Low prevalence of abdominal aortic aneurysm among 65-year-old Swedish men indicates a change in the epidemiology of the disease

How to improve epidemiological trustworthiness concerning abdominal aortic aneurysms

BackgroundResearch on degenerative abdominal aortic aneurysms (AAA) is hampered by complex pathophysiology, sub-optimal pre-clinical models, and lack of effective medical therapies. In addition, trustworthiness of existing epidemiological data is impaired by elements of ambiguity, inaccuracy, and inconsistency. Our aim is to foster debate concerning the trustworthiness of AAA epidemiological data and to discuss potential solutions.MethodsWe searched the literature from the last five decades for relevant epidemiological data concerning AAA development, rupture, and repair. We then discussed the main issues burdening existing AAA epidemiological figures and proposed suggestions potentially beneficial to AAA diagnosis, prognostication, and management.ResultsRecent data suggest a heterogeneous scenario concerning AAA epidemiology with rates markedly varying by country and study cohorts. Overall, AAA prevalence seems to be decreasing worldwide while mortality is apparently increasing regardless of recent improvements in aortic-repair techniques. Prevalence and mortality are decreasing in high-income countries, whereas low-income countries show an increase in both. However, several pieces of information are missing or outdated, thus systematic renewal is necessary. Current AAA definition and surgical criteria do not consider inter-individual variability of baseline aortic size, further decreasing their reliability.ConclusionsSwitching from flat aortic-size thresholds to relative aortic indices would improve epidemiological trustworthiness regarding AAAs. Aortometry standardization focusing on simplicity, univocity, and accuracy is crucial. A patient-tailored approach integrating clinical data, multi-adjusted indices, and imaging parameters is desirable. Several novel imaging modalities boast promising profiles for investigating the aortic wall. New contrast agents, computational analyses, and artificial intelligence-powered software could provide further improvements.

Proteinuria is risk factor for abdominal aortic aneurysm: a nationwide population-based study

BACKGROUND

Proteinuria is a well-known risk factor for cardiovascular disease. However, the impact of proteinuria on abdominal aortic aneurysm (AAA) remains unclear. In this study, we aimed to investigate the association between proteinuria and AAA. To assess the correlation between proteinuria measured by the urine dipstick test (UDT) and the risk of AAA by using nationwide population cohort data.

METHODS

This retrospective cohort study used data from the Korean National Health Insurance database for individuals who had health check-ups in 2009. Incident AAA was ascertained through the end of 2019. The study population was classified into the following five groups based on the UDT result: negative; trace; 1+; 2+; and ≥ 3+. The primary endpoint was newly developed AAA during the study period.

RESULTS

A total of 9,938,329 patients were enrolled. During a median follow-up of 9.3 years (interquartile range 9.1-9.6), 20,760 (0.2%) AAA events were identified, and the incidence rates of AAA were 2.21, 2.55, 4.20, 5.77 and 7.49 per 10,000 per year in the negative, trace, 1+, 2 + and 3 + ≤ proteinuria groups, respectively, compared with those without proteinuria (P <.001). There was a positive correlation between the degree of proteinuria and the risk of AAA, which was consistent regardless of all estimated glomerular filtration rate categories.

CONCLUSION

Proteinuria as measured by the UDT was strongly associated with AAA and acted as an independent risk factor. These findings suggest that proteinuria may serve as a potential marker for identifying individuals at higher risk of AAA.

Expand the success of screening to reduce aortic aneurysm mortality: progress interpretation and new fronts

Aortic aneurysm is a leading cause of death across the world. Many victicms carry it without knowing. Ruputre of aortic aneurysms leads to devastating sudden death. This brings trauma to families and our society. Based upon sound results out of several cohort studies, US Preventive Services Task Force (USPST) crafted the 1st nationwide abdominal aorta aneurysm (AAA) screening program in 2005. It was renewed and expanded in subsequent revisions in 2014 and 2019. UK and Sweden estalished their own programs as well. Since then, a significant decline in AAA prevalence and mortality has been observed. Two decades into the practice, the state of the art on diagnostics, surgical approaches, and pharmacological options have drastically changed. Patients previously ineligible for treatment or inconclusive on diagnostics now have valid options. The screening program is on the verge for a bold expansion. In this review, we summarize the chroncles leading to the inception of the screening programs, progress in interpretation after implementation including gains, gaps and controversies, advents of new technologies and approaches, new fronts facing us, as well as priorities to be addressed in future phases. Particularly, screening asssys with a clinically tested biomarker, tetrahydrobiopterin (H4B), enables unpresended accessibility, consistency and throughput to accommodate the needs of a larger population. Furthermore, patients with AAAs at size below the eligibility threhold for surgical intervention (e.g., < 5.5 cm) can be treated with novel oral medications. Confronting factors such as changing demographics and COVID-19 aftermath are putting up new challenges. Nevertheless, running a program at national scale demands both unwavering commitment and agile fine-tuning. Technical innovation will be an indispensable chapter of its continued success. The burden of aortic aneurysm-led sudden death is too heavy for any family and the society to bear; it is time to step up our resolve with additional capacities as discussed in the present review.

Current Management of Uncomplicated Type B Aortic Dissection

Aortic dissection is the most common thoracic aortic emergency and is associated with significant morbidity and mortality. Initial complications are dependent on reduction of sheer stress against the aortic wall to protect against rupture and minimize progression of the aortic wall injury. In patients with dissection starting at or distal to the left subclavian artery (Stanford type B), initial management includes strict blood pressure and heart rate control with monitoring for any complications such as malperfusion, rupture, or hemodynamic instability. Following the acute dissection event, survivors are faced with the lifelong need for blood pressure control and surveillance imaging to monitor for potential aortic deterioration leading to rupture or aneurysm formation. This review will discuss the latest recommendations for current management of uncomplicated type B aortic dissection including the evolving role of endovascular therapies.

Current Status of Diagnostic Process in Asymptomatic Abdominal Aortic Aneurysm in Japan

Objectives: This study aimed to investigate the actual detection process and diagnostic methods for asymptomatic abdominal aortic aneurysm (AAA) in a multicenter setting, and to plan an effective screening strategy for asymptomatic AAA. Methods: The subjects of this multicenter study were collected in a retrospective manner at 7 facilities. A total of 1894 patients with AAA, including iliac artery aneurysms, who were considered asymptomatic with a confirmed initial diagnosis from January 2018 to December 2022, were collected and reviewed. Results: A total of 1666 patients who were diagnosed with asymptomatic AAA were included [83.9% males, median age of 75 (69-81) years]. Asymptomatic AAAs were frequently diagnosed during examinations for other diseases in 1339 patients (80.4%), whereas health screenings accounted for only 313 (18.8%). Computed tomography (CT) was the most commonly used diagnostic method (n = 1352, 81.2%) compared to abdominal ultrasonography (n = 252, 15.2%). Conclusions: Asymptomatic AAAs are detected incidentally during examinations for other diseases, and there is an urgent need to promote health screening. Most AAAs are diagnosed by CT; nevertheless, we consider that abdominal ultrasonography would be the most appropriate modality for AAA screening because of its reasonable accuracy, noninvasiveness, and low cost.

Atherosclerotic Abdominal Aortic Aneurysms on Computed Tomography Angiography: A Narrative Review on Spectrum of Findings, Structured Reporting, Treatment, Secondary Complications and Differential Diagnosis

Atherosclerotic abdominal aortic aneurysms (AAAs) are a common vascular pathology with significant morbidity and mortality risks. Timely diagnosis, accurate characterization, and standardized reporting are critical for effective management and monitoring of atherosclerotic AAAs. Imaging modalities, particularly computed tomography angiography (CTA), play a pivotal role in the detection, treatment planning, and identification of both primary and secondary complications, as well as distinguishing AAAs from other etiologies. This narrative review provides a comprehensive exploration of the spectrum of imaging findings in atherosclerotic AAAs on CTA, underscoring the importance of structured reporting. Additionally, it examines therapeutic approaches and complications, and it differentiates AAAs from inflammatory, mycotic, and traumatic variants, serving as a primer for radiologists in AAA evaluation.

