High-risk and low-risk screening for abdominal aortic aneurysm both reduce aneurysm-related mortality. A stratified analysis from a single-centre randomised screening trial

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.

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.

The association of ANRIL with coronary artery disease and aortic aneurysms, how far does the gene desert go?

BACKGROUND

Coronary artery disease (CAD) and aortic aneurysms (AA) are two cardiovascular diseases that share a multifactorial aetiology. The influence of family history and genetics on the two diseases separately and in association is well known, but poorly elucidated. This comprehensive review aims to examine the current literature on the gene ANRIL (antisense non-coding RNA in the INK4 locus) and its associations with CAD and AA.

METHODS

A database search on OVID, PubMed and Cochrane to identify articles concerning single nucleotide polymorphisms (SNPs) associated with ANRIL and their respective incidences of, and impact on, CAD and AA across populations.

RESULTS

Cohort studies across various ethnicities reveal that various ANRIL SNPs are significantly associated separately with CAD (rs1333040, rs1333049 and rs2383207) and AA (rs564398, rs10757278 and rs1333049), and that these SNPs are present in significant proportions of the population. SNP rs1333049 is significantly associated with both diseases, but is positively correlated with AAA and negatively correlated with CAD. This review further outlines several pathophysiological links via endothelial and adventitial cells, vascular smooth muscle cells and sense gene interaction, which may explain these genetic associations identified.

CONCLUSION

Given the associations uncovered between ANRIL polymorphisms and CAD and AA, as well as the molecular mechanisms which may explain the underlying pathophysiology, ANRIL appears to be strongly linked with both diseases. ANRIL may hence have a future application in screening normal patients and risk stratifying patients with both diseases. Its role in linking the two diseases is yet unclear, warranting further studies.

Screening for aneurysms of the abdominal aorta using a simple screening device

Introduction

Several countries advocate screening for aneurysms of the abdominal aorta (AAA) in selected patients. In the Netherlands, routine screening is currently under review by the National Health Council. In any screening programme, cost-efficiency and accuracy are key. In this study, we evaluate the Aorta Scan (Verathon, Amsterdam, Netherlands), a cost-effective and easy-to-use screening device based on bladder scan technology, which enables untrained personnel to screen for AAA.

Methods

We subjected 117 patients to an Aorta Scan and compared the results to the gold standard (abdominal ultrasound). We used statistical analysis to determine sensitivity and specificity of the Aorta Scan, as well as the positive and negative predictive values, accuracy, and inter-test agreement (Kappa).

Results

Sensitivity and specificity were 0.86 and 0.98, respectively. Positive predictive value was 0.98 and negative predictive value was 0.88. Accuracy was determined at 0.92 and the Kappa value was 0.85. When waist–hip circumferences (WHC) of > 115 cm were excluded, sensitivity raised to 0.96, specificity stayed 0.98, positive and negative predictive value were 0.98 and 0.96, respectively, accuracy to 0.97, and Kappa to 0.94.

Conclusion

Herein, we show that the Aorta Scan is a cost-effective and very accurate screening tool, especially in patients with WHC below 115 cm, which makes it a suitable candidate for implementation into clinical practice, specifically in the setting of screening selected populations for the presence of AAA.

Primary Care Screening for Abdominal Aortic Aneurysm: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Ruptured abdominal aortic aneurysms (AAAs) have mortality estimated at 81%.

OBJECTIVE

To systematically review the evidence on benefits and harms of AAA screening and small aneurysm treatment to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed (publisher supplied only), Database of Abstracts of Reviews of Effects, and Cochrane Central Register of Controlled Trials for relevant English-language studies published through September 2018. Surveillance continued through July 2019.

STUDY SELECTION

Trials of AAA screening benefits and harms; trials and cohort studies of small (3.0-5.4 cm) AAA treatment benefits and harms.

DATA EXTRACTION AND SYNTHESIS

Two investigators independently reviewed abstracts and full-text articles and extracted data. The Peto method was used to pool odds ratios (ORs) for AAA-related mortality, rupture, and operations; the DerSimonian and Laird random-effects model was used to pool calculated risk ratios for all-cause mortality.

MAIN OUTCOMES AND MEASURES

AAA and all-cause mortality; AAA rupture; treatment complications.

