International Variations in AAA Screening

Managing anxiety in men undergoing surveillance in the NHS abdominal aortic aneurysm screening programme: A survey of screening staff in England

BACKGROUND

AAA is an enlargement in the aorta that can increase in size and rupture. In England, the National Health Service (NHS) AAA Screening Programme offers screening to all men aged 65 to identify those with an AAA. Men with small or medium sized aneurysm enter surveillance where they receive ultrasound scans annually or every three months respectively. Due to concerns about mortality from AAA rupture, anxiety levels may be high for men and their families and impact on their quality of life.

AIM

To obtain the views of staff providing Abdominal Aortic Aneurysm (AAA) screening on how best to help men in surveillance to manage AAA-related anxiety.

METHODS

A cross-sectional online survey of the 38 AAA regional screening services in England was conducted. Four staff with different roles from each service (doctor, nurse, manager and scanning technician) were asked to complete an online questionnaire.

RESULTS

The response rate was 71 % (27/38) for regional AAA screening services and 65 % (99/152) for the staff approached. 93 % (79/84) of respondents strongly or somewhat agreed that men in surveillance may need help to manage anxiety. The size of the aneurysm was rated as the factor most likely to cause anxiety. 63 % (51/81) considered AAA Programme Nurses to be the best people to deliver an intervention. Staff suggested that improved information about AAA and associated risks, group support/networking sessions, and more contact with the screening service were ways of helping with management of anxiety.

CONCLUSION

Staff providing AAA screening recognised that being in surveillance can cause anxiety for men and their families, and identified that potential interventions, such as organised support groups and improved provision of information, might help manage anxiety. Programme Nurses were considered the ideal healthcare professional to help men in surveillance manage AAA-related anxiety.

Lower Rates of Abdominal Aortic Aneurysm Repair and Higher Long-term Aortic Mortality in Women Compared With Men: Results of a Population-Based Study Spanning 4 Decades

OBJECTIVE

To determine the population-level impact of screening and endovascular repair as well as mortality in women with abdominal aortic aneurysms (AAAs).

PATIENTS AND METHODS

We conducted a population-based cohort study of patients from Olmsted County, Minnesota, in whom AAA was diagnosed between January 1, 1980, and December 31, 2017. The AAAs were identified using the International Classification of Diseases, Ninth and Tenth Revisions and Current Procedural Terminology codes with medical record review to confirm the diagnosis and identify late events. Survival analysis for overall and aortic mortality was performed and stratified based on sex and repair status.

RESULTS

There were 1537 patients in our study cohort (75% [1156] male; median age, 74 years). Compared with men, women were older (80 vs 73 years; P<.001), had smaller initial aneurysm size (4 vs 4.3 cm; P<.001), underwent AAA repair less frequently (26% [99] vs 41% [475]; P<.001), and had similar 30-day mortality from AAA repair (4% [4 of 381] vs 5% [22 of 1156]; P=.50). Median follow-up was 18 years. Aortic and all-cause mortality at 10 and 20 years were highest in females who did not undergo repair (hazard ratio, 3; 95% CI, 1.8 to 4.5; P<.001), as compared with all men and women who underwent AAA repair. Cumulative aortic mortality analyzed with non-aortic-related deaths as a competing risk factor remained significantly higher in NRF (15% [40 of 282] vs 5% to 8% in other groups; 5/99 in females undergoing repair, 39/681 in non repaired males and 37/475 in males who underwent repair, P=.001). All patients with aortic-related mortality had refused repair due to older age and comorbidities, except 2 females with ruptures of 4.8 and 5.5 cm AAAs awaiting repair.

CONCLUSION

Abdominal aortic aneurysms are diagnosed in women almost a decade later and repaired less often than in men. There is a 3-fold greater long-term aortic-related mortality in women not undergoing AAA repair compared with men and women who underwent AAA repair.

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 aneurysms in a general population cohort: prevalence and risk factors in men and women

AIMS

The prevalence and difference in risk factors for having thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA) in men compared with women in the general population is not well described. This study aimed to test the hypotheses that (i) cardiovascular risk factors for TAA and AAA differ and (ii) the prevalence of TAA and AAA is sex specific.

METHODS AND RESULTS

Aortic examination using computed tomography angiography was performed in 11 294 individuals (56% women), with a mean age of 62 (range 40-95) years participating in the Copenhagen General Population Study. TAAs were defined as an ascending aortic diameter ≥45 mm and a descending aortic diameter ≥35 mm, while AAAs were defined as an abdominal aortic diameter ≥30 mm. Demographic data were obtained from questionnaires. Overall prevalence of aortic aneurysms (AAs) in the study population included: total population 2.1%, men 4.0% and women 0.7% (P-value men vs. women P < 0.001). AAs were independently associated with male sex, increasing age, and body surface area (BSA). While TAAs were associated with hypertension, odds ratio (OR) = 2.0 [95% confidence interval (CI): 1.5-2.8], AAAs were associated with hypercholesterolaemia and smoking, OR = 2.4 (95% CI: 1.6-3.6) and 3.2 (95% CI: 1.9-5.4).

CONCLUSION

Subclinical AAs are four times more prevalent in men than in women. In both sexes, increasing age and BSA are risk factors for AAs of any anatomical location. Whereas arterial hypertension is a risk factor for TAAs, hypercholesterolaemia and smoking are risk factors for AAAs.

Association between metabolic dysfunction-associated fatty liver disease and abdominal aortic aneurysm

BACKGROUND AND AIMS

Abdominal aortic aneurysm (AAA) is the second most common aortic pathological manifestation. Metabolic dysfunction-associated fatty liver disease (MAFLD) has a wide impact on the cardiovascular system and may be a risk factor for AAA. The aim of this study was to investigate whether MAFLD is associated with the risk of AAA.

METHODS AND RESULTS

We used data from the prospective UK Biobank cohort study. MAFLD is defined as hepatic steatosis plus metabolic abnormality, type 2 diabetes, or overweight/obesity. AAA is collected by ICD-10 code. Cox regression was established to analyze the association between MAFLD and AAA. A total of 370203 participants were included; the average age of the participants was 56.7 ± 8.0 years, and 134649 (36.4 %) were diagnosed with MAFLD. During the 12.5 years of follow-up, 1561 (0.4 %) participants developed AAA. After fully adjusting for confounding factors, individuals with MAFLD had a significantly increased risk of AAA (HR 1.521, 95 % CI 1.351-1.712, p < 0.001). Importantly, the risk of AAA increases with the severity of MAFLD as assessed by fibrosis scores. These associations were consistent according to sex, weight, and alcohol consumption but weaker in elderly or diabetics (P for interaction <0.05). The association between the MAFLD phenotype and AAA was independent of the polygenic risk score. Additionally, MAFLD was not associated with thoracic aortic aneurysm or aortic dissection events.

CONCLUSIONS

There was a significant relationship between MAFLD and AAA. These findings strongly recommend early prevention of AAA by intervening in MAFLD.

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.

Abdominal aortic aneurysm: A case report

Abdominal aortic aneurysm (AAA) is a medical condition characterized by abnormal enlargement or the ballooning of the aorta, the largest blood vessel in the human body, in the abdomen. AAA usually develops slowly and asymptomatically and becomes a potentially life-threatening condition if left untreated. Although the exact cause of AAA is not always clear, risk factors such as age, sex, smoking, hypertension, and family history may increase the likelihood of developing AAA. It is essential to manage and prevent AAA rupture, which can lead to severe internal bleeding and pose a serious risk to a person's health if not diagnosed in a timely manner and appropriate medical attention. Awareness, early diagnosis and appropriate medical care are critical factors when addressing this condition, providing a glimpse into the complex and critical nature of AAA. The present study describes the case of a patient who applied to the family medicine unit with hypertension and dysuria, and was diagnosed with AAA incidentally.

Dysregulations of Key Regulators of Angiogenesis and Inflammation in Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a chronic vascular disease caused by localized weakening and broadening of the abdominal aorta. AAA is a clearly underdiagnosed disease and is burdened with a high mortality rate (65-85%) from AAA rupture. Studies indicate that abnormal regulation of angiogenesis and inflammation contributes to progression and onset of this disease; however, dysregulations in the molecular pathways associated with this disease are not yet fully explained. Therefore, in our study, we aimed to identify dysregulations in the key regulators of angiogenesis and inflammation in patients with AAA in peripheral blood mononuclear cells (using qPCR) and plasma samples (using ELISA). Expression levels of ANGPT1, CXCL8, PDGFA, TGFB1, VEGFB, and VEGFC and plasma levels of TGF-alpha, TGF-beta 1, VEGF-A, and VEGF-C were found to be significantly altered in the AAA group compared to the control subjects without AAA. Associations between analyzed factors and risk factors or biochemical parameters were also explored. Any of the analyzed factors was associated with the size of the aneurysm. The presented study identified dysregulations in key angiogenesis- and inflammation-related factors potentially involved in AAA formation, giving new insight into the molecular pathways involved in the development of this disease and providing candidates for biomarkers that could serve as diagnostic or therapeutic targets.

