Risk Factors For Abdominal Aortic Aneurysm Research Articles

Systematic Review and Meta-Analysis of Mendelian Randomisation Analyses of Abdominal Aortic Aneurysms

Abstract Introduction Mendelian randomisation (MR) has been suggested to be able to overcome biases of observational studies, but no meta-analysis is available on MR studies on abdominal aortic aneurysm (AAA). This systematic review and Meta-analysis examined the evidence of causal risk factors for AAA identified in MR studies. Methods Publicly available databases were systematically searched for MR studies that reported any causal risk factors for AAA diagnosis. Meta-analyses were performed using random effect models and reported as odds ratio (OR) and 95% confidence intervals (CI). Study quality was assessed using a modified version of Strengthening the Reporting of Mendelian Randomisation Studies (STROBE-MR) guidelines. Results Sixteen MR studies involving 34,050 patients with AAA and 2,205,894 controls were included. Meta-analyses suggested that one standard deviation increase in high density lipoprotein (HDL) significantly reduced (OR: 0.66, 95% CI: 0.61, 0.72) and one standard deviation increase in low density lipoprotein (LDL) significantly increased the risk (OR: 1.68, 95%, CI: 1.55, 1.82) of AAA. One standard deviation increase in triglycerides did not significantly increase the risk of AAA (OR: 1.21, 95% CI: 0.86, 1.71). Quality assessment suggested that ten and five studies were of low and moderate risk of bias respectively, with one study considered as high risk of bias. Conclusion This meta-analysis suggests LDL and HDL are positive and negative casual risk factors for AAA.

Smoking, Hypertension, and GG Genotype of the IL-6 rs1800796 Polymorphism are Independent Risk Factors for Abdominal Aortic Aneurysm in Han Population

BackgroundRecent researches have investigated the link between the rs1800796 polymorphism (−572G/C) in the interleukin-6 (IL-6) gene and the risk of abdominal aortic aneurysm (AAA). However, no Chinese studies have addressed the association between the risk of AAA and this polymorphism.MethodsThis case-control study included 153 AAA patients and 205 controls. Diabetes mellitus, hypertension, dyslipidemia, and coronary artery disease (CAD) status were collected. The AAA and control groups were 69.20 ± 7.56 and 68.50 ± 7.12 years old, respectively.ResultsThe analysis revealed that the G allele and GG genotype of the IL-6 rs1800796 polymorphism were remarkedly correlated with an elevated risk of AAA. The GG genotype displayed an association with the risk of AAA after adjustment for gender, body mass index, age, drinking, and smoking. Subgroup analyses indicated that this polymorphism elevated the risk of AAA among males, individuals aged ≥70 years, smokers, drinkers, individuals with a body mass index (BMI) ≥25 kg/m2, patients without diabetes, and patients with hypertension. Univariate and multivariate analyses indicated that smoking, hypertension, and the GG genotype (rs1800796 polymorphism) were independently related with the risk of AAA.ConclusionThe IL-6 rs1800796 polymorphism increases the risk of AAA. In addition, smoking, hypertension, and the GG genotype of the rs1800796 polymorphism are independent risk factors for AAA. Further studies of Chinese populations are needed to validate these findings.

Investigating the Link between Alpha-1 Antitrypsin Deficiency and Abdominal Aortic Aneurysms

Alpha-1-Antitrypsin (AAT) is one of the major plasmatic protease inhibitors. In the last decade, an association between Alpha-1-Antitrypsin Deficiency (AATD) and Abdominal Aortic Aneurysms (AAA) has been hypothesized. Multiple factors may be involved in AAA's etiopathogenesis, and an underlying structural defect of the extracellular matrix (ECM) is always present. AATD could be a reasonable risk factor for AAA because it is related to protease/antiprotease imbalance and enhanced ECM degradation of the vessel wall. We performed genotyping of 138 patients hospitalized in the Vascular Surgery Division of the ASST-Spedali Civili di Brescia, Italy, for nontraumatic rupture of AAA. The second purpose was to observe the distribution of main nongenetic risk factors for AAA between patients with and without AATD. Out of 138 patients, 22 were found with AATD: 16 MS, 1 SS, 3 MZ, and 2 with a new rare AAT variant. When compared to the general Italian population, our cohort's frequency of deficient S allele was significantly higher (7.8 vs. 2.2% respectively, P < 0.01), whereas the deficient Z allele was similar (1.1 vs. 1.3% respectively, P > 0.05). Although we found no differences in age, gender, hypertension, diabetes, and smoke habits between AAA patients with and without AATD, hyperlipidemia was significantly less frequent in patients with AATD (46.4 vs. 12.5% respectively, P < 0.05). In our AAA patients' cohort, the S allele frequency was higher than in the general Italian population. Our results support the hypothesis that AATD might be a risk factor for AAA.

