Smoking, sex, risk factors and abdominal aortic aneurysms: a prospective study of 18 782 persons aged above 65 years in the Southern Community Cohort Study

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

Background

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

Methods

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

Results

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

Conclusion

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

Body mass index and the risk of abdominal aortic aneurysm presence and post-operative mortality: a systematic review and dose-response meta-analysis

BACKGROUND

The clinical data regarding the relationships between body mass index (BMI) and abdominal aortic aneurysm (AAA) are inconsistent, especially for the obese and overweight patients. The aims of this study were to determine whether obesity is associated with the presence of AAA and to investigate the quantitative relationship between BMI and the risk of AAA presence and post-operative mortality.

MATERIALS AND METHODS

PubMed, Web of Science and Embase databases were used to search for pertinent studies updated to December 2023. The pooled relative risk (RR) with 95% confidence interval (CI) was estimated by conventional meta-analysis based on random effects model. Dose-response meta-analyses using robust-error meta-regression (REMR) model were conducted to quantify the associations between BMI and AAA outcome variables. Subgroup analysis, sensitivity analysis and publication bias analysis were performed according to the characteristics of participants.

RESULTS

18 studies were included in our study. The meta-analysis showed a higher prevalence of AAA with a RR of 1.07 in patients with obesity. The dose-response meta-analysis revealed a non-linear relationship between BMI and the risk of AAA presence. A "U" shape curve reflecting the correlation between BMI and the risk of post-operative mortality in AAA patients was also uncovered, suggesting the "safest" BMI interval [28.55, 31.05] with the minimal RR.

CONCLUSIONS

Obesity is positively but nonlinearly correlated with the increased risk of AAA presence. BMI is related to AAA post-operative mortality in a "U" shaped curve, with the lowest RR observed among patients suffering from overweight and obesity. These findings offer a preventive strategy for AAA morbidity and provide guidance for improving the prognosis in patients undergone AAA surgical repair.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Comprehensive framework of factors accounting for worse aortic aneurysm outcomes in females: A scoping review

Sex-based outcome studies have consistently documented worse results for females undergoing care for abdominal aortic aneurysms. This review explores the underlying factors that account for worse outcomes in the females sex. A scoping review of studies reporting sex-based disparities on abdominal aortic aneurysms was performed. The review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping reviews. Factors that account for worse outcomes in the females sex were identified, grouped into themes, and analyzed. Key findings of each study are reported and a comprehensive framework of these factors is presented. A total of 35 studies were identified as critical in highlighting sex-based disparities in care of patients with aortic aneurysms. We identified the following 10 interrelated themes in the chain of aneurysm care that account for differential outcomes in females: natural history, risk factors, pathobiology, biomechanics, screening, morphology, device design and adherence to instructions for use, technique, trial enrollment, and social determinants. Factors accounting for worse outcomes in the care of females with aortic aneurysms were identified and described. Some factors are immediately actionable, such as screening criteria, whereas device design improvement will require further research and development. This comprehensive framework of factors affecting care of aneurysms in females should serve as a blueprint to develop education, outreach, and future research efforts to improve outcomes in females.

Pharmacological Inhibition of Gasdermin D Suppresses Angiotensin II-Induced Experimental Abdominal Aortic Aneurysms

BACKGROUND

Gasdermin D, a molecule downstream of the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing inflammasome, forms the membrane pore for the secretion of interleukin (IL)-1β and IL-18, and also mediates pyroptosis. This study was to explore the influence of treatment with disulfiram, a small molecule inhibitor to gasdermin D, on the formation and progression of experimental abdominal aortic aneurysms (AAA).

METHODS

AAAs were induced in 10-week-old male apolipoprotein E deficient mice by subcutaneous infusion of angiotensin II (1000 ng/min/kg body weight) for 28 days via osmotic minipumps. Three days prior to angiotensin II infusion, disulfiram (50 mg/kg) or an equal volume of saline as the vehicle control was administered daily via oral gavage. The influence on experimental AAAs was analyzed by serial measurements of aortic diameters via ultrasonography, grading AAA severity and histopathology at sacrifice. Serum IL-1β and IL-18 levels, systolic blood pressure, total cholesterol, and triglyceride were also measured. Additional experiments assayed the influences on the cell viability and IL-1β secretion of in vitro activated macrophages.

RESULTS

Disulfiram significantly reduced the enlargement, incidence, and severity of angiotensin II-induced experimental AAAs with attenuation of medial elastin breaks, mural macrophage accumulation, and systolic blood pressure. The AAA suppression was also associated with reduced systemic levels of IL-1β but not IL-18. However, disulfiram treatment had no impact on body weight gain and lipid levels in aneurysmal mice. Additionally, disulfiram treatment also markedly reduced the secretion of IL-1β from activated macrophages with a limited effect on cell viability in vitro.

CONCLUSIONS

Gasdermin D inhibition by disulfiram attenuated angiotensin II-induced experimental AAAs with reduced systemic IL-1β levels and in vitro activated macrophage IL-1β secretion. Our study suggests that pharmacological gasdermin D inhibition may have translational potential for limiting clinical AAA progression.

Tributyrin Intake Attenuates Angiotensin II-Induced Abdominal Aortic Aneurysm in LDLR-/- Mice

Abdominal aortic aneurysm (AAA) is a multifactorial cardiovascular disease with a high risk of death, and it occurs in the infrarenal aorta with vascular dilatation. High blood pressure acts on the aortic wall, resulting in rupture and causing life-threatening intra-abdominal hemorrhage. Vascular smooth muscle cell (VSMC) dysregulation and extracellular matrix (ECM) degradation, especially elastin breaks, contribute to structural changes in the aortic wall. The pathogenesis of AAA includes the occurrence of oxidative stress, inflammatory cell infiltration, elastic fiber fragmentation, VSMC apoptosis, and phenotypic transformation. Tributyrin (TB) is decomposed by intestinal lipase and has a function similar to that of butyrate. Whether TB has a protective effect against AAA remains uncertain. In the present study, we established an AAA murine model by angiotensin II (AngII) induction in low-density lipoprotein receptor knockout (LDLR^-/-) mice and investigated the effects of orally administered TB on the AAA size, ratio of macrophage infiltration, levels of matrix metalloproteinase (MMP) expression, and epigenetic regulation. TB attenuates AngII-induced AAA size and decreases elastin fragmentation, macrophage infiltration, and MMP expression in the medial layer of the aorta and reduces the levels of SBP (systolic blood pressure, p < 0.001) and MMP-2 (p < 0.02) in the serum. TB reduces the AngII-stimulated expression levels of MMP2 (p < 0.05), MMP9 (p < 0.05), MMP12, and MMP14 in human aortic smooth muscle cells (HASMCs). Moreover, TB and valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, suppress AngII receptor type 1 (AT1R, p < 0.05) activation and increase the expression of acetyl histone H3 by HDAC activity inhibition (p < 0.05). Our findings suggest that TB exerts its protective effect by suppressing the activation of HDAC to attenuate the AngII-induced AT1R signaling cascade.

Normative reference values of major thoracic arterial vasculature in Turkiye

OBJECTIVE

The aim of this study was to determine normative reference values for major thoracic arterial vasculature in Turkiye and to evaluate differences according to age and gender.

METHODS

Low-dose unenhanced chest computerized tomography images acquired with pre-diagnosis of COVID-19 between March and June 2020 were evaluated retrospectively. Patients with known chronic lung parenchymal disease, pleural effusion, pneumothorax, chronic diseases such as diabetes, hypertension, obesity, and chronic heart diseases (coronary artery disease, atherosclerosis, congestive heart failure, valve replacement, and arrhythmia) were excluded from the study. The ascending aorta diameter (AAD), descending aorta diameter (DAD), aortic arch diameter (ARCAD), main pulmonary artery diameter (MPAD), right pulmonary artery diameter (RPAD), and the left pulmonary artery diameter (LPAD) were measured in the same sections by standardized methods. The variability of parameters according to age (<40 years; ≥40 years) and gender (male to female) was evaluated by statistical methods. The Student's t test was used to compare the normal distribution according to the given quantitative age and gender, while the data that did not fit the normal distribution were compared with the Mann-Whitney U test. The conformity of the data to the normal distribution was tested with the Kolmogorov-Smirnov, Shapiro-Wilk test, and graphical examinations.