Novel Risk Score Calculator for Perioperative Mortality after EVAR with Incorporation of Anatomical Factors

BACKGROUND

Hostile proximal aortic neck anatomy has been associated with an increased risk of perioperative mortality after endovascular aneurysm repair (EVAR). However, all available mortality risk prediction models after EVAR lack neck anatomic associations. The aim of this study is to develop a preoperative prediction model for perioperative mortality after EVAR incorporating important anatomic factors.

METHODS

Data were obtained from the Vascular Quality Initiative database on all patients who underwent elective EVAR between January 2015 and December 2018. A stepwise multivariable logistic regression analysis was implemented to identify independent predictors and develop a risk calculator for perioperative mortality after EVAR. Internal validation was done using bootstrap of 1,000 reps.

RESULTS

A total of 25,133 patients were included, of whom 1.1% (N = 271) died within 30 days or before discharge. Significant preoperative predictors of perioperative mortality were age (odds ratio [OR], 1.053; 95% confidence interval [CI], 1.050-1.056; P < 0.001), female sex (OR, 1.46; 95% CI, 1.38-1.54; P < 0.001), chronic kidney disease (OR, 1.65; 95% CI, 1.57-1.73; P < 0.001), chronic obstructive pulmonary disease (OR, 1.86; 95% CI, 1.77-1.94; P < 0.001), congestive heart failure (OR, 2.02; 95% CI, 1.91-2.13, P < 0.001), aneurysm diameter ≥ 6.5 cm (OR, 2.35; 95% CI, 2.24-2.47, P < 0.001), proximal neck length < 10 mm (OR, 1.96; 95% CI, 1.81-2.12; P < 0.001), proximal neck diameter ≥ 30 mm (OR, 1.41; 95% CI, 1.32-1.5; P < 0.001), infrarenal neck angulation ≥ 60° (OR, 1.27; 95% CI, 1.18-1.26; P < 0.001), and suprarenal neck angulation ≥ 60° (OR, 1.26; 95% CI, 1.16-1.37; P < 0.001). Significant protective factors included aspirin use (OR, 0.89; 95% CI, 0.85-0.93; P < 0.001) and statin intake (OR, 0.77; 95% CI, 0.73-0.81; P < 0.001). These predictors were incorporated to build an interactive risk calculator of perioperative mortality after EVAR (C-statistic = 0.749).

CONCLUSIONS

This study provides a prediction model for mortality following EVAR that incorporates aortic neck features. The risk calculator can be used to weigh risk/benefit ratio when counseling patients preoperatively. Prospective use of this risk calculator may show its benefit in long-term prediction of adverse outcomes.

High prevalence of abdominal aortic aneurysm in older men with cerebrovascular disease: Evaluation of a local screening program

Introduction

Patients with cerebrovascular disease may suffer from other vascular morbidities, such as abdominal aortic aneurysm (AAA). Previously, a high prevalence of AAA has been demonstrated in men 60 years of age and older who have experienced TIA or stroke. This report evaluates the results of a decade's operation of a local screening program for AAA in this selected neurologic population.

Methods

Men aged ≥60 years and admitted to the neurology ward of a community-based hospital in the Netherlands from 2006 to 2017 with a diagnosis of TIA or stroke were selected for screening. The diameter of the abdominal aorta was assessed by abdominal ultrasonography. Patients with detected AAA were referred for evaluation by a vascular surgeon.

Results

AAA was detected in 72 of 1,035 screened patients (6.9%). AAAs with a diameter of 3.0-3.9 cm accounted for 61.1% of the total aneurysms found; AAAs with a diameter of 4.0-5.4 cm accounted for 20.8% of the total; and large aneurysms with a diameter of ≥5.5 cm accounted for 18.1% of all aneurysms discovered. A total of 18 patients (1.7%) underwent elective aneurysm repair.

Discussion

The detection rate of AAA in older men with cerebrovascular disease was roughly 5-fold the detection rate in known European screening programs in older men from the general population. The proportion of large AAAs (≥5.5 cm) was also substantially higher. These findings reveal a previously unknown co-morbidity in patients with cerebrovascular disease and may be helpful for cardiovascular management of this large group of neurologic patients. Current and future AAA screening programs may also benefit from this knowledge.

Projection of global burden and risk factors for aortic aneurysm - timely warning for greater emphasis on managing blood pressure

RATIONALE

Aortic aneurysm (AA) is a serious condition that largely increases the risk of aortic dissection and sudden death. Exploring the global burden of disease and changes in risk factors for AA is essential for public health policy development.

OBJECTIVE

To project the death burden from AA and its attributable risk factors in the following decade based on the epidemiological data over the past 30 years.

METHODS AND RESULTS

We analysed the death burden of AA and trends of four risk factors from 1990-2019 using the updated 2019 Global Burden of Disease study database by Joinpoint regression analysis. Furthermore, we project the AA-related death burden for the next decade using the Bayesian age-period-cohort model. This study discovered that the global burden of death attributable to AA began to increase after decreasing for two decades. This upward trend will continue in the subsequent decade (average annual percent change: 0.318%, 95% CI: 0.288 to 0.348). Meanwhile, the disease burdens in all economic regions except high-middle socio-demographic index (SDI) regions will continuously increase in the next decade, with the fastest acceleration in the low-middle SDI region (average annual percent change: 1.183%, 95% CI: 1.166 to 1.200). Notably, high systolic blood pressure will surpass the contribution of smoking to become the most important risk factor for mortality due to AA.

CONCLUSION

This study discovered a rebounding trend in the aortic aneurysm-related death burden globally. High systolic blood pressure will be the top risk factor attributed to death from AA. Therefore, it should be considered as the first-degree risk factor in the guidance of AA management and criteria for population-based screening programs.Key messagesThe death burden of aortic aneurysms is beginning to rebound globally, and the trend will continue for the next decade.High systolic blood pressure will replace smoking as the most important risk factor associated with aortic aneurysm death.

Editor's Choice - Risk of Rupture and All Cause Mortality of Abdominal Aortic Ectasia: A Systematic Review and Meta-Analysis

OBJECTIVE

To clarify the natural history of abdominal aortic ectasia (AAE) measuring 25 - 29 mm in maximum diameter, and to determine the optimal follow up based on the growth, risk of rupture, and overall mortality of AAE.

DATA SOURCES

MEDLINE, Web of Science Core Collection, and Google Scholar.

REVIEW METHODS

This was a systematic review and meta-analysis of AAE in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, Web of Science Core Collection, and Google Scholar were searched, with the help of a health sciences librarian, up to 11 August 2021. Studies with longitudinal outcomes of AAE (prevalence, annual growth rate, aneurysmal enlargement, rupture, aneurysm related death, and all cause mortality) were included. Meta-analyses were conducted with a random effects model RESULTS: Twelve studies describing a total of 8 369 patients were eligible. The prevalence at population based settings was 3.2% (95% confidence interval [CI] 2.4 - 4.0); annual growth rate was 0.82 mm/year (95% CI 0.20 - 1.45). The estimated risks of aortic diameters exceeding 30 mm and 55 mm in five years were 45.0% (95% CI 28.5 - 61.5) and 0.3% (95% CI 0 - 0.6) respectively, while those beyond five years were 70.2% (95% CI 46.9 - 93.6) and 5.2% (95% CI 2.2 - 8.2). The rates of rupture and aneurysm related death were minimal until five years (0.1% and 0.1%, respectively) and beyond (0.4% and 0.2%, respectively). Overall mortality was 7.5% (95% CI 3.9 - 11.0) and 17.3% (95% CI 9.5 - 25.1) up to and beyond five years. Overall mortality from three studies showed no statistical difference between AAE and aneurysms (hazard ratio 0.62, 95% CI 0.32 - 1.21; p = .16). Cancer (35.0%) and cardiovascular diseases (31.9%) were major causes of death.

CONCLUSION

AAE carries minimal risk of aneurysm related lethal events during the first five years, but a similar overall mortality risk as abdominal aortic aneurysm. Cancer and cardiovascular diseases are leading causes of death in patients with AAE.