Screening for Prevalence of Abdominal Aortic Aneurysm During Transthoracic Echocardiography in Patient With Significant Coronary Artery Disease.

BackgroundPrevalence of abdominal aortic aneurysm (AAA) has ethnic differences, and coronary artery disease (CAD) shares several risk factors with AAA. Sparse Indian data are available on this. We evaluated the prevalence of AAA during transthoracic echocardiography (TTE) and risk factors of AAA in patients with CAD. MethodsThis was a prospective observational study carried out in the cardiology department at a tertiary care center from January 1, 2017 to November 30, 2017. All patients with CAD/acute coronary syndrome (ACS) were included in the study, and patients with AAA due to other etiology were excluded. Screening for an AAA was performed directly using an echocardiographic 3.5-MHz cardiac probe.ResultsA total of 526 patients were screened; and AAA was present in 25 (4.8%) of CAD patients. Smoking, hypertension and hyperlipidemia were predominant risk factors for AAA in our study, but were not statistically significant because same risk factors were also prevalent in the comparison group. Diabetes, peripheral vascular disease and family history were statistically significant risk factors for AAA in our study. The mean size of AAA was 34 mm.ConclusionsPresence of AAA is significantly higher among CAD patients. CAD shares several risk factors with AAA. Therefore, opportunistic examination of the abdominal aorta during routine TTE could be an effective way of screening. Diabetes mellitus, peripheral artery disease and family history were the significant associated risk factors of AAA in CAD patients.

Systematic review and Meta-Analysis of Mendelian randomisation analyses of Abdominal aortic aneurysms.

IntroductionMendelian randomisation (MR) has been suggested to be able to overcome biases of observational studies, but no meta-analysis is available on MR studies on abdominal aortic aneurysm (AAA). This systematic review and Meta-analysis examined the evidence of causal risk factors for AAA identified in MR studies.MethodsPublicly available databases were systematically searched for MR studies that reported any causal risk factors for AAA diagnosis. Meta-analyses were performed using random effect models and reported as odds ratio (OR) and 95% confidence intervals (CI). Study quality was assessed using a modified version of Strengthening the Reporting of Mendelian Randomisation Studies (STROBE-MR) guidelines.ResultsSixteen MR studies involving 34,050 patients with AAA and 2,205,894 controls were included. Meta-analyses suggested that one standard deviation increase in high density lipoprotein (HDL) significantly reduced (OR: 0.66, 95% CI: 0.61, 0.72) and one standard deviation increase in low density lipoprotein (LDL) significantly increased the risk (OR: 1.68, 95%, CI: 1.55, 1.82) of AAA. One standard deviation increase in triglycerides did not significantly increase the risk of AAA (OR: 1.21, 95% CI: 0.86, 1.71). Quality assessment suggested that ten and five studies were of low and moderate risk of bias respectively, with one study considered as high risk of bias.ConclusionThis meta-analysis suggests LDL and HDL are positive and negative casual risk factors for AAA.

Association of Differential Leukocyte Count With Incident Abdominal Aortic Aneurysm Over 22.5 Years: The ARIC Study.