RESULTS

Totally 777 cases between the ages of 18-96 (43.80±15.98) were included in the study. Among these, 52.8% (n=410) were male and 47.2% (n=367) were female. Mean diameters were 28.52±5.13 mm (12-48 mm in range) for AAD, 30.83±5.25 mm (12-52 mm in range) for ARCAD, DAD 21.27±3.57 mm (11-38 mm in range) for DAD; 23.27±4.03 mm (14-40 mm in range) for MPAD, 17.27±3.19 mm (10-30 mm in range) for RPAD, and 17.62±3.06 mm (10-37 mm in range) for LPAD. Statistically significantly higher values were obtained in all diameters for cases over 40 years of age. Similarly, higher values were obtained in all diameters for males compared to females.

CONCLUSION

The diameters of all thoracic main vascular structures are larger in men than in women and increase with age.

Totally percutaneous versus surgical cut-down femoral artery access for elective bifurcated abdominal endovascular aneurysm repair

BACKGROUND

Abdominal aortic aneurysms (AAAs) are a vascular condition with significant risk attached, particularly if they rupture. Therefore, it is critical to identify and repair these as an elective procedure before they rupture and require emergency surgery. Repair has traditionally been an open surgical technique that required a large incision across the abdomen. Endovascular abdominal aortic aneurysm repairs (EVARs) are now a common alternative. In this procedure, the common femoral artery is exposed via a cut-down approach and a graft is introduced to the aneurysm in this way. This Cochrane Review examines a totally percutaneous approach to EVAR. This technique gives a minimally invasive approach to femoral artery access that may reduce groin wound complication rates and improve recovery time. However, the technique may be less applicable in people with, for example, groin scarring or arterial calcification. This is an update of the previous Cochrane Review published in 2017.

OBJECTIVES

To evaluate the benefits and harms of totally percutaneous access compared to cut-down femoral artery access in people undergoing elective bifurcated abdominal endovascular aneurysm repair (EVAR).

SEARCH METHODS

We used standard, extensive Cochrane search methods The latest search was 8 April 2022.

SELECTION CRITERIA

We included randomised controlled trials in people diagnosed with an AAA comparing totally percutaneous versus surgical cut-down access endovascular repair. We considered all device types. We only considered studies investigating elective repairs. We excluded studies reporting emergency surgery for ruptured AAAs and those reporting aorto-uni-iliac repairs.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. short-term mortality, 2. failure of aneurysm exclusion and 3. wound infection. Secondary outcomes were 4. major complications (30-day or in-hospital); 5. medium- to long-term (6 and 12 months) complications and mortality; 6. bleeding complications and haematoma; and 7. operating time, duration of intensive treatment unit (ITU) stay and hospital stay. We used GRADE to assess the certainty of evidence for the seven most clinically relevant primary and secondary outcomes.

MAIN RESULTS

Three studies with 318 participants met the inclusion criteria, 189 undergoing the percutaneous technique and 129 treated by cut-down femoral artery access. One study had a small sample size and did not adequately report the method of randomisation, allocation concealment or preselected outcomes. The other two larger studies had few sources of bias and good methodology; although one study had a high risk of bias in selective reporting. We observed no clear difference in short-term mortality between groups, with only one death occurring overall, in the totally percutaneous group (risk ratio (RR) 1.50, 95% confidence interval (CI) 0.06 to 36.18; 2 studies, 181 participants; low-certainty evidence). One study reported failure of aneurysm exclusion. There was one failure of aneurysm exclusion in the surgical cut-down femoral artery access group (RR 0.17, 95% CI 0.01 to 4.02; 1 study, 151 participants; moderate-certainty evidence). For wound infection, there was no clear difference between groups (RR 0.18, 95% CI 0.01 to 3.59; 3 studies, 318 participants; moderate-certainty evidence). There was no clear difference between percutaneous and cut-down femoral artery access groups in major complications (RR 1.21, 95% CI 0.61 to 2.41; 3 studies, 318 participants; moderate-certainty evidence), bleeding complications (RR 1.02, 95% CI 0.29 to 3.64; 2 studies, 181 participants; moderate-certainty evidence) or haematoma (RR 0.88, 95% CI 0.13 to 6.05; 2 studies, 288 participants). One study reported medium- to long-term complications at six months, with no clear differences between the percutaneous and cut-down femoral artery access groups (RR 0.82, 95% CI 0.25 to 2.65; 1 study, 135 participants; moderate-certainty evidence). We detected differences in operating time, with the percutaneous approach being faster than cut-down femoral artery access (mean difference (MD) -21.13 minutes, 95% CI -41.74 to -0.53 minutes; 3 studies, 318 participants; low-certainty evidence). One study reported the duration of ITU stay and hospital stay, with no clear difference between groups.

AUTHORS' CONCLUSIONS

Skin puncture may make little to no difference to short-term mortality. There is probably little or no difference in failure of aneurysm exclusion (failure to seal the aneurysms), wound infection, major complications within 30 days or while in hospital, medium- to long-term (six months) complications and bleeding complications between the two groups. Compared with exposing the femoral artery, skin puncture may reduce the operating time slightly. We downgraded the certainty of the evidence to moderate and low as a result of imprecision due to the small number of participants, low event rates and wide CIs, and inconsistency due to clinical heterogeneity. As the number of included studies was limited, further research into this technique would be beneficial.

Brucella Infectious Aneurysm: A Retrospective Study of 14 Cases and Review of the Literature - Case Report and Literature Review

Objective

To analyze the clinical characteristics and treatment process of 14 patients with aneurysm due to brucellosis, summarize the morbidity characteristics, and improve the knowledge and diagnosis of the disease.

Methods

The clinical data of patients with aneurysms who were diagnosed to have brucellosis through Rose Bengal Test (RBT), Serum Agglutination Test (SAT), blood culture, and computed tomography angiography from January 2012 to November 2022 in Bethune Hospital, Shanxi Province, China, were retrospectively analyzed, and their clinical characteristics and disease regression findings were summarized.

Results

Of the 14 patients, 13 were men, and 1 was a woman; the youngest patient was 48-year-old, and the oldest patient was of 74 years. All had a history of smoking. The sites of lesion occurrence included the abdominal aorta (5 patients), abdominal aorta +iliac artery (5 patients), iliac artery (2 patients), thoracic aorta and brachial artery were less common (1 case each). Symptoms in the patients mostly began with abdominal pain, which was accompanied by fever, nausea, and vomiting. Six patients had a clear history of livestock exposure. Fourteen patients showed elevated D-dimer and C-reactive protein levels and decreased hemoglobin and albumin levels. Thirteen of the 14 cases were treated surgically, there were no complications of surgery, and 3 patients were readmitted with recurrence of brucellosis, it is related to the treatment that did not reach the early stage, combination, full dose and full course of treatment, with a mean recurrence time of 8 months. In the telephone follow-up, the patient's recovery proceeded well.

Conclusion

The present study revealed that the recurrence in male gender, advanced age, smoking and irregular treatment is higher. On the contrast, early intervention, a combination of adequate course of anti-infection treatment and timely surgery can improve the prognosis.

Predictive models for abdominal aortic aneurysms using polygenic scores and PheWAS-derived risk factors

Abdominal aortic aneurysms (AAA) are common enlargements of the abdominal aorta which can grow larger until rupture, often leading to death. Detection of AAA is often by ultrasonography and screening recommendations are mostly directed at men over 65 with a smoking history. Recent large-scale genome-wide association studies have identified genetic loci associated with AAA risk. We combined known risk factors, polygenic risk scores (PRS) and precedent clinical diagnoses from electronic health records (EHR) to develop predictive models for AAA, and compared performance against screening recommendations. The PRS included genome-wide summary statistics from the Million Veteran Program and FinnGen (10,467 cases, 378,713 controls of European ancestry), with optimization in Vanderbilt's BioVU and validated in the eMERGE Network, separately across both White and Black participants. Candidate diagnoses were identified through a temporally-oriented Phenome-wide association study in independent EHR data from Vanderbilt, and features were selected via elastic net. We calculated C-statistics in eMERGE for models including PRS, phecodes, and covariates using regression weights from BioVU. The AUC for the full model in the test set was 0.883 (95% CI 0.873-0.892), 0.844 (0.836-0.851) for covariates only, 0.613 (95% CI 0.604-0.622) when using primary USPSTF screening criteria, and 0.632 (95% CI 0.623-0.642) using primary and secondary criteria. Brier scores were between 0.003 and 0.023 for our models indicating good calibration, and net reclassification improvement over combined primary and secondary USPSTF criteria was 0.36-0.60. We provide PRS for AAA which are strongly associated with AAA risk and add to predictive model performance. These models substantially improve identification of people at risk of a AAA diagnosis compared with existing guidelines, with evidence of potential applicability in minority populations.