AAA Revisited: A Comprehensive Review of Risk Factors, Management, and Hallmarks of Pathogenesis

Despite declining incidence and mortality rates in many countries, the abdominal aortic aneurysm (AAA) continues to represent a life-threatening cardiovascular condition with an overall prevalence of about 2-3% in the industrialized world. While the risk of AAA development is considerably higher for men of advanced age with a history of smoking, screening programs serve to detect the often asymptomatic condition and prevent aortic rupture with an associated death rate of up to 80%. This review summarizes the current knowledge on identified risk factors, the multifactorial process of pathogenesis, as well as the latest advances in medical treatment and surgical repair to provide a perspective for AAA management.

Analysis of High-Risk Factors Associated with the Progression of Subaneurysmal Aorta to Abdominal Aortic Aneurysm in Rural Area in China

Objective

To determine the risk factors associated with the progress of subaneurysmal aorta (SAA) to abdominal aortic aneurysm (AAA) and provide a reference for the prevention of AAA in rural areas.

Methods

A total of 747 SAA patients screened by the Health Management Center of the Second Hospital of Lanzhou University from January 2015 to January 2016 were recruited. The ratio of SAA progressing to AAA was observed through 5 years of follow-up. Logistic stepwise regression analysis was performed to analyze the high-risk factors. The relevant clinical prediction model score table (Nom) was made and the C-index and calibration chart were used to verify the prediction ability of the model.

Results

Of the 747 patients diagnosed with SAA, 260 developed to AAA, with an incidence of 34.8%. Univariate analysis showed that age (62–65 years old), abdominal aorta diameter greater than 2.7 cm, smoking after 30 years old, moderate to severe hypertension, and blood pressure variability were the important high-risk factors of SAA progressing to AAA. Logistic regression analysis showed that these factors were statistically significant. The nomogram of clinical prediction model score showed that when 50–60% of SAA developed to AAA, the score was 189–201 and the C-index was 0.883, verifying the moderate predictive ability of this model.

Conclusion

Age, smoking habit, degree of hypertension, and control situation were high-risk factors associated with the progression of SAA to AAA. The control of the above high-risk factors was imperative for the prevention of AAA in rural areas without sufficient medical resources.

Screening for abdominal aortic aneurysms in Canada: 2020 review and position statement of the Canadian Society for Vascular Surgery

Abdominal aortic aneurysms (AAAs) remain a major risk to patients, despite level 1 evidence for screening to prevent rupture events and decrease mortality. In 2007, the Canadian Society for Vascular Surgery (CSVS) published a review and position statement for AAA screening in Canada. Since that publication, there have been a number of updates in the published literature affecting screening recommendations. In this paper, we present a review of some of the controversies in the AAA screening literature to help elucidate differences in the various published screening guidelines. This article represents a review of the data and updated recommendations for AAA screening in the Canadian population on behalf of the CSVS.

Les anévrismes de l’aorte abdominale (AAA) continuent de poser un risque majeur pour les patients, malgré des données probantes de niveau 1 à l’appui du dépistage pour prévenir les ruptures et réduire la mortalité. En 2007, la Société canadienne de chirurgie vasculaire (SCCV) a publié une revue et un énoncé de position sur le dépistage de l’AAA au Canada. Depuis lors, plusieurs mises à jour ont paru dans la littérature et elles ont un impact sur les recommandations relatives au dépistage. Dans le présent article, nous présentons une synthèse de quelques controverses soulevées dans la littérature sur le dépistage de l’AAA afin d’expliquer les différences entre les diverses lignes directrices publiées à ce sujet. Cet article propose au nom de la SCCV une revue des données probantes et des recommandations à jour sur le dépistage de l’AAA dans la population canadienne.

Derivation and Validation of a 10-Year Risk Score for Symptomatic Abdominal Aortic Aneurysm: Cohort Study of Nearly 500 000 Individuals

BACKGROUND

Abdominal aortic aneurysm (AAA) can occur in patients who are ineligible for routine ultrasound screening. A simple AAA risk score was derived and compared with current guidelines used for ultrasound screening of AAA.

METHODS

United Kingdom Biobank participants without previous AAA were split into a derivation cohort (n=401 820, 54.6% women, mean age 56.4 years, 95.5% White race) and validation cohort (n=83 816). Incident AAA was defined as first hospital inpatient diagnosis of AAA, death from AAA, or an AAA-related surgical procedure. A multivariable Cox model was developed in the derivation cohort into an AAA risk score that did not require blood biomarkers. To illustrate the sensitivity and specificity of the risk score for AAA, a theoretical threshold to refer patients for ultrasound at 0.25% 10-year risk was modeled. Discrimination of the risk score was compared with a model of US Preventive Services Task Force (USPSTF) AAA screening guidelines.

RESULTS

In the derivation cohort, there were 1570 (0.40%) cases of AAA over a median 11.3 years of follow-up. Components of the AAA risk score were age (stratified by smoking status), weight (stratified by smoking status), antihypertensive and cholesterol-lowering medication use, height, diastolic blood pressure, baseline cardiovascular disease, and diabetes. In the validation cohort, over 10 years of follow-up, the C-index for the model of the USPSTF guidelines was 0.705 (95% CI, 0.678-0.733). The C-index of the risk score as a continuous variable was 0.856 (95% CI, 0.837-0.878). In the validation cohort, the USPSTF model yielded sensitivity 63.9% and specificity 71.3%. At the 0.25% 10-year risk threshold, the risk score yielded sensitivity 82.1% and specificity 70.7% while also improving the net reclassification index compared with the USPSTF model +0.176 (95% CI, 0.120-0.232). A combined model, whereby risk scoring was combined with the USPSTF model, also improved prediction compared with USPSTF alone (net reclassification index +0.101 [95% CI, 0.055-0.147]).

CONCLUSIONS

In an asymptomatic general population, a risk score based on patient age, height, weight, and medical history may improve identification of asymptomatic patients at risk for clinical events from AAA. Further development and validation of risk scores to detect asymptomatic AAA are needed.

Long Term Outcome of Screen Detected Sub-Aneurysmal Aortas in 65 Year Old Men: a Single Scan After Five Years Identifies Those at Risk of Needing AAA Repair

OBJECTIVE

The epidemiology of sub-aneurysmal aortic dilatation (SAA) 25 - 29 mm is not fully understood, and the management of SAA is debated. Lack of evidence is particularly problematic in the screening setting. This study aimed to evaluate the long term outcome of men with screen detected SAAs, focusing on progression to an abdominal aortic aneurysm (AAA), and on the AAAs reaching the threshold diameter for surgical repair.

METHODS

Between 2006 and 2015, all 65 year old men with a screen detected SAA in middle Sweden were re-examined with ultrasound after five and 10 years. The primary outcomes were expansion to AAA ≥ 30 mm and progression to AAA ≥ 55 mm. Secondary outcomes were risk factors for progression, repair rate, and mortality.

RESULTS

A total of 1 020 65 year old men with a SAA were identified, of whom 940 (92.2%; 95% confidence interval 91.0 - 93.8) had follow up. The Kaplan-Meier estimated incidence of AAA ≥ 30 mm development after the five year follow up (which was de facto carried out after a mean of 4.9 years) was 65.8% (61.6 - 69.4), all < 55 mm. The corresponding KM-estimated incidence after the 10 year follow up (carried out after a mean of 11.9 years) was 95.1% (90.1 - 97.4), and 29.7% (18.0 - 39.7) reached ≥ 55 mm. All 41 SAAs eventually expanding to ≥ 55 mm were ≥ 30 mm at the five year follow up. Of these, 32 had surgical repair with 100% survival, six have scheduled repairs, and three (7.3%) were unfit for repair. The KM estimated all cause mortality rates at five and 10 years were 7.0% and 17.9%, respectively, with no proven AAA related deaths.

CONCLUSION

A majority of SAAs eventually progress to an AAA, of which 30% are estimated to eventually reach the threshold for repair within 10 years. A follow up policy with an ultrasound examination after five years can safely and effectively identify those SAAs at risk of developing into clinically significant AAAs needing repair and may be considered for anyone with reasonably good life expectancy.

Cost-effectiveness of a population-based AAA screening program for men over 65 years old in Iran

BACKGROUND

Screening program tend to recognized patients in their early stage and consequently improve health outcomes. Cost-effectiveness of the abdominal aortic aneurysm (AAA) screening program has been scarcely studied in developing countries. We sought to evaluate the cost-effectiveness of a screening program for the abdominal aortic aneurysm (AAA) in men aged over 65 years in Iran.