RESULTS

Fifty studies (N = 323 279) met inclusion criteria. Meta-analysis of population-based randomized clinical trials (RCTs) estimated that a screening invitation to men 65 years or older was associated with a reduction in AAA-related mortality over 12 to 15 years (OR, 0.65 [95% CI, 0.57-0.74]; 4 RCTs [n = 124 926]), AAA-related ruptures over 12 to 15 years (OR, 0.62 [95% CI, 0.55-0.70]; 4 RCTs [n = 124 929]), and emergency surgical procedures over 4 to 15 years (OR, 0.57 [95% CI, 0.48-0.68]; 5 RCTS [n = 175 085]). In contrast, no significant association with all-cause mortality benefit was seen at 12- to 15-year follow-up (relative risk, 0.99 [95% CI 0.98-1.00]; 4 RCTs [n = 124 929]). One-time screening was associated with significantly more procedures over 4 to 15 years in the invited group compared with the control group (OR, 1.44 [95% CI, 1.34-1.55]; 5 RCTs [n = 175 085]). Four trials (n = 3314) of small aneurysm surgical treatment demonstrated no significant difference in AAA-related mortality or all-cause mortality compared with surveillance over 1.7 to 12 years. These 4 early surgery trials showed a substantial increase in procedures in the early surgery group. For small aneurysm treatment, registry data (3 studies [n = 14 424]) showed that women had higher surgical complications and postoperative mortality compared with men.

CONCLUSIONS AND RELEVANCE

One-time AAA screening in men 65 years or older was associated with decreased AAA-related mortality and rupture rates but was not associated with all-cause mortality benefit. Higher rates of elective surgery but no long-term differences in quality of life resulted from screening.

Screening based on risk factors for abdominal aortic aneurysm in the cardiology clinic

BACKGROUND

The risk factors for abdominal aortic aneurysm (AAA) are present in many of the patients that attend our cardiology service. The aim of this study was the evaluation of the prospects of examining the abdominal aorta during our consultations and the relationship of AAA with risk factors and ischemic cardiopathy.

METHODS

A descriptive transversal observational study was designed including 274 male patients aged ≥60 years, attended consecutively in the cardiology service, in which we studied the abdominal aorta and adjusted a logistic regression model to determine the risk factors associated with AAA.

RESULTS

We were able to visualize and measure the abdominal aorta in 95.4% of cases in a fast and reliable way. The prevalence of AAA was 8.76%. 75% of patients with AAA presented ischemic heart disease. Patients with AAA were characterized by the presence of ischemic cardiopathy (Odds Ratio (OR): 4.27, 95% Confidence Interval (CI): 1.37-13.31, p = 0.012), dyslipidemia (OR: 4.99, 95% CI: 1, 07-23.31; p = 0.041), arterial hypertension (OR: 4.14, 95% CI: 1.07-15.98, p = 0.039), and a longer history of smoking (OR: 1.03; 95% CI: 1002-1.054; p = 0.037).

CONCLUSIONS

The evaluation of the abdominal aorta during cardiology consultations is feasible with the standard resources. Patients treated in the cardiology service present a high prevalence of AAA. We have adjusted and validated a clinical prediction model based on risk factors that allows the identification, in the cardiology consult, of patients with the highest risk of suffering from AAA.

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.

The UK EndoVascular Aneurysm Repair (EVAR) randomised controlled trials: long-term follow-up and cost-effectiveness analysis

BACKGROUND

Short-term survival benefits of endovascular aneurysm repair (EVAR) compared with open repair (OR) of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is soon lost. Survival benefit of EVAR was unclear at follow-up to 10 years.

OBJECTIVE

To assess the long-term efficacy of EVAR against OR in patients deemed fit and suitable for both procedures (EVAR trial 1; EVAR-1); and against no intervention in patients unfit for OR (EVAR trial 2; EVAR-2). To appraise the long-term significance of type II endoleak and define criteria for intervention.

DESIGN

Two national, multicentre randomised controlled trials: EVAR-1 and EVAR-2.

SETTING

Patients were recruited from 37 hospitals in the UK between 1 September 1999 and 31 August 2004.

PARTICIPANTS

Men and women aged ≥ 60 years with an aneurysm of ≥ 5.5 cm (as identified by computed tomography scanning), anatomically suitable and fit for OR were randomly assigned 1 : 1 to either EVAR (n = 626) or OR (n = 626) in EVAR-1 using computer-generated sequences at the trial hub. Patients considered unfit were randomly assigned to EVAR (n = 197) or no intervention (n = 207) in EVAR-2. There was no blinding.