3D Ultrasound Measurements Are Highly Sensitive to Monitor Formation and Progression of Abdominal Aortic Aneurysms in Mouse Models

Background

Available mouse models for abdominal aortic aneurysms (AAAs) differ substantially in the applied triggers, associated pathomechanisms and rate of vessel expansion. While maximum aortic diameter (determined after aneurysm excision or by 2D ultrasound) is commonly applied to document aneurysm development, we evaluated the sensitivity and reproducibility of 3D ultrasound to monitor aneurysm growth in four distinct mouse models of AAA.

Methods

The models included angiotensin-II infusion in ApoE deficient mice, topical elastase application on aortas in C57BL/6J mice (with or without oral administration of β-aminoproprionitrile) and intraluminal elastase perfusion in C57BL/6J mice. AAA development was monitored using semi-automated 3D ultrasound for aortic volume calculation over 12 mm length and assessment of maximum aortic diameter.

Results

While the models differed substantially in the time course of aneurysm development, 3D ultrasound measurements (volume and diameter) proved highly reproducible with concordance correlation coefficients > 0.93 and variations below 9% between two independent observers. Except for the elastase perfusion model where aorta expansion was lowest and best detected by diameter increase, all other models showed high sensitivity of absolute volume and diameter measurements in monitoring AAA formation and progression by 3D ultrasound. When compared to standard 2D ultrasound, the 3D derived parameters generally reached the highest effect size.

Conclusion

This study has yielded novel information on the robustness and limitations of semi-automated 3D ultrasound analysis and provided the first direct comparison of aortic volume increase over time in four widely applied mouse models of AAA. While 3D ultrasound generally proved highly sensitive in detecting early AAA formation, the 3D based volume analysis was found inferior to maximum diameter assessment in the elastase perfusion model where the extent of inflicted local injury is determined by individual anatomical features.

Racial and Ethnic Disparities in Abdominal Aortic Aneurysm Evaluation and Treatment Rates in Texas

INTRODUCTION

Screening identifies intact abdominal aortic aneurysm (iAAA) before progression to ruptured AAA (rAAA). However, screening efforts have been limited by low overall diagnostic yield and by unequal screening among minority populations. The goal was to identify equitable AAA screening strategies for both majority and minority populations.

METHODS

We performed epidemiological and geospatial analyses of inpatient and outpatient procedures for iAAA or rAAA at Texas hospitals from 2006 through 2014 at all non-federal hospitals and clinics in Texas. Data were aggregated by area (metropolitan statistical area or rural region), then supplemented by six additional data sources to estimate AAA repair incidence rates, rates of AAA-related clinic and ultrasonography visits, distance to providers, and location and number of unrecognized AAAs.

RESULTS

The majority of AAA repairs occurred among 65-84 year-old men in large metropolitan areas categorized as White. Area procedure rates for rAAA and iAAA were strongly correlated (R²=0.47). Two other variables-the proportions of persons categorized as White and persons aged ≥65 years in a region-identified subgroups within the majority population that were at high risk for iAAA (R²=0.46). Lower rates of clinic visits and AAA ultrasonograms were seen among persons categorized as Black. The several areas with disproportionately-higher rAAA:iAAA ratios were found, mainly affecting persons categorized as Black.

CONCLUSIONS

Multiple focused AAA screening strategies may be needed to address disproportionately-lower AAA identification among persons categorized as Black.

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.

Translating mouse models of abdominal aortic aneurysm to the translational needs of vascular surgery

Introduction

Abdominal aortic aneurysm (AAA) is a condition that has considerable socioeconomic impact and an eventual rupture is associated with high mortality and morbidity. Despite decades of research, surgical repair remains the treatment of choice and no medical therapy is currently available. Animal models and, in particular, murine models, of AAA are a vital tool for experimental in vivo research. However, each of the different models has individual limitations and provide only partial mimicry of human disease. This narrative review addresses the translational potential of the available mouse models, highlighting unanswered questions from a clinical perspective. It is based on a thorough presentation of the available literature and more than a decade of personal experience, with most of the available models in experimental and translational AAA research.

Results

From all the models published, only the four inducible models, namely the angiotensin II model (AngII), the porcine pancreatic elastase perfusion model (PPE), the external periadventitial elastase application (ePPE), and the CaCl₂ model have been widely used by different independent research groups. Although the angiotensin II model provides features of dissection and aneurysm formation, the PPE model shows reliable features of human AAA, especially beyond day 7 after induction, but remains technically challenging. The translational value of ePPE as a model and the combination with β-aminopropionitrile to induce rupture and intraluminal thrombus formation is promising, but warrants further mechanistic insights. Finally, the external CaCl₂ application is known to produce inflammatory vascular wall thickening. Unmet translational research questions include the origin of AAA development, monitoring aneurysm growth, gender issues, and novel surgical therapies as well as novel nonsurgical therapies.

Conclusion

New imaging techniques, experimental therapeutic alternatives, and endovascular treatment options provide a plethora of research topics to strengthen the individual features of currently available mouse models, creating the possibility of shedding new light on translational research questions.

Female sex is independently associated with in-hospital mortality after endovascular aortic repair for ruptured aortic aneurysm

OBJECTIVE

Endovascular aortic repair (EVAR) can treat anatomically compatible ruptured abdominal aortic aneurysms (rAAA), but registry data suggests that women undergo more open abdominal aneurysm repairs than men. We evaluate in-hospital outcomes of EVAR for rAAA by sex.

METHODS

The Vascular Quality Initiative (VQI) registry was queried from 2013 to 2019 for rAAA patients treated with EVAR. Univariate analysis was performed with Student's t-test and chi-squared tests. Multivariable logistic regression was then performed to assess the association between female sex and inpatient mortality.

RESULTS

1775 patients were included (23.8% female). Female rAAA patients were older (p < 0.01) and weighed less (p < 0.01). They were less likely to have smoked (p <. 001) and had lower creatinine (1.29 vs 1.43, p <0.01) and hemoglobin (10.7 vs 11.7, p < 0.01). Women had smaller maximum aortic diameters (74 vs 66 mm, p < 0.01) and were less likely to have iliac aneurysms (p <.001). Women were more likely to have concomitant femoral endarterectomy (8.5% vs 4.6%, p=.03). Despite having no significant difference in complication or reintervention rates, women had higher rates of in-hospital mortality (45.9% vs 34.5%, p < 0.01). In a logistic regression model for predictors of in-hospital mortality (χ² < .01), increased age (OR 1.08, p < 0.01), female sex (OR 1.7, p=0.02), preoperative cardiac arrest (OR 5.29, p<0.01), concurrent iliac stenting (OR 2.38, p =0.02), postoperative mesenteric ischemia (OR 2.51, p<0.01) and postoperative transfusion (OR 1.06, p <0.01) were independently associated with in-hospital mortality. Increased preoperative hemoglobin was protective (OR 0.89, p < 0.01) CONCLUSIONS: Female sex is independently associated with in-hospital mortality after EVAR for rAAA, suggesting a relationship beyond anatomical, biochemical, and procedural covariates.

The Femoral Venoarterial Perfusion During Open Abdominal Aortic Aneurysm Repair in Patient With Renal Transplant

We report of a patient with abdominal aortic aneurysm and renal transplant who underwent aneurysm repair. These patients can be treated by eather open or endovascular approach, depending on several factors, including aneurysm morphologic suitability for endovascular tretament, age of patient, and comorbidities.The main challange with open repair approach is to maintain renal transplant perfusion during the aortic cross clamping. Several methods of renal transplant perfusion during aneurysm repair have been described. In this case, we opted for open aneurysm repair beacuse of the age of the patient. The femoral venoarterial perfusion technique using extracorporal circulation machine was employed. We found this technique safe and easy in treating such patients.