METHODS

A Markov cohort model with 11 mutually exclusive health statuses was used to evaluate the cost-effectiveness of a population-based AAA screening program compared with a no-screening strategy. Transitions between the health statuses were simulated by using 3-month cycles. Data for disease transition probabilities and quality of life outcomes were obtained from published literature, and costs were calculated based on the price of medical services in Iran and the examination of the patients' medical records. The outcomes were life-years gained, the quality-adjusted life-year (QALY), costs, and the incremental cost-effectiveness ratio (ICER). The analysis was conducted for a lifetime horizon from the payer's perspective. Costs and effects were discounted at an annual rate of 3%. Uncertainty surrounding the model inputs was tested with deterministic and probabilistic sensitivity analyses.

RESULTS

The mean incremental cost of the AAA screening strategy compared with the no-screening strategy was $140 and the mean incremental QALY gain was 0.025 QALY, resulting in an ICER of $5566 ($14,656 PPP) per QALY gained. At a willingness-to-pay of 1 gross domestic product (GDP) per capita ($5628) per QALY gained, the probability of the cost-effectiveness of AAA screening was about 50%. However, at a willingness-to-pay of twice the GDP per capita per QALY gained, there was about a 95% probability for the AAA screening program to be cost-effective in Iran.

CONCLUSIONS

The results of this study showed that at a willingness-to-pay of 1 GDP per capita per QALY gained, a 1-time AAA screening program for men aged over 65 years could not be cost-effective. Nevertheless, at a willingness-to-pay of twice the GDP per capita per QALY gained, the AAA screening program could be cost-effective in Iran. Further, AAA screening in high-risk groups could be cost-effective at a willingness-to-pay of 1 GDP per capita per QALY gained.

Screening Older Adult Men for Abdominal Aortic Aneurysm: A Scoping Review

Abdominal aortic aneurysm (AAA) is a potentially fatal condition predominantly affecting older adult men (60 years or over). Based on evidence, preventative health-care guidelines recommend screening older males for AAA using ultrasound. In attempts to reduce AAA mortality among men, screening has been utilized for early detection in some Western countries including the UK and Sweden. The current scoping review includes 19 empirical studies focusing on AAA screening in men. The findings from these studies highlight benefits and potential harms of male AAA screening. The benefits of AAA screening for men include decreased incidence of AAA rupture, decreased AAA mortality, increased effectiveness of elective AAA repair surgery, and cost-effectiveness. The potential harms of AAA screening included lack of AAA mortality reduction, negative impacts on quality of life, and inconsistent screening eligibility criteria being applied by primary care practitioners. The current scoping review findings are discussed to suggest changes to AAA screening guidelines and improve policy and practice.

Optimising intervals for abdominal aortic aneurysm surveillance: A pilot study analysing patient opinion

Introduction

Optimising abdominal aortic aneurysm surveillance intervals will improve current surveillance programmes. To the author's knowledge, no known study has exclusively asked patient opinion with regards to their surveillance interval. The aim of this study was to therefore determine a patient's perspective of their optimal intervals, encouraging shared decision-making and creating a patient-focused service.

Methods

Fifty patients, currently under abdominal aortic aneurysm surveillance, were interviewed. Patients were asked their opinions before and after seeing a patient decision aid. A patient decision aid presents information of risk in an easy-to-understand format. This specific patient decision aid, designed and created for this study, informed patients of the 'risk of exceeding the 5.5 cm surgical threshold' with regards to various surveillance intervals. The chosen optimal surveillance interval was recorded for each patient, and a median interval was calculated for each abdominal aortic aneurysm group. Groups were categorised based upon maximum aortic diameter (3.0-3.4 cm, 3.5-3.9 cm, 4.0-4.4 cm and 4.5-4.9 cm).

Results

After assessing the patient decision aid, the median surveillance interval calculated for each abdominal aortic aneurysm group was 24 months (3.0-3.4 cm), 12 months (3.5-3.9 cm), 12 months (4.0-4.4 cm) and 6 months (4.5-4.9 cm), respectively. The majority of patients (78%, n = 39) agreed that the patient decision aid was a useful tool to help make an informed choice.

Conclusion

Overall, patients in abdominal aortic aneurysm groups 3.0-3.4 cm and 4.5-4.9 cm would choose to lengthen abdominal aortic aneurysm surveillance intervals. Lengthening the current surveillance intervals to 24 months (currently 12 months) for abdominal aortic aneurysm group 3.0-3.4 cm and to 6 months (currently 3 months) for abdominal aortic aneurysm group 4.5-4.9 cm would not only increase capacity but also reflect the needs and wishes of those using the National Health Service. The use of a patient decision aid is an effective way of communicating, to the patient, the risk of the proposed changes and thus alleviating potential anxiety.

Intraluminal thrombus effect on the progression of abdominal aortic aneurysms by using a multistate continuous-time Markov chain model

OBJECTIVE

To investigate the relationship between the characteristics of intraluminal thrombus (ILT) with abdominal aortic aneurysm (AAA) expansion.

METHODS

This retrospective clinical study applied homogeneous multistate continuous-time Markov chain models to longitudinal computed tomography (CT) data from Korean patients with AAA. Four AAA states were considered (early, mild, severe, fatal) and the maximal thickness of the ILT (max_ILT), the fraction of the wall area covered by the ILT (area_frac) and the fraction of ILT volume (vol_frac) were used as covariates.

RESULTS

The analysis reviewed longitudinal CT images from 26 patients. Based on likelihood-ratio statistics, the area_frac was the most significant biomarker and max_ILT was the second most significant. In addition, within AAAs that developed an ILT layer, the analysis found that the AAA expands relatively quickly during the early stage but the rate of expansion reduces once the AAA has reached a larger size.

CONCLUSION

The results recommend surgical intervention when a patient has an area_frac more than 60%. Although this recommendation should be considered with caution given the limited sample size, physicians can use the proposed model as a tool to find such recommendations with their own data.

Screening for abdominal aortic aneurysm in patients with clinically manifest vascular disease

AIMS

Declining prevalence of abdominal aortic aneurysm (AAA) might force a more targeted screening approach (high-risk populations only) in order to maintain (cost-)effectiveness. We aimed to determine temporal changes in the prevalence of screening-detected AAA, to assess AAA-related surgery, and evaluate all-cause mortality in patients with manifest vascular disease.

METHODS AND RESULTS

We included patients with manifest vascular disease but without a history of AAA enrolled in the ongoing single-centre prospective UCC-SMART cohort study. Patients were screened at baseline for AAA by abdominal ultrasonography. We calculated sex- and age-specific prevalence of AAA, probability of survival in relation to the presence of AAA, and the proportion of patients undergoing AAA-related surgery. Prevalence of screening-detected AAA in 5440 screened men was 2.5% [95% confidence interval (CI) 2.1-2.9%] and in 1983 screened women 0.7% (95% CI 0.4-1.1%). Prevalence declined from 1997 until 2017 in men aged 70-79 years from 8.1% to 3.2% and in men aged 60-69 years from 5.7% to 1.0%. 36% of patients with screening-detected AAA received elective AAA-related surgery during follow-up (median time until surgery = 5.3 years, interquartile range 2.5-9.1). Patients with screening-detected AAA had a lower probability of survival (sex and age adjusted) compared to patients without screening-detected AAA (51%, 95% CI 41-64% vs. 69%, 95% CI 68-71%) after 15 years of follow-up.

CONCLUSION

The prevalence of screening-detected AAA has declined over the period 1997-2017 in men with vascular disease but exceeds prevalence in already established screening programs targeting 65-year-old men. Screening for AAA in patients with vascular disease may be cost-effective, but this remains to be determined.

Collard M, Sutphin PD, Kalva SP, Majdalany BS, Collins JD, Eldrup-Jorgensen J, Francois CJ, Ganguli S, Gunn AJ, Kendi AT, Khaja MS, Obara P, Reis SP, Vijay K, Dill KE. ACR Appropriateness Criteria® Abdominal Aortic Aneurysm Follow-up (Without Repair)

Abdominal aortic aneurysm (AAA) is defined as aneurysmal dilation of the abdominal aorta to 3 cm or greater. A high degree of morbidity and mortality is associated with AAA rupture, and imaging surveillance plays an essential role in mitigating the risk of rupture. Aneurysm size and growth rate are factors associated with the risk of rupture, thus surveillance imaging studies must be accurate and reproducible to characterize aneurysm size. Ultrasound, CT angiography, and MR angiography provide an accurate and reproducible assessment of size, while radiographs and aortography provide limited evaluation. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Early Detection of Undiagnosed Abdominal Aortic Aneurysm and Sub-Aneurysmal Aortic Dilatations in Patients with High-Risk Coronary Artery Disease: The Value of Targetted Screening Programme

INTRODUCTION

Abdominal aortic aneurysm (AAA) and coronary artery disease (CAD) share common risk factors. The objective of this study was to determine the prevalence of undiagnosed AAA in patients with angiographically diagnosed significant CAD.

