No association of chronic obstructive pulmonary disease with abdominal aortic aneurysm growth

Gut microbiome sheds light on the development and treatment of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is an inflammatory vascular disease with high disability and mortality. Its susceptible risk factors include old age, being male, smoking, hypertension, and aortic atherosclerosis. With the improvement of screening techniques, AAA incidence and number of deaths caused by aneurysm rupture increase annually, attracting much clinical attention. Due to the lack of non-invasive treatment, early detection and development of novel treatment of AAA is an urgent clinical concern. The pathophysiology and progression of AAA are characterized by inflammatory destruction. The gut microbiota is an "invisible organ" that directly or indirectly affects the vascular wall inflammatory cell infiltration manifested with enhanced arterial wall gut microbiota and metabolites, which plays an important role in the formation and progression of AAA. As such, the gut microbiome may become an important risk factor for AAA. This review summarizes the direct and indirect effects of the gut microbiome on the pathogenesis of AAA and highlights the gut microbiome-mediated inflammatory responses and discoveries of relevant therapeutic targets that may help manage the development and rupture of AAA.

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.

Outcomes of Endovascular Repair for Abdominal Aortic Aneurysms: A Nationwide Survey in Japan

OBJECTIVE

To analyze data on patients treated with a bifurcated stent graft for abdominal aortic aneurysm (AAA).

BACKGROUND

The Japan Committee for Stentgraft Management (JACSM) was established in 2007 to manage the safety of endovascular aortic aneurysm repair (EVAR) in Japan. The JACSM registry includes detailed anatomical and clinical data of all patients who undergo stent graft insertion in Japan.

METHODS

Among 51,380 patients treated with bifurcated stent graft for AAA, we identified 38,008 eligible patients (excluding those with rupture or insufficient data). The analyzed factors included age, sex, comorbidities, AAA pathology and etiology, aneurysm and neck diameters, 7 anti-instructions for use (IFU) factors, and endoleaks at hospital discharge. The endpoints were death, adverse events, sac dilatation (≥5 mm), and reintervention.

RESULTS

The rates of intraoperative and in-hospital mortality were 0.08% and 1.07%, respectively. Infectious aneurysm and pseudo-aneurysm were associated with overall survival and reintervention. Older age, large aneurysm diameter, and all types of persistent endoleaks were strong predictors of adverse events, sac dilatation, and reintervention. Comorbid cerebrovascular disease, renal dysfunction, and respiratory disorders were also risk factors. In total, 47.6% of patients violated the IFU; among the anti-IFU factors assessed, poor access and severe neck calcification were strong risk factors for mortality, reintervention, and adverse events. The sac dilatation rate at 5 years was 23.3%.

CONCLUSIONS

Although the analysis included EVAR with poor anatomy, the perioperative mortality rate was acceptable compared with that in previous large population studies.

Risk Factor Assessment in a Greek Cohort of Patients With Large Abdominal Aortic Aneurysms

Environmental and genetic risk factors contribute to the etiology of abdominal aortic aneurysms (AAAs). Matrix metalloproteinases (MMPs) have been associated with the pathophysiology of AAAs. A prospective, nonrandomized case-control study was undertaken to investigate the risk factors for large AAAs (≥5.5 cm) among 175 male Greek AAA patients and to compare the results with a cohort of 166 male controls free from any aortic dilatation, as confirmed by ultrasonography from an existing AAA screening program in the same region. We also assessed the potential association between 2 functional single nucleotide polymorphisms in the genes MMP9 (-1561C/T; rs3918242) and MