Age-specific incidence, risk factors and outcome of acute abdominal aortic aneurysms in a defined population

Tropoelastin: an in vivo imaging marker of dysfunctional matrix turnover during abdominal aortic dilation

Aims

Dysfunctional matrix turnover is present at sites of abdominal aortic aneurysm (AAA) and leads to the accumulation of monomeric tropoelastin rather than cross-linked elastin. We used a gadolinium-based tropoelastin-specific magnetic resonance contrast agent (Gd-TESMA) to test whether quantifying regional tropoelastin turnover correlates with aortic expansion in a murine model. The binding of Gd-TESMA to excised human AAA was also assessed.

Methods and results

We utilized the angiotensin II (Ang II)-infused apolipoprotein E gene knockout (ApoE^-/-) murine model of aortic dilation and performed in vivo imaging of tropoelastin by administering Gd-TESMA followed by late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) and T₁ mapping at 3 T, with subsequent ex vivo validation. In a cross-sectional study (n = 66; control = 11, infused = 55) we found that Gd-TESMA enhanced MRI was elevated and confined to dilated aortic segments (control: _LGE=0.13 ± 0.04 mm², control _R1= 1.1 ± 0.05 s^-1 vs. dilated _LGE=1.0 ± 0.4 mm², dilated _R1 =2.4 ± 0.9 s^-1) and was greater in segments with medium (8.0 ± 3.8 mm³) and large (10.4 ± 4.1 mm³) compared to small (3.6 ± 2.1 mm³) vessel volume. Furthermore, a proof-of-principle longitudinal study (n = 19) using Gd-TESMA enhanced MRI demonstrated a greater proportion of tropoelastin: elastin expression in dilating compared to non-dilating aortas, which correlated with the rate of aortic expansion. Treatment with pravastatin and aspirin (n = 10) did not reduce tropoelastin turnover (0.87 ± 0.3 mm² vs. 1.0 ± 0.44 mm²) or aortic dilation (4.86 ± 2.44 mm³ vs. 4.0 ± 3.6 mm³). Importantly, Gd-TESMA-enhanced MRI identified accumulation of tropoelastin in excised human aneurysmal tissue (n = 4), which was confirmed histologically.

Conclusion

Tropoelastin MRI identifies dysfunctional matrix remodelling that is specifically expressed in regions of aortic aneurysm or dissection and correlates with the development and rate of aortic expansion. Thus, it may provide an additive imaging marker to the serial assessment of luminal diameter for surveillance of patients at risk of or with established aortopathy.

Comparison of the Short and Long-Term Outcomes of Endovascular Repair and Open Surgical Repair in the Treatment of Unruptured Abdominal Aortic Aneurysms: Meta-Analysis and Systematic Review

Background

Although the initial results of endovascular repair (EVAR) were promising, a comparison of its long-term efficacy against open surgical repair (OSR) remains largely elusive, and late-onset adverse events have not been systematically evaluated. Since OSR and EVAR are currently the only treatment options available in the management of abdominal aortic aneurysms (AAAs), the main question arising in clinical practice is whether EVAR or OSR confers more favourable short and long-term outcomes for patients presenting with unruptured AAAs.

Aims

The present meta-analysis aims to draw a head-to-head comparison between EVAR and OSR and facilitate the formulation of an evidence-based approach to the clinical management of unruptured AAAs.

Methods

A systematic review was conducted using three databases to identify all relevant studies with comparative data on EVAR vs. OSR. All-cause mortality was the primary outcome. Procedural outcomes, such as stroke, myocardial infarction, renal complications, rupture, and reintervention rates, were determined as secondary outcomes.

Results

Sixteen studies were included for comparative analysis, including four randomised-controlled trials and six non-randomised comparative clinical trials. EVAR conferred a clear perioperative survival advantage as compared to OSR (P < 0.00001). However, this survival advantage did not persist beyond two years post-procedure; all-cause mortality rates were comparable between the two treatment groups at two years (P = 0.09), four years (P = 0.58), and six years (P = 0.88) post-procedure. Although no statistically significant differences in aneurysm-related mortality, postoperative stroke, or myocardial infarction were identified, the OSR group had a statistically significant higher rate of postoperative renal complications. On the other hand, there was a statistically significant higher rate of rupture and reintervention following EVAR.

Conclusion

Whether the initial survival advantage afforded by EVAR is sufficient to justify the long-term risk of rupture, reintervention, and long-term mortality should be determined on a case-by-case basis by the multidisciplinary team overseeing the clinical care of the patient. Currently, it is reasonable to conclude that EVAR is as efficacious as OSR, but it would be invalid to claim it as superior. Ultimately, longer follow-up data must be presented before any definitive conclusions can be established for this potentially revolutionary technique. Presently, one can neither advocate nor refute EVAR over OSR.

The Incidence of Chronic Mesenteric Ischemia in the Well-Defined Region of a Dutch Mesenteric Ischemia Expert Center

INTRODUCTION

This study aimed to determine the incidence of chronic mesenteric ischemia (CMI) and to examine the influence of the etiological cause, location, and severity of a mesenteric artery stenosis on the probability of having CMI.

METHODS

A prospective database, containing the details of all patients with suspected CMI referred to a renowned CMI expert center, was used. Patients residing within the expert centers' well-defined region, between January 2014 and October 2019, were included. CMI was diagnosed when patients experienced sustained symptom improvement after treatment.

RESULTS

This study included 358 patients, 75 had a ≥50% atherosclerotic stenosis of 1 vessel (CMI 16%), 96 of 2 or 3 vessels (CMI 81%), 81 celiac artery compression (CMI 25%), and 84 no stenosis (CMI 12%). In total, 138 patients were diagnosed with CMI, rendering a mean incidence of 9.2 (95% confidence interval [CI] 6.2-13.7) per 100,000 inhabitants. Atherosclerotic CMI was most common, with a mean incidence of 7.2 (95% CI 4.6-11.3), followed by median arcuate ligament syndrome 1.3 (95% CI 0.5-3.6) and chronic nonocclusive mesenteric ischemia 0.6 (95% CI 0.2-2.6). The incidence of CMI was highest in female patients (female patients 12.0 [95% CI 7.3-19.6] vs male patients 6.5 [95% CI 3.4-12.5]) and increased with age. CMI was more prevalent in the presence of a ≥70% atherosclerotic single-vessel stenosis of the superior mesenteric artery (40.6%) than the celiac artery (5.6%).