The Impact of Physical Activity on Abdominal Aortic Aneurysm: A Scoping Review

BACKGROUND

Abdominal aortic aneurysm (AAA), a condition primarily affecting older men, is often asymptomatic but becomes life-threatening if rupture occurs. While AAA risk factors such as age, gender, and smoking are well-studied, physical activity (PA) may also play a critical role in managing AAA progression, though this relationship remains understudied. This scoping review aims to synthesize current knowledge on the impact of PA on AAA, examining safety, physiological effects, and potential protective effects against AAA progression.

METHODS

A comprehensive scoping review methodology was applied, covering databases from their inception to October 2024, including MEDLINE, CINAHL, Scopus, and Web of Science. Seven studies meeting the inclusion criteria were analyzed, with intervention designs ranging from cross-sectional to longitudinal studies.

RESULTS

After full-text review of 44 articles, 38 were excluded due to focus on surgical intervention or flow models. The manual screening adding one study, resulting in 7 articles included in this review. PA appears generally safe for individuals with small AAAs, with minimal adverse events reported in most studies, though one study noted a cardiac incident during exercise. PA interventions often improved cardiovascular metrics, including ventilatory threshold and inflammatory markers, yet demonstrated mixed effects on AAA growth. Notably, the protective effect of PA against AAA progression remains inconclusive, requiring further investigation.

CONCLUSIONS

This review indicates that moderate PA is generally safe and may provide health benefits for individuals with small AAAs. However, significant knowledge gaps remain, especially regarding the optimal frequency, intensity, and duration of PA, as well as its long-term impact on aneurysm progression. All these issues require objective measurement of PA to develop targeted physical activity guidelines for this population.

Optimising Abdominal Aortic Aneurysm Screening of 65 Year Old Men by Exploring Risk Factor Based Targeted Screening Strategies in the Light of Declining Prevalence of the Disease

OBJECTIVE

A decline in abdominal aortic aneurysm (AAA) prevalence calls into question the credibility of general population screening of 65 year old men. Selectively targeting high risk individuals among this group could be more effective in preventing death from AAA rupture. This cross sectional study analysed risk factor data in a cohort of 65 year old men screened in the Swedish general population based AAA screening programme, with the aim of exploring the effectiveness of hypothetical targeted screening strategies.

METHODS

All men attending AAA screening in four neighbouring counties in Sweden between 2006 and 2010 completed a health questionnaire on smoking habits and medical history. Abdominal aortic aneurysm was defined as measuring ≥ 30 mm. The sensitivity and specificity of different targeted screening strategies, with targeted subpopulations defined by duration of smoking with and without additional risk factors, were explored using receiver operating characteristic (ROC) curves.

RESULTS

A total of 16 232 men were screened, with 236 (1.5%) screen detected AAAs. A strategy combining smoking, presence of coronary artery disease (CAD), or both was associated with the mathematically optimal balance between sensitivity and specificity (optimal threshold) in the ROC analysis. The optimal threshold corresponded to targeting men having smoked for thirty years or more, a history of CAD, or both, where 74.0% of all AAAs could be detected by screening 33.0% of the population, compared with general screening. Targeting men that have smoked for ten years or more indicated that 84.0% of all AAAs could be detected by screening 55.0% of the population. A simplified strategy of targeting ever smokers resulted in detecting 85.0% of all AAAs by screening 61.0% of the population.

CONCLUSION

Targeted screening of men at high risk of AAA, focusing on smoking history for inclusion, may be a safe and effective alternative to general population screening.

Sexual dimorphism in aortic aneurysm: A review of the contributions of sex hormones and sex chromosomes

Aortic aneurysm is a common cardiovascular disease. Over time, the disease damages the structural and functional integrity of the aorta, causing it to abnormally expand and potentially rupture, which can be fatal. Sex differences are evident in the disease, with men experiencing an earlier onset and higher incidence. However, women may face a worse prognosis and a higher risk of rupture. While there are some studies on the cellular and molecular mechanisms of aneurysm formation, it remains unclear how sex factors contribute to sexual dimorphism. Therefore, this review aims to summarize the role of sex in the occurrence of aortic aneurysms, offering valuable insights for disease prevention and the development of appropriate treatment options.

Advances in Imaging and Diagnosis of Abdominal Aortic Aneurysm: A Shift in Clinical Practice

Abdominal aortic aneurysm (AAA) is a potentially life-threatening vascular condition, with rupture carrying a high mortality risk. Advances in imaging technologies have significantly improved the detection, risk stratification, and management of AAA, necessitating periodic updates to international clinical guidelines. This review examines recent advancements in AAA imaging modalities, their role in diagnosis and risk assessment, and evolving screening strategies in response to changing epidemiological trends. A systematic literature search was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, identifying key studies on diagnostic imaging techniques such as ultrasonography (US), computed tomography angiography (CTA), magnetic resonance angiography (MRA), intravascular US (IVUS), positron emission tomography-computed tomography (PET-CT), and artificial intelligence (AI)-driven imaging. US remains the preferred screening tool due to its cost-effectiveness, while CTA is the gold standard for preoperative planning. MRA is an alternative for patients with renal impairment, and emerging technologies such as AI-based imaging, IVUS, and PET-CT enhance risk prediction and surgical decision-making. Declining AAA prevalence, attributed to reduced smoking rates and improved cardiovascular risk management, has led to a shift from population-wide screening to targeted screening based on individual risk factors. Additionally, the standardization of imaging protocols and caliper placement techniques is crucial for accurate measurements and consistent clinical decision-making. As imaging technology continues to evolve, integrating AI, genetic markers, and biomarkers into screening and diagnostic protocols may enable more precise and personalized AAA management. Future research should focus on refining imaging-based risk stratification models to optimize screening and treatment strategies.

An international, expert-based, Delphi consensus document on controversial issues in the management of abdominal aortic aneurysms

OBJECTIVE

As a result of conflicting, inadequate or controversial data in the literature, several issues concerning the management of patients with abdominal aortic aneurysms (AAAs) remain unanswered. The aim of this international, expert-based Delphi consensus document was to provide some guidance for clinicians on these controversial topics.

METHODS

A three-round Delphi consensus document was produced with 44 experts on 6 prespecified topics regarding the management of AAAs. All answers were provided anonymously. The response rate for each round was 100%.

RESULTS

Most participants (42 of 44 [95.4%]) agreed that a minimum case volume per year is essential (or probably essential) for a center to offer open or endovascular AAA repair (EVAR). Furthermore, 33 of 44 (75.0%) believed that AAA screening programs are (probably) still clinically effective and cost effective. Additionally, most panelists (36 of 44 [81.9%]) voted that surveillance after EVAR should be (or should probably be) lifelong. Finally, 35 of 44 participants (79.7%) thought that women smokers should (or should probably/possibly) be considered for screening at 65 years of age, similar to men. No consensus was achieved regarding lowering the threshold for AAA repair and the need for deep venous thrombosis prophylaxis in patients undergoing EVAR.

CONCLUSIONS

This expert-based Delphi consensus document provides guidance for clinicians regarding specific unresolved issues. Consensus could not be achieved on some topics, highlighting the need for further research in those areas.

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.

Characteristics and Ethnic Distribution of Aortic Aneurysms in a Caribbean Cohort

BACKGROUND

 There is a paucity of data regarding relationships between patient demographics and aneurysm characteristics in the West Indies. With this in mind, a retrospective cross-sectional review was conducted analyzing the computed tomography aortogram reports/images of 273 aortic aneurysms.

METHODS

 Data were collected and analyzed on ethnicity, size, type, morphology, presence and maximum size of thrombus and aneurysm location, demographics, and clinical presentation with correlations.

RESULTS

 There were 273 patients with aortic aneurysms giving an incidence rate of 4.33 per 100,000 people per annum. Statistically significant associations were noted with age, gender, and ethnicity. All false aneurysms were male (p = 0.004). The average size of aortic aneurysms being 0.7 cm larger in males than females (p < 0.001). Females were more likely to present with rupture (p = 0.001). Thrombus was more likely in males, Black and mixed races, and in the 8th decade (p < 0.001). Mean age of presentation was the highest in East Indians at 78 than the other ethnicities (Chinese: 65, Black: 70, mixed: 71, White: 73).