OBJECTIVE: Leukocytes contribute to the development of abdominal aortic aneurysm (AAA). We evaluated whether associations of differential leukocyte counts with AAA persist after accounting for traditional risk factors of AAA. APPROACH AND RESULTS: Among 11 217 adults from the Atherosclerosis Risk in Communities Study, we evaluated associations of differential leukocyte counts at baseline (1987–1989) with incident AAAs over a median follow-up of 22.5 years, using Cox proportional hazards regression. Each differential leukocyte count was categorized into 5 groups—below normal, tertiles within the normal range, and above normal, with the first tertile serving as the referent. We identified 377 incident AAAs through 2011, using hospital discharge diagnoses, linked Medicare records, or death certificates. At baseline, higher neutrophil, monocyte, and eosinophil counts were associated with higher risk of AAA, independent of smoking, other differential leukocyte counts, and other traditional risk factors. The association with incident AAA was the strongest for above normal neutrophil count, with an adjusted hazard ratio (95% CI) of 2.17 (1.29–3.64). Below normal neutrophil, lymphocyte, eosinophil and basophil counts were associated with higher risk of AAA with adjusted hazard ratio (95% CI) between 1.86 (1.04–3.35) and 1.62 (1.10–2.39). CONCLUSIONS: Higher neutrophil, monocyte, and eosinophil counts in midlife are associated with higher risk of AAA, even after accounting for traditional risk factors such as smoking, obesity, and atherosclerosis. This suggests the need to identify nontraditional risk factors and treatment strategies to mitigate the residual risk of AAA conferred by midlife inflammation. Whether immunosuppression is associated with higher risk of AAA needs further investigation.

Point of care ankle pulse waveform: A biomarker for abdominal aortic aneurysm?

To explore the potential relationship between the presence of abdominal aortic aneurysm and point of care ankle brachial index acquired posterior tibial artery Doppler waveform to inform on a potential novel biomarker of abdominal aortic aneurysm presence. Abdominal aortic aneurysm presence and posterior tibial artery waveform acquired at time of routine point of care ankle brachial index were determined in 182 patients from an abdominal aortic aneurysm evaluation vascular outpatient clinic. Multivariate technical random forest analysis and logistical regression analysis assessed the outcome of abdominal aortic aneurysm presence and included the independent variables of monophasic initial posterior tibial artery waveform and known abdominal aortic aneurysm risk factors. Technical random forest analysis produced a model with an accuracy of 0.59. Initial waveform phase was the most important variable included in the model. Logistical regression analysis revealed a statistically significant negative association between initial monophasic posterior tibial artery waveform and abdominal aortic aneurysm presence in patients with ankle brachial index > 0.9. Leave one out cross validation analysis produced a bias-corrected prediction error value of 0.22. No robust association between abdominal aortic aneurysm and point of care ankle brachial index acquired posterior tibial artery waveform was found, suggesting that monophasic posterior tibial artery waveform alone may not be a biomarker of abdominal aortic aneurysm presence.

Eosinophils Protect Mice From Angiotensin-II Perfusion-Induced Abdominal Aortic Aneurysm.

Blood eosinophil count and ECP (eosinophil cationic protein) associate with human cardiovascular diseases. Yet, whether eosinophils play a role in cardiovascular disease remains untested. The current study detected eosinophil accumulation in human and murine abdominal aortic aneurysm (AAA) lesions, suggesting eosinophil participation in this aortic disease. To test whether and how eosinophils affect AAA growth. Population-based randomized clinically controlled screening trials revealed higher blood eosinophil count in 579 male patients with AAA than in 5063 non-AAA control (0.236±0.182 versus 0.211±0.154, 109/L, P<0.001). Univariate (odds ratio, 1.381, P<0.001) and multivariate (odds ratio, 1.237, P=0.031) logistic regression analyses indicated that increased blood eosinophil count in patients with AAA served as an independent risk factor of human AAA. Immunostaining and immunoblot analyses detected eosinophil accumulation and eosinophil cationic protein expression in human and murine AAA lesions. Results showed that eosinophil deficiency exacerbated AAA growth with increased lesion inflammatory cell contents, matrix-degrading protease activity, angiogenesis, cell proliferation and apoptosis, and smooth muscle cell loss using angiotensin-II perfusion-induced AAA in Apoe-/- and eosinophil-deficient Apoe-/-ΔdblGATA mice. Eosinophil deficiency increased lesion chemokine expression, muted lesion expression of IL (interleukin) 4 and eosinophil-associated-ribonuclease-1 (mEar1 [mouse EOS-associated-ribonuclease-1], human ECP homolog), and slanted M1 macrophage polarization. In cultured macrophages and monocytes, eosinophil-derived IL4 and mEar1 polarized M2 macrophages, suppressed CD11b+Ly6Chi monocytes, and increased CD11b+Ly6Clo monocytes. mEar1 treatment or adoptive transfer of eosinophil from wild-type and Il13-/- mice, but not eosinophil from Il4-/- mice, blocked AAA growth in Apoe-/-ΔdblGATA mice. Immunofluorescent staining and immunoblot analyses demonstrated a role for eosinophil IL4 and mEar1 in blocking NF-κB (nuclear factor-κB) activation in macrophages, smooth muscle cells, and endothelial cells. Eosinophils play a protective role in AAA by releasing IL4 and cationic proteins such as mEar1 to regulate macrophage and monocyte polarization and to block NF-κB activation in aortic inflammatory and vascular cells.