DISCUSSION

The incidence of CMI is higher than previously believed and increases with age. Probability of CMI seems highest in suspected CMI patients with multivessel disease or a ≥70% atherosclerotic single-vessel superior mesenteric artery stenosis.

Endovascular repair of abdominal aortic aneurysm in octogenarians: clinical outcomes and complications

Background

Endovascular aneurysm repair (EVAR) is associated with decreased perioperative morbidity and mortaliy in comparison with open repair, and thus octagenarians are traditionally offered EVAR given their age and medical comorbidities. The aim of this study was to investigate outcomes and predictors of complications associated with EVAR in octogenarians.

Methods

We conducted a retrospective chart review of consecutive patients aged 80 years and older who received an EVAR between August 2010 and January 2017 at a single centre in Toronto, Ontario. We conducted univariate comparisons and then completed logistic regression to determine predictors of complications. We used Kaplan-Meier analysis to explore survival times.

Results

A total of 154 octogenarians underwent an EVAR during the study period for an infrarenal aneurysm with a mean size of 64.8 (standard deviation [SD] 12.7) mm. The mean age of the patients was 84.1 (SD 3.7) years, and most patients (81%) were men. Eighteen patients presented with a ruptured abdominal aortic aneurysm (AAA). Ninety-five (62%) patients sustained a complication. Fifty percent of patients experienced an intraoperative complication. A majority of these (77%) resulted in an endoleak, with type II endoleaks requiring no further intervenion being the most common (58%, n = 45). The remaining complications (n = 70) occurred postoperatively, with myocardial ischemia (n = 24) and dysrhythmias (n = 10) being the most common. Past aortic surgery (χ2 = 8.62, p = 0.014, Cramer V = 0.27) was found to be a multivariate predictor of complications. Most patients (88%) continued follow-up to an average of 20.9 months. Twenty-one patients (13%) died. Nine of these deaths (43%) occurred during the index admission and involved a ruptured AAA. Past aortic surgery was the only predictor of vascular complications. The mean survival time after EVAR was 57.63 months for patients without events.

Conclusion

Endovascular aneurysm repair in octogenarians is a suitable form of therapy with acceptable short- and long-term results in the elective setting. Past aortic surgery was a predictor of complications in this population.

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.

Ruptured abdominal aortic aneurysm identified on point-of-care ultrasound in the emergency department

Background

Ruptured abdominal aortic aneurysm (AAA) is a highly lethal condition which requires rapid identification and treatment to improve the chance of survival. Computed tomography is the diagnostic modality of choice for ruptured AAA though it is time-consuming and often requires movement of the patient out of the emergency department (ED). Point-of-care ultrasound in the ED has excellent sensitivity and specificity for the detection of AAA, though less is known about its use to diagnose AAA rupture. We report a case of ruptured AAA identified on ultrasound performed at the bedside in the ED.

Case presentation

A 77-year-old woman on warfarin with a known AAA presented to our ED with 2 days of epigastric abdominal pain. Point-of-care ultrasound revealed several findings suggestive of rupture of the AAA, which was confirmed on computed tomography. The patient was subsequently taken for emergent operative repair of the AAA and was later discharged from the hospital.

Conclusions

Characteristics suggestive of AAA rupture may be seen on ultrasound. As ED physicians become more familiar with the use of point-of-care ultrasound in the evaluation of abdominal pain, identification of these characteristics may aid in the rapid diagnosis of AAA rupture.

Computational Hemodynamic Modeling of Arterial Aneurysms: A Mini-Review

Arterial aneurysms are pathological dilations of blood vessels, which can be of clinical concern due to thrombosis, dissection, or rupture. Aneurysms can form throughout the arterial system, including intracranial, thoracic, abdominal, visceral, peripheral, or coronary arteries. Currently, aneurysm diameter and expansion rates are the most commonly used metrics to assess rupture risk. Surgical or endovascular interventions are clinical treatment options, but are invasive and associated with risk for the patient. For aneurysms in locations where thrombosis is the primary concern, diameter is also used to determine the level of therapeutic anticoagulation, a treatment that increases the possibility of internal bleeding. Since simple diameter is often insufficient to reliably determine rupture and thrombosis risk, computational hemodynamic simulations are being developed to help assess when an intervention is warranted. Created from subject-specific data, computational models have the potential to be used to predict growth, dissection, rupture, and thrombus-formation risk based on hemodynamic parameters, including wall shear stress, oscillatory shear index, residence time, and anomalous blood flow patterns. Generally, endothelial damage and flow stagnation within aneurysms can lead to coagulation, inflammation, and the release of proteases, which alter extracellular matrix composition, increasing risk of rupture. In this review, we highlight recent work that investigates aneurysm geometry, model parameter assumptions, and other specific considerations that influence computational aneurysm simulations. By highlighting modeling validation and verification approaches, we hope to inspire future computational efforts aimed at improving our understanding of aneurysm pathology and treatment risk stratification.

Extended screening guidelines for the diagnosis of abdominal aortic aneurysm

BACKGROUND

The U.S. Preventive Services Task Force (USPSTF) guidelines are the most widely used criteria for screening for abdominal aortic aneurysms (AAA). However, when the USPSTF criteria are applied retrospectively to a group of patients who have undergone treatment for AAA, there are many patients who satisfy none of the AAA screening criteria. The more sensitive Society for Vascular Surgery (SVS) guidelines have expanded the criteria for screening for AAA with the hope of capturing a greater fraction of those individuals who can undergo treatment for their AAA before presenting with AAA rupture. We sought to identify the number of patients who would have been identified as having criteria for screening for AAA by both the USPSTF and SVS criteria, in a cohort of patients who have undergone treatment for AAA.

METHODS

We assessed demographic, comorbidity, and perioperative complication data for all patients undergoing endovascular and open AAA repair in the Vascular Quality Initiative. Patients meeting each of the screening criteria were identified. Clinical factors and demographic variables were collected.

RESULTS

We identified 55,197 patients undergoing AAA repair in the Vascular Quality Initiative, including 44,602 patients who underwent endovascular aneurysm repair (EVAR) and 10,595 patients undergoing open repair. Of these, the USPTF guidelines would have identified fewer than one-third of patients (32% EVAR and 33% open repair). Applying the SVS guidelines increased the number meeting criteria for screening by 6% and 12% for the EVAR and open repair cohorts, respectively. Finally, adoption of the expanded SVS guidelines (including the "weak recommendations") would have identified an additional 34% of EVAR patients and 21% of open AAA repair patients. Use of the expanded criteria would have resulted in 27% of patients undergoing EVAR and 33% of patients undergoing open AAA repair who would not have met any screening criteria. In EVAR patients not meeting the criteria, 52% were younger than 65 years had a history of heavy smoking. Of all those who did not meet screening criteria, ruptured AAA was twice as prevalent as those who met screening criteria (8.5% vs 4.4%; P ≤ .0001).