CONCLUSION

 Aortic aneurysmal disease is increasing in Trinidad and the Caribbean. Infrarenal fusiform aneurysms are the most common types with many significant differences based on age, gender, and ethnicity in the Caribbean population.

Clinical and computed tomography angiography characteristics of infected vs. non-infected abdominal aortic aneurysm: a comparative study

PURPOSE

The aim of this study was to investigate the clinical and multi-slice spiral computed tomography angiography (MSCTA) characteristics for the diagnosis of infected AAA.

METHODS

This retrospective comparative study included patients who were diagnosed with AAA at our hospital between January 2014 and May 2023.

RESULTS

A total of 40 patients were included, comprising 20 with infected AAA and 20 with non-infected AAA. Patients with infected AAA were more likely to be younger (62.9 ± 10.1 vs. 70.0 ± 4.4 years, P = 0.007) and to present with fever [7 (35%) vs. 1 (5%), P = 0.026], pain [15 (75%) vs. 2 (10%), P < 0.001], higher C-reactive protein levels (60.4 ± 57.0 vs. 4.1 ± 2.9 mg/l, P = 0.005), and higher erythrocyte sedimentation rates (47.7 ± 23.4 vs. 15.2 ± 8.3 mm/h, P < 0.001) compared to those with non-infected AAA. Moreover, those with infected AAA exhibited significantly more eccentric saccular morphology [17 (85%) vs. 1 (5%), P = 0.002], a smaller longitudinal-transverse ratio (1.12 ± 0.33 vs. 2.33 ± 0.54, P = 0.001), thicker peri-aneurysmal soft tissue (2.29 ± 1.48 vs. 0.73 ± 0.55 cm, P < 0.001), more lobulated margins [18 (90%) vs. 1 (5%), P = 0.001], lower aortic calcification scores (49 vs. 56, P < 0.001), more pneumatosis [6 (30%) vs. 0 (0%), P = 0.014], more ruptures [15 (75%) vs. 5 (20%), P = 0.002], more blurred peri-abdominal aortic fat spaces [16 (80%) vs. 2 (10%), P = 0.001], more adjacent bone destruction [5 (25%) vs. 0 (0%), P = 0.025], more involvement of the psoas major muscle [8 (40%) vs. 1 (5%), P = 0.005], more lymphadenectasis [8 (40%) vs. 1 (5%), P = 0.020], and less tortuous aortas [2 (10%) vs. 9 (45%), P = 0.034] compared with those with non-infected AAA.

CONCLUSION

The clinical manifestations and MSCTA characteristics may differ between infected and non-infected AAA.

Evidence for a Role of Gut Microbiota and Probiotics in Aneurysmal Pathogenesis and Possible Therapeutics: A Systematic Review of the Literature

INTRODUCTION

Several studies investigated the implication of the gut microbiota (GM) in the formation and progression of aneurysms, suggesting a key role for GM metabolites in aneurysmal pathogenesis and prognosis.

AIM

This systematic review aims to collect key findings concerning the impact of gut bacterial compositions, GM-related metabolites, probiotics administration, and inflammatory markers in aneurysmal development and rupture.

METHODS

A PubMed, Medline, Embase, and Web of Science database search was conducted in accordance with PRISMA guidelines for systematic reviews, targeting all studies assessing the GM's role in aneurysms till 2023.

RESULTS

Data from 19 out of 292 non-duplicated studies were included. Based on the published literature, aneurysmal incidents in several locations were accompanied by an alteration in specific intestinal bacteria that may affect the prognosis of the aneurysm. The gut dysbiosis was also accompanied by modifications in the metabolic pathways. Hence, the administration of specific probiotics showed a significant implication in reversing the GM-related changes that were affecting the aneurysm, leading to a decrease in its severity, a better prognosis, and even serving as a prophylactic approach.

CONCLUSIONS

The outcomes of this review highlight the role of GM in the pathogenesis of aneurysms, assessing some involved mechanistic pathways such as gut dysbiosis, inflammation, and the alteration of gut-derived metabolites levels, which orient new research on developing therapeutic strategies.

A Decade-Long Retrospective Study of Factors Influencing Survival in Ruptured Abdominal Aortic Aneurysm

Background: Ruptured abdominal aortic aneurysm (rAAA) carries a high mortality risk, requiring rapid diagnosis and intervention. This study assesses various clinical factors influencing rAAA management outcomes in alignment with evolving guidelines from 2011 to 2024. Methods: A retrospective analysis of 62 rAAA patients treated at Vivantes Clinic, Berlin, from July 2014 to May 2024 was conducted. Data were obtained from medical records, focusing on vital parameters at admission and during treatment. Both numerical and categorical variables were analyzed to identify survival determinants. Results: The overall survival rate was 55%. Significant differences in systolic and diastolic blood pressures during surgery were noted between survivors and non-survivors, with lower pressures observed in non-survivors at critical surgical stages. Other vital signs showed no significant variations. Survival was significantly associated with gender, fluid therapy, and aneurysm location. Conclusions: Effective blood pressure management during surgery is crucial for improving survival in rAAA cases. This study emphasizes adherence to current clinical guidelines and highlights the need for ongoing research to fill existing knowledge gaps. Further investigations are essential to enhance patient care and outcomes in rAAA.

Psoas muscle analysis as a surrogate marker of sarcopenia and frailty: A multicenter analysis of predictive capacities over short- and long-term outcomes after abdominal aortic aneurysm repair

OBJECTIVES

Several predictive models exist for estimating the postoperative risks of abdominal aortic aneurysm (AAA) repair, although no particular tool has seen widespread use. We present the results of a multicenter, historic cohort study comparing the predictive capacity of the psoas muscle area (PMA), radiodensity (PMD), and lean muscle area (LMA) as surrogate markers of sarcopenia, over short- and long-term outcomes after AAA repair, compared to the mFI-5 and American Society of Anesthesiologists (ASA) scales.

METHODS

Retrospective review was conducted of all consecutive AAA elective repair cases (open or endovascular) in three tertiary-care centers from 2014 to 2019. Cross-sectional PMA, PMD, and LMA at the mid-body of the L3 vertebra were measured by two independent operators in the preoperative computed tomography. Receiver operating characteristic (ROC) curves were used to determine optimal cutoff values. Bivariate analysis, logistic regression, and Cox's proportional hazards models were built to examine the relationship between baseline variables and postoperative mortality, long-term mortality, and complications.

RESULTS

596 patients were included (mean age 72.7 ± 8 years, 95.1% male, 66.9% EVAR). Perioperative mortality was 2.3% (EVAR 1.2% vs open repair 4.6%, p = .015), and no independent predictors could be identified in the multivariate analysis. Conversely, an age over 74 years old (OR 1.84 95%CI 1.25-2.70), previous heart diseases (OR 1.62 95%CI 1.13-2.32), diabetes mellitus (OR 1.61 95%CI 1.13-2.32), and a PMD value over 66 HU (OR 0.58 95%CI 0.39-0.84) acted as independent predictors of long-term mortality in the Cox's proportional hazards model. Heart diseases (congestive heart failure or coronary artery disease), serum creatinine levels over 1.05 mg/dL, and an aneurysm diameter over 60 mm were independent predictors of major complications.

CONCLUSION

Surrogate markers of sarcopenia had a poor predictive profile for postoperative mortality after AAA repair in our sample. However, PMD stood out as an independent predictor of long-term mortality. This finding can guide future research and should be confirmed in larger datasets.

Evaluation of outcomes and utility of abdominal aortic aneurysm surveillance in octogenarians and nonagenarians

INTRODUCTION

The aim of this study was to evaluate the utility of our regional abdominal aortic aneurysm (AAA) screening programme in octogenarians and nonagenarians. This was to help decide whether discontinuation might be appropriate in certain instances. Primary outcomes were the number of patients who reached threshold (5.5cm) and the number where intervention was offered. Secondary outcome was cost effectiveness.