Profiling of Histone Modifications Reveals Epigenomic Dynamics During Abdominal Aortic Aneurysm Formation in Mouse Models.

Introduction: Abdominal aortic aneurysms (AAA) are characterized by localized inflammation, extracellular matrix degradation, and apoptosis of smooth muscle cells, which together lead to progressive and irreversible aortic dilation. Major risk factors for AAA include smoking and aging, both of which prominently alter gene expression via epigenetic mechanisms, including histone methylation (me) and acetylation (ac).However, little is known about epigenomic dynamics during AAA formation. Here, we profiled histone modification patterns in aortic tissues during AAA formation in two distinct mouse models; (1) angiotensin II (AngII) infusion in low density lipoprotein receptor (LDLR) knockout (KO) mice, and (2) calcium chloride (CaCl2) application in wild type mice.Methods and Results: AAA formed in both models, in conjunction with enhanced macrophage infiltration, elastin degradation and matrix metalloproteinases expression as evaluated by immunohistochemistry. To investigate the histone modification patterns during AAA formation, total histone proteins were extracted from AAA tissues, and histone H3 modifications were quantified using profiling kits. Intriguingly, we observed dynamic changes in histone H3 modifications of lysine (K) residues at different time points during AAA formation. In mature aneurysmal tissues at 3 weeks after AngII infusion, we detected reduced K4/K27/K36 monomethylation, K9 trimethylation K9, and K9/K56 acetylation (<70%), and increased K4 trimethylation (>130%). Conversely, in CaCl2-induced AAA, K4/K9/K27/K36/K79 monomethylation and K9/K18/K56 acetylation were reduced in AAA tissues, whereas K27 di-/tri-methylation and K14 acetylation were upregulated. Interestingly, K4/K27/K36 monomethylation, K9 trimethylation, and K9/K56 acetylation were commonly downregulated in both animal models, while no H3 modifications were uniformly upregulated. Western blot of AAA tissues confirmed markedly reduced levels of key H3 modifications, including H3K4me1, H3K9me3, and H3K56ac. Furthermore, pathway enrichment analysis using an integrative bioinformatics approach identified specific molecular pathways, including endocytosis, exon guidance and focal adhesion signaling, that may potentially be linked to these histone H3 modifications during AAA formation.Conclusions: Dynamic modifications of histone H3 occur during AAA formation in both animal models. We identified 6 discreet H3 modifications that are consistently downregulated in both models, suggesting a possible role in AAA pathobiology. Identifying the functional mechanisms may facilitate development of novel strategies for AAA prevention or treatment.