CONCLUSIONS

Expanding established USPSTF screening guidelines to include the expanded SVS criteria may potentially double the number of patients identified with AAA. Smokers under the age of 65, and elderly patients 70 and older with no smoking history, represent two groups with AAA and potentially twice the risk of presenting with rupture.

Endovascular aneurysm repair in a centenarian: case report and systematic literature review

The prevalence of abdominal aortic aneurysms (AAA) in the nonagenarian and centenarian populations is set to increase. Endovascular aneurysm repair (EVAR) has been shown to be achievable with excellent outcomes in carefully selected nonagenarians. However, experience with centenarians is limited. We report the case of a 100-year-old who presented with a tender 8-cm AAA and successfully underwent EVAR. This report describes the second case of AAA repair in a centenarian in the literature and the first reported EVAR in this demographic. The patient survived for 2 years after the procedure, was free of EVAR or aneurysm-related complications. Furthermore, we present a systematic review of the existing literature and insights pertaining to outcomes in nonagenarians undergoing EVAR.

Calprotectin and Receptor for Advanced Glycation End Products as a Potential Biomarker in Abdominal Aortic Aneurysm

Experiments conducted in recent years on animals and research works worldwide show a linkage between calprotectin and occurrence and development of the abdominal aortic aneurysm (AAA). Additionally, a correlation between the level of the receptor for advanced glycation end products (RAGE) and the diameter of the abdominal aorta was found. The purpose of this study was to investigate whether calprotectin and the RAGE plasma level may be a biomarker of human AAA occurrence. We determined two groups of research participants: a group of 32 patients aged 53–88 undergoing primary endovascular aneurysm repair and a control group of 43 volunteers aged 59–82 without the AAA. All the patients from the study group had their blood samples drawn in order to determine the level of calprotectin and RAGE in plasma. The second follow-up examination was carried out after three months. The concentration of calprotectin and RAGE in plasma was determined with the use of the immunoenzymatic method (ELISA). The study showed that patients with the AAA had significantly higher mean calprotectin and RAGE plasma levels (p = 0.0001 and p = 0.0002, respectively) as compared to the control group. After the AAA repair operations, the level of concentration of the calprotectin decreased significantly (p = 0.0002). So far, no studies on the connection between the increase of the calprotectin and RAGE in the patient’s plasma with the AAA have been published. Calprotectin may be a promising biomarker related to the occurrence of AAA. Larger studies are needed to fully elucidate and confirm the role of calprotectin in the development and progression of the aneurysm.

Sex-Specific Associations of Vascular Risk Factors With Abdominal Aortic Aneurysm: Findings From 1.5 Million Women and 0.8 Million Men in the United States and United Kingdom

Background

Large studies are required for reliable estimates of important risk factors for abdominal aortic aneurysm (AAA). This could guide targeted AAA screening programs, particularly in subgroups like women who are currently excluded from such programs.

Method and Results

In a cross‐sectional study, 1.5 million women and 0.8 million men without known vascular disease attended commercial screening clinics in the United Kingdom or United States from 2008 to 2013. Measurements of vascular risk factors were related to AAA using logistic regression with correction for regression dilution bias. Screening detected 12 729 new AAA cases (0.6%). Compared with never smoking, current smoking was associated with 15 times the risk of AAA among women (risk ratio 15.0, 95% CI 13.2–17.0) and 7 times among men (7.3, 6.4–8.2). In women aged <75 years, the risk of AAA was nearly 30 times greater in current smokers (26.4, 20.3–34.2). In every age group, the prevalence of AAA in female smokers was greater than in male never‐smokers. Positive log‐linear associations with AAA for women and men were also observed for usual body mass index, usual systolic blood pressure, height, usual low‐density lipoprotein cholesterol, and usual triglycerides.

Conclusions

Log‐linear increases in the risks of AAA with traditional vascular risk factors should be considered when evaluating populations that may be at‐risk for the development of AAA, and when considering potential treatments. However, at any given age, female smokers are at higher risk of AAA than male never‐smokers, and a policy of screening male never‐smokers but not higher‐risk female smokers is questionable.

Prevalence and Epidemiological Pattern of Abdominal Aortic Aneurysms in Africa: A Systematic Review

Introduction

The incidence of abdominal aortic aneurysms (AAAs) in high-income countries has been declining in the last three decades. However, in most low-income and middle-income countries especially in Africa, little is known about its burden. The absence of screening services for AAA in African countries makes it difficult to detect and promptly manage AAA before rupture, which has significant implications for mortality. This study sought to systematically assess the prevalence of AAA amongst patients visiting hospitals in Africa and evaluate its epidemiological pattern.

Materials and Methods

A systematic review was performed on the EMBASE, GLOBAL HEALTH, MEDLINE, and PUBMED databases. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement standards and protocol registered with PROSPERO (CRD42020162214). A data extraction tool was used to get relevant information from these studies. Quality assessment and risk of bias were performed using the Newcastle Ottawa Scale for cross-sectional studies. Results were summarised in tables, figures, and a forest plot. A narrative synthesis approach of the articles was taken.

Results

Two hundred and sixty-one studies were identified and after the exclusion of 246, a final 15 were deemed suitable for analysis. A total of 4012 participants were screened for AAA and of these, 129 cases were identified. The prevalence of AAA in these studies ranged from 0.7 to 6.4%. Male participants accounted for 115 (89.1%) of the cases. There was a wide age range (31-72 years) reflective of both its possible infective and degenerative aetiology. AAA was reported to be associated with hypertension, smoking, advanced age, coronary artery disease, and HIV infection. There was no association between AAA and diabetes. Over 50% of cases were identified incidentally. About one-third (23-54%) of the participants presented aortic rupture with a mortality rate ranging between 65 and 72%.

Conclusions

AAA prevalence in Africa is probably higher than the current thinking as there is no baseline data to compare with. Aetiologically, AAA was shown to be associated with hypertension, smoking, coronary artery disease, and possibly infectious pathologies like HIV. Large epidemiological studies would help better characterise AAA in this setting. Lastly, efforts targeting the reduction of the risk factors for AAA would go a long way in reducing the burden 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.