METHODS

A retrospective review of a regional AAA surveillance database was carried out to evaluate outcomes. Data collected included patient age, sex, date of first and last scan, initial and latest size of aneurysm, outcome, time under surveillance and total number of scans. Patients were divided into three groups (80-84 years, 85-89 years and 90+ years).

RESULTS

The number of patients in this age group was 354. Only 2.0% (n=7) of patients underwent intervention. Threshold size was achieved in 8.3% (n=18), 14.8% (n=18) and 26.7% (n=4), in the age groups 80-84 years, 85-89 years and 90+ years, respectively. Of these patients, operative intervention was possible in 2.8% (n=6), 0.8% (n=1) and 0% (n=0), respectively.

CONCLUSION

A relatively small number of octogenarians and nonagenarians reach the threshold size during surveillance. An even smaller proportion require repair of their aneurysm. While there may be a role for AAA surveillance in octogenarians in highly selected groups, these data should inform the discussions made with individual patients. It should also inform future evaluation of such surveillance.

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.

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.

Screening Men and Women above the Age of 50 Years for Abdominal Aortic Aneurysm: A Pilot Study in an Upper Middle Income Country

OBJECTIVE

Screening for abdominal aortic aneurysm (AAA) is recommended in high risk populations based on local conditions. Differences in lifestyle and risk factors between countries with different income status make risk stratification based on geographic location necessary. The majority of epidemiological studies on AAA have reported data from high income countries. The aim of this study was to explore the prevalence and risk factors for AAA in an upper middle income country in Eastern Europe.

METHODS

A pilot screening project for AAA, supported by a mass media campaign, was conducted in 2023 in seven cities in Serbia. Ultrasound evaluation of the abdominal aorta was performed by a registered vascular surgeon on individuals who agreed to participate. Participants who attended screening completed a questionnaire on demographic and clinical information. To assess risk factors for AAA, univariable logistic regression analysis was performed to compute the odds ratio (OR) with 95% confidence interval (CI). Multivariable logistic regression was subsequently performed with adjustments for sex, age, family history of AAA, and other relevant factors.

RESULTS

A total of 4 046 participants (51.2% male and 48.8% female; mean age 68.8 ± 7.6 years) responded to the campaign. An aneurysm was found in 195 (4.8%) screened individuals (8.2% of men and 1.3% of women). In males aged 50 - 64 years, the prevalence of AAA was 5.4%. Male sex, older age, family history of AAA, being a smoker or ex-smoker, being overweight, and alcohol consumption were predictors of AAA in the univariable analysis. After adjustments in the multivariable analysis, male sex (OR 8.04, 95% CI 4.87 - 13.28), older age (OR 1.04, 95% CI 1.02 - 1.07), positive family history (OR 2.47, 95% CI 1.61 - 3.78), smoker status (OR 3.10, 95% CI 2.10 - 4.59), ex-smoker status (OR 2.13, 95% CI 1.39 - 3.27), and being overweight (OR 1.85, 95% CI 1.25 - 2.74) were independent risk factors for AAA.

CONCLUSION

The prevalence of AAA has not been reduced in all countries, and screening strategies might be changed based on local epidemiological data. The results of this pilot study underline the importance of exploring the prevalence of AAA in populations with a high prevalence of smoking.

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.

Co-prevalence of arterial aneurysm location - a correlation analysis based on a retrospective cross-sectional observational study

Background: The aim of this retrospective single-centre cross-sectional observational study was to investigate co-prevalence of arterial aneurysm location systematically. Patients and methods: Patients with the diagnosis of any arterial aneurysm from January 2006 to January 2016 were investigated in a single centre. Patients with hereditary disorders of connective tissue, systemic inflammatory disease, or arterial pathologies other than true aneurysms were excluded. Aneurysm locations were assessed for every patient included. For patients with at least two co-existing aneurysms, co-prevalence of aneurysm location was investigated by calculating correlation coefficients and applying Fisher's exact test. This study report is prepared according to the STROBE statement. Results: Of 3107 identified patients with arterial aneurysms, 918 were excluded. Of the remaining 2189 patients, 951 patients with at least two aneurysms were included in the study. Bilateral aneurysm combinations of paired iliac, femoral and popliteal arteries showed the highest correlation (ϕ=0.35 to 0.67), followed by bilateral combinations of subclavian (ϕ=0.36) and internal carotid (ϕ=0.38) arteries. Abdominal aortic aneurysms in combination with visceral artery aneurysms (ϕ=-0.24 to -0.12), popliteal arteries (ϕ=-0.22) and the ascending aorta (ϕ=-0.19) showed the lowest correlation, followed by the descending aorta in combination with the common iliac arteries (ϕ=-0.12 to -0.13). Conclusions: In our study sample, aneurysm co-prevalence was highly non-random. This should be considered in the context of aneurysm screening programs.

[Recommendations for the specialist further training of nursing personnel on intensive care units in the treatment of abdominal aortic aneurysms: results of a modified Delphi procedure with experts]

INTRODUCTION

The medical development in the previous 15 years and the changes in treatment reality of the comprehensive elective treatment of abdominal aortic aneurysms necessitate a re-evaluation of the quality assurance guidelines of the Federal Joint Committee in Germany (QBAA-RL). In the current version this requires a specialist further training quota for nursing personnel in intensive care wards of 50%. The quota was determined in 2008 based on expert opinions, although a direct empirical evidence base for this does not exist.

METHODS

Representatives from the fields of patient representation, physicians, nursing personnel and other relevant interface areas were invited to participate in a modified Delphi procedure. Following a comprehensive narrative literature search, a survey and focus group discussions with national and international experts, a total of three anonymized online-based voting rounds were carried out for which previously determined key statements were assessed with a 4‑point Likert scale (totally disagree up to totally agree). In addition, the expert panel had also defined a recommendation for a minimum quota for the specialist training of nursing personnel on intensive care wards in the treatment of abdominal aortic aneurysms, whereby an a priori agreement of 80% of the participants was defined as the consensus limit.

RESULTS

Overall, 37 experts participated in the discussions and three successive voting rounds (participation rate 89%). The panel confirmed the necessity of a re-evaluation of the guideline recommendations and recommended the introduction of a shift-related minimum quota of 30% of the full-time equivalent of nursing personnel on intensive care wards and the introduction of structured promotional programs for long-term elevation of the quota.

CONCLUSION

In this national Delphi procedure with medical and nursing experts as well as representatives of patients, the fundamental benefits and needs of professional specialist qualifications in the field of intensive care medicine were confirmed. The corresponding minimum quota for specialist further training of intensive care nursing personnel should generally apply without limitations to specific groups. The expert panel stipulates a shift-related minimum quota for intensive care nursing personnel with specialist training of 30% of the nursing personnel on intensive care wards and the obligatory introduction of structured and transparent promotion programs for the long-term enhancement.

Incorporating machine learning and PPI networks to identify mitochondrial fission-related immune markers in abdominal aortic aneurysms

Purpose

The aim of this study is to investigate abdominal aortic aneurysm (AAA), a disease characterised by inflammation and progressive vasodilatation, for novel gene-targeted therapeutic loci.

Methods

To do this, we used weighted co-expression network analysis (WGCNA) and differential gene analysis on samples from the GEO database. Additionally, we carried out enrichment analysis and determined that the blue module was of interest. Additionally, we performed an investigation of immune infiltration and discovered genes linked to immune evasion and mitochondrial fission. In order to screen for feature genes, we used two PPI network gene selection methods and five machine learning methods. This allowed us to identify the most featrue genes (MFGs). The expression of the MFGs in various cell subgroups was then evaluated by analysis of single cell samples from AAA. Additionally, we looked at the expression levels of the MFGs as well as the levels of inflammatory immune-related markers in cellular and animal models of AAA. Finally, we predicted potential drugs that could be targeted for the treatment of AAA.