High prevalence of abdominal aortic aneurysms in patients with lung cancer

BackgroundLung cancer and abdominal aortic aneurysms (AAAs) possess multiple shared risk factors. Whereas both have screening guidelines in place, they vary in methodology despite having significant overlap in populations of patients screened. MethodsOur hospital system's Lung Cancer Program database was used to identify patients diagnosed with primary lung cancer within the past 15 years. Demographic and risk factor data were obtained, and patients' original positron emission tomography-computed tomography scans were re-read for measurements of the abdominal aorta (aortic diameter ≥3.0 cm). A cancer-free control group was obtained for comparison. Multilinear regression modeling was used to evaluate the independent associations of multiple variables on the presence of AAA. ResultsAmong 814 patients with primary lung cancer, 90 (11.1%; 95% confidence interval [CI], 8.9%-13.3%) had AAA compared with 4 of 200 (2%; 95% CI, 0.1%-3.9%) in the control group (P = .0001). Patients who smoked were more likely than nonsmokers to have AAA (11.9% [95% CI, 9.8-14.6] vs 2.2% [95% CI, 0.1-8.1]; P = .0021). In patients with AAA, 12% (11/90) had aneurysms that required treatment, and 76.6% had early-stage lung cancer. Women in our study also had a high prevalence of AAA (4.6%). Logistic regression analysis showed male sex (odds ratio [OR], 3.70; P <.001), increasing age (OR, 1.07 per year; P <.001), smoking amount (OR, 1.01 per pack-year; P = .004), and hypertension (OR, 2.30; P = .020) to be independent risk factors for AAA. ConclusionsPatients with lung cancer have a high prevalence of AAA. If future studies can demonstrate a reduction in AAA mortality by screening for AAA and lung cancer simultaneously, it may prove worthwhile to extend the low-dose computed tomography scan through the lower abdomen in select patients.

Associations of global DNA methylation and homocysteine levels with abdominal aortic aneurysm: A cohort study from a population-based screening program in Sweden

Abdominal aortic aneurysm (AAA) is a life-threatening condition with a mortality rate of over 80%. Persistent smoking, which is a risk factor for AAA, has lasting effects on DNA methylation. Moreover, a plasma-amino acid, homocysteine, previously implicated in vascular diseases, including aneurysms, has well-established biological association with methylation. In the present study, we aimed to determine the global DNA methylation, homocysteine levels and their association with AAA and its growth. Enzyme-linked immunosorbent assay (ELISA) was used to quantify global DNA methylation in whole blood-DNA samples and diagnostic enzymatic assay quantified plasma homocysteine, from 65-year old men with (n = 116) and without AAA (n = 230) diagnosed at ultrasound screening. We found significantly higher global DNA methylation (p < .001) and homocysteine levels (p < .001) in men with AAA compared to those without AAA, and direct linear associations with baseline aortic diameter. On multivariable regression analysis, global DNA methylation (odds ratio [OR]: 1.8; 95% confidence interval [CI]: 1.1–2.9) and homocysteine levels (OR: 1.1; 95% CI:1.0–1.1) were positively associated with AAA, independent of smoking, medication use, and major co-morbidities. However, we did not find any significant association between DNA methylation or homocysteine levels with AAA growth during follow-up. We found that global DNA methylation and homocysteine levels are higher in men with AAA but are not associated with AAA growth. This indicates that different pathways and mechanisms may be involved in initiation and progression of AAA. More studies are needed to understand the precise role of DNA methylation, homocysteine and their interplay in AAA pathophysiology.

Aortic aneurysm screening using duplex ultrasound: Choosing wisely who to examine

The noninvasive vascular laboratory plays a critical role in screening patients at risk for development of abdominal aortic aneurysm (AAA). One-time duplex ultrasound screening reduces aneurysm-related mortality due to rupture and is cost-effective. Population screening based on AAA risk factors is recommended, as it allows for proactive, elective repair of aneurysms at risk for rupture, and surveillance of smaller aneurysms for enlargement. Utilization of societal screening guidelines, such as those published by the Society for Vascular Surgery, can be employed by vascular laboratories to justify individual patient screening, aid primary care physicians to refer patients for testing, and encourage integrated medical health care systems to build prompts in patient electronic health records to ensure compliance with a AAA screening program. Risk factors for developing AAA, that is, age older than 65 years, male sex, family history, and a smoking history of >100 cigarettes, should be used to recommend patient screening, including for women and other elderly (older than 75 years) patients who fall outside of professional societal guidelines.

Pulmonary complications and survival after elective infrarenal endovascular abdominal aneurysm repair in patients with documented chronic obstructive pulmonary disease.

