P.W. Stather

Systematic review and meta-analysis of the early and late outcomes of open and endovascular repair of abdominal aortic aneurysm.

Any possible long‐term benefit from endovascular (EVAR) versus open surgical repair for abdominal aortic aneurysm (AAA) remains unproven. Long‐term data from the Open Versus Endovascular Repair (OVER) trial add to the debate regarding long‐term all‐cause and aneurysm‐related mortality. The aim of this study was to investigate 30‐day and long‐term mortality, reintervention, rupture and morbidity after EVAR and open repair for AAA in a systematic review.

Type II endoleak after endovascular aneurysm repair

The aim was to assess the risk of rupture, and determine the benefits of intervention for the treatment of type II endoleak after endovascular abdominal aortic aneurysm repair (EVAR).

Aneurysm Global Epidemiology Study Public Health Measures Can Further Reduce Abdominal Aortic Aneurysm Mortality

Background— Contemporary data from Western populations suggest steep declines in abdominal aortic aneurysm (AAA) mortality; however, international trends are unclear. This study aimed to investigate global AAA mortality trends and to analyze any association with common cardiovascular risk factors. Methods and Results— AAA mortality (1994–2010) using International Classification of Diseases codes were extracted from the World Health Organization mortality database and age standardized. The World Health Organization InfoBase and International Mortality and Smoking Statistics provided risk factor data. Nineteen World Health Organization member states were included (Europe, 14; Australasia, 2; North America, 2; Asia, 1). Regression analysis of temporal trends in cardiovascular risk factors (1946–2010) was done independently for correlations to AAA mortality trends. Global AAA mortality trends show substantial heterogeneity, with the United States and United Kingdom recording the greatest national decline, whereas internationally, male individuals and those <75 years of age demonstrated the greatest reductions. AAA mortality has increased in Hungary, Romania, Austria, and Denmark; therefore, the mortality decline is not universal. A positive linear relationship exists between global trends in systolic blood pressure (P⩽0.03), cholesterol (P⩽0.03), and smoking prevalence (P⩽0.02) in males and females. Body mass index demonstrated a negative linear association with AAA mortality (P⩽0.007), whereas fasting blood glucose showed no association. Conclusions— AAA mortality has not declined globally, and this study reveals that differences between nations can be explained by variations in traditional cardiovascular risk factors. Declines in smoking prevalence correlate most closely with declines in AAA mortality, and a novel obesity paradox has been identified that requires further investigation. Public health measures could therefore further reduce global AAA mortality, with greatest benefits in the younger age group.

Endovascular Aortic Aneurysm Repair in Patients with Hostile Neck Anatomy

Purpose To report a systematic review and meta-analysis of outcomes following endovascular aneurysm repair (EVAR) in patients with hostile neck anatomy (HNA) vs. those with favorable neck anatomy (FNA). Methods Systematic review and meta-analysis of data on EVAR in patients with HNA and FNA was performed by 2 reviewers in February 2013. An eligible study was required to have at least 50 participants and to incorporate one or more of the HNA criteria of neck length <15 mm, neck diameter >28 mm, and/or angulation >60°. Of the 24 full-length articles ultimately reviewed, 8 were excluded, resulting in 16 articles that were suitable for inclusion in the meta-analysis. The study size ranged from 55 to 5183 participants, with a total of 8920 patients in the FNA group and 3039 patients in the HNA group. Mean follow-up ranged from 9 to 49 months. Results Analysis of the pooled data revealed a significant increase in 30-day mortality (2.4% FNA vs. 3.5% HNA; OR 1.60, 95% CI 1.13 to 2.27; p<0.01), intraoperative adjuncts (8.8% FNA vs. 15.4% HNA; OR 1.88, 95% CI 1.15 to 3.07; p=0.01), and 30-day migration (0.9% FNA vs. 1.6% HNA; OR 2.08, 95% CI 1.20 to 3.62; p=0.009) in patients with HNA. A decrease in primary technical success (97.5% FNA vs. 93.8% HNA; OR 0.41, 95% CI 0.18 to 0.93; p=0.03) was significant when all 3 criteria were used to define HNA. For outcomes at >30 days, the increase in secondary interventions (OR 1.29, 95% CI 1.00 to 1.66; p=0.05) approached significance, but aneurysm-related mortality, all-cause mortality, migration, and aortic rupture did not achieve statistical significance. There was no difference in rates of sac expansion. Analysis of endoleak rates revealed a significant increase in 30-day type I endoleaks (OR 2.92,95% CI 1.61 to 5.30; p<0.001) and late type I endoleaks (OR 1.71,95% CI 1.31 to 2.23; p<0.0001) in patients with HNA. Conclusion These results suggest that performing EVAR in patients with HNA increases the technical difficulty and results in poorer short-term outcomes. The higher rates of early and late type I endoleaks, along with secondary interventions, suggest that increased monitoring should be performed in this category of patient to ensure rapid treatment.

International variations in AAA screening.

INTRODUCTION Abdominal aortic aneurysm (AAA) screening programmes reduce AAA-related mortality and are cost-effective. This study aims to assess the state and variability of AAA screening programmes worldwide. METHODS Data were obtained from an international expert group convened at the 34th Charing Cross Symposium as well as government websites and published reports on screening programmes. RESULTS Six countries are in the process of implementing national AAA screening programmes, with Italy still performing screening trials. There is wide variability in inclusion criteria between countries with the majority screening only men in their 65th year, however 3 programmes include women, 2 programmes only include patients with high cardiovascular risk, and 2 trials are also screening for hypertension and lower limb atherosclerosis. Surveillance intervals vary between screening programmes, with the most common regimen being to vary the surveillance interval depending upon aneurysm size, however the optimum surveillance interval in terms of decreasing mortality and cost effectiveness remains uncertain. DISCUSSION International dissemination of current AAA screening programme outcomes is required to inform developing programmes about optimum screening intervals, benefits of surveillance of the subaneurysmal aorta, and screening for other cardiovascular disease.