Results

Our research identified 1249 up-regulated differential genes and 3653 down-regulated differential genes. Through WGCNA, we also discovered 44 genes in the blue module. By taking the point where several strategies for gene selection overlap, the MFG (ITGAL and SELL) was produced. We discovered through single cell research that the MFG were specifically expressed in T regulatory cells, NK cells, B lineage, and lymphocytes. In both animal and cellular models of AAA, the MFGs' mRNA levels rose.

Conclusion

We searched for the AAA novel targeted gene (ITGAL and SELL), which most likely function through lymphocytes of the B lineage, NK cells, T regulatory cells, and B lineage. This analysis gave AAA a brand-new goal to treat or prevent the disease.

Major depressive disorder and aneurysm: A genetic study of association and causality

BACKGROUND

Association between depression and aneurysm has been implicated but the specific role of depression in aneurysm remains unclear. We aimed to comprehensively characterize the relation of major depressive disorder (MDD) with aneurysm by subtype.

METHODS

Harnessing summary statistics from genome-wide association studies (Ncase/Ncontrol = 7603/317,899 for aortic aneurysm; 7321/317,899 for thoracic aortic aneurysm; 3201/317,899 for abdominal aortic aneurysm; 1788/317,899 for cerebral aneurysm; and 246,363/561,190 for major depressive disorder), we estimated the genetic correlation between MDD and each of four aneurysm subtypes via LD Score Regression and tested the causality via various estimators under the bi-directional Mendelian randomization (MR) framework.

RESULTS

Positive genetic correlation of statistical significance, ranging between 0.15 (with thoracic aortic aneurysm, P = 0.005) and 0.25 (with abdominal aortic aneurysm, P = 0.001), was consistently observed for MDD with each aneurysm subtype. In the MR analysis of MDD as an exposure, genetic liability to MDD causally increased the risk of cerebral (odds ratio: 1.71; 95 % confidence interval: 1.26-2.34) but not aortic aneurysm. Replication analysis of an independent dataset (Ncase/Ncontrol = 6242/59,418) corroborated this signal. In contrast, causal effect was not evident for any neurysm subtype on susceptibility to MDD.

LIMITATIONS

Aneurysm could have been underdiagnosed if asymptomatic, leading to an underestimated causal impact on MDD. Non-linearity of the causal effect was not tested due to the lack of individual-level data.

CONCLUSIONS

Depression and aneurysm may share common pathomechanisms. Screening depressed population and improving the clinical management for depression may benefit the primary prevention of cerebral aneurysm.

Trends in Abdominal Aortic Aneurysm Repair Incidence, Comorbidity, Treatment, and Mortality: A Danish Nationwide Cohort Study, 1996-2018

Background

Significant changes in Western populations' abdominal aortic aneurysm (AAA) epidemiology have been reported following the introduction of screening, endovascular AAA repair, and reduced tobacco consumption. We report incidence and mortality of AAA repair in Denmark from 1996 to 2018, where AAA screening was not implemented.

Methods

Nationwide cohort study of prospective data from population-based Danish registries covering 1996 to 2018. We identified 15,395 patients undergoing first-time AAA repair using the Danish Vascular Registry. Comorbidity was assessed by Charlson's Comorbidity Index (CCI). Incidence rate (IR) ratios and mortality rate ratios (MRR) were estimated by multivariable Poisson and Cox regression, respectively.

Results

Overall AAA repair IR decreased by 24% from 1996 through 2018, mainly reflecting a 53% IR reduction in ruptured AAA repairs in men. Overall, the IR decreased 52-63% in age groups below 70 years and increased 81% among octogenarians. The proportion of intact AAAs repaired endovascularly increased from 2% in 1996-1999 to 42% in 2015-2018. For both ruptured and intact AAAs the CCI score increased by 0.9% annually independently of age and sex. The adjusted five-year MRR in 2016-2018 vs.1996-2000 was 0.46 (95% confidence interval (CI): 0.39-0.54) following ruptured and 0.51 (95% CI: 0.44-0.59) following intact AAA repair.

Conclusion

In Denmark, overall AAA repair incidence decreased between 1996 and 2018, primarily reflecting a reduction among males and a shift to an older population requiring intervention. These trends mirror changes in tobacco consumption in Denmark. Regardless of age and comorbidity, AAA repair mortality decreased markedly during the study period.

Regional and Global Aortic Pulse Wave Velocity in Patients with Abdominal Aortic Aneurysm

OBJECTIVE

Abdominal aortic aneurysm (AAA) is commonly defined as localised aortic dilatation with a diameter > 30 mm. The pathophysiology of AAA includes chronic inflammation and enzymatic degradation of elastin, possibly increasing aortic wall stiffness and pulse wave velocity (PWV). Whether aortic stiffness is more prominent in the abdominal aorta at the aneurysm site is not elucidated. The aim of this study was to evaluate global and regional aortic PWV in patients with AAA.

METHODS

Experimental study of local PWV in the thoracic descending and abdominal aorta in patients with AAA and matched controls. The study cohort comprised 25 patients with an AAA > 30 mm (range 36 - 70 mm, all male, age range 65 - 76 years) and 27 age and sex matched controls free of AAA. PWV was measured with applanation tonometry (carotid-femoral PWV, cfPWV) as well as a 4D flow MRI technique, assessing regional aortic PWV. Blood pressure and anthropometrics were measured.

RESULTS

Global aortic PWV was greater in men with an AAA than controls, both by MRI (AAA 8.9 ± 2.4 m/s vs. controls 7.1 ± 1.5 m/s; p = .007) and cfPWV (AAA 11.0 ± 2.1 m/s vs. controls 9.3 ± 2.3 m/s; p = .007). Regionally, PWV was greater in the abdominal aorta in the AAA group (AAA 7.0 ± 1.8 m/s vs. controls 5.8 ± 1.0 m/s; p = .022), but similar in the thoracic descending aorta (AAA 8.7 ± 3.2 m/s vs. controls 8.2 ± 2.4 m/s; p = .59). Furthermore, PWV was positively associated with indices of central adiposity both in men with AAA and controls.

CONCLUSION

PWV is higher in men with AAA compared with matched controls in the abdominal but not the thoracic descending aorta. Furthermore, aortic stiffness was linked with central fat deposition. It remains to be seen whether there is a causal link between AAA and increased regional aortic stiffness.

Evaluation of associations between outflow morphology and rupture risk of abdominal aortic aneurysms

PURPOSE

This study aimed to evaluate the association between the outflow morphology and abdominal aortic aneurysm (AAA) rupture risk, to find risk factors for future prediction models.

MATERIALS AND METHODS

We retrospectively analyzed 46 patients with ruptured AAAs and 46 patients with stable AAAs using a 1:1 match for sex, age, and maximum aneurysm diameter. The chi-square test, paired t-test, and Wilcoxon signed-rank test were used to compare variables. Logistic regression was performed to evaluate variables potentially associated with AAA rupture. Receiver operating characteristic curve analysis and the area under the curve (AUC) were used to assess the regression models.

RESULTS

Ruptured AAAs had a shorter proximal aortic neck (median (interquartile range, IQR): 24.0 (9.4-34.2) mm vs. 33.3 (20.0-52.8) mm, p = 0.004), higher tortuosity (median(IQR): 1.35 (1.23-1.49) vs. 1.29 (1.23-1.39), p = 0.036), and smaller minimum luminal area of the right common iliac artery (CIA) (median (IQR): 86.7 (69.9-126.4) mm2 vs. 118.9 (86.3-164.1)mm2, p = 0.001) and left CIA (median(IQR): 92.2 (67.3,125.1) mm2 vs. 110.7 (80.12, 161.1) mm2, p = 0.010) than stable AAA did. Multiple regression analysis demonstrated significant associations of the minimum luminal area of the bilateral CIAs (odds ratio [OR] = 0.996, 95 % confidence interval [CI] 0.991-0.999, p = 0.037), neck length (OR = 0.969, 95 % CI 0.941-0.993, p = 0.017), and aneurysm tortuosity (OR = 1.031, 95 % CI 1.003-1.063, p = 0.038) with ruptured AAAs. The AUC of this regression model was 0.762 (95 % CI 0.664-0.860, p < 0.001).