Elective abdominal aortic aneurysm (AAA) repair is advocated in patients where risk of rupture exceeds the risks of peri-procedural morbidity and mortality. Chronic obstructive pulmonary disease (COPD) is a known risk factor for AAA and increased operative morbidity in general. Since literature on the correlation between the clinical classification of COPD and morbidity following endovascular infrarenal AAA repair (EVAR) is scarce, assessment per individual remains a challenge. To analyse the pulmonary and all-cause morbidity and mortality in patients with documented COPD and relate this to their GOLD classification. Sixty-eight patients with COPD, documented by a lung function test, who underwent elective EVAR between July 2002 and July 2018 were retrospectively reviewed. The primary endpoint was the incidence of 30-day pulmonary adverse events. Procedural characteristics, length of hospital stay, pulmonary and all-cause morbidity including major adverse events (MAEs) during follow-up and five-year survival divided per GOLD classification were the secondary endpoints. There was no statistically significant difference in the incidence of pulmonary adverse events between GOLD I/II and GOLD III/IV patients. There was neither procedural nor 30-day mortality in either group. Through 30 days and 1 year, there was no difference in pulmonary and all-cause morbidity between groups. Three MAEs occurred in the GOLD I/II group versus 2 MAE in the GOLD III/IV group during the first postoperative year. The five-year survival was 66.0%, 60.9% and 61.9% for patients with GOLD I, GOLD II and GOLD III, respectively. Three of four GOLD IV died within the first year after EVAR. EVAR can be safely performed in patients with COPD, with low 30-day morbidity and mortality rates. Although severe co-morbidity should be taken into account, EVAR seems to be justified in patients with COPD with a GOLD classification I, II or III. Further research should focus on optimising the pulmonary condition in patients selected for EVAR.

Evaluating the prevalence of abdominal aortic aneurysms in the United States through a national screening database

ObjectiveThe U.S. Preventative Services Task Force guidelines for abdominal aortic aneurysm (AAA) screening are based mainly on studies of older Caucasian males from non-U.S. populations. This study was designed to analyze the findings of a large, all-inclusive AAA screening program in the United States. MethodsScreening events were held nationally by a U.S. nonprofit organization between 2001 and 2017. AAA screening was offered regardless of risk profile. Participants filled out a demographics form with known comorbidities. Significant risk factors were determined using logistic regression with backward stepwise variable selection. Odds ratios (OR) are reported with 95% confidence intervals (CIs). ResultsA total of 9457 screened participants (47% male) were analyzed. The mean age was 67 ± 9 years with 40.8% between 65 and 75 years old. Most participants were Caucasian (83.4%), followed by African American (13.1%). Screened risk factors included hypertension (58.1%), hyperlipidemia (54.9%), smoking (52.0%), cardiac disease (29.2%), diabetes mellitus (18.4%), a family history of AAA (22.4%) or brain aneurysms (8.6%), and body mass index (26.9 ± 5.28). Overall, 267 participants (2.82%) were found to have an AAA (>3 cm). Those ages 65 to 75 had a prevalence of 2.98%. In a fully adjusted, multivariate logistic regression, there was an increased risk of AAA in males (OR, 3.24; 95% CI, 2.39-4.40), current smokers (OR, 3.28; 95% CI, 2.36-4.54), previous smokers (OR, 1.86; 95% CI, 1.41-2.47), cardiac disease (OR, 1.30; 95% CI, 1.01-1.68), family history of AAA (OR, 1.60; 95% CI, 1.20-2.14), and advancing age (P < .0001). Female ever smokers 65 to 75 years old had a prevalence of 1.7%. Male smokers 45 to 54 and 55 to 64 years old had a prevalence of 3.37% and 4.43%, respectively. There was an increased risk of AAA in females with morbid obesity (OR, 5.54; 95% CI, 1.34-22.83 in never smokers and OR, 5.61; 95% CI, 1.04-30.15 in smokers), female smokers with hypertension (OR, 3.22; 95% CI, 1.21-8.58), males with cardiac disease (OR, 2.06; 95% CI, 1.08-3.90 in never smokers and OR, 1.48; 95% CI, 1.05-2.09), male smokers with a family history of AAA (OR, 1.69; 95% CI, 1.61-2.46), and current smokers (OR, 6.33; 95% CI, 2.62-15.24 for females and OR, 2.50; 95% CI, 1.70-3.65 for males). ConclusionsThis study shows that there remain high-risk groups outside the current guidelines that would likely benefit from AAA screening. Risk factors for AAA include male gender, smoking, cardiac disease, family history of AAA, and advancing age. The most significant risk factor is current smoking status.