An evaluation of reports of ciprofloxacin, levofloxacin, and moxifloxacin-association neuropsychiatric toxicities, long-term disability, and aortic aneurysms/dissections disseminated by the Food and Drug Administration and the European Medicines Agency

Introduction: Ciprofloxacin, levofloxacin, and moxifloxacin belong to the fluoroquinolone class of antibiotics and are amongst the most commonly prescribed antibiotics. In 2018 and 2019, Food and Drug Administration (FDA) and the European Medicine Agency (EMA) requested that manufacturers harmonize FQ safety information related to neuropsychiatric, aortic dissection, and long-term disability. The authors hypothesize that FDA and EMA epidemiologists support a strong association between these drugs and the three toxicities. Areas covered: Studies of FQ-associated neuropsychiatric toxicity, long-term disability, and aortic ruptures/dissections. Clinical sources include FDA Advisory Committee documents, a 2014 Citizen Petition filed with the FDA requesting safety information additions to FQ labels for neuropsychiatric toxicities (partially granted in 2018), an under-review Citizen Petition under review by the FDA requesting a FQ Risk Evaluation and Mitigation Strategy, and safety notifications from the EMA. Expert opinion: FDA and the EMA report state that neuropsychiatric toxicity, long-term disability, and aortic dissections//aneurysms occur with all FQs. Disability and neuropsychiatric toxicity can occur after one dose or several months after FQs. United States' and European' regulators warn physicians not to prescribe FQs for uncomplicated acute urinary tract infection, sinusitis, or bronchitis, unless other possible choices are tried first, as risks outweigh benefits in these settings.

18F-Sodium Fluoride Uptake in Abdominal Aortic Aneurysms: The SoFIA3 Study

Background

Fluorine-18–sodium fluoride (¹⁸F-NaF) uptake is a marker of active vascular calcification associated with high-risk atherosclerotic plaque.

Objectives

In patients with abdominal aortic aneurysm (AAA), the authors assessed whether ¹⁸F-NaF positron emission tomography (PET) and computed tomography (CT) predicts AAA growth and clinical outcomes.

Methods

In prospective case-control (n = 20 per group) and longitudinal cohort (n = 72) studies, patients with AAA (aortic diameter >40 mm) and control subjects (aortic diameter <30 mm) underwent abdominal ultrasound, ¹⁸F-NaF PET-CT, CT angiography, and calcium scoring. Clinical endpoints were aneurysm expansion and the composite of AAA repair or rupture.

Results

Fluorine-18-NaF uptake was increased in AAA compared with nonaneurysmal regions within the same aorta (p = 0.004) and aortas of control subjects (p = 0.023). Histology and micro-PET-CT demonstrated that ¹⁸F-NaF uptake localized to areas of aneurysm disease and active calcification. In 72 patients within the longitudinal cohort study (mean age 73 ± 7 years, 85% men, baseline aneurysm diameter 48.8 ± 7.7 mm), there were 19 aneurysm repairs (26.4%) and 3 ruptures (4.2%) after 510 ± 196 days. Aneurysms in the highest tertile of ¹⁸F-NaF uptake expanded 2.5× more rapidly than those in the lowest tertile (3.10 [interquartile range (IQR): 2.34 to 5.92 mm/year] vs. 1.24 [IQR: 0.52 to 2.92 mm/year]; p = 0.008) and were nearly 3× as likely to experience AAA repair or rupture (15.3% vs. 5.6%; log-rank p = 0.043).

Conclusions

Fluorine-18-NaF PET-CT is a novel and promising approach to the identification of disease activity in patients with AAA and is an additive predictor of aneurysm growth and future clinical events. (Sodium Fluoride Imaging of Abdominal Aortic Aneurysms [SoFIA³]; NCT02229006; Magnetic Resonance Imaging [MRI] for Abdominal Aortic Aneurysms to Predict Rupture or Surgery: The MA3RS Trial; ISRCTN76413758)

Contrast-enhanced ultrasound and/or colour duplex ultrasound for surveillance after endovascular abdominal aortic aneurysm repair: a systematic review and economic evaluation

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) is less invasive than open surgery, but may be associated with important complications. Patients receiving EVAR require long-term surveillance to detect abnormalities and direct treatments. Computed tomography angiography (CTA) has been the most common imaging modality adopted for EVAR surveillance, but it is associated with repeated radiation exposure and the risk of contrast-related nephropathy. Colour duplex ultrasound (CDU) and, more recently, contrast-enhanced ultrasound (CEU) have been suggested as possible, safer, alternatives to CTA.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of imaging strategies, using either CDU or CEU alone or in conjunction with plain radiography, compared with CTA for EVAR surveillance.

DATA SOURCES

Major electronic databases were searched, including MEDLINE, EMBASE, Science Citation Index, Scopus' Articles-in-Press, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE) and NHS Economic Evaluation Database from 1996 onwards. We also searched for relevant ongoing studies and conference proceedings. The final searches were undertaken in September 2016.

METHODS

We conducted a systematic review of randomised controlled trials and cohort studies of patients with AAAs who were receiving surveillance using CTA, CDU and CEU with or without plain radiography. Three reviewers were involved in the study selection, data extraction and risk-of-bias assessment. We developed a Markov model based on five surveillance strategies: (1) annual CTA; (2) annual CDU; (3) annual CEU; (4) CDU together with CTA at 1 year, followed by CDU on an annual basis; and (5) CEU together with CTA at 1 year, followed by CEU on an annual basis. All of these strategies also considered plain radiography on an annual basis.

RESULTS

We identified two non-randomised comparative studies and 25 cohort studies of interventions, and nine systematic reviews of diagnostic accuracy. Overall, the proportion of patients who required reintervention ranged from 1.1% (mean follow-up of 24 months) to 23.8% (mean follow-up of 32 months). Reintervention was mainly required for patients with thrombosis and types I-III endoleaks. All-cause mortality ranged from 2.7% (mean follow-up of 24 months) to 42% (mean follow-up of 54.8 months). Aneurysm-related mortality occurred in < 1% of the participants. Strategies based on early and mid-term CTA and/or CDU and long-term CDU surveillance were broadly comparable with those based on a combination of CTA and CDU throughout the follow-up period in terms of clinical complications, reinterventions and mortality. The economic evaluation showed that a CDU-based strategy generated lower expected costs and higher quality-adjusted life-year (QALYs) than a CTA-based strategy and has a 63% probability of being cost-effective at a £30,000 willingness-to-pay-per-QALY threshold. A CEU-based strategy generated more QALYs, but at higher costs, and became cost-effective only for high-risk patient groups.