CONCLUSIONS

The smaller minimum luminal area of the CIA is associated with an increased risk of rupture. This study highlights the potential of utilizing outflow parameters as novel and additional tools in risk assessment. It also provides a compelling rationale to further intensify research in this area.

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.

Influence of cardiometabolic medications on abdominal aortic aneurysm growth in the UK Aneurysm Growth Study: metformin and angiotensin-converting enzyme inhibitors associated with slower aneurysm growth

BACKGROUND

There is a clinical need for treatments that can slow or prevent the growth of an abdominal aortic aneurysm, not only to reduce the need for surgery, but to provide a means to treat those who cannot undergo surgery.

METHODS

Analysis of the UK Aneurysm Growth Study (UKAGS) prospective cohort was conducted to test for an association between cardiometabolic medications and the growth of an abdominal aortic aneurysm above 30 mm in diameter, using linear mixed-effect models.

RESULTS

A total of 3670 male participants with data available on abdominal aortic aneurysm growth, smoking status, co-morbidities, and medication history were included. The mean age at recruitment was 69.5 years, the median number of surveillance scans was 6, and the mean(s.e.) unadjusted abdominal aortic aneurysm growth rate was 1.75(0.03) mm/year. In a multivariate linear mixed-effect model, smoking (mean(s.e.) +0.305(0.07) mm/year, P = 0.00003) and antiplatelet use (mean(s.e.) +0.235(0.06) mm/year, P = 0.00018) were found to be associated with more rapid abdominal aortic aneurysm growth, whilst metformin was strongly associated with slower abdominal aortic aneurysm growth (mean(s.e.) -0.38(0.1) mm/year, P = 0.00019), as were angiotensin-converting enzyme inhibitors (mean(s.e.) -0.243(0.07) mm/year, P = 0.0004), angiotensin II receptor antagonists (mean(s.e.) -0.253(0.08) mm/year, P = 0.00255), and thiazides/related diuretics (mean(s.e.) -0.307(0.09) mm/year, P = 0.00078).

CONCLUSION

The strong association of metformin with slower abdominal aortic aneurysm growth highlights the importance of the ongoing clinical trials assessing the effectiveness of metformin with regard to the prevention of abdominal aortic aneurysm growth and/or rupture. The association of angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, and diuretics with slower abdominal aortic aneurysm growth points to the possibility that optimization of cardiovascular risk management as part of abdominal aortic aneurysm surveillance may have the secondary benefit of also reducing abdominal aortic aneurysm growth rates.

Editor's Choice - Systematic Review and Meta-Analysis of Contemporary Abdominal Aortic Aneurysm Growth Rates

OBJECTIVE

To evaluate the contemporary growth rate of small abdominal aortic aneurysms (AAAs) in view of recent epidemiological changes, such as decreasing smoking rates and establishment of population screening programmes.

DATA SOURCES

MEDLINE, CENTRAL, PsycINFO, Web of Science Core Collection, and OpenGrey databases.

REVIEW METHODS

Systematic review following the PRISMA guidelines. In October 2021, databases were queried for studies reporting on AAA growth rates published from 2015 onwards. The primary outcome was contemporary AAA growth rates in mm/year. Data were pooled in a random effects model meta-analysis, and heterogeneity was assessed through the I2 statistic. GRADE assessment of the findings was performed. The protocol was published in PROSPERO (CRD42022297404).

RESULTS

Of 8 717 titles identified, 43 studies and 28 277 patients were included: 1 241 patients from randomised controlled trials (RCTs), 23 941 from clinical observational studies, and 3 095 from radiological or translational research studies. The mean AAA growth rate was 2.38 mm/year (95% CI 2.16 - 2.60 mm/year; GRADE = low), with meta-regression analysis adjusted for baseline diameter showing an increase of 0.08 mm/year (95% CI 0.024 - 0.137 mm/year; p = .005) for each millimetre of increased baseline diameter. When analysed by study type, the growth rate estimated from RCTs was 1.88 mm/year (95% CI 1.69 - 2.06 mm/year; GRADE = high), while it was 2.31 mm/year (95% CI 1.95 - 2.67 mm/year; GRADE = moderate) from clinical observational studies, and 2.85 mm/year (95% CI 2.44 - 3.26 mm/year; GRADE = low) from translational and radiology based studies (p < .001). Heterogeneity was high, and small study publication bias was present (p = .003), with 27 studies presenting a moderate to high risk of bias. The estimated growth rate from low risk studies was 2.09 mm/year (95% CI 1.87 - 2.32; GRADE = high).

CONCLUSION

This study estimated a contemporaneous AAA growth rate of 2.38 mm/year, being unable to demonstrate any clinically meaningful AAA growth rate reduction concomitant with changed AAA epidemiology. This suggests that the RESCAN recommendations on small AAA surveillance are still valid. However, sub-analysis results from RCTs and high quality study data indicate potential lower AAA growth rates of 1.88 - 2.09 mm/year, findings that should be validated in a high quality prospective registry.

Association of alcohol consumption with aortic aneurysm and dissection risk: results from the UK Biobank cohort study

BACKGROUND

Previous studies have reported inconsistent results with positive, negative, and J-shaped associations between alcohol consumption and the hazard of aortic aneurysm and dissection (AAD). This study aimed to examine the connections between weekly alcohol consumption and the subsequent risk of AAD.

METHODS

The UK Biobank study is a population-based cohort study. Weekly alcohol consumption was assessed using self-reported questionnaires and the congenital risk of alcohol consumption was also evaluated using genetic risk score (GRS). Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the associations between alcohol consumption and AAD. Several sensitivity analyses were performed to assess the robustness of the results.

RESULTS

Among the 388,955 participants (mean age: 57.1 years, 47.4% male), 2,895 incident AAD cases were documented during a median follow-up of 12.5 years. Compared with never-drinkers, moderate drinkers (adjusted HR: 0.797, 95%CI: 0.646-0.984, P<0.05) and moderate-heavy drinkers (adjusted HR: 0.794, 95%CI: 0.635-0.992, P<0.05) were significantly associated with a decreased risk of incident AAD. Interaction-based subgroup analysis revealed that the protective effect of moderate drinking was reflected mainly in participants younger than 65 years and women.

CONCLUSION

Our findings support a protective effect of moderate alcohol consumption on AAD, but are limited to participants younger than 65 years and women.

A population-based survey of FBN1 variants in Iceland reveals underdiagnosis of Marfan syndrome

Marfan syndrome (MFS) is an autosomal dominant condition characterized by aortic aneurysm, skeletal abnormalities, and lens dislocation, and is caused by variants in the FBN1 gene. To explore causes of MFS and the prevalence of the disease in Iceland we collected information from all living individuals with a clinical diagnosis of MFS in Iceland (n = 32) and performed whole-genome sequencing of those who did not have a confirmed genetic diagnosis (27/32). Moreover, to assess a potential underdiagnosis of MFS in Iceland we attempted a genotype-based approach to identify individuals with MFS. We interrogated deCODE genetics' database of 35,712 whole-genome sequenced individuals to search for rare sequence variants in FBN1. Overall, we identified 15 pathogenic or likely pathogenic variants in FBN1 in 44 individuals, only 22 of whom were previously diagnosed with MFS. The most common of these variants, NM_000138.4:c.8038 C > T p.(Arg2680Cys), is present in a multi-generational pedigree, and was found to stem from a single forefather born around 1840. The p.(Arg2680Cys) variant associates with a form of MFS that seems to have an enrichment of abdominal aortic aneurysm, suggesting that this may be a particularly common feature of p.(Arg2680Cys)-associated MFS. Based on these combined genetic and clinical data, we show that MFS prevalence in Iceland could be as high as 1/6,600 in Iceland, compared to 1/10,000 based on clinical diagnosis alone, which indicates underdiagnosis of this actionable genetic disorder.