PATIENTS AND METHODS

Male patients aged 50 years and above (including indigenous people) with angiographically diagnosed significant CAD in the recent one year were screened for AAA. Standard definition of abdominal aortic aneurysm and CAD was used. All new patients were followed up for six months for AAA events (ruptured AAA and AAA-related mortality).

RESULTS

A total of 277 male patients were recruited into this study. The total prevalence of undiagnosed AAA in this study population was 1.1% (95% CI 0.2-3.1). In patients with high-risk CAD, the prevalence of undiagnosed AAA was 1.7% (95% CI 0.3-4.8). The detected aneurysms ranged in size from 35.0mm to 63.8mm. Obesity was a common factor in these patients. There were no AAA-related mortality or morbidity during the follow-up. Although the total prevalence of undiagnosed AAA is low in the studied population, the prevalence of sub-aneurysmal aortic dilatation in patients with significant CAD was high at 6.6% (95% CI 3.9-10.2), in which majority were within the younger age group than 65 years old.

CONCLUSION

This was the first study on the prevalence of undiagnosed AAA in a significant CAD population involving indigenous people in the island of Borneo. Targeted screening of patients with high-risk CAD even though they are younger than 65 years old effectively discover potentially harmful asymptomatic AAA and sub-aneurysmal aortic dilatations.

Mortality from abdominal aortic aneurysm: trends in European Union 15+ countries from 1990 to 2017

BACKGROUND

This observational study assessed trends in abdominal aortic aneurysm (AAA) death rates in European Union (EU) 15+ countries for the years 1990 to 2017.

METHODS

Age-standardized death rates (ASDRs) were extracted from the Global Burden of Disease Study Global Health Data Exchange. Trends were analysed using joinpoint regression analysis.

RESULTS

Between 1990 and 2017, ASDRs from AAA decreased in all 19 EU15+ countries for women, and in 18 of 19 countries for men. Increasing AAA mortality was observed only for men in Greece (+5·3 per cent). The largest relative decreases in ASDR between 1990 and 2017 were observed in Australia (men -65·6 per cent, women -50·4 per cent) and Canada (men -60·8 per cent, women -48·6 per cent). Over the 28-year interval, the smallest decreases in ASDR for women were noted in Greece (-2·3 per cent) and in Italy (-2·5 per cent). In 2017, the highest mortality rates were observed in the UK for both men and women (7·5 per 100 000 and 3·7 per 100 000 respectively). The lowest ASDR was observed in Portugal for men (2·8 per 100 000) and in Spain for women (1·0 per 100 000). ASDRs for AAA in 2017 were higher for men than women in all 19 EU15+ countries. The most recent trends demonstrated increasing AAA ASDRs in 14 of 19 countries for both sexes; the increases were relatively small compared with the improvements in the preceding years.

CONCLUSION

This observational study identified decreasing mortality from AAA across EU15+ countries since 1990. The most recent trends demonstrated relatively small increases in AAA mortality across the majority of EU15+ countries since 2012.

Prevalence of abdominal aortic aneurysm and associated lower extremity artery aneurysm in men hospitalized for suspected or known cardiopulmonary disease

BACKGROUND

AAA is a disease affecting predominantly male patients ≥65 years and its dreaded complications such as rupture led to population-based screening programs as preventive measure. Nonetheless, the supposed prevalence may have been overestimated, so that targeted screening of high risk populations may be more effective. This study was performed to evaluate the prevalence of abdominal aortic aneurysm (AAA) of an inpatient high-risk cohort and to estimate the co-prevalence of lower extremity arterial aneurysms.

METHODS

Participants: 566 male inpatients, ≥ 65 years of age, hospitalized for suspected or known cardiopulmonary disease. Primary and secondary outcome measures: Maximal infrarenal aortic diameters using abdominal ultrasound (leading edge to leading edge method). Upon detection of an AAA (diameter ≥ 30 mm), the lower extremity arteries were examined with regard to associated aneurysms.

RESULTS

In 40 of 566 patients (7.1%) AAAs were detectable. Fourteen patients (2.5%) had a first diagnosis of AAA, none of which was large (> 55 mm), the remaining 26 patients were either already diagnosed (14 patients, 2.5%) or previously repaired (12 patients, 2.1%). The three most common main diagnoses at discharge were acute coronary syndrome (43.3%), congestive heart failure (32.2%), and chronic obstructive pulmonary disease (12%). The cohort showed a distinct cardiovascular risk profile comprising arterial hypertension (82.9%), diabetes mellitus (44.4%), and a history of smoking (57.6%). In multivariate analysis, three-vessel coronary artery disease (Odds ratio (OR): 4.5, 95% confidence interval (CI): 2.3-8.9, p <  0.0001) and history of smoking (OR: 3.7, CI: 1.6-8.6, p <  0.01) were positively associated with AAA, while diabetes mellitus (OR: 0.5, CI: 0.2-0.9, p = 0.0295) showed a negative association with AAA. Among the subjects with AAA, we found two large iliac and two large popliteal aneurysms.

CONCLUSION

Ultrasound screening in male inpatients, hospitalized for suspected or known cardiopulmonary disease, revealed a high AAA prevalence in comparison to the present epidemiological screening programs. There was a moderate proportion of newly-screen detected AAA and additional screening of the lower extremity arteries yielded some associated aneurysms with indication for possible intervention.

Prevalence and natural history of and risk factors for subaneurysmal aorta among 65-year-old men

Background: The aims of this study were to determine the prevalence of screening-detected subaneurysmal aorta (SAA), i.e. an aortic diameter of 2.5-2.9 cm, its associated risk factors, and natural history among 65-year-old men. Methods: A total of 14,620 men had their abdominal aortas screened with ultrasound and completed a health questionnaire containing information on smoking habits and medical history. They were categorized based on the aortic diameter: normal aorta (<2.5 cm; n = 14,129), SAA (2.5-2.9 cm; n = 258), and abdominal aortic aneurysm (AAA) (≥3.0 cm; n = 233). The SAA-group was rescanned after 5 years. Associated risk factors were analyzed. Results: The SAA-prevalence was 1.9% (95% confidence interval 1.7%-2.1%), with 57.0% (50.7%-63.3%) expanding to ≥3.0 cm within 5 years. Frequency of smoking, coronary artery disease, hypertension, hyperlipidemia, and claudication were significantly higher in those with SAA and AAA compared to those with normal aortic diameter. Current smoking was the strongest risk factor for SAA (odds ratio [OR] 2.8; P < 0.001) and even stronger for AAA (OR 3.6; P < 0.001). Men with SAA expanding to AAA within 5 years presented pronounced similarities to AAA at baseline. Conclusions: Men with SAA and AAA presented marked similarities in the risk factor profile. Smoking was the strongest risk factor with an incremental association with disease severity, and disease progression. This indicates that SAA and AAA may have the same pathophysiological origin and that SAA should be considered as an early stage of aneurysm formation. Further research on the cost-effectiveness and potential benefits of surveillance as well as smoking cessation and secondary cardiovascular prevention in this subgroup is warranted.

Retrospective review of abdominal aortic aneurysm deaths in New Zealand: what proportion of deaths is potentially preventable by a screening programme in the contemporary setting?

OBJECTIVES

To describe the proportions of people dying from abdominal aortic aneurysm (AAA) who might have benefited from a formal screening programme for AAA.

DESIGN

Retrospective cross-sectional review of deaths.

SETTING AND STUDY POPULATIONS

All AAA deaths registered in New Zealand from 2010 to 2014 in the absence of a national AAA screening programme.

MAIN OUTCOME MEASURES

Known history of AAA prior to the acute event leading to AAA death, prognosis limiting comorbidities, history of prior abdominal imaging and a validated multimorbidity measure (M3-index scores).