INTERVENTIONS

EVAR, OR or no intervention.

MAIN OUTCOME MEASURES

The primary end points were total and aneurysm-related mortality until mid-2015 for both trials. Secondary outcomes for EVAR-1 were reinterventions, costs and cost-effectiveness.

RESULTS

In EVAR-1, over a mean of 12.7 years (standard deviation 1.5 years; maximum 15.8 years), we recorded 9.3 deaths per 100 person-years in the EVAR group and 8.9 deaths per 100 person-years in the OR group [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.97 to 1.27; p = 0.14]. At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0.61, 95% CI 0.37 to 1.02 for total mortality; HR 0.47, 95% CI 0.23 to 0.93 for aneurysm-related mortality; p = 0.031), but beyond 8 years of follow-up patients in the OR group had a significantly lower mortality (adjusted HR 1.25, 95% CI 1.00 to 1.56, p = 0.048 for total mortality; HR 5.82, 95% CI 1.64 to 20.65, p = 0.0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture, with increased cancer mortality also observed in the EVAR group. Overall, aneurysm reintervention rates were higher in the EVAR group than in the OR group, 4.1 and 1.7 per 100 person-years, respectively (p < 0.001), with reinterventions occurring throughout follow-up. The mean difference in costs over 14 years was £3798 (95% CI £2338 to £5258). Economic modelling based on the outcomes of the EVAR-1 trial showed that the cost per quality-adjusted life-year gained over the patient's lifetime exceeds conventional thresholds used in the UK. In EVAR-2, patients died at the same rate in both groups, but there was suggestion of lower aneurysm mortality in those who actually underwent EVAR. Type II endoleak itself is not associated with a higher rate of mortality.

LIMITATIONS

Devices used were implanted between 1999 and 2004. Newer devices might have better results. Later follow-up imaging declined, particularly for OR patients. Methodology to capture reinterventions changed mainly to record linkage through the Hospital Episode Statistics administrative data set from 2009.

CONCLUSIONS

EVAR has an early survival benefit but an inferior late survival benefit compared with OR, which needs to be addressed by lifelong surveillance of EVAR and reintervention if necessary. EVAR does not prolong life in patients unfit for OR. Type II endoleak alone is relatively benign.

FUTURE WORK

To find easier ways to monitor sac expansion to trigger timely reintervention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN55703451.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the results will be published in full in Health Technology Assessment; Vol. 22, No. 5. See the NIHR Journals Library website for further project information.

Screening for abdominal aortic aneurysm in asymptomatic adults

BACKGROUND

This report was produced for the Canadian Task Force on Preventive Health Care to provide guidelines on screening for abdominal aortic aneurysm (AAA) with ultrasound scan.

PURPOSE

The aim of this systematic review is to examine the evidence on benefits and harms of AAA screening.

SEARCH STRATEGY

This systematic review considered studies from the most recent United States Preventive Services Task Force review on AAA screening and passed through the screening process with citations identified in our search up to April 2015 (PROSPERO Registration #CRD42015019047).

RESULTS

For benefits of one-time AAA screening in men compared with controls, pooled analyses from four randomized controlled trials with moderate quality evidence showed significant reductions in AAA-related mortality and AAA rupture rate up to 13 to 15 years of follow-up with 42% reduction (risk ratio [RR], 0.58; 95% confidence interval [CI], 0.39-0.88; number needed to screen = 212) and 38% reduction (RR, 0.62; 95% CI, 0.45-0.86; number needed to screen = 200), respectively. The effect of on all-cause mortality was marginally significant for longer follow-up. The Chichester trial examined the benefits of one-time AAA screening in women and found no significant differences between screening and control arms for up to 10 years of follow-up (RR, 0.88; 95% CI, 0.72-1.07). For consequences of one-time AAA screening in men compared with controls, there was a significant increase in the total number of AAA-related procedures over a follow-up of 13 to 15 years (2.16 times more likely) compared with controls. For harms of one-time AAA screening, no significant differences were observed in 30-day postoperative mortality for elective and emergency operations with compared control groups. Evidence from the Multicenter Aneurysm Screening Study trial using 13-year follow-up data showed that one-time AAA screening with ultrasound scan was potentially associated with an overdiagnosis of 45% (95% CI, 42%-47%) among screen-detected men.