Early Relative Growth Rate of Abdominal Aortic Aneurysms and Future Risk of Rupture or Repair

OBJECTIVE

This study aimed to test whether the relative growth rate of subthreshold abdominal aortic aneurysms (AAAs) in the first 24 months of surveillance predicts the risk of future rupture or repair.

METHODS

This was a single centre retrospective observational analysis of all small (< 45 mm diameter) and medium (45 - 54 mm in men, 45 - 50 mm in women) AAAs entered into ultrasound surveillance between January 2002 and December 2019, which received ≥ 24 months of surveillance. Relative growth rates were calculated from measurements taken in the first 24 months of surveillance. The Kaplan-Meier method was used to estimate intervention and rupture free proportions five years following diagnosis for AAAs growing by < 5% and by ≥ 5% in the first 24 months of surveillance. Multivariable Cox regression analysis was used to further analyse this relationship by adjusting for factors found to be significantly associated with outcome in univariable analysis.

RESULTS

A total of 556 patients with AAAs (409 men, 147 women) were followed for ≥ 24 months. This included 431 small AAAs. Of these, 109 (25.3%) grew by < 5% in the first 24 months of surveillance and had a cumulative event free proportion of 0.98 ± 0.05 at five years compared with 0.78 ± 0.05 for the ≥ 5% growth group (p < .001). Of 125 medium AAAs, 26 (20.8%) grew by < 5% in the first 24 months of surveillance and had a cumulative event free proportion of 0.73 ± 0.11 at five years compared with 0.29 ± 0.13 for the ≥ 5% growth group (p = .024). Baseline diameter and early relative growth rate were strongly and independently predictive of future intervention or rupture with hazard ratios of 9.16 (95% CI 5.98 - 14.03, p < .001) and 4.46 (95% CI 2.45 - 8.14, p < .001), respectively.

CONCLUSION

The results suggest that slow expansion of small (< 45 mm) AAAs observed over an isolated 24 month period is indicative of a very low risk of rupture or repair in the medium term. Isolated growth rates may be a useful tool with which to triage low risk AAAs and prevent unnecessary surveillance.

Brazilian Society for Angiology and Vascular Surgery guidelines on abdominal aortic aneurysm

The Brazilian Society of Angiology and Vascular Surgery, through the Guidelines Project, presents new Abdominal Aortic Aneurysm Guidelines, on the subject of care for abdominal aortic aneurysm patients. Its development prioritized descriptive guidelines, using the EMBASE, LILACS, and PubMed databases. References include randomized controlled trials, systematic reviews, meta-analyses, and cohort studies. Quality of evidence was evaluated by a pair of coordinators, aided by the RoB 2 Cochrane tool and the Newcastle Ottawa Scale forms. The subjects include juxtarenal aneurysms, infected aneurysms, and new therapeutic techniques, especially endovascular procedures. The current version of the guidelines include important recommendations for the primary topics involving diagnosis, treatment, and follow-up for abdominal aortic aneurysm patients, providing an objective guide for medical practice, based on scientific evidence and widely available throughout Brazil.

Disturbed hemodynamics and oxidative stress interaction in endothelial dysfunction and AAA progression: Focus on Nrf2 pathway

Hemodynamic shear stress is one of the major factors that are involved in the pathogenesis of many cardiovascular diseases including atherosclerosis and abdominal aortic aneurysm (AAA), through its modulatory effect on the endothelial cell's redox homeostasis and mechanosensitive gene expression. Among important mechanisms, oxidative stress, endoplasmic reticulum stress activation, and the subsequent endothelial dysfunction are attributed to disturbed blood flow and low shear stress in the vascular curvature and bifurcations which are considered atheroprone regions and aneurysm occurrence spots. Many pathways were shown to be involved in AAA progression. Of particular interest from recent findings is, the (Nrf2)/Keap-1 pathway, where Nrf2 is a transcription factor that has antioxidant properties and is strongly associated with several CVDs, yet, the exact mechanism by which Nrf2 alleviates CVDs still to be elucidated. Nrf2 expression is closely affected by shear stress and was shown to participate in AAA. In the current review paper, we discussed the link between disturbed hemodynamics and its effect on Nrf2 as a mechanosensitive gene and its role in the development of endothelial dysfunction which is linked to the progression of AAA.

Long-term Mortality and Reintervention After Endovascular and Open Abdominal Aortic Aneurysm Repairs in Australia, Germany, and the United States

OBJECTIVE

To examine long-term outcomes after endovascular (EVAR) and open repairs (OAR) for intact abdominal aortic aneurysms in Australia, Germany, and the United States, using a unified study design.

BACKGROUND

Similarities and differences in long-term outcomes after EVAR versus OAR across countries remained unclear, given differences in designs across existing studies.

METHODS

We identified patients aged >65 years undergoing intact abdominal aortic aneurysm repairs during 2010-2017/2018. We compared long-term patient mortality and reintervention after EVAR and OAR using Kaplan-Meier analyses and Cox regressions. Propensity score matching was performed within each country to adjust for differences in baseline patient characteristics between procedure groups.

RESULTS

We included 3311, 4909, and 145363 patients from Australia, Germany, and the United States, respectively. The median patient age was 76 to 77 years, and most patients were males (77%-84%). Patient mortality was lower after EVAR than OAR within the first 60 days and became similar at 3-year follow-up (Australia 14.7% vs 16.5%, Germany 18.2% vs 19.7%, United States: 24.4% vs 24.4%). At the end of follow-up, patient mortality after EVAR was higher than OAR in Australia [ hazard ratio (HR) 95% CI: 1.21 (0.96-1.54)] but similar to OAR in Germany [HR 95% CI: 0.92 (0.80-1.07)] and the United States [HR 95% CI: 1.02 (0.99-1.05)]. The risk of reintervention after EVAR was more than twice that after OAR in Australia [HR 95% CI: 2.60 (1.09-6.15)], Germany [HR 95% CI: 4.79 (2.56-8.98)], and the United States [HR 95% CI: 2.67 (2.38-3.00)]. The difference in reintervention risk appeared early in German and United States patients.

CONCLUSIONS

This multinational study demonstrated important similarities in long-term outcomes after EVAR versus OAR across 3 countries. Variation in long-term mortality and reintervention comparisons indicates possible differences in patient profiles, surveillance, and best medical therapy across countries.

Trends in Incidence of Abdominal Aortic Aneurysm Rupture, Repair, and Mortality in Nova Scotia

BACKGROUND

The purpose of this study was to examine sex-based trends in incidence of elective abdominal aortic aneurysm (AAA), ruptured AAA, ruptured AAA repair, and AAA-related mortality.

METHODS

A retrospective analysis of patients presenting with AAA from 2005 to 2015 was conducted. Rates of elective AAA repair, ruptured AAA, ruptured AAA repair, and mortality were obtained from linking provincial administrative data using medical services insurance billing number. The age-adjusted incidence of elective AAA repair, overall rate of ruptured AAA, ruptured AAA repair, and AAA-related mortality was calculated for each sex based on Canadian census estimates, adjusted to the Canadian standard population. Weighted linear regression was performed to analyze trends in incidence over time.

RESULTS

One thousand nine hundred eighty-six elective AAA repairs were identified, of which 1,098 were repaired open and 898 underwent endovascular abdominal aneurysm repair (EVAR). Five hundred and seventy ruptured AAAs were identified, of which 295 (52%) were repaired: 259 open and 36 EVAR. The proportion of ruptured AAA that was repaired did not change over time (P = 0.54). The proportion repairs performed using EVAR increased significantly in both elective (P < 0.001) and rupture repairs (P < 0.001). During the study period, 662 patients died of AAA-associated mortality. The average incidence of elective AAA repair in men was 29.3 (95% confidence interval (CI): 27.8 to 30.8) per 100,000 and decreased over time (P = 0.04), whereas the average incidence in women was 9.2 [8.3 to 10.0] and stable (P = 0.07). The incidence of open elective AAA repair was 10.5 [9.9-11.1] with a decreasing trend over time (P < 0.001) and EVAR was 9.0 (8.5-9.6) with an increasing trend over time (P < 0.001). A decreasing trend of overall ruptured AAA (5.4 [5.0-5.9], P < 0.001), ruptured AAA repair (2.9 [2.5-3.2], P = 0.02), and of AAA-related mortality (6.2 [5.8-6.8], P < 0.001) was found, with consistent trends in both sexes. The incidence of open ruptured AAA repair decreased over time (P = 0.001) whereas the incidence of ruptured EVAR remained stable (P = 0.23).