RESULTS

1094 AAA deaths were registered in the 5 years between 2010 and 2014 in New Zealand. Prior to the acute AAA event resulting in death, 31.3% of the cohort had a known AAA diagnosis, and 10.9% had a previous AAA procedure. On average, the AAA diagnosis was known 3.7 years prior to death. At least 77% of the people dying from AAA also had one or more other prognosis limiting diagnosis. The hazard of 1-year mortality associated with the non-AAA related comorbidities for the AAA cohort aged 65 or above were 1.5-2.6 times higher than to the age matched general population based on M3-index scores. In 2014, overall AAA deaths accounted for only 0.7% of total deaths, and 1.0% of deaths among men aged 65 or above in New Zealand. At most, 20% of people dying from AAA in New Zealand between 2010 and 2014 might have had the potential to derive full benefit from a screening programme. About 51% of cases would have derived no or very limited benefit from a screening programme.

CONCLUSION

Falling AAA mortality, and high prevalence of competing comorbidities and/or prior AAA diagnosis and procedure raises the question about the likely value of a national AAA screening programme in a country such as New Zealand.

Impact on Quality of Life of Men with Screening-Detected Abdominal Aortic Aneurysms Attending Regular Follow ups: A Narrative Literature Review

OBJECTIVE

This study aimed to review, summarise, and assess the available evidence regarding the impact on the quality of life (QoL) of men undergoing screening for abdominal aortic aneurysm (AAA) and attending regular follow ups.

METHODS

PubMed, MEDLINE, CINAHL, and PsycINFO were used for searching. The search was performed from April to July 2016, with an update in February-March 2018. The quality of the studies was appraised with respective checklists from the Critical Appraisal Skills Programme. A narrative synthesis of the included studies was performed. The analysis included studies evaluating QoL in relation to one or more of the following concepts: physical function, psychological impact and social life in men undergoing AAA screening, but excluded studies evaluating QoL in AAA patients diagnosed outside a screening program.

RESULTS

The initial results from the search were 128 articles. Duplicates were removed, titles and abstracts were screened, and 22 full text articles were collected. Based on the inclusion criteria, 11 quantitative studies were included. Inferior quality of life among men with detected AAA was identified compared to those without the diagnosis and the general population in the included studies. The self-perceived health decreased over time for the participants with AAA. Assessments after surgery showed that the participants returned to similar health as before the screening. A wide variety of factors regarding the methodologies, designs, measurements, sample sizes, and the time for the assessment were noted in the included studies.

CONCLUSION

Quality of life is an important outcome for AAA screening and studies have been conducted in an attempt to address the imbalance between benefits and harm. However, it is still difficult to draw clear conclusions, possibly due to the heterogeneity of the original studies. Nevertheless, it is important to identify men with an AAA who develop conditions influencing their health and QoL in order to understand their care needs to further support them and improve their situation.

Screening Program of Abdominal Aortic Aneurysm

In Europe, the prevalence of abdominal aortic aneurysms (AAAs) in the elderly population (≥65 year old) has declined in the past decades to <4%. Aneurysmal degeneration of the aorta is a serious and potentially life-threatening vascular disease. Abdominal aortic aneurysms typically develop subclinically and often only become symptomatic when complicated by impending rupture. Most AAAs are discovered incidentally while investigating for an unrelated pathology. Ruptured AAA is the tenth leading cause of death in Belgium (0.32% of all deaths in 2014). Health-care providers have emphasized the importance of early detection of AAA and elective repair when the rupture risk outweighs operative risk (usual diameter threshold of 55 mm). Routine AAA screening programs, consisting of a single abdominal ultrasonography at the age of 65 years, aim to reduce the number of AAA-related deaths. Does population-based ultrasound screening for AAA achieve its objective and is it cost-effective? This literature review tries to answer these challenging questions.

Coronary Artery Disease as a Relevant Risk Factor in Screening of Abdominal Aortic Ectasia and Aneurysm

BACKGROUND

The aim of this study was to investigate the prevalence of abdominal aortic aneurysm (AAA) and abdominal aortic ectasia (AAE) in coronary artery disease (CAD) patients in a multicenter setting to obtain significant data to establish an AAA screening program in our departments.

METHODS

Between January and September 2016, 500 patients with suspected or diagnosed CAD planned for coronary angiography or coronary artery bypass graft (CABG) underwent a sonographic examination of the infrarenal abdominal aorta to diagnose AAA or AAE. We calculated the prevalence of AAA and AAE in patients diagnosed of CAD and investigated factors potentially associated with the occurrence of AAA.

RESULTS

The overall prevalence in all grades of CAD for AAE was 35.1% and for AAA 5.4%. In patients with three-vessel CAD, the prevalence of AAE was 34% and of AAA 6.8%. Significant correlation was found between the three-vessel CAD and AAA (p = 0.039). The logistic regression analysis showed significant correlation between AAA and age > 65 years (p = 0.05). The multivariate analysis of risk factors and CAD revealed significant correlations between one-vessel CAD and arterial hypertension (AH) (p = 0.004) and age > 65 years (p = 0.001) as well as between three-vessel CAD and AH (p = 0.01), peripheral artery disease (p = 0.01), and age > 65 years (p = 0.03).

CONCLUSION

Our results confirm, that in comparison to other data, the prevalence of AAA in patients with CAD is high. Thus, it is recommended to include patients with CAD, especially elderly patients with three-vessel CAD, in future AAA screening programs.

Usefulness of Screening for Abdominal Aortic Aneurysm During Transthoracic Echocardiography in Women ≥50 Years of Age

Usefulness of screening for abdominal aortic aneurysm (AAA) during transthoracic echocardiography (TTE) in women is uncertain. The aim of the present study was to clarify the clinical usefulness of screening for AAA during TTE and to identify important TTE indices associated with AAA in women in a routine clinical setting. We prospectively studied 1,495 women (≥50 years) referred for TTE. AAA was defined as ≥30 mm in size. The additional screening time for AAA was <1 minute. The abdominal aorta was visualized in 95.1 % (1,422 of 1,495) using the same TTE probe. AAA was identified in 1.9% (27 of 1422). The aortic root size was larger in patients with AAA than those without (33.3 ± 3.2 vs 30.5 ± 3.4 mm, p < 0.001). The aortic root size had a correlation with abdominal aortic size (r = 0.22, p < 0.001). The aortic root size of ≥30.3 mm was predictive of AAA (area under the curve = 0.74, p < 0.001) and all patients with AAA had the aortic root size of ≥28.0 mm. Multiple logistic regression analysis revealed that the aortic root size (Odds ratio 1.17, p = 0.007) was a most independent TTE index of AAA. In conclusion, the visibility of the abdominal aorta using TTE probe was excellent. When the aortic root size is ≥28.0 mm during TTE in women ≥50 years of age, screening for AAA should be carried out.

Risk Factors for Abdominal Aortic Aneurysm in Population-Based Studies: A Systematic Review and Meta-Analysis

Abdominal aortic aneurysm (AAA) represents an important public health problem with a prevalence between 1.3% and 12.5%. Several population-based randomized trials have evaluated ultrasound screening for AAA providing evidence of a reduction in aneurysm-related mortality in the screened population. The aim of our study was to perform a systematic review and meta-analysis of the risk factors for AAA. We conducted a systematic review of observational studies and we performed a meta-analysis that evaluated the following risk factors: gender, smoking habits, hypertension, coronary artery disease and family history of AAA. Respect to a previous a meta-analysis we added the funnel plot to examine the effect sizes estimated from individual studies as measure of their precision; sensitivity analysis to check the stability of study findings and estimate how the overall effect size would be modified by removal of one study; cumulative analysis to evaluate the trend between studies in relation to publication year. Abdominal aortic aneurysm prevalence is higher in smokers and in males. On the other hand, while diabetes is a risk factor for many cardiovascular diseases, it is not a risk factor for AAA. In addition, it is important to underline that all countries, where AAA screening was set up, had high income level and the majority belong to Western Europe (United Kingdom, Sweden, Italy, Poland, Spain and Belgium). Abdominal aortic aneurysm screening is fundamental for public health. It could avoid deaths, ruptures, and emergency surgical interventions if abdominal aortic aneurysm was diagnosed early in the population target for screening.

Correcting for Body Surface Area Identifies the True Prevalence of Abdominal Aortic Aneurysm in Screened Women

OBJECTIVE

Recently, the prevalence of abdominal aortic aneurysm (AAA) using screening strategies based on elevated cardiovascular disease (CVD) risk was reported. AAA was defined as a diameter ≥30 mm, with prevalence of 6.1% and 1.8% in men and women respectively, consistent with the widely reported AAA predominant prevalence in males. Given the obvious differences in body size between sexes this study aimed to re-evaluate the expanded CVD risk based AAA screening dataset to determine the effect of body size on sex specific AAA prevalence.