LIMITATIONS

Most studies were rated as being at a high or moderate risk of bias. No studies compared CDU with CEU. Substantial clinical heterogeneity precluded a formal synthesis of results. The economic model was hindered by a lack of suitable data.

CONCLUSIONS

Current surveillance practice is very heterogeneous. CDU may be a safe and cost-effective alternative to CTA, with CTA being reserved for abnormal/inconclusive CDU cases.

FUTURE WORK

Research is needed to validate the safety of modified, more-targeted surveillance protocols based on the use of CDU and CEU. The role of radiography for surveillance after EVAR requires clarification.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016036475.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Blood pressure, hypertension and the risk of abdominal aortic aneurysms: a systematic review and meta-analysis of cohort studies

Abdominal aortic aneurysms (AAA) are fatal in 80% of the cases when ruptured. Hypertension has been considered a potential risk factor for AAA; but the findings from prospective cohort studies have not been entirely consistent, nor have they been summarised in a comprehensive meta-analysis. Our aim was to conduct a systematic review and meta-analysis of cohort studies of the association between blood pressure, hypertension and AAA to clarify the strength and shape of these associations. We searched PubMed and Embase databases for relevant cohort studies up to April 30th, 2018. Random-effects models were used to calculate summary relative risks (RRs) and 95% confidence intervals (CIs). The meta-analysis included 21 cohort studies (20 publications) with data on 28,162 cases and 5,440,588 participants. The findings indicate that the RR of AAA in hypertensive patients is 1.66 times (95% CI: 1.49–1.85, I² = 79.3%, n = 13) that of non-hypertensive patients. In addition, there was a 14% (95% CI: 6–23%, I² = 30.5%, n = 6) and a 28% (95% CI: 12–46%, I² = 80.1%, n = 6) increase in the RR of AAA for every 20 mmHg and 10 mmHg increase in systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively. The analysis of DBP showed evidence of a strong and highly significant nonlinear dose–response relationship (p < 0.001) with a steeper association from 80 mmHg and above. This meta-analysis suggests that hypertension increases the risk of developing AAA by 66%. Further studies are needed to clarify the underlying mechanism explaining the much stronger association between DBP and AAA than for SBP.

Role of Noncoding RNAs in the Pathogenesis of Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a local dilatation of the abdominal aortic vessel wall and is among the most challenging cardiovascular diseases as without urgent surgical intervention, ruptured AAA has a mortality rate of >80%. Most patients present acutely after aneurysm rupture or dissection from a previously asymptomatic condition and are managed by either surgery or endovascular repair. Patients usually are old and have other concurrent diseases and conditions, such as diabetes mellitus, obesity, and hypercholesterolemia making surgical intervention more difficult. Collectively, these issues have driven the search for alternative methods of diagnosing, monitoring, and treating AAA using therapeutics and less invasive approaches. Noncoding RNAs-short noncoding RNAs (microRNAs) and long-noncoding RNAs-are emerging as new fundamental regulators of gene expression. Researchers and clinicians are aiming at targeting these microRNAs and long noncoding RNAs and exploit their potential as clinical biomarkers and new therapeutic targets for AAAs. While the role of miRNAs in AAA is established, studies on long-noncoding RNAs are only beginning to emerge, suggesting their important yet unexplored role in vascular physiology and disease. Here, we review the role of noncoding RNAs and their target genes focusing on their role in AAA. We also discuss the animal models used for mechanistic understanding of AAA. Furthermore, we discuss the potential role of microRNAs and long noncoding RNAs as clinical biomarkers and therapeutics.

Incidence, Treatment and Mortality in Patients with Abdominal Aortic Aneurysms

BACKGROUND

Aim of this study was to analyze hospital incidence, type of treatment, and hospital mortality rates of patients with abdominal aortic aneurysm (AAA) in Germany from 2005 to 2014.

METHODS

Microdata of the diagnosis-related group (DRG) statistics compiled by the German Federal Statistical Office for the years 2005-2014 were analyzed. Patients who were hospitalized for a ruptured AAA (rAAA, ICD-10 code I71.3, treated either surgically or conservatively) or received surgical treatment for an unruptured AAA (nrAAA, ICD-10-Code I71.4, treated either with open surgery or an endovascular procedure) were included in the analysis. The "European Standard Population 2013" was used for direct standardization of the hospital incidences. In-hospital mortality was calculated with standardization for age and risk.

RESULTS

The standardized overall hospital incidence of AAA was 27.9 and 3.3 cases per 100 000 people for men and women, respectively; over the period of the study, the incidence of rAAA fell by 30% in both sexes and that of nrAAA rose by 16% in men and 42% in women. The percentage of patients receiving endovascular treatment rose from 29% to 75% in patients with nrAAA and from 8% to 36% in patients with rAAA. The age- and risk-standardized in-hospital mortality of nrAAA was 3.3% in men and 5.3% in women. The in-hospital mortality of surgically treated rAAA was 39% in men and 48% in women.

CONCLUSION

The hospital incidence of AAA rose from 2005 to 2014, while that of rAAA fell. Endovascular treatment became more common for nrAAA as well as rAAA, and in-hospital mortality fell for both.

Vascular Surgery and Geriatric Patients

As the population ages, surgical decision-making in vascular surgery has become more complex. Older patients may not have been offered vascular surgical intervention in the past because of prohibitive physiologic demands and poor health. Patients now have more aggressive management of vascular risk factors with medications, such as statin therapy, and less invasive endovascular or hybrid treatment options. Outcomes in elderly patients may not be comparable with younger patients for entities such as aortic aneurysm repair, carotid endarterectomy, or lower extremity revascularization. Despite this, desirable outcomes can be successfully achieved and should be offered to carefully selected elderly individuals.

Tobacco smoking and the risk of abdominal aortic aneurysm: a systematic review and meta-analysis of prospective studies

Several studies have found that smoking increases the risk of abdominal aortic aneurysm, however, the strength of the association has differed between studies and data from cohort studies have not yet been summarized. A systematic review and meta-analysis was therefore conducted to clarify this association. We searched PubMed and Embase databases up to May 2nd 2018. A random effects model was used to estimate summary relative risks (RRs) and 95% confidence intervals (CIs). Twenty three prospective studies were included. Comparing current, former and ever smokers with never smokers the summary RRs were 4.87 (95% CI: 3.93-6.02, I2 = 92%, n = 20), 2.10 (95% CI: 1.76-2.50, I2 = 71%, n = 15) and 3.28 (95% CI: 2.60-4.15, I2 = 96%, n = 18), respectively. The summary RR was 1.87 (95% CI: 1.45-2.40, I2 = 97%) per 10 cigarettes per day, 1.78 (95% CI: 1.54-2.06, I2 = 83%) per 10 pack-years was and 0.45 (95% CI: 0.32-0.63, I2 = 92.3%) per 10 years of smoking cessation. There was evidence of nonlinearity for cigarettes per day and pack-years (pnonlinearity < 0.0001 and pnonlinearity = 0.02, respectively), but not for smoking cessation, pnonlinearity = 0.85. Among smokers who quit, the RR was similar to that of never smokers by 25 years of smoking cessation. These findings confirm a strong association between smoking and the risk of developing abdominal aortic aneurysms.