CONCLUSIONS

The incidence of elective AAA repair is decreasing in males but not females, whereas the incidence of rupture has decreased in both sexes. This has translated into reduced incidence of AAA-related mortality. Increased adoption of EVAR for ruptured AAA should continue these trends.

The Fate of Patients Opportunistically Screened for Abdominal Aortic Aneurysms During Echocardiogram or Arterial Duplex Scans

OBJECTIVE

To evaluate the long term outcomes of individuals who attended for transthoracic echocardiograms (TTEs) or lower limb arterial duplex scans (LLADS) and were opportunistically screened for abdominal aortic aneurysms (AAA).

METHODS

Follow up of a prospective single centre pilot cohort study conducted between December 2012 and September 2014 at a tertiary vascular centre in the United Kingdom. Men and Women aged 65 and over were invited to undergo AAA screening when attending hospital for TTE or LLADS. Screening was performed by ultrasonographic examination of the abdomen at the end of their planned scans. AAA was defined as an abdominal aorta outer wall to outer wall anteroposterior diameter of 30 mm or more. Patients were excluded if they had a known AAA or previous abdominal aorta intervention. Follow up outcomes were evaluated in December 2020.

RESULTS

762 patients were enrolled in this study; 486 had TTE and 276 patients had LLADS. The overall incidence of AAA was 54 (7.1%) in the combined cohort, 25 (5.1%) in the TTE group, and 29 (10.5%) in the LLADS group. After a median 7.6 years, two of the 54 AAAs received intervention in the form of endovascular repair. Three others reached treatment threshold but were managed conservatively. The overall intervention rate was 3.7% of detected AAAs. Adjusted mortality rates in those with AAA vs. without was 64.8% and 36%, respectively (hazard ratio [HR] 2.02, p < .001). Diabetes (HR 1.35, p = .015) and older age (HR 1.18, p = .17) were the other factors associated with death.

CONCLUSION

AAA is associated with a significantly increased mortality rate. Populations attending hospital for TTE or LLADS demonstrate a higher prevalence of AAA than population based screening; however, the proportion offered AAA intervention was low. Further research into opportunistic screening should target those more likely to undergo AAA repair, unless other interventions are demonstrated, to reduce the general increased mortality in AAA patients.

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.

Umbrella review and meta-analysis of reconstructed individual patient data of mortality following conventional endovascular and open surgical repair of infrarenal abdominal aortic aneurysm

OBJECTIVES

This umbrella review aims to quality assess published meta-analyses, conduct a de-novo meta-analysis of the available randomized control trials (RCTs), and test the hypothesis that there is a long-term difference in mortality between OSR and EVAR.

METHODS

A systematic search was conducted in MEDLINE and EMBASE's bibliographic databases (June 2022). Data were extracted using standardized extraction forms. The methodological quality of publications was assessed using the ROBIS tool. Data were analyzed with 'one-stage' and 'two-stage' approaches.

RESULTS

According to two-stage analysis, EVAR has significantly favorable mortality for up to four years (increasing evidence). Subsequently, until the longest available time period, there is no difference between EVAR and OSR; all the results are statistically non-significant.In one stage analysis, the Cox model demonstrated a non-significant (weak evidence) hazard ratio of 1.03 (95% confidence interval [CI]: 0.94-1.12) in favor of OSR. The best-fitting parametric model (generalized gamma), leads to an hazard ratio of 0.97 (95% CI: 0.93-1.01) in favor of EVAR, with the results approaching significance (weak evidence).

CONCLUSION

The results of this umbrella systematic review and meta-analysis failed to demonstrate any difference in long-term mortality following planned EVAR, compared with OSR of infrarenal AAA.

The association between diabetes and abdominal aortic aneurysms in men: results of two Danish screening studies, a systematic review, and a meta-analysis of population-based screening studies

BACKGROUND

A paradoxical protective effect of diabetes on the development and progression of abdominal aortic aneurysms (AAA) has been known for years. This study aimed to investigate whether the protective role of diabetes on AAAs has evolved over the years.

METHODS

A cross-sectional study, a systematic review and meta-analysis. This study was based on two large, population-based, randomised screening trials of men aged 65-74; VIVA (2008-2011) and DANCAVAS (2014-2018), including measurement of the abdominal aorta by ultrasound or CT, respectively. Analyses were performed using multiple logistic regressions to estimate the odds ratios (ORs) for AAAs in men with diabetes compared to those not having diabetes. Moreover, a systematic review and meta-analysis of population-based screening studies of AAAs to visualise a potential change of the association between diabetes and AAAs. Studies reporting only on women or Asian populations were excluded.

RESULTS

In VIVA, the prevalence of AAA was 3.3%, crude OR for AAA in men with diabetes 1.04 (95% confidence interval, CI, 0.80-1.34), and adjusted OR 0.64 (CI 0.48-0.84). In DANCAVAS, the prevalence of AAA was 4.2%, crude OR 1.44 (CI 1.11-1.87), and adjusted OR 0.78 (CI 0.59-1.04). Twenty-three studies were identified for the meta-analysis (N = 224 766). The overall crude OR was 0.90 (CI 0.77-1.05) before 2000 and 1.16 (CI 1.03-1.30) after 1999. The overall adjusted OR was 0.63 (CI 0.59-0.69) before 2000 and 0.69 (CI 0.57-0.84) after 1999.

CONCLUSION

Both the crude and adjusted OR showed a statistically non-significant trend towards an increased risk of AAA by the presence of diabetes. If this represents an actual trend, it could be due to a change in the diabetes population.

TRIAL REGISTRATION

DANCAVAS: Current Controlled Trials: ISRCTN12157806. VIVA: ClinicalTrials.gov NCT00662480.

Long-term Survival After Repair of Ruptured Abdominal Aortic Aneurysms Is Improving Over Time: Nationwide Analysis During Twenty-four Years in Sweden (1994-2017)

OBJECTIVE

To investigate long-term survival after ruptured abdominal aortic aneurysms (rAAA) repair in Sweden during twenty-four years (1994-2017).

SUMMARY BACKGROUND DATA

Management of rAAA has seen significant changes in the past decades, with the shifting from open (OAR) to endovascular (EVAR) being the most striking, thereby enabling treatment of elderly patients with multiple comorbidities.

METHODS

A registry-based nationwide cohort study was performed, and three 8-year periods (1994-2001, 2002-2009, 2010-2017) were compared for crude long-term survival with Kaplan-Meier and multivariable Cox proportional hazards analyses. Relative survival compared to matched general population referents was estimated.

RESULTS

Overall, 8928 rAAA repair subjects were identified (1994-2001 N = 3368; 2002-2009 N = 3405; 2010-2017 N = 2155). The proportion of octogenarians (20.6%; 27.5%; 34.0%; P < 0.001), women (14.3%; 18.5%; 20.6%; P < 0.001), and EVAR procedures (1.5%; 14.9%; 35.5%; P < 0.001) increased over time. The crude 5-year survival was 36%; 44%; 43% (P < 0.0001). Multivariable Cox proportional hazard analysis displayed a decreasing mortality hazard ratio (HR) over time (1.00; 0.80; 0.72; P < 0.001). Use of EVAR was associated with reduced hazards of crude long-term mortality (HR = 0.80, P < 0.001). Relative survival for patients surviving the perioperative period (ie, 90 days) was lower than matched general population referents, and was stable over time (relative 5-year survival: 86% vs 88%, vs 86% P < 0.001).

CONCLUSIONS

Nationwide analysis of long-term outcomes after repair of rAAA in Sweden during 24 years (1994-2017) has revealed that, despite changes in the baseline population characteristics as well as in the treatment strategy, long-term survival improved over time.