Coenzyme Q10 amends testicular function and spermatogenesis in male mice exposed to cigarette smoke by modulating oxidative stress and inflammation

This study explored the effects of coenzyme Q₁₀ (CoQ₁₀) on the testicular functions of male mice exposed to cigarette smoke. Eight-week-old BALB/c male mice were divided into the following groups: the AV group (air with a vehicle), the AQ group (air with CoQ₁₀), the SV group (smoke with a vehicle), and the SQ group (smoke with CoQ₁₀). The results showed that the CoQ₁₀ concentrations in the sera and testes were decreased in the groups subjected to smoke but they were improved after the administration of CoQ₁₀. Neither smoke nor CoQ₁₀ supplementation affected the serum or testis testosterone concentrations. Regarding the antioxidant system in the testis, the exposure to smoke induced malondialdehyde and hydrogen peroxide production and decreased the catalase and glutathione peroxidase activities. Oral CoQ₁₀ administration reversed the oxidative damage. In apoptosis, the cytochrome c, c-caspase 9, and c-caspase 3 proteins were increased in the groups exposed to smoke but they were decreased after the CoQ₁₀ administration. In mitochondrial biogenesis, smoke exposure led to decreases in the PGC1-α, NRF1, and NRF2 levels, but CoQ₁₀ increased the expressions of these proteins. Additionally, oral CoQ₁₀ administration improved the mitochondrial copy numbers that were reduced following the exposure to smoke. In summary, CoQ₁₀ administration reduces smoke-induced testicular damage by regulating the antioxidant capacity, the cell apoptosis, the mitochondrial biogenesis, and the copy numbers in the testes.

Sex-specific normal values and determinants of infrarenal abdominal aortic diameter among non-aneurysmal elderly population

To establish age- and sex-specific distribution of the infrarenal abdominal aortic diameters (IAD) among non-aneurysmal elderly population and to investigate the associations between traditional cardiovascular risk factors and IAD in men and women. We included 4032 participants (mean age 67.2 years; 60.4% women) from the population-based Rotterdam Study, free of cardiovascular disease, who underwent IAD ultrasound assessment between 2009-2014. Linear regression analysis was used to identify determinants of IAD. The medians (inter-quartile range) of absolute IAD and body surface area (BSA)-adjusted IAD were 17.0 (15.0-18.0) mm and 9.3 (8.5-10.2) mm for women and 19.0 (18.0-21.0) mm and 9.4 (8.6-10.3) mm for men, respectively. There was a non-linear relationship between age and IAD. IAD increased steeply with advancing age and up to 70 years. After around 75 years of age, the diameter values reached a plateau. Waist circumference and diastolic blood pressure were associated with larger diameters in both sexes. Body mass index [Effect estimate (95% CI): 0.04 (0.00 to 0.08)], systolic blood pressure [- 0.01(- 0.02 to 0.00)], current smoking [0.35 (0.06 to 0.65)], total cholesterol levels [- 0.21 (- 0.31 to - 0.11)], and lipid-lowering medication [- 0.43 (- 0.67 to - 0.19)] were significantly associated with IAD in women. Sex differences in IAD values diminished after taking BSA into account. The increase in diameters was attenuated after 70 years. Differences were observed in the associations of several cardiovascular risk factors with IAD among men and women.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Prehabilitation exercise therapy before elective abdominal aortic aneurysm repair

BACKGROUND

An abdominal aortic aneurysm (AAA) is an abnormal dilation in the diameter of the abdominal aorta of 50% or more of the normal diameter or greater than 3 cm in total. The risk of rupture increases with the diameter of the aneurysm, particularly above a diameter of approximately 5.5 cm. Perioperative and postoperative morbidity is common following elective repair in people with AAA. Prehabilitation or preoperative exercise is the process of enhancing an individual's functional capacity before surgery to improve postoperative outcomes. Studies have evaluated exercise interventions for people waiting for AAA repair, but the results of these studies are conflicting.

OBJECTIVES

To assess the effects of exercise programmes on perioperative and postoperative morbidity and mortality associated with elective abdominal aortic aneurysm repair.

SEARCH METHODS

We searched the Cochrane Vascular Specialised register, Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Physiotherapy Evidence Database (PEDro) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 6 July 2020. We also examined the included study reports' bibliographies to identify other relevant articles.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) examining exercise interventions compared with usual care (no exercise; participants maintained normal physical activity) for people waiting for AAA repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed the included studies, extracted data and resolved disagreements by discussion. We assessed the methodological quality of studies using the Cochrane risk of bias tool and collected results related to the outcomes of interest: post-AAA repair mortality; perioperative and postoperative complications; length of intensive care unit (ICU) stay; length of hospital stay; number of days on a ventilator; change in aneurysm size pre- and post-exercise; and quality of life. We used GRADE to evaluate certainty of the evidence. For dichotomous outcomes, we calculated the risk ratio (RR) with the corresponding 95% confidence interval (CI).

MAIN RESULTS

This review identified four RCTs with a total of 232 participants with clinically diagnosed AAA deemed suitable for elective intervention, comparing prehabilitation exercise therapy with usual care (no exercise). The prehabilitation exercise therapy was supervised and hospital-based in three of the four included trials, and in the remaining trial the first session was supervised in hospital, but subsequent sessions were completed unsupervised in the participants' homes. The dose and schedule of the prehabilitation exercise therapy varied across the trials with three to six sessions per week and a duration of one hour per session for a period of one to six weeks. The types of exercise therapy included circuit training, moderate-intensity continuous exercise and high-intensity interval training. All trials were at a high risk of bias. The certainty of the evidence for each of our outcomes was low to very low. We downgraded the certainty of the evidence because of risk of bias and imprecision (small sample sizes). Overall, we are uncertain whether prehabilitation exercise compared to usual care (no exercise) reduces the occurrence of 30-day (or longer if reported) mortality post-AAA repair (RR 1.33, 95% CI 0.31 to 5.77; 3 trials, 192 participants; very low-certainty evidence). Compared to usual care (no exercise), prehabilitation exercise may decrease the occurrence of cardiac complications (RR 0.36, 95% CI 0.14 to 0.92; 1 trial, 124 participants; low-certainty evidence) and the occurrence of renal complications (RR 0.31, 95% CI 0.11 to 0.88; 1 trial, 124 participants; low-certainty evidence). We are uncertain whether prehabilitation exercise, compared to usual care (no exercise), decreases the occurrence of pulmonary complications (RR 0.49, 95% 0.26 to 0.92; 2 trials, 144 participants; very low-certainty evidence), decreases the need for re-intervention (RR 1.29, 95% 0.33 to 4.96; 2 trials, 144 participants; very low-certainty evidence) or decreases postoperative bleeding (RR 0.57, 95% CI 0.18 to 1.80; 1 trial, 124 participants; very low-certainty evidence). There was little or no difference between the exercise and usual care (no exercise) groups in length of ICU stay, length of hospital stay and quality of life. None of the studies reported data for the number of days on a ventilator and change in aneurysm size pre- and post-exercise outcomes.

AUTHORS' CONCLUSIONS

Due to very low-certainty evidence, we are uncertain whether prehabilitation exercise therapy reduces 30-day mortality, pulmonary complications, need for re-intervention or postoperative bleeding. Prehabilitation exercise therapy might slightly reduce cardiac and renal complications compared with usual care (no exercise). More RCTs of high methodological quality, with large sample sizes and long-term follow-up, are needed. Important questions should include the type and cost-effectiveness of exercise programmes, the minimum number of sessions and programme duration needed to effect clinically important benefits, and which groups of participants and types of repair benefit most.

