD.

METHODS

Family histories for 73 probands with FMD were obtained, which included an analysis of 463 total first-degree relatives focusing on FMD and related arterial disorders. A polygenic risk score for FMD (PRSFMD) was constructed from prior genome-wide association findings of 584 FMD cases and 7139 controls and evaluated for association with an abdominal aortic aneurysm (AAA) in a cohort of 9693 AAA cases and 294 049 controls. A previously published PRSAAA was also assessed among the FMD cases and controls.

RESULTS

Of all first degree relatives of probands, 9.3% were diagnosed with FMD, aneurysms, and dissections. Aneurysmal disease occurred in 60.5% of affected relatives and 5.6% of all relatives. Among 227 female first-degree relatives of probands, 4.8% (11) had FMD, representing a relative risk (RR)FMD of 1.5 ([95% CI, 0.75-2.8]; P=0.19) compared with the estimated population prevalence of 3.3%, though not of statistical significance. Of all fathers of FMD probands, 11% had AAAs resulting in a RRAAA of 2.3 ([95% CI, 1.12-4.6]; P=0.014) compared with population estimates. The PRSFMD was found to be associated with an AAA (odds ratio, 1.03 [95% CI, 1.01-1.05]; P=2.6×10-3), and the PRSAAA was found to be associated with FMD (odds ratio, 1.53 [95% CI, 1.2-1.9]; P=9.0×10-5) as well.

CONCLUSIONS

FMD and AAAs seem to be sex-dimorphic manifestations of a heritable arterial disease with a partially shared complex genetic architecture. Excess risk of having an AAA according to a family history of FMD may justify screening in family members of individuals having FMD.

Abdominal Aortic Aneurysms (Etiology, Epidemiology, and Natural History)

Abdominal aortic aneurysm is a potentially lethal condition that is decreasing in frequency as tobacco use declines. The exact etiology remains unknown, but smoking and other perturbations seem to trigger an inflammatory state in the tunica media. Male sex and advanced age are clear demographic risk factors for the development of abdominal aortic aneurysms. The natural history of this disease varies, but screening remains vital as it is rarely diagnosed on physical examination, and elective repair (most commonly done endovascularly) offers significant morbidity and mortality advantages over emergent intervention for aortic rupture.