Targeting cysteinyl-leukotrienes in abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is an asymptomatic dilatation of the vessel wall exceeding the normal vessel diameter by 50%, accompanied by intramural thrombus formation. Since the aneurysm can rupture, AAA is a life-threatening vascular disease, which may be amenable to surgical repair. At present, no pharmacological therapy for AAA is available. The 5-lipoxygenase (5-LOX) pathway of arachidonic acid metabolism leads to biosynthesis of leukotrienes (LTs), potent lipid mediators with pro-inflammatory biological actions. Among the LTs, cysteinyl-leukotrienes (cys-LT) are well-recognized signaling molecules in human asthma and allergic rhinitis. However, the effects of these molecules in cardiovascular diseases have only recently been explored. Drugs antagonizing the CysLT1 receptor, termed lukasts and typified by montelukast, are established therapeutics for clinical management of asthma. Lukasts are safe, well-tolerated drugs that can be administered during long time periods. Here we describe recent data indicating that montelukast may be used for prevention and treatment of AAA, thus representing a promising pharmacological tool for a deadly vascular disease with significant socio-economic impact.

Serum anion gap on admission predicts intensive care unit mortality in patients with aortic aneurysm

It has been widely reported that the serum anion gap is significantly associated with mortality in intensive care unit (ICU); however, it remains unknown whether the association is present in aortic aneurysm (AA) patients. The present study aimed to investigate the association between the admission serum anion gap and ICU mortality in AA patients. Data extracted from a publicly accessible clinical database using a modifiable data mining technique were analyzed retrospectively, mainly by employing multivariable logistic regression analysis. The primary study outcome was ICU mortality. A total of 273 patient records were analyzed. The ICU mortality was 8.79% (24/273). The median serum anion gap was significantly higher in non-survivors [17.50 mEq/l, interquartile range (IQR) 15.75-22.50 mEq/l] compared with survivors [13.00 mEq/l, IQR 11.00-15.00 mEq/l, P<0.001]. Multivariate analysis resulted in identification of a clear association between admission serum anion gap and ICU mortality in AA patients [odds ratio (OR) 1.38 per 1 mEq/l increase, 95% confidence interval (CI) 1.08-1.76]. The area under the receiver operating characteristic curve showed an outstanding discrimination ability in predicting ICU mortality (area under curve 0.8513, 95% CI 0.7698-0.9328). In conclusion, admission serum anion gap may serve as a strong predictor of ICU mortality for AA patients.

Decision uncertainty and value of further research: a case-study in fenestrated endovascular aneurysm repair for complex abdominal aortic aneurysms

Background

Fenestrated endovascular aneurysm repair (fEVAR) is a new approach for complex abdominal aortic aneurysms, limited to a few specialist centers, with limited evidence base. We developed a cost-effectiveness decision model of fEVAR compared to open surgical repair (OSR) to investigate the likely direction of costs and benefits and inform further research projects on this technology.

Methods

A systematic review with meta-analysis and a four-state Markov model were used to estimate the cost-effectiveness of fEVAR versus OSR. We used a recent coverage with evidence development framework to characterize the main sources of uncertainty and inform decisions about the type of further research that would be most worthwhile and feasible.

Results

Seven observational comparative studies were identified, of which four presented odds ratios adjusted for confounders. The odds ratios for operative mortality varied widely between studies. Assuming a central estimate of the odds ratio of 0.54 (95% CI 0.05–6.24), the decision model estimated that the incremental cost per quality adjusted life year (QALY) was £74,580/QALY with a probability of 9 and 16% of being cost-effective at standard cost-effectiveness thresholds of £20,000/QALY and £30,000/QALY, respectively. The Expected Value of Perfect Information over 10 years at a threshold of £20,000/QALY was £11.2 million. Operative mortality contributed to most of the uncertainty in the decision model.

Conclusions

In the case of “maturing technologies”, decision modelling indicates the likely direction of costs and benefits and guides the development of further research projects. In our analysis of fEVAR versus OSR, decision uncertainty, particularly around operative mortality, might be effectively resolved by a short-term RCT, or possibly a well-conducted comparative observational study. Decision makers may consider that a conditional coverage decision is warranted with assessments required to make this type of recommendation depending on local priorities and circumstances.

Electronic supplementary material

The online version of this article (10.1186/s12962-018-0098-7) contains supplementary material, which is available to authorized users.

An evaluation of the effect of an angiotensin-converting enzyme inhibitor on the growth rate of small abdominal aortic aneurysms: a randomised placebo-controlled trial (AARDVARK)

BACKGROUND

Although data are inconsistent, angiotensin-converting enzyme inhibitors (ACE-Is) have been associated with a reduced incidence of abdominal aortic aneurysm (AAA) rupture in analysis of administrative databases.

OBJECTIVES

(1) To investigate whether or not the ACE-I perindopril (Coversyl arginine, Servier) reduces small AAA growth rate and (2) to evaluate blood pressure (BP)-independent effects of perindopril on small AAA growth and to compare the repeatability of measurement of internal and external aneurysm diameters.

DESIGN

A three-arm, multicentre, single-blind, randomised placebo-controlled trial.

SETTING

Fourteen hospitals in England.

PARTICIPANTS

Men or women aged ≥ 55 years with an AAA of 3.0-5.4 cm in diameter by internal or external measurement according to ultrasonography and who met the trial eligibility criteria.

INTERVENTIONS

Patients were randomised to receive 10 mg of perindopril arginine daily, 5 mg of the calcium channel blocker amlodipine daily or placebo daily.

MAIN OUTCOME MEASURES

The primary outcome was AAA diameter growth using external measurements in the longitudinal plane, which in-trial studies suggested was the preferred measure. Secondary outcome measures included AAA rupture, AAA repair, modelling of the time taken for the AAA to reach the threshold for intervention (5.5 cm) or referral for surgery, tolerance of study medication (measured by compliance, adverse events and quality of life) and a comparison of the repeatability of measures of internal and external AAA diameter. Patients were followed up every 3-6 months over 2 years.