Antioxidants in smokers

Cigarette smoke (CS) is likely the most common preventable cause of human morbidity and mortality worldwide. Consequently, inexpensive interventional strategies for preventing CS-related diseases would positively impact health systems. Inhaled CS is a powerful inflammatory stimulus and produces a shift in the normal balance between antioxidants and oxidants, inducing oxidative stress in both the respiratory system and throughout the body. This enduring and systemic pro-oxidative state within the body is reflected by increased levels of oxidative stress and inflammation biomarkers seen in smokers. Smokers might benefit from consuming antioxidant supplements, or a diet rich in fruit and vegetables, which can reduce the CS-related oxidative stress. This review provides an overview of the plasma profile of antioxidants observable in smokers and examines the heterogeneous literature to elucidate and discuss the effectiveness of interventional strategies based on antioxidant supplements or an antioxidant-rich diet to improve the health of smokers. An antioxidant-rich diet can provide an easy-to-implement and cost-effective preventative strategy to reduce the risk of CS-related diseases, thus being one of the simplest ways for smokers to stay in good health for as long as possible. The health benefits attributable to the intake of antioxidants have been observed predominantly when these have been consumed within their natural food matrices in an optimal antioxidant-rich diet, while these preventive effects are rarely achieved with the intake of individual antioxidants, even at high doses.

LOXL4 Abrogation Does Not Exaggerate Angiotensin II-Induced Thoracic or Abdominal Aortic Aneurysm in Mice

It has been shown that thoracic aortic aneurysm and dissection (TAAD) could be a Mendelian trait caused by a single gene mutation. The LOX gene mutation leads to the development of human TAAD. The LOXL4 gene is a member of the lysyl oxidase gene family. We identified seven variants in the LOXL4 gene in 219 unrelated patients with TAAD by whole-exome sequencing (WES). To further investigate whether LOXL4 is a candidate causative gene for human TAAD, a Loxl4 knockout mouse was generated, and the mutant mice were treated by subcutaneous infusion of angiotensin II. We found that abrogation of Loxl4 did not induce a more severe thoracic or abdominal aortic aneurysm compared with the wild-type C57BL/6J mice. Our results suggest that LOXL4 may not play a major role in the development of angiotensin II-induced aortic aneurysm. The functional study using this animal model system is important for the evaluation of candidate genes of TAAD identified by WES.

Endovascular repair for abdominal aortic aneurysms

Management of abdominal aortic aneurysms has been the subject of rigorous scientific scrutiny. Prevalence studies have directed the formation of screening programmes, and observational studies and randomised controlled trials have defined aneurysm growth and treatment thresholds. Pre-emptive intervention with traditional open surgical repair has been the bedrock of improving long-term outcome and survival in patients with abdominal aortic aneurysms but it is associated with a significant procedural morbidity and mortality. Endovascular aneurysm repair (EVAR) has substantially reduced these early complications and has been associated with promising results in both elective and emergency aneurysm repair. However, the technique has brought its own unique complications, endoleaks. An endoleak is the presence of blood flow within the aneurysm sac but outside the EVAR graft. Although in randomised control trials EVAR was associated with a reduced early mortality compared with open repair, its longer-term morbidity and mortality was higher because endoleak development is associated with a higher risk of rupture. These endoleak complications have necessitated the development of postoperative imaging surveillance and re-intervention. These contrasting benefits and risks inform the selection of the mode of repair and are heavily influenced by individual patient factors. An improved strategy to predict endoleak development could further help direct treatment choice for patients and improve both early and late outcomes. This article reviews current EVAR practice, recent updates in clinical practice guidelines and the potential future developments to facilitate the selection of mode of aneurysm repair.Trial registration number: ClinicalTrials.gov NCT04577716.

Inhibition of CXCR2 alleviates the development of abdominal aortic aneurysm in Apo E-/- mice

PURPOSE

To investigate the relationship between atherosclerotic abdominal aortic aneurysm (AAA) and CXC chemokine receptor type 2 (CXCR2).

METHODS

Mouse AAA model was established by embedding angiotensin-II pump (1000 ng/kg/min) in ApoE-/- mice. Mice were received SB225002, a selective CXCR2 antagonist, for treatment. Blood pressure was recorded, and CXCR2+ macrophages were examined by flow cytometry analysis. Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining was performed to detect cell apoptosis of abdominal aortic aneurysms. Macrophages were isolated from ApoE-/- mice and treated with Ang II and/or SB225002. Dihydroethidium staining was carried out to determine reactive oxygen species (ROS) activity. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the production of IL-1β and TNF-α. The corresponding gene expressions were measured using real-time polymerase chain reaction (PCR), western blot, and immunohistochemistry staining.

RESULTS

We found that Ang II activated the expression of CXCR2 in monocytes during the formation of AAA. Inhibition of CXCR2 significantly reduced the size of AAA, attenuated inflammation and phenotypic changes in blood vessels. Ang II-induced macrophages exhibited elevated ROS activity, and elevated levels of 1β and TNF-α, which were then partly abolished by SB225002.

CONCLUSIONS

CXCR2 plays an important role in AAA, suggesting that inhibiting CXCR2 may be a new treatment for AAA.

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

The association between physical activity and risk of abdominal aortic aneurysm has been inconsistent with some studies reporting a reduced risk while others have found no association. We conducted a systematic review and meta-analysis of prospective studies to quantify the association. PubMed and Embase databases were searched up to 3 October 2020. Prospective studies were included if they reported adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) of abdominal aortic aneurysm associated with physical activity. Summary RRs (95% CIs) were estimated using a random effects model. Nine prospective studies (2073 cases, 409,732 participants) were included. The summary RR for high vs. low physical activity was 0.70 (95% CI: 0.56-0.87, I² = 58%) and per 20 metabolic equivalent task (MET)-hours/week increase of activity was 0.84 (95% CI: 0.74-0.95, I² = 59%, n = 6). Although the test for nonlinearity was not significant (p = 0.09) the association appeared to be stronger when increasing the physical activity level from 0 to around 20-25 MET-hours/week than at higher levels. The current meta-analysis suggest that higher physical activity may reduce the risk of abdominal aortic aneurysm, however, further studies are needed to clarify the dose-response relationship between different subtypes and intensities of activity and abdominal aortic aneurysm risk.

Diabetes, its duration, and the long-term risk of abdominal aortic aneurysm: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND AND AIMS

We aimed at comprehensively evaluate the independent association of diabetes and its duration with incident abdominal aortic aneurysm (AAA) and aortic diameter.

METHODS AND RESULTS

We prospectively studied incident AAA according to baseline glycemic status (diabetes, prediabetes, normal glycemia) in 13,116 ARIC participants (1990-1992) and the time-varying exposure of duration post incident diabetes in 11,675 participants (1987-1989) using Cox models. Additionally, we cross-sectionally explored ultrasound-based abdominal aortic diameter by glycemic status and cumulative duration of diabetes in 4710 participants (2011-2013) using linear regression models. Over ~20 years of follow-up, diabetes (vs. normal glycemia) at baseline was independently associated with lower AAA risk (489 cases) (hazard ratio: 0.71 [95%CI 0.51-0.99]), especially after 10 years (hazard ratio: 0.58 [0.38-0.87]). Prediabetes did not demonstrate an independent association. The inverse association was more evident with longer duration of diabetes (p for trend = 0.045), with 30-50% lower risk in eight years after diabetes diagnosis. The cross-sectional analysis demonstrated smaller aortic diameters with longer duration of diabetes (e.g., -0.76 mm [-1.24, -0.28] in diabetes with 8-12 years) compared to non-diabetes, whereas prediabetes consistently showed nominally greater diameter.

CONCLUSIONS

Diabetes, especially with longer duration, but not prediabetes, was independently associated with lower risk of AAA and smaller aortic diameter. Our findings suggest that long lasting clinical hyperglycemia plays an important role in the reduced AAA risk, and the reduced aortic diameter may be a structural mechanism behind this paradoxical association.