METHODS

Absolute (26 and 30 mm) and relative (aortic size index [ASI] equals the maximum infrarenal aorta diameter (cm) divided by body surface area (m²), ASI ≥ 1.5) thresholds were used to assess targeted AAA screening groups (n = 4115) and compared with a self reported healthy elderly control group (n = 800).

RESULTS

Male AAA prevalence was the same using either the 30 mm or ASI ≥1.5 aneurysm definitions (5.7%). In females, AAA prevalence was significantly different between the 30 mm (2.4%) and ASI ≥ 1.5 (4.5%) or the 26 mm (4.4%) thresholds.

CONCLUSION

The results suggest the purported male predominance in AAA prevalence is primarily an artefact of body size differences. When aortic size is adjusted for body surface area there is only a modest sex difference in AAA prevalence. This observation has potential implications in the context of the ongoing discussion regarding AAA screening in women.

Proteomic analysis of aortic smooth muscle cell secretions reveals an association of myosin heavy chain 11 with abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a life-threatening disease, and no disease-specific circulating biomarkers for AAA screening are currently available. We have identified a smooth muscle cell (SMC)-specific biomarker for AAA. We cultured aneurysmal tunica media that were collected from eight patients undergoing elective open-repair surgeries. Secreted proteins in culture medium were subjected to liquid chromatography/tandem mass spectrometry. Myosin heavy chain 11 (myosin-11) was identified as a SMC-specific protein in the tunica media-derived secretions of all patients. We then examined myosin-11 protein concentrations by ELISA in plasma samples from patients with AAA ( n = 35) and age-matched healthy control subjects ( n = 34). Circulating myosin-11 levels were significantly higher in patients with AAA than control subjects. The area under the receiver-operating characteristic curve (AUC) of myosin-11 was 0.77, with a specificity of 65% at a sensitivity of 91%. Multivariate logistic regression analysis showed a significant association between the myosin-11 level and presence of AAA. When the myosin-11 level was combined with hypertension, it improved the prediction of AAA (AUC 0.88) more than hypertension per se. We then investigated the correlation between aortic diameter and circulating myosin-11 levels using AAA serum samples from patients undergoing endovascular aneurysm repair ( n = 20). Circulating myosin-11 levels were significantly correlated with maximum aortic diameter. Furthermore, changes in myosin-11 concentrations from the baseline 12 mo after endovascular aneurysm repair were associated with those in aortic diameter. These data suggest that circulating levels of myosin-11, which is a SMC-specific myosin isoform, may be useful as a biomarker for AAA.

NEW & NOTEWORTHY Extensive studies have revealed that inflammation- or proteolysis-related proteins are proposed as biomarkers for abdominal aortic aneurysm (AAA). Changes in these protein concentrations are not specific for smooth muscle, which is a major part of AAA pathologies. Hence, no disease-specific circulating markers for AAA are currently available. We found, using secretome-based proteomic analysis on human AAA tunica media, that myosin heavy chain 11 was associated with AAA. Circulating myosin heavy chain 11 may be a new tissue-specific AAA marker.

Abdominal aortic aneurysm screening attendance: Effect of removing the examination fee

OBJECTIVES

The organized population-based screening programme for abdominal aortic aneurysm in Stockholm, Sweden, started in 2010. An examination fee was initially charged, but later removed because of a policy change. We examined the effect on screening attendance of removing the fee.

METHODS

The periods before and after removing the examination fee were compared with regard to screening attendance, overall, by municipality and by district.

RESULTS

Screening attendance was 79.2% in the period with an examination fee and 79.9% in the period without an examination fee (p = 0.1787), with no significant change in screening attendance between the periods.

CONCLUSIONS

Although removing examination fees has been shown to have a positive impact on attendance in other screening programmes, we did not find this association in our study.

Discrete Event Simulation for Decision Modeling in Health Care: Lessons from Abdominal Aortic Aneurysm Screening

Markov models are often used to evaluate the cost-effectiveness of new healthcare interventions but they are sometimes not flexible enough to allow accurate modeling or investigation of alternative scenarios and policies. A Markov model previously demonstrated that a one-off invitation to screening for abdominal aortic aneurysm (AAA) for men aged 65 y in the UK and subsequent follow-up of identified AAAs was likely to be highly cost-effective at thresholds commonly adopted in the UK (£20,000 to £30,000 per quality adjusted life-year). However, new evidence has emerged and the decision problem has evolved to include exploration of the circumstances under which AAA screening may be cost-effective, which the Markov model is not easily able to address. A new model to handle this more complex decision problem was needed, and the case of AAA screening thus provides an illustration of the relative merits of Markov models and discrete event simulation (DES) models. An individual-level DES model was built using the R programming language to reflect possible events and pathways of individuals invited to screening v. those not invited. The model was validated against key events and cost-effectiveness, as observed in a large, randomized trial. Different screening protocol scenarios were investigated to demonstrate the flexibility of the DES. The case of AAA screening highlights the benefits of DES, particularly in the context of screening studies.

Meta-analysis of Renal Function Following Infrarenal EVAR using Suprarenal or Infrarenal Fixation Devices

OBJECTIVE/BACKGROUND

The effect of suprarenal (SR) as opposed to infrarenal (IR) fixation on renal outcomes post-endovascular aneurysm repair (EVAR) remains controversial. This meta-analysis aims to update current understanding of this issue.

METHODS

A prior meta-analysis was updated through a Preferred Reporting Items for Systematic reviews and Meta-Analyses search for additional studies published in the last 3 years reporting on renal dysfunction or related outcomes post-EVAR. Random effects meta-analysis was undertaken using SPSS.

RESULTS

A total of 25 non-randomised studies comparing SR with IR fixation were included, totalling 54,832 patients. In total, 16,634 underwent SR and 38,198 IR. Baseline characteristics, including age, baseline estimated glomerular filtration rate, diabetes, cardiac disease, and smoking, were similar between the groups. There was a small but significant difference in outcomes for renal dysfunction at the study end point (SR 5.98% vs. IR 4.83%; odds ratio [OR] 1.29, 95% confidence interval [CI] 1.18-1.40 [p < .001]); however, at 30 days and 12 months there was no significant difference, and this did not hold up to sensitivity analysis. Incidence of renal infarcts (SR 6.6% vs. IR 2.3%; OR 2.78, 95% CI 1.46-5.29 [p = .002]), renal stenosis (SR 2.4% vs. IR 0.8%; OR 2.89, 95% CI 1.00-8.38 [p = .05]), and renal artery occlusion (SR 2.4% vs. IR 1.2%; OR 2.21, 95% CI 1.15-4.25 [p = 0.02]) favoured IR fixation; however, there was no difference in haemodialysis rates.

CONCLUSION

This meta-analysis has identified small but significantly worse renal outcomes in patients having SR fixation devices compared with IR; however, there was no difference in dialysis rates and a small effect on renal dysfunction, which did not stand up to rigorous sensitivity analysis. This should be taken into consideration during graft selection, and further studies must assess renal outcomes in the longer term, and in those with pre-existing renal dysfunction.

Association of high sensitivity C-reactive protein and abdominal aortic aneurysm: a meta-analysis and systematic review

OBJECTIVE

To evaluate the association of high sensitivity C-reactive protein (hsCRP) with the presence of abdominal aortic aneurysm (AAA).

METHODS

Medline, Cochrane, Embase, and Google Scholar databases were searched until 22 June 2016 using the keywords predictive factors, biomarkers, abdominal aortic aneurysm, prediction, high sensitivity C-reactive protein, and hsCRP. Prospective studies, retrospective studies, and cohort studies were included.

RESULTS

Twelve case-control studies were included in the meta-analysis with a total of 8345 patients (1977 in the AAA group and 6368 in the control group). The pooled results showed that AAA patients had higher hsCRP value than the control group (difference in means = 1.827, 95% CI = 0.010 to 3.645, p = .049). Subgroup analysis found AAA patients with medium or small aortic diameter (<50 mm) had higher hsCRP plasma levels than the control group (difference in means = 1.301, 95% CI = 0.821 to 1.781, p < .001). In patients with large aortic diameter (≥50 mm), no difference was observed in hsCRP levels between the AAA and control groups (difference in means = 1.769, 95% CI = -1.387 to 4.925, p = .272). Multi-regression analysis found the difference in means of hsCRP plasma levels between AAA and control groups decreased as aortic diameter increased (slope = -0.04, p < .001), suggesting that hsCRP levels may be inversely associated with increasing aneurysm size.