The Aging Population and Research into Treatments for Abdominal Aortic Aneurysms.

Abdominal aortic aneurysms (AAAs) usually expand asymptomatically until the occurrence of a life-threatening event such as aortic rupture, which is closely associated with high mortality. AAA and aortic dissection are ranked among the top 10 causes of death in Japan. The major risk factors for AAA are age over 65 years, male gender, family history, and smoking. Thus, for prevention, smoking cessation is the most important lifestyle-intervention. For treatment, since AAA generally affects elderly people, less invasive treatment is preferable. However, the only established treatment for AAA is open repair and endovascular repair. This review describes potential medical treatments to slow aneurysm growth or prevent AAA rupture.

Sub-classification of non-inflammatory and inflammatory surgical aortic aneurysms and the association of histological characteristics with potential risk factors.

The present study aimed to analyze the histological characteristics of surgical thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA) specimens on the basis of the most recent consensus documents on non-inflammatory and inflammatory lesions. The current study also aimed to establish an association with various risk factors. Aortic wall specimens were collected from 52 patients (38 men and 14 women; age, 19–80 years) undergoing surgery for aortic dilatation at The Cardiovascular Disease Institute (Iasi, Romania). For histological evaluation, the aortic specimens (39 TAAs and 13 AAAs) were stained with hematoxylin-eosin, Van Giessen, alcian blue and Movat pentachrome. The specimens were evaluated and graded according to the severity of histopathological conditions: Fragmentation of elastic fibers, medial mucoid accumulation, smooth muscle cell loss and medial fibrosis. The severity of atherosclerotic lesions in surgically resected segments of the aorta were graded as follows: i) mild=1; ii) moderate=2; and iii) severe=3. The risk factors associated with TAA were the male sex (80%), smoking (56%), hypertension (33%) and bicuspid aortic valve (13%). Advanced age (70 years), male sex (69%) and smoking (54%) were determined to be the risk factors of AAA. The histopathological abnormalities included medial degeneration (MD) (82%), atherosclerosis (ATS) (42%) and aortitis (10%). MD was the leading histopathological diagnosis in TAA and the severity of lesions were graded as follows: Mild (8% of cases), moderate (44% of cases) and severe (31% of cases). Severe atherosclerotic lesions were identified in AAA (100% of cases). In the present study, medial degenerative aortic lesions (1, mild; 2, moderate; and 3, severe) significantly correlated with advanced age (>65 years; r=−0.39; P<0.01) and male sex (r=0.27; P<0.05). Significant correlations were also identified between atherosclerotic aortic lesions (1, mild; 2, moderate; and 3, severe) and advanced age (>65 years) (r=−0.40, P<0.01) or smoking (r=−0.29; P<0.05). Advanced age, male sex and smoking were determined to be the main risk factors for the development of degenerative aortic aneurysms.

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.

The review of selected biomarkers of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a disease affecting the main artery transporting oxidized blood to the abdominal and pelvic organs. Abdominal aortic aneurysms occur 4-8 times more often in men than in women, usually develop after the age of 55. Among men over 65, 4–7.6%, this diagnosis can be expected. More aneurysms occur in Caucasian people. Among the most frequently mentioned in the literature, AAA risk factors are older age, male gender, positive family history, smoking, chronic obstructive pulmonary disease, hypertension, hypercholesterolemia, peripheral arterial occlusive disease, ischemic heart disease. Biochemical tests to determine the level of AAA-specific markers appear with potential. There are reports in the literature on the possible use of concentrations of selected molecules in the diagnosis of AAA. According to cadaveric research, there are noticed dimensions of the abdominal aorta at its different levels. The relation between aortic size and shape can be the factor contributing to the development of AAA. Previous studies have shown that the development of AAA is a crucial fundamental inflammatory response in conjunction with proteolysis tissue, which causes the destruction and reconstruction of the blood vessel wall. Numerous factors contribute to the pathogenesis of AAA: proteins, transcription factors, enzymes and microRNAs. The increase in the concentration of most factors is associated with inflammation. The biomarkers presented in the paper are not limited to AAA, and thus can be used only for visual assessment of the degree of abdominal aortic aneurysm development.