Insight into the expression of toll-like receptors 2 and 4 in patients with abdominal aortic aneurysm

An abdominal aortic aneurysm (AAA) is a relatively common, life-threatening disease prevalent in persons over the age of 65. In recent years, an increasing number of studies have suggested that pattern-recognition receptors (PRRs), including Toll-like receptors (TLRs), may serve as important regulators in the development of AAAs. In this study, we evaluated the TLR2 and TLR4 expression in the aortic wall and blood of patients with AAA. The TLR2 and TLR4 mRNA expression were significantly higher in the blood of patients with AAA than in the blood of healthy volunteers (p = 0.009 and p = 0.010, respectively). The expression of TLR2 and TLR4 transcripts was also higher in the blood compared with the aortic wall tissue of AAA patients (p = 0.001 for both). Higher TLR2 protein expression was observed in the aortic wall of AAA patients compared with the blood (p = 0.026). A significantly higher concentration of TNF-α and IL-4 in patients with AAA than in healthy volunteers (p < 0.001 for both) was noticed. This study suggests that TLR2 may play a role in the inflammatory response in the aorta, both locally and systemically, in patients with 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.

Comprehensive Cardiac Rehabilitation as a Therapeutic Strategy for Abdominal Aortic Aneurysm

Abdominal aortic aneurysms (AAA) are referred to as “time bombs”. The only way to prevent AAA rupture is elective repair beforehand using surgical replacement or an endovascular procedure. Non-surgical strategies to prevent AAA expansion are under intense investigation. At each AAA stage, that is, occurrence, expansion, and rupture, the mechanisms and risk factors are different, as discussed in this review. Based on the mechanism and risk factors for AAA expansion, the most effective strategy against AAA expansion need to be identified, but so far none has. Exercise is known to be essential for preventing atherosclerosis related to the coexistence of AAA and CAD, but some doctors are hesitant to prescribe exercise programs to AAA patients given that BP elevation during exercise can cause AAA expansion or rupture. In our retrospective study and prospective study on the safety and effectiveness of exercise for AAA patients, the protective role of mild-moderate exercise against expansion of small AAA was clearly shown. The stability of AAA on exercise might be related to reduced inflammatory activity in the aortic wall, stabilized elevation in BP during exercise, increased aortic blood flow, upregulation of transforming growth factor-β1, moderated BMI and/or fat, or improved endothelial function. Until a revolutionary drug emerges that can regress AAA, cardiac rehabilitation remains the best strategy for preventing AAA expansion and rupture.

Symptoms of Depression and Risk of Abdominal Aortic Aneurysm: A HUNT Study

Background

Depression is associated with cardiovascular diseases, but the evidence is scarce regarding depression and risk of abdominal aortic aneurysms (AAA). The aim was to determine whether individuals with depressive symptoms have increased risk of AAA.

Methods and Results

This population‐based prospective study included 59 136 participants (52.4% women) aged 50 to 106 years from the HUNT (Norwegian Nord‐Trøndelag Health Study). Symptoms of depression were assessed using the depression subscale of the Hospital Anxiety and Depression Scale (HADS). During a median follow‐up of 13 years, there were 742 incident cases of AAA (201 women). A total of 6401 individuals (12.3%) reported depressive symptoms (defined as HADS depression scale [HADS‐D]) ≥8) (52.5% women). The annual incidence rate of AAA was 1.0 per 1000 individuals. At all ages, the estimated proportion of individuals diagnosed with AAA was higher among those with depressive symptoms (log‐rank test, P<0.001). People with HADS‐D ≥8 were older than those with HADS‐D<8 (median 57.8 versus 52.3 years, P<0.001) and a statistically significantly higher proportion of them (P<0.001) were smokers, overweight or obese, and reported a history of coronary heart disease, diabetes mellitus, and hypertension. In a Cox proportional hazard regression model adjusted for these factors, individuals with depressive symptoms had a ≈30% higher risk of AAA than those without (hazard ratio, 1.32, 95% CI 1.08–1.61, P=0.007).

Conclusions

This study shows that individuals with depressive symptoms have significantly higher risk of incident AAA, after adjustments for established risk factors.

Screening women aged 65 years or over for abdominal aortic aneurysm: a modelling study and health economic evaluation

BACKGROUND

Abdominal aortic aneurysm (AAA) screening programmes have been established for men in the UK to reduce deaths from AAA rupture. Whether or not screening should be extended to women is uncertain.

OBJECTIVE

To evaluate the cost-effectiveness of population screening for AAAs in women and compare a range of screening options.

DESIGN

A discrete event simulation (DES) model was developed to provide a clinically realistic model of screening, surveillance, and elective and emergency AAA repair operations. Input parameters specifically for women were employed. The model was run for 10 million women, with parameter uncertainty addressed by probabilistic and deterministic sensitivity analyses.

SETTING

Population screening in the UK.

PARTICIPANTS

Women aged ≥ 65 years, followed up to the age of 95 years.

INTERVENTIONS

Invitation to ultrasound screening, followed by surveillance for small AAAs and elective surgical repair for large AAAs.

MAIN OUTCOME MEASURES

Number of operations undertaken, AAA-related mortality, quality-adjusted life-years (QALYs), NHS costs and cost-effectiveness with annual discounting.

DATA SOURCES

AAA surveillance data, National Vascular Registry, Hospital Episode Statistics, trials of elective and emergency AAA surgery, and the NHS Abdominal Aortic Aneurysm Screening Programme (NAAASP).

REVIEW METHODS

Systematic reviews of AAA prevalence and, for elective operations, suitability for endovascular aneurysm repair, non-intervention rates, operative mortality and literature reviews for other parameters.

RESULTS

The prevalence of AAAs (aortic diameter of ≥ 3.0 cm) was estimated as 0.43% in women aged 65 years and 1.15% at age 75 years. The corresponding attendance rates following invitation to screening were estimated as 73% and 62%, respectively. The base-case model adopted the same age at screening (65 years), definition of an AAA (diameter of ≥ 3.0 cm), surveillance intervals (1 year for AAAs with diameter of 3.0-4.4 cm, 3 months for AAAs with diameter of 4.5-5.4 cm) and AAA diameter for consideration of surgery (5.5 cm) as in NAAASP for men. Per woman invited to screening, the estimated gain in QALYs was 0.00110, and the incremental cost was £33.99. This gave an incremental cost-effectiveness ratio (ICER) of £31,000 per QALY gained. The corresponding incremental net monetary benefit at a threshold of £20,000 per QALY gained was -£12.03 (95% uncertainty interval -£27.88 to £22.12). Almost no sensitivity analyses brought the ICER below £20,000 per QALY gained; an exception was doubling the AAA prevalence to 0.86%, which resulted in an ICER of £13,000. Alternative screening options (increasing the screening age to 70 years, lowering the threshold for considering surgery to diameters of 5.0 cm or 4.5 cm, lowering the diameter defining an AAA in women to 2.5 cm and lengthening the surveillance intervals for the smallest AAAs) did not bring the ICER below £20,000 per QALY gained when considered either singly or in combination.

LIMITATIONS

The model for women was not directly validated against empirical data. Some parameters were poorly estimated, potentially lacking relevance or unavailable for women.

CONCLUSION

The accepted criteria for a population-based AAA screening programme in women are not currently met.

FUTURE WORK

A large-scale study is needed of the exact aortic size distribution for women screened at relevant ages. The DES model can be adapted to evaluate screening options in men.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015020444 and CRD42016043227.

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.

[Prevalence and risk factors of sub-renal abdominal aortic aneurysm in an Algerian population aged over 60]

INTRODUCTION

The prevalence of abdominal aortic aneurysm (AAA) in the general population in our country is not known, our aim was to evaluate it in patients over 60 years of age, to specify the risk factors and to evaluate the extension of aneurysmal disease and multisite subclinical atherosclerosis.

METHODS

Descriptive, transversal, study collecting the data of a systematic ultrasound screening of sub-renal AAA in subjects receiving care in two Algerian hospital structures. Epidemiological data, AAA risk factors, cardiovascular disease risk factors (CVD RF) and the personal history (cardiovascular diseases, chronic obstructive pulmonary disease) and family history of AAA were collected during the screening. An abdominal echography was performed in all patients. A biological and morphological assessment was carried out for AAA cases detected. Multivariate logistic regression analysis was used to study the factors associated with AAA.

RESULTS

Systematic screening for 600 patients revealed an overall AAA prevalence of 2.2% (n=13). In multivariate analysis a positive association with AAA was observed with active smoking, its duration in years and its intensity in year-packages; with hypertension, dyslipidemia and a history of cardiovascular events. While a negative association was observed with a smoking cessation of more than 20 years, type 2 diabetes and android obesity. The study of detected AAA cases found five cases of aneurysm isolated from the primary iliac artery but no popliteal and/or femoral aneurysm. The carotids were atheromatous in more than 80% of cases and the arteries of the lower limbs in more than one-third of cases.