RESULTS

In total, 227 patients were recruited and randomised into the three groups, which were generally well matched at baseline. Multilevel modelling was used to determine the maximum likelihood estimates for AAA diameter growth. No significant differences in the estimates of annual growth were apparent [1.68 (standard error 0.02) mm, 1.77 (0.02) mm and 1.81 (0.02) mm in the placebo, perindopril and amlodipine groups, respectively]. Similarly, no significant differences in the slopes of modelled growth over time were apparent between perindopril and placebo (p = 0.78) or between perindopril and amlodipine (p = 0.89). The results were essentially unaffected by adjustment for potential confounders. Compliance, measured by pill counts, was good throughout (> 80% at all visit time points). There were no significant in-trial safety concerns. Six patients withdrew because of adverse events attributed to the study medications (n = 2 perindopril, n = 4 amlodipine). No patients ruptured their AAA and 27 underwent elective surgery during the trial (n = 9 placebo, n = 10 perindopril, n = 8 amlodipine).

CONCLUSIONS

We were unable to demonstrate a significant impact of perindopril compared with placebo or amlodipine on small AAA growth over a 2-year period. Furthermore, there were no differences in the times to reach a diameter of 5.5 cm or undergo surgery among the three groups. Perindopril and amlodipine were well tolerated by this population. External AAA measurements were found to be more repeatable than internal measurements. The observed AAA growth measurement variability was greater than that expected pre trial. This, combined with slower than expected mean growth rates, resulted in our having limited power to detect small differences between growth rates and hence this adds uncertainty to the interpretation of the results. Several further analyses are planned including a multivariate analysis of determinants of AAA growth, an evaluation of the possible differential effect of perindopril on fast AAA growth and an investigation into the roles of central BP and BP variability on AAA growth.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN51383267.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 59. See the NIHR Journals Library website for further project information. The NIHR Biomedical Research Centre based at Imperial College NHS Trust supported the trial. Servier provided perindopril at no charge.

Abdominal aortic aneurysm and omega-3 polyunsaturated fatty acids: Mechanisms, animal models, and potential treatment

Abdominal aortic aneurysm (AAA) is an inflammatory disease associated with macrophage accumulation in the adventitia, oxidative stress, medial elastin degradation and aortic dilation. Progression of AAA is linked to increased risk of rupture, which carries a high mortality rate. Drug therapies trialled to date lack efficacy and although aneurysm repair is available for patients with large aneurysm, peri-surgical morbidity and mortality have been widely reported. Recent studies using rodent models of AAA suggest that long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs) and their metabolites can moderate inflammation and oxidative stress perpetuated by infiltrating macrophages and intervene in the destruction of medial elastin. This review examines evidence from these animal studies and related reports of inhibition of inflammation and arrest of aneurysm development following prophylactic supplementation with LC n-3 PUFAs. The efficacy of LC n-3 PUFAs for management of existing aneurysm is unclear and further investigations involving human clinical trials are warranted.

Associations of Diabetes and Obesity with Risk of Abdominal Aortic Aneurysm in Men

Background. The associations of diabetes and obesity with the risk of abdominal aortic aneurysm (AAA) are inconclusive in previous studies. Subjects/Methods. We conducted prospective analysis in the Physicians' Health Study. Among 25,554 male physicians aged ≥ 50 years who reported no AAA at baseline, 471 reported a newly diagnosed AAA during a mean of 10.4 years' follow-up. Results. Compared with men who had baseline body mass index (BMI) < 25 kg/m², the multivariable hazard ratio (HR [95% CI]) of newly diagnosed AAA was 1.30 [1.06-1.59] for BMI 25-<30 kg/m² and 1.69 [1.24-2.30] for BMI ≥ 30 kg/m². The risk of diagnosed AAA was significantly higher by 6% with each unit increase in baseline BMI. This association was consistent regardless of the other known AAA risk factors and preexisting vascular diseases. Overall, baseline history of diabetes tended to be associated with a lower risk of diagnosed AAA (HR = 0.79 [0.57-1.11]); this association appeared to vary by follow-up time (HR = 1.56 and 0.63 during ≤ and >2 years' follow-up, resp.). Conclusion. In a large cohort of middle-aged and older men, obesity was associated with a higher risk, while history of diabetes tended to associate with a lower risk of diagnosed AAA, particularly over longer follow-up.

Tauroursodeoxycholic Acid Attenuates Angiotensin II Induced Abdominal Aortic Aneurysm Formation in Apolipoprotein E-deficient Mice by Inhibiting Endoplasmic Reticulum Stress

OBJECTIVE/BACKGROUND

Abdominal aortic aneurysm (AAA) is characterised by the infiltration of smooth muscle cell (SMC) apoptosis, inflammatory cells, neovascularisation, and degradation of the extracellular matrix. Previous work has shown that endoplasmic reticulum (ER) stress and SMC apoptosis were increased both in a mouse model and human thoracic aortic aneurysm. However, whether the ER stress is activated in AAA formation and whether suppressing ER stress attenuates AAA is unknown.

METHODS

Human AAA and control aorta samples were collected. Expression of ER stress chaperones glucose-regulated protein (GRP)-78 and GRP-94 was detected by immunohistochemical staining. The effect of ER stress inhibitor tauroursodeoxycholic acid (TUDCA) on AAA formation in angiotensin (Ang) II induced apolipoprotein E^-/- mice was explored. Elastin staining was used to observe the rupture of elastic fragmentation. Immunohistochemistry and Western blot analysis were performed, to detect the protein expression of ER stress chaperones and apoptosis molecules.

RESULTS

There was significant upregulation of GRP-78 and GRP-94 in aneurysmal areas of human AAA and Ang II induced ApoE^-/- mice (p < .05). TUDCA significantly attenuated the maximum diameters of abdominal aortas in Ang II induced ApoE^-/- mice (p < .05). TUDCA significantly reduced expression of ER stress chaperones and the apoptotic cell numbers (p < .05). Furthermore, TUDCA significantly reduced expression of apoptosis molecules, such as caspase-3, caspase-12, C/EBP homologous protein, c-Jun N-terminal kinase activating transcription factor 4, X-box binding protein, and eukaryotic initiation factor 2α in Ang II induced ApoE^-/- mice (p < .05).

CONCLUSION

The results suggest that ER stress is involved in human and Ang II induced AAA formation in ApoE^-/- mice. TUDCA attenuates Ang II induced AAA formation in ApoE^-/- mice by inhibiting ER stress mediated apoptosis.