Prevalence and risk factors of abdominal aortic aneurysm among over 65 years old population in Lublin, Poland

Introduction: Abdominal aortic aneurysm (AAA) is a disease exceptionally well suited to screening. Ultrasound- based screening meets all criteria for a screening program according to the WHO, and there is a large evidence supporting its usefulness. Risk factors, mentioned in the available literature, associated with aneurysm formation are advanced age, male gender, tobacco smoking, hypertension, atherosclerotic disease and family or personal history of aortic aneurysms. The aim of the study was to evaluate the incidence of abdominal aortic aneurysms in the population of men and women older than 65 years, in Lublin, Poland and to identify the correlation between risk factors and the AAA incidence. Material and methods: A single-center screening study, for men and women older than 65-years was conducted in Lublin, Poland in May 2018. Patients underwent basic screening ultrasound with measurement of the diameter of abdominal aorta and iliac arteries. Each patient completed anonymous questionnaire to investigate risk factors of developing AAA. Results: 1032 patients, aged 65–91 (median age 71.37) were examined. 569 of them were women and 463 men. 27 aortic aneurysms were detected — 7 in a group of women and 20 in a group of men. The total incidence rate of AAA in our study was 2.62%; 1,23% in women and 4,32% in men. Male gender, cigarette smoking, coronary artery disease and a history of myocardial infarction all appeared to be major risk factors of AAA, with relative risk ranging from 2,75 to 4.53. The median diameter of the abdominal aorta was 19.24 mm and varied in groups of patients with different risk factors. Conclusions: The estimated prevalence of AAA in the screened population is within the range of the values reported in previous publications, however, it may confirm a trend of declining prevalence of AAA showed in some recent studies. The presented study confirms the correlation between the AAA and its major risk factors (male sex, smoking cigarettes, coronary artery disease and history of myocardial infarct) as well as a weak association between AAA and hypertension and a negative correlation with diabetes.

Abstract MP24: Women Experience Higher Rates of Surgical Repair and Mortality for Abdominal Aortic Aneurysm

Background: It is unknown how gender disparities in the clinical presentation of abdominal aortic aneurysm (AAA) affects AAA repair type and long-term survival. We assessed the hypothesis that compared to men, women face a higher risk of death after AAA repair due to differences in demographics, disease severity, and repair type. Methods: We analyzed all endovascular (EVAR) and open surgical (OPEN) AAA repairs from 2003-2015 in the Vascular Quality Initiative-Medicare linked registry. Using inverse probability weighting, we balanced patient demographics, comorbidities, and disease severity among men and women. Then, we evaluated the effect of gender on AAA treatment and subsequent survival using Poisson and Cox regression, respectively. Results: In this cohort (n=16,085), patients undergoing EVAR (79%) or OPEN (21%) had up to 12 years of follow-up. Women comprised 22% of the cohort and were older (mean age 77 ±6.6 vs. 75 ±6.5 years, p&lt;0.001), less likely to smoke (28% vs. 33%, p&lt;0.001), and had smaller aneurysms (58.7 ±18.5 mm vs 56.5 ±12 mm) than men (Figure). After balancing key risk factors, women were 1.6 times more likely to receive OPEN vs. EVAR (RR: 1.59, 95% CI: 1.46-1.72). The 12-year mortality rate after AAA repair was 74% in men vs 84% in women. After adjustment, women faced a 12% increased risk of death (HR: 1.12, 95% CI: 1.04-1.21). Sub-analysis by repair type revealed a gender discrepancy among EVAR patients, where women experienced poorer survival (HR: 1.18, 95% CI: 1.09-1.29), while men and women faced an equal risk of death after OPEN (HR: 1.00, 95% CI: 0.90-1.12). Conclusion: In conclusion, women were 1.6 times more likely to undergo OPEN repair than men, despite balancing key baseline AAA risk factors associated between men and women. After EVAR, women were 12% more likely to die than men, though no gender-based morality difference exists following OPEN repair. The differential treatment benefit of EVAR in women is concerning given the trend toward an endovascular-first treatment approach to AAA.