CONCLUSION

The prevalence of AAA in our population (2.2%) corresponds to the prevalence reported recently in Europe, but it would have been higher if the screening had targeted males and smokers. The factors associated with AAA in our patients are similar to those described in the literature.

Diabetes mellitus and the risk of abdominal aortic aneurysm: A systematic review and meta-analysis of prospective studies

BACKGROUND

Diabetes mellitus has been associated with reduced risk of abdominal aortic aneurysm in a number of epidemiological studies, however, until recently little data from prospective studies have been available. We therefore conducted a systematic review and meta-analysis of prospective studies to quantify the association.

MATERIAL AND METHODS

Two investigators searched the PubMed and Embase databases for studies of diabetes and abdominal aortic aneurysm up to May 8th 2018. Prospective studies were included if they reported adjusted relative risk (RR) estimates and 95% confidence intervals (95% CIs) of abdominal aortic aneurysm associated with a diabetes diagnosis. Summary relative risks were estimated by use of a random effects model.

RESULTS

We identified 16 prospective studies with 16,572 cases among 4,563,415 participants that could be included in the meta-analysis. The summary RR for individuals with diabetes compared to individuals without diabetes was 0.58 (95% CI: 0.51-0.66, I² = 40.4%, p_{heterogeneity} = 0.06). The results persisted when stratified by sex, duration of follow-up, and in most of the other subgroup analyses. There was no evidence of publication bias with Egger's test, p = 0.64 or by inspection of the funnel plots.

CONCLUSIONS

These results suggest that individuals with diabetes mellitus are at a reduced risk of abdominal aortic aneurysm, however, whether pharmacological agents for diabetes mellitus explain this observation needs to be clarified in future studies.

Analysis of host Toll-like receptor 3 and RIG-I-like receptor gene expression in patients with abdominal aortic aneurysm

OBJECTIVE

Abdominal aortic aneurysm (AAA) is a vascular disease relatively common in the elderly population. Although some events that contribute to the development and progression of AAA are known, there are limited data examining the association of Toll-like receptor 3 (TLR3) and RIG-I-like receptor expression with the pathogenesis of AAAs. In this study, we investigated the gene and protein expression of TLR3 and RIG-I-like receptors (RIG-I and MDA5) in aortic wall and blood of AAA patients and examined the relationship between their expression and immune response.

METHODS

Total RNA was extracted from aortic wall tissues and blood samples collected from 20 patients with AAA and blood samples of 17 healthy volunteers without aortic aneurysm. To evaluate the DDX58 (RIG-I), IFIH1 (MDA5), and TLR3 gene expression level, quantitative real-time polymerase chain reaction was used. Extracellular cytokine and pattern recognition receptor levels were quantified by enzyme-linked immunosorbent assays.

RESULTS

TLR3, RIG-I, and MDA5 were constitutively expressed in both aortic tissues and blood samples from AAA patients and healthy volunteers. In patients with AAA, higher TLR3 expression in aortic tissues than in blood was found (P = .004). The DDX58 messenger RNA expression was higher in blood of patients with AAA compared with healthy subjects (P = .021). A significantly higher level of plasma interleukin 4 was noticed in patients with AAA than in healthy individuals (P = .008).

CONCLUSIONS

This study suggests that RIG-I and TLR3 seem to be important factors in the pathogenesis of AAA.

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.

Analysis of the Correlation Between Central Obesity and Abdominal Aortic Diseases

BACKGROUND

Atherosclerosis and abdominal aortic aneurysms (AAAs) have several similar risk factors but different pathogenesis. Inflammation of the arteries is common to both. Central obesity can act as an endocrine organ through the secretion of inflammatory cytokines, and the perivascular fat has a local effect that could contribute to diseases of the abdominal aorta. Although the relation between central obesity and atherosclerosis occlusive arterial disease has been demonstrated, the correlation with AAA has conflicting results. The aim of this study was to analyze the correlation between central obesity and the presence of abdominal aortic diseases using computed tomography.

METHODS

Six hundred thirty-nine consecutive patients classified into 3 groups (AAA, aortic atherosclerotic occlusive disease (AAOD), and without aortic disease [control group]) who underwent computed tomography had the aorta diameter, the visceral fat area (VFA), and the subcutaneous fat area (SFA) measured at the level of third and fourth lumbar vertebrae.

RESULTS

VFA showed no difference between the groups. SFA was lower in atherosclerotic group (AAOD) than control (P < 0.01 in general and P < 0.04 in male). In AAA group, we found in men that the first tertile of aorta diameter had higher VFA than third tertile (P = 0.02).

CONCLUSIONS

There was no difference in VFA between patients in AAA, AAOD, and without aortic disease groups. In men with aneurysm, there was an inverse relationship between VFA and aortic diameter. In AAOD, visceral to subcutaneous ratio is higher due to lower SFA.

Prospective study of the E-liac Stent Graft System in patients with common iliac artery aneurysms: 30-Day results

OBJECTIVES

To study the safety and feasibility of the E-liac Stent Graft System® in patients with aorto/iliac aneurysms.

METHODS

A prospective multicentric European registry of patients receiving the E-liac Stent Graft System® was conducted. Endpoints of the study included the technical success as well as periprocedural events and 30-day endoleaks, reinterventions, internal and external iliac artery patency and mortality.

RESULTS

Between July 2014 and June 2016, a total of 45 patients (93% men, mean age 72 years, range 53-90 years) were enrolled at 11 sites in four European countries. Five patients received an isolated iliac treatment. Thirty-seven patients were treated with a combination of an abdominal stent graft and a unilateral E-liac and three in combination with bilateral E-liac. All E-liac Stent Grafts (48) were implanted in the intended position and the internal iliac arteries were successfully bridged. Two patients did not receive clinical success, due to endoleak type Ia of the aortic stent graft. At 30-day follow-up, clinical success rate was 96%. Three successful endovascular reinterventions were performed within the 30-day follow-up: one due to a type Ia endoleak in the common iliac artery, one due to type Ia endoleak of the aortic stent graft, and one due to bilateral lower limb claudication provoked by stent graft limb stenosis. At 30-day, a 100% survival rate and complete absence of pelvic or buttock ischemia/claudication were reported. Primary patency at 30 days was 100% for the internal iliac artery and 98% for the external iliac artery with an assisted patency of 100% in the latter.

CONCLUSIONS

The high clinical success rate, low rates of device-related reinterventions (2%), and excellent patency rate demonstrate the safety and feasibility of the E-liac Stent Graft System. Long-term results are awaited to state efficacy and durability. Clinical Trials.gov. Identifier no. NCT02209194.

Gender differences in abdominal aortic aneurysm therapy - a systematic review

This article analyses if and to what extent gender differences exist in abdominal aortic aneurysm (AAA) therapy. For this purpose Medline (PubMed) was searched from January 1999 to January 2018. Keywords were: "abdominal aortic aneurysm", "gender", "prevalence", "EVAR", and "open surgery of abdominal aortic aneurysm". Regardless of open or endovascular treatment of abdominal aortic aneurysms, women have a higher rate of complications and longer hospitalizations compared to men. The majority of studies showed that women have a lower survival rate for surgical and endovascular treatment of abdominal aneurysms after both elective and emergency interventions. Women receive less surgical/interventional and protective medical treatment. Women seem to have a higher risk of rupture, a lower survival rate in AAA, and a higher rate of complications, regardless of endovascular or open treatment. The gender differences may be due to a higher age of women at diagnosis and therapy associated with higher comorbidity, but also because of genetic, hormonal, anatomical, biological, and socio-cultural differences. Strategies for treatment in female patients must be further defined to optimize outcome.