CONCLUSIONS

Our findings suggest that hsCRP levels may possibly be used as a diagnostic biomarker for AAA patients with medium or small aortic diameter but not for AAA patients with large aortic diameter. The correlation between serum hsCRP level and AAA aneurysm is not conclusive due to the small number of included articles and between-study heterogeneity.

Editor's Choice - Trend-break in Abdominal Aortic Aneurysm Repair With Decreasing Surgical Workload

BACKGROUND

The epidemiology and management of abdominal aortic aneurysms (AAAs) has changed drastically in the past decades, with implementation of nationwide screening programs, introduction of endovascular repair (EVAR), and reduced prevalence of the disease. This report aims to assess recent trends in AAA repair epidemiology in Sweden in this context.

METHODS

Primary AAA repairs registered in the nationwide Swedish Vascular Registry (Swedvasc) 1994-2014 were analyzed regarding patient characteristics, repair incidence, technique, and outcome. Four time periods were compared: 1994-1999, 2000-2004, 2005-2009, and 2010-2014.

RESULT

The incidence of intact AAA repair increased (18.4/100,000 1994-1999, 27.3/100,000 2010-2014, p < .001) predominantly among octogenarians (12.7/100,000 1994-1999, 36.0/100,000 2010-2014, p < .001). The utilization of EVAR increased (58% of all intact AAA repairs 2010-2014), especially among octogenarians (80% 2010-2014). During the last time period, however, the incidence of intact AAA repair stabilized, despite an increasing number of screening-detected AAAs operated on (19% in 2010-2014). Short- and long-term outcome after intact AAA repair continued to improve, most pronounced among octogenarians (30-day mortality 9% 1994-1999, 2% 2010-2014, p < .001). The incidence of ruptured AAA repair steadily decreased (9.2/100,000 1994-1999, 6.9/100,000 2010-2014, p < .001) and the use of EVAR for ruptures increased (30% in 2010-2014). The previously observed improvement of short- and long-term outcome after ruptured AAA repair (30-day mortality 38% 1994-1999, 28% 2010-2014, p < .001) stalled during the last time period. The overall 30-day mortality after ruptured AAA repair was 22% after EVAR versus 31% after open repair in 2010-2014. The corresponding mortality for octogenarians was 28% versus 42%.

CONCLUSIONS

For the first time, a halt in intact AAA repair workload could be identified. This trend-break occurred despite continued increase in treatment of octogenarians and screening-detected aneurysms. Additionally, the ruptured AAA repair incidence continued to decrease. These findings, together with the sustained improvement in survival after AAA repair, may have important impact on planning of vascular surgical services.

Spontaneous Retroperitoneal Hematoma Simulating Ruptured Infrarenal Aortic Aneurysm in a Patient with End-Stage Renal Disease

We reported a case of spontaneous retroperitoneal hematoma (SRH) simulating a ruptured infrarenal aortic aneurysm. A 72-year-old man with a history of infrarenal aortic aneurysm and end-stage renal disease on hemodialysis presented with malaise and nonspecific central abdominal pain and left loin discomfort. An emergency computed tomography scan showed a large retroperitoneal hematoma and clinical suspicion of ruptured infrarenal aortic aneurysm. However, the hematoma was discontinuous with the aneurysm sac and raised the clinical suspicion on dual pathology. The SRH was treated conservatively with transfusion of blood products, and the aneurysm was treated with nonemergency endovascular repair electively. This case demonstrates the importance of recognizing different clinical and radiological characteristics and be aware of dual pathology.

Plasma D-dimer as a predictor of the progression of abdominal aortic aneurysm

Essentials D-dimer could provide important information about abdominal aortic aneurysm (AAA) progression. The greatest diameter of the infrarenal aorta and the value of plasma D-dimer were determined. AAA progression is correlated with increasing plasma D-dimer levels. The increasing value of plasma D-dimer could be a predictor of aneurysm progression.

SUMMARY

Background The natural course of abdominal aortic aneurysm (AAA) is mostly asymptomatic and unpredictable. D-dimer could provide potentially important information about subsequent AAA progression. Objectives The aims of this study were to establish the relationship between the progression of an abdominal aortic aneurysm (AAA) and plasma D-dimer concentration over a 12-month period and determine the value of plasma D-dimer in patients with sub-aneurysmal aortic dilatation. Patients/Methods This was a prospective observational study that involved 33 patients with an AAA, 30 patients with sub-aneurysmal aortic dilatation and 30 control subjects. The greatest diameter of the infrarenal aorta, which was assessed by ultrasound, and the value of plasma D-dimer were determined for all subjects at baseline assessment, as well as after 12 months for those with an AAA. Results A positive correlation was found between the diameter of an AAA and plasma D-dimer concentration at the baseline and the control measurement stages. There was a strong positive correlation between AAA progression and increasing plasma D-dimer concentration over a 12-month period. Among patients with sub-aneurysmal aortic dilatation (n = 30), the value of plasma D-dimer was higher compared with matched controls (n = 30). Conclusions There is a strongly positive correlation between AAA progression and increasing plasma D-dimer concentration. The value of plasma D-dimer is higher in patients with sub-aneurysmal aortic dilatation than in control subjects.

The impact of CT colonography on abdominal aortic aneurysm referrals in a tertiary hospital

INTRODUCTION

Computed tomography colonography (CTC) for the detection of colorectal disease is gaining popularity as an alternative to colonoscopy. This has been associated with an increase in incidental extra-colonic findings such as abdominal aortic aneurysms. However, due to the patient selection process of obtaining a CTC, it was hypothesised that this patient cohort might represent a high-risk group. The primary aim of this study was to determine the impact that CTC had on small aneurysm referrals. Owing to the potential selection bias, the secondary aim was to compare baseline characteristics referred by CTC to the cohort referred by other radiological modalities.

METHODS

Consecutive patients attending the small aneurysm clinic at a single tertiary centre were included. Baseline patient comorbidities were collected and recorded on a prospective database. The characteristics of patients who had a CTC-detected aneurysm were compared to patients referred by other radiological modalities.

RESULTS

There were 566 patients with small aneurysms included. Of these, 96 (17.0%) had their aneurysm detected from CTC and the remaining aneurysms were detected by other radiological modalities. These patients were on average 2 years older and were less likely to have a smoking history. There was no difference in other patient characteristics.

CONCLUSION

Computed tomography colonography contributed to the initial diagnosis of one in five patients with small aneurysms. Despite a potential selection bias for patients undergoing CTC, there were no major baseline differences between the CTC cohort and patients referred by other radiological modalities. Routine assessment of the aorta during a CTC may aid in aneurysm detection.

Assessing the Stability of Aortic Aneurysms with Pulse Wave Imaging

Purpose To assess whether the stability of murine aortic aneurysms is associated with the homogeneity of pulse wave propagation within the saccular wall. Materials and Methods All animal procedures were approved by the institutional Animal Care and Use Committee. Apolipoprotein E and tissue inhibitor of metalloproteinases-1 knockout mice (n = 26) were infused with angiotensin II by using subcutaneously implanted osmotic pumps, with an additional control mouse used for histologic examination (n = 1). Pulse wave imaging (PWI) was performed just before infusion and 15 days after infusion by using 40-MHz ultrasonography at 8000 frames per second (with electrocardiographic gating). Aneurysm appearance on B-mode images was monitored every 2-3 days for 30 days. On the basis of B-mode images obtained after 30 days, aneurysms were deemed to have been unstable if they had ruptured; otherwise, they were deemed stable. Statistical significance was assessed by using two-tailed t tests. Results In normal aortas, the pulse waves propagated at relatively constant velocities (mean ± standard deviation, 2.8 m/sec ± 0.9). Fifteen days after infusion, all mice had developed aneurysms, with significant (P < .001/12) changes in maximum anterior-posterior diameter (increase of 54.9% ± 2.5) and pulse wave velocity (PWV) (decrease of 1.3 m/sec ± 0.8). While there was no significant difference in these parameters (P = .45 for diameter and P = .55 for PWV) between stable aneurysms (n = 12) and unstable aneurysms (n = 14), the standard deviation of the high-resolution PWV was significantly higher (P < .001/12) in unstable aneurysms (5.7 m/sec ± 1.6) than in stable ones (3.2 m/sec ± 0.9). Conclusion High-resolution PWI was used to measure the local homogeneity of pulse wave propagation within the saccular wall, which is lower in unstable aneurysms than in stable ones. Hence, if proven to add additional information beyond size and appearance in human studies, PWI could potentially be used to assess the stability of aneurysms by providing information that is complementary to the anatomic data obtained with conventional B-mode imaging. ^© RSNA, 2016 Online supplemental material is available for this article.