CONCLUSIONS

Population-based screening for AAA with ultrasound scan in asymptomatic men aged 65 years and older showed statistically significant reductions in AAA-related mortality and rupture and, hence, avoids unnecessary AAA-related deaths. The current evidence showed no benefit of one-time AAA screening in woman. Limited evidence is available on the benefits of repeat AAA screening and targeted screening approaches based on risk factors for AAA. Future research should explore the differential benefits of AAA screening based on risk factors that increase risk for developing AAA.

A Meta-Analysis of the Association of Chronic Obstructive Pulmonary Disease with Abdominal Aortic Aneurysm Presence

BACKGROUND

Several case-control and population-based abdominal aortic aneurysm (AAA) screening studies have reported inconclusive results of the association of chronic obstructive pulmonary disease (COPD) with AAA presence. To determine whether COPD is associated with AAA presence, we performed a meta-analysis of contemporary clinical studies.

METHODS

To identify all contemporary case-control and population-based AAA screening studies evaluating the association of COPD with AAA presence, databases including MEDLINE and EMBASE were searched from January 2000 to May 2015 using Web-based search engines (PubMed and OVID). An adjusted odds ratio (OR) and 95% confidence intervals (CI) for COPD or AAA presence (using multivariable logistic regression) were abstracted from each individual study. We took an OR for AAA presence to be representative of an OR for COPD presence.

RESULTS

Of 159 potentially relevant articles screened initially, there were 7 case-control and 4 population-based AAA screening studies that met eligibility requirements and were included. Pooled analysis of all the 11 studies (14 estimates, 155,731 participants), 7 case-control studies (4171 participants), and 4 population-based AAA screening studies (7 estimates, 151,560 participants) respectively demonstrated a statistically significant 1.78-fold (OR 1.78, 95% CI 1.38-2.30, P < 0.00001), 3.05-fold (OR 3.05, 95% CI 1.44-6.49, P = 0.004), and 1.24-fold (OR 1.24, 95% CI 1.04-1.48, P = 0.02) increased prevalence/incidence of COPD in patients with AAA relative to subjects without AAA (i.e., a statistically significant 1.78-, 3.05-, and 1.24-fold increased prevalence/incidence of AAA in patients with COPD relative to subjects without COPD) (P for subgroup differences = 0.02).

CONCLUSION

The present meta-analysis demonstrated 1.8-fold increased prevalence/incidence of COPD in patients with AAA relative to subjects without AAA (i.e., 1.8-fold increased prevalence/incidence of AAA in patients with COPD relative to subjects without COPD), which suggests that COPD is associated with AAA presence.

Simple renal cyst and abdominal aortic aneurysm

OBJECTIVE

To summarize the association of simple renal cyst (SRC) with abdominal aortic aneurysm (AAA), we reviewed currently available clinical studies with a systematic literature search and meta-analytic evaluation.

METHODS

To identify all case-control studies evaluating the association of SRC with AAA, databases including MEDLINE and Embase were searched through April 2015 using web-based search engines (PubMed and Ovid). For each study, data regarding SRC prevalence in both the AAA and control groups were used to generate unadjusted odds ratios (ORs) and 95% confidence intervals. When an adjusted OR (by the use of multivariable logistic regression) was available, we preferentially abstracted the adjusted OR rather than an unadjusted OR.

RESULTS

Of 139 potentially relevant articles screened initially, 5 eligible case-control studies enrolling a total of 2897 participants were identified and included. A pooled analysis of seven estimates from the five studies demonstrated a statistically significant 2.54-fold prevalence of SRC in patients with AAA relative to subjects without AAA (OR, 2.54; 95% confidence interval, 1.93-3.34; P < .00001).

CONCLUSIONS

Our meta-analytic evaluation demonstrated 2.5-fold prevalence of SRC in patients with AAA relative to subjects without AAA, which suggests that SRC is associated with AAA.

The Danish Cardiovascular Screening Trial (DANCAVAS): study protocol for a randomized controlled trial

Background

The significant increase in the average life expectancy has increased the societal challenge of managing serious age-related diseases, especially cancer and cardiovascular diseases. A routine check by a general practitioner is not sufficient to detect incipient cardiovascular disease.

Design

Population-based randomized clinically controlled screening trial.

Methods

Participants: 45,000 Danish men aged 65–74 years living on the Island of Funen, or in the surrounding communities of Vejle and Silkeborg. No exclusion criteria are used.

Interventions: One-third will be invited to cardiovascular seven-faceted screening examinations at one of four locations. The screening will include: (1) low-dose non-contrast CT scan to detect coronary artery calcification and aortic/iliac aneurysms, (2) brachial and ankle blood pressure index to detect peripheral arterial disease and hypertension, (3) a telemetric assessment of the heart rhythm, and (4) a measurement of the cholesterol and plasma glucose levels. Up-to-date cardiovascular preventive treatment is recommended in case of positive findings.

Objective: To investigate whether advanced cardiovascular screening will prevent death and cardiovascular events, and whether the possible health benefits are cost effective.

Outcome: Registry-based follow-up on all cause death (primary outcome), and costs after 3, 5 and 10 years (secondary outcome).

Randomization: Each of the 45,000 individuals is, by EPIDATA, given a random number from 1–100. Those numbered 67+ will be offered screening; the others will act as a control group.

Blinding: Only those randomized to the screening will be invited to the examination;the remaining participants will not.

Numbers randomized: A total of 45,000 men will be randomized 1:2.

Recruitment: Enrollment started October 2014.

Outcome: A 5 % reduction in overall mortality (HR = 0.95), with the risk for a type 1 error = 5 % and the risk for a type II error = 80 %, is expected. We expect a 2-year enrollment, a 10-year follow-up, and a median survival of 15 years among the controls. The attendance to screening is assumed to be 70 %.

Discussion

The primary aim of this so far stand-alone population-based, randomized trial will be to evaluate the health benefits and costeffectiveness of using non-contrast full truncus computer tomography (CT) scans (to measure coronary artery calcification (CAC) and identify aortic/iliac aneurysms) and measurements of the ankle brachial blood pressure index (ABI) as part of a multifocal screening and intervention program for CVD in men aged 65–74.

Attendance rate and compliance to initiated preventive actions must be expected to become of major importance.

Trial registration

Current Controlled Trials: ISRCTN12157806 (21 March 2015).

The prevalence of abdominal aortic aneurysm is consistently high among patients with coronary artery disease

OBJECTIVE

Emerging evidence suggests high prevalence of abdominal aortic aneurysm (AAA) among patients with coronary disease. Accurate characterization of the association between coronary disease and AAA and of the actual prevalence of AAA among patients with angiography-verified coronary artery disease (CAD) is needed to evaluate the possible benefits of systematic screening for AAA.

METHODS

We searched for studies that reported the association between AAA and CAD or coronary heart disease (CHD; wider phenotype definition) in the general population (randomized controlled trials, prospective population cohorts) and those that reported the prevalence of AAA among patients with angiography-verified CAD through PubMed, Embase, and reference lists for the period between 1980 and 2014. Random-effects models were applied because of the high heterogeneity between included studies.

RESULTS

Among the general population, 23 studies reported the association between CHD and the occurrence of subclinical AAA (positive ultrasound screening; meta-analyzed odds ratio of 2.38 with 95% confidence interval [CI] of 1.78-3.19; P = 4.1 × 10(-9)). According to four prospective studies, CHD is a strong predictor of future AAA events (fatal and nonfatal; meta-analyzed hazard ratio of 3.49 with 95% CI of 2.56-4.76; P = 2.4 × 10(-15)). Altogether, 10 studies reported the prevalence of AAA among patients with angiography-verified CAD or undergoing coronary artery bypass grafting. Among men, meta-analyzed prevalence was 9.5% (95% CI, 7.6%-11.7%). Among men undergoing coronary artery bypass grafting or with three-vessel disease, the prevalence was 11.4% (95% CI, 9.1%-13.9%). Among women, the prevalence was low (0.35%).

CONCLUSIONS

The risk of subclinical AAA and future AAA events is high among patients with coronary disease. Screening for AAA among CAD patients by cardiologists would be easy and inexpensive, with possible benefits to survival and risk evaluation.

Academic vascular unit collaboration with advertising agency yields higher compliance in screening for abdominal aortic aneurysm

To improve compliance with abdominal aortic aneurysm (AAA) screening in low compliance areas, individually tailored invitations were developed in collaboration with a professional advertising agency. Compliance increased in two intervention municipalities from 71.4% in 2010–2012 to 78.1% in 2013 (p = 0.025), and was then higher [odds ratio 1.7; 95% confidence interval 1.1–2.6; p = 0.013] than in two control municipalities in which compliance was unchanged (417/552 [75.5%] in 2010–12 and 122/180 [67.8%] in 2013). Compliance with AAA-screening can be increased by collaboration with a professional advertising agency, albeit at a comparably high cost.

Abdominal Aortic Aneurysms

Abdominal aortic aneurysms represent both an individual risk of mortality and a socioeconomic burden for health care systems worldwide, but screening is not performed in all countries. Here, the authors summarize the pros and cons of screening to reduce abdominal aortic aneurysm–related mortality.

Novel aspects of the pathogenesis of aneurysms of the abdominal aorta in humans

Aneurysm of the abdominal aorta (AAA) is a particular, specifically localized form of atherothrombosis, providing a unique human model of this disease. The pathogenesis of AAA is characterized by a breakdown of the extracellular matrix due to an excessive proteolytic activity, leading to potential arterial wall rupture. The roles of matrix metalloproteinases and plasmin generation in progression of AAA have been demonstrated both in animal models and in clinical studies. In the present review, we highlight recent studies addressing the role of the haemoglobin-rich, intraluminal thrombus and the adventitial response in the development of human AAA. The intraluminal thrombus exerts its pathogenic effect through platelet activation, fibrin formation, binding of plasminogen and its activators, and trapping of erythrocytes and neutrophils, leading to oxidative and proteolytic injury of the arterial wall. These events occur mainly at the intraluminal thrombus-circulating blood interface, and pathological mediators are conveyed outwards, where they promote matrix degradation of the arterial wall. In response, neo-angiogenesis, phagocytosis by mononuclear cells, and a shift from innate to adaptive immunity in the adventitia are observed. Abdominal aortic aneurysm thus represents an accessible spatiotemporal model of human atherothrombotic progression towards clinical events, the study of which should allow further understanding of its pathogenesis and the translation of pathogenic biological activities into diagnostic and therapeutic applications.

Long-term benefit and cost-effectiveness analysis of screening for abdominal aortic aneurysms from a randomized controlled trial

Background

The aim was to estimate long-term mortality benefits and cost-effectiveness of screening for abdominal aortic aneurysm (AAA) in men aged 64–73 years.

Methods

All men aged 64–73 years living in Viborg County were randomized to be controls (n = 6306) or invited for abdominal ultrasonography at a regional hospital (n = 6333). Mortality and AAA-related interventions were recorded in national databases. The cost of initial screening was based on actual costs of the programme. Incremental cost-effectiveness ratios (ICERs) were calculated on gains in life years and Quality Adjusted Life Years (QALY). Discounting (3 per cent) was applied to both costs and effects, and all costs were adjusted to euros at 2007 prices.

Results

The relative risk reduction of the screening programme in AAA-related mortality was 66 per cent (hazard ratio 0·34, 95 per cent confidence interval (c.i.) 0·20 to 0·57). The corresponding risk reduction in all-cause mortality was 2 per cent (hazard ratio 0·98, 95 per cent c.i. 0·93 to 1·03). The ICER was estimated at €157 (−3292 to 4401) per life year gained and €179 (−4083 to 4682) per QALY gained. Screening was found to be cost effective at a probability above 0·97 for a willingness-to-pay threshold of only €5000. One-way sensitivity analysis demonstrated that this result was robust to various alternative assumptions, as the probability did not drop below 0·90 for any scenario.

Conclusion

The mortality benefit of screening for AAA in men aged 64–73 years was maintained in the longer term and screening was cost effective. Registration number: ISRCTN65822028 (http://www.controlled-trials.com).

Screening for abdominal aortic aneurysm--areas where information is still inadequate

Abdominal aortic aneurysm (AAA) fulfils the criteria for a disease suitable for screening. However, important aspects need to be further analysed; the optimal age of the male population considered for screening has not yet been established, and whether women or specific high risk groups would benefit from screening has not been sufficiently evaluated. The impact of the current shift toward a high proportion of AAA repair done with endovascular technique and the long-term effect on QoL are additional issues that have not been adequately studied. Furthermore, therapeutic options for small AAA as well as secondary prevention programmes have to be developed.