Evaluation of the relationship between plasma lipids and abdominal aortic aneurysm: A Mendelian randomization study

Studies have reported that higher circulating levels of total cholesterol (TC), low-density lipoprotein (LDL) cholesterol and lower of high-density lipoprotein (HDL) cholesterol may be associated with increased risk of abdominal aortic aneurysm (AAA). Whether dyslipidemia causes AAA is still unclear and is potentially testable using a Mendelian randomization (MR) approach. We investigated the associations between blood lipids and AAA using two-sample MR analysis with SNP-lipids association estimates from a published genome-wide association study of blood lipids (n = 188,577) and SNP-AAA association estimates from European Americans (EAs) of the Atherosclerosis Risk in Communities (ARIC) study (n = 8,793). We used inverse variance weighted (IVW) MR as the primary method and MR-Egger regression and weighted median MR estimation as sensitivity analyses. Over a median of 22.7 years of follow-up, 338 of 8,793 ARIC participants experienced incident clinical AAA. Using the IVW method, we observed positive associations of plasma LDL cholesterol and TC with the risk of AAA (odds ratio (OR) = 1.55, P = 0.02 for LDL cholesterol and OR = 1.61, P = 0.01 for TC per 1 standard deviation of lipid increment). Using the MR-Egger regression and weighted median methods, we were able to validate the association of AAA risk with TC, although the associations were less consistent for LDL cholesterol due to wider confidence intervals. Triglycerides and HDL cholesterol were not associated with AAA in any of the MR methods. Assuming instrumental variable assumptions are satisfied, our finding suggests that higher plasma TC and LDL cholesterol are causally associated with the increased risk of AAA in EAs.

Abdominal aortic aneurysm: Sex differences

OBJECTIVE

Abdominal aortic aneurysm (AAA) predominantly affects an elderly male population. Even so, AAA appears more detrimental in women, who experience a higher risk of aneurysm rupture and a worse outcome after surgery than men. Why women are privileged from yet are worse off once affected has been attributed to an effect of sex hormones. This review summarizes the knowledge of sex differences in AAA and addresses the changes in the aneurysm wall from a gender perspective.

METHOD

Standard reporting guidelines set by the PRISMA Group were followed to identify studies examining AAA from a gender perspective. Relevant reports were identified using two electronic databases: PubMed and Web of Science. The systematic search was performed in two stages: firstly, using the terms AAA and gender/sex/women; and secondly, adding the terms "elastin", "collagen" and "vascular smooth muscle cells", in order to filter the search for studies relevant to our focus on the aneurysm wall.

CONCLUSION

Current studies support the theory that sex has an effect on aneurysm formation, yet are inconclusive about whether or not aneurysm formation is dependent on female/male sex hormones or a lack thereof. The studies in women are scarce and out of those most reports primarily address other end-points, which limit their ability to illuminate an effect of sex on aneurysm formation. The complexity of the human menstrual cycle and menopausal transition are difficult to mimic in animal models, which limit their applicability to AAA formation in humans.

Stimulation of Alpha7 Nicotinic Acetylcholine Receptor Attenuates Nicotine-Induced Upregulation of MMP, MCP-1, and RANTES through Modulating ERK1/2/AP-1 Signaling Pathway in RAW264.7 and MOVAS Cells

Vagus nerve stimulation through alpha7 nicotine acetylcholine receptors (α7-nAChR) signaling had been demonstrated attenuation of inflammation. This study aimed to determine whether PNU-282987, a selective α7-nAChR agonist, affected activities of matrix metalloproteinase (MMP) and inflammatory cytokines in nicotine-treatment RAW264.7 and MOVAS cells and to assess the underlying molecular mechanisms. RAW264.7 and MOVAS cells were treated with nicotine at different concentrations (0, 1, 10, and 100 ng/ml) for 0–120 min. Nicotine markedly stimulated the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2) and c-Jun in RAW264.7 cells. Pretreatment with U0126 significantly suppressed phosphorylation of ERK1/2 and further attenuated nicotine-induced activation of c-Jun and upregulation of MMP-2, MMP-9, monocyte chemotactic protein- (MCP-) 1, and regulated upon activation normal T cell expressed and secreted (RANTES). Similarly, nicotine treatment also increased phosphorylation of c-Jun and expressions of MMP-2, MMP-9, MCP-1, and RANTES in MOVAS cells. When cells were pretreated with PNU-282987, nicotine-induced activations of ERK1/2 and c-Jun in RAW264.7 cells and c-Jun in MOVAS cells were effectively inhibited. Furthermore, nicotine-induced secretions of MMP-2, MMP-9, MCP-1, and RANTES were remarkably downregulated. Treatment with α7-nAChR agonist inhibits nicotine-induced upregulation of MMP and inflammatory cytokines through modulating ERK1/2/AP-1 signaling in RAW264.7 cells and AP-1 in MOVAS cells, providing a new therapeutic for abdominal aortic aneurysm.

Meta-analysis of the association between alcohol consumption and abdominal aortic aneurysm

Background

Alcohol is a possible risk factor for abdominal aortic aneurysm (AAA), but evidence from individual studies is weak and inconsistent. Existing narrative reviews suggest the possibility of non-linear associations. The aim here was to quantify any association using a systematic literature review, followed by dose–response meta-analysis of prospective studies.

Methods

MEDLINE, Embase and Web of Science were searched systematically to January 2017 for relevant prospective studies of alcohol consumption and AAA risk. Summary estimates of highest versus lowest levels of consumption, and linear and non-linear dose–response curves were quantified using random-effects models.

Results

Eleven relevant cohorts were identified describing results from 3580 individuals with among 473 092 participants. Data were extracted from ten cohorts for meta-analyses of high versus low levels of alcohol consumption (risk ratio for AAA 0·93, 95 per cent c.i. 0·78 to 1·11; P = 0·4, I2 = 47 per cent). The linear dose–response risk ratio for AAA, derived from 11 cohorts, was 1·00 (0·97 to 1·04) per 8 g alcohol per day (P = 0·9, I2 = 73 per cent). Non-linear dose–response results showed a tick-shaped curve with lower risk up to 2 units/day, but increasing risk beyond that (P = 0·05). The increase in risk beyond 2 units/day was stronger in men than in women.

Conclusion

Although the linear dose–response analysis revealed little evidence of an association between alcohol consumption and AAA risk, a tick-shaped trend in the association was observed. This non-linear dose–response analysis revealed reduced risks for alcohol consumption below 2 units/day, masking increased risks for 2 or more units/day.

Adolescent Body Mass Index and Cardiovascular Disease-Specific Mortality by Midlife

CONTEXT

As opposed to coronary heart disease (CHD) mortality, cardiovascular mortality attributed to non-CHD causes has increased.

OBJECTIVE

To evaluate the association of body mass index (BMI) in late adolescence with mortality attributed to non-CHD cardiovascular sequelae.

DESIGN AND SETTING

A nationwide cohort.

PARTICIPANTS

A total of 2,294,139 adolescents examined between 1967 and 2010.

INTERVENTIONS

Height and weight were measured at age 17. All cardiovascular disease-specific outcomes, coded by the Central Bureau of Statistics from death notifications as the underlying cause of death, were obtained by linkage. Cox hazards models were applied.

MAIN OUTCOME MEASUREMENTS

Death attributed to fatal arrhythmias, hypertensive heart disease, cardiomyopathies, arterial disease, heart failure, and pulmonary embolism.

RESULTS

During 42,297,007 person-years of follow-up, there were 3178 deaths due to cardiovascular causes, of which 279, 122, 121, 114, 94, and 70 were attributed to the main outcomes, respectively. BMI was positively associated with all study outcomes with hazard ratios (HRs) per unit increment in BMI ranging from 1.09 [95% confidence interval (CI): 1.03 to 1.16] for arterial disease to 1.16 (95% CI: 1.11 to 1.21) for hypertensive heart disease. When BMI was treated as a categorical variable, a graded increase in risk was evident from the high-normal (22.0 to <25.0 kg/m2) to the overweight to the obese categories, with HRs of 1.4, 1.7, and 3.7 for arrhythmias; 1.9, 4.1, and 8.0 for hypertensive heart disease; 1.5, 2.4, and 4.0 for cardiomyopathies, 2.7, 5.0, and 3.5; for arterial disease, 1.7, 2.7, and 5.4 for heart failure; and 1.3, 1.8, and 3.0 for pulmonary embolism. Findings persisted in extensive sensitivity analyses.

CONCLUSIONS

Adolescent BMI within the accepted normal range is associated with non-CHD nonstroke cardiovascular outcomes.