Differential microRNA expression profiles in peripheral arterial disease.

Background—Peripheral arterial disease (PAD) is a clinical condition caused by an atherosclerotic process affecting the arteries of the limbs. Despite major improvements in surgical endovascular techniques, PAD is still associated with high mortality and morbidity. Recently, microRNAs (miRNAs), a class of short noncoding RNA controlling gene expression, have emerged as major regulators of multiple biological processes. Methods and Results—A whole-miRNA transcriptome profiling was performed in peripheral blood from an initial sample set of patients and controls. A 12-miRNA PAD-specific signature, which includes let 7e, miR-15b, -16, -20b, -25, -26b, -27b, -28-5p, -126, -195, -335, and -363, was further investigated and validated in 2 additional sample sets. Each of these 12 miRNAs exhibited good diagnostic value as evidenced by receiver operating characteristic curve analyses. Pathway enrichment analysis using predicted and validated targets identified several signaling pathways relevant to vascular disorders. Several of these pathways, including cell adhesion molecules, were confirmed by quantifying the expression level of several candidate genes regulating the initial stages of the inflammatory atherosclerotic process. The expression level of 7 of these candidate genes exhibits striking inverse correlation with that of several, if not all, of the miRNAs of the PAD-specific miRNA signature. Conclusions—These results demonstrate the potential of miRNAs for the diagnosis of PAD and provide further insight into the molecular mechanisms leading to the development of PAD, with the potential for future therapeutic targets.

A multicentre observational study of the outcomes of screening detected sub-aneurysmal aortic dilatation.

OBJECTIVES Currently most abdominal aortic aneurysm screening programmes discharge patients with aortic diameter of less than 30 mm. However, sub-aneurysmal aortic dilatation (25 mm-29 mm) does not represent a normal aortic diameter. This observational study aimed to determine the outcomes of patients with screening detected sub aneurysmal aortic dilatation. DESIGN AND METHODS Individual patient data was obtained from 8 screening programmes that had performed long term follow up of patients with sub aneurysmal aortic dilatation. Outcome measures recorded were the progression to true aneurysmal dilatation (aortic diameter 30 mm or greater), progression to size threshold for surgical intervention (55 mm) and aneurysm rupture. RESULTS Aortic measurements for 1696 men and women (median age 66 years at initial scan) with sub-aneurysmal aortae were obtained, median period of follow up was 4.0 years (range 0.1-19.0 years). Following Kaplan Meier and life table analysis 67.7% of patients with 5 complete years of surveillance reached an aortic diameter of 30 mm or greater however 0.9% had an aortic diameter of 54 mm. A total of 26.2% of patients with 10 complete years of follow up had an AAA of greater that 54 mm. CONCLUSION Patients with sub-aneurysmal aortic dilatation are likely to progress and develop an AAA, although few will rupture or require surgical intervention.

Meta‐analysis and meta‐regression analysis of biomarkers for abdominal aortic aneurysm

Many studies have investigated the systemic and local expression of biomarkers in patients with abdominal aortic aneurysm (AAA). The natural history of AAA varies between patients, and predictors of the presence and diameter of AAA have not been determined consistently. The aim of this study was to perform a systematic review, meta‐analysis and meta‐regression of studies comparing biomarkers in patients with and without AAA, with the aim of summarizing the association of identified markers with both AAA presence and size.

A Review of Current Reporting of Abdominal Aortic Aneurysm Mortality and Prevalence in the Literature

BACKGROUND It is common for authors to introduce a paper by demonstrating the importance of the clinical condition being addressed, usually by quoting data such as mortality and prevalence rates. Abdominal aortic aneurysm (AAA) epidemiology is changing, and therefore such figures for AAA are subject to error. The aim of this study was to analyse the accuracy of AAA prevalence and mortality citations in the contemporaneous literature. METHODS Two separate literature searches were performed using PubMed to identify studies reporting either aneurysm prevalence or mortality. The first 40 articles or those published over the last 2 years were included in each search to provide a snapshot of current trends. For a prevalence citation to be appropriate, a paper had to cite an original article publishing its own prevalence of AAA or a national report. In addition, the cited prevalence should match that published within the referenced article. These reported statistics were compared with the most recent data on aneurysm-related mortality. RESULTS The prevalence of AAA was reported to be as low as 1% and as high as 12.7% (mean 5.7%, median 5%). Only 47.5% of studies had referenced original articles, national reports or NICE, and only 32.4% of cited prevalences matched those from the referenced article. In total 5/40 studies were completely accurate. 80% of studies cited aneurysm mortality in the USA, with the majority stating 15,000 deaths per year (range 9,000 to 30,000). Current USA crude AAA mortality is 6,289 (2010). CONCLUSION References for AAA mortality and prevalence reported in the current literature are often inaccurate. This study highlights the importance of accurately reporting mortality and prevalence data and using up-to-date citations.

Identification of microRNAs associated with abdominal aortic aneurysms and peripheral arterial disease

MicroRNAs are crucial in the regulation of cardiovascular disease and represent potential therapeutic targets to decrease abdominal aortic aneurysm (AAA) expansion. The aim of this study was to identify circulating microRNAs associated with AAA.