Abdominal aortic aneurysm repair in octogenarians is associated with higher mortality compared with nonoctogenarians

OBJECTIVE

Age is a well-known independent risk factor for death after abdominal aortic aneurysm (AAA) repair. However, there is significant debate about the utility of AAA repair in older patients. In this study, mortality outcomes after endovascular AAA repair (EVAR) and open AAA repair (OAR) in octogenarians (aged ≥80 years) were compared with younger patients (aged <80 years).

METHODS

All patients recorded in the Vascular Quality Initiative database (2002-2012) who underwent infrarenal AAA repair were included. Univariable and multivariable statistics were used to compare perioperative (30-day) and 1-year mortality outcomes between octogenarians vs nonoctogenarians for OAR and EVAR.

RESULTS

During the study period, 21,874 patients underwent AAA repair (OAR, 5765; EVAR, 16,109), including 4839 octogenarians (OAR, 765; EVAR, 4074) and 17,035 nonoctogenarians (OAR, 5000; EVAR, 12,035). Octogenarians (mean age, 83.0 ± 0.1 years) were less frequently male (66% vs 75%) and had a higher prevalence of congestive heart failure (9.9% vs 7.1%), chronic renal insufficiency (12.2% vs 7.5%), and a history of aortic surgery (14.3% vs 7.7%) compared with nonoctogenarians (P < .01 for all). Intraoperative use of blood transfusions and vasopressors was more common in octogenarians for OAR (blood: 3.3 ± 4.4 vs 1.8 ± 3.7 units; vasopressors: 45.2% vs 32.8%) and EVAR (blood: 0.43 ± 1.7 vs 0.31 ± 1.6 units; vasopressors: 7.6% vs 5.7%; P < .01 for all). Contrast dye volumes used during EVAR were similar in octogenarians and nonoctogenarians (108 ± 71 vs 107 ± 68 mL; P = .18). Perioperative mortality after OAR was 20.1% in octogenarians compared with 7.1% in nonoctogenarians (P < .01). Perioperative mortality after EVAR was 3.8% in the octogenarians compared with 1.6% in nonoctogenarians (P < .01). One-year mortality among octogenarians vs nonoctogenarians was 26% vs 9.7% for OAR and 8.9% vs 4.3% for EVAR (log-rank test, P < .01 for both). Multivariable analysis controlling for baseline and intraoperative differences between groups demonstrated that age ≥80 years increased the risk of 30-day and 1-year mortality after AAA repair by 223% and 187%, respectively (P < .01 for both).

CONCLUSIONS

AAA repair should be approached with extreme caution in octogenarians. Perioperative and 1-year mortality rates after OAR are particularly high in the older population, suggesting that the appropriate aneurysm size threshold for OAR might be larger due to the greater operative risk in octogenarian patients.

Biases in detection of apparent "weekend effect" on outcome with administrative coding data: population based study of stroke

OBJECTIVES

 To determine the accuracy of coding of admissions for stroke on weekdays versus weekends and any impact on apparent outcome.

DESIGN

 Prospective population based stroke incidence study and a scoping review of previous studies of weekend effects in stroke.

SETTING

 Primary and secondary care of all individuals registered with nine general practices in Oxfordshire, United Kingdom (OXVASC, the Oxford Vascular Study).

PARTICIPANTS

 All patients with clinically confirmed acute stroke in OXVASC identified with multiple overlapping methods of ascertainment in 2002-14 versus all acute stroke admissions identified by hospital diagnostic and mortality coding alone during the same period.

MAIN OUTCOMES MEASURES

 Accuracy of administrative coding data for all patients with confirmed stroke admitted to hospital in OXVASC. Difference between rates of "false positive" or "false negative" coding for weekday and weekend admissions. Impact of inaccurate coding on apparent case fatality at 30 days in weekday versus weekend admissions. Weekend effects on outcomes in patients with confirmed stroke admitted to hospital in OXVASC and impacts of other potential biases compared with those in the scoping review.

RESULTS

 Among 92 728 study population, 2373 episodes of acute stroke were ascertained in OXVASC, of which 826 (34.8%) mainly minor events were managed without hospital admission, 60 (2.5%) occurred out of the area or abroad, and 195 (8.2%) occurred in hospital during an admission for a different reason. Of 1292 local hospital admissions for acute stroke, 973 (75.3%) were correctly identified by administrative coding. There was no bias in distribution of weekend versus weekday admission of the 319 strokes missed by coding. Of 1693 admissions for stroke identified by coding, 1055 (62.3%) were confirmed to be acute strokes after case adjudication. Among the 638 false positive coded cases, patients were more likely to be admitted on weekdays than at weekends (536 (41.0%) v 102 (26.5%); P<0.001), partly because of weekday elective admissions after previous stroke being miscoded as new stroke episodes (267 (49.8%) v 26 (25.5%); P<0.001). The 30 day case fatality after these elective admissions was lower than after confirmed acute stroke admissions (11 (3.8%) v 233 (22.1%); P<0.001). Consequently, relative 30 day case fatality for weekend versus weekday admissions differed (P<0.001) between correctly coded acute stroke admissions and false positive coding cases. Results were consistent when only the 1327 emergency cases identified by "admission method" from coding were included, with more false positive cases with low case fatality (35 (14.7%)) being included for weekday versus weekend admissions (190 (19.5%) v 48 (13.7%), P<0.02). Among all acute stroke admissions in OXVASC, there was no imbalance in baseline stroke severity for weekends versus weekdays and no difference in case fatality at 30 days (adjusted odds ratio 0.85, 95% confidence interval 0.63 to 1.15; P=0.30) or any adverse "weekend effect" on modified Rankin score at 30 days (0.78, 0.61 to 0.99; P=0.04) or one year (0.76, 0.59 to 0.98; P=0.03) among incident strokes.

CONCLUSION

 Retrospective studies of UK administrative hospital coding data to determine "weekend effects" on outcome in acute medical conditions, such as stroke, can be undermined by inaccurate coding, which can introduce biases that cannot be reliably dealt with by adjustment for case mix.

Screening for abdominal aortic aneurysms

Ultrasonography remains the screening modality of choice for abdominal aortic aneurysms despite many advances in imaging modalities. Several randomized trials were performed that demonstrated the effectiveness of ultrasound-based screening to reduce aneurysm-related mortality. Ultrasound is both cost effective and low risk. Controversies do persist in selecting the appropriate populations for screening, and several national societies have set recommendations.

Aortic aneurysm screening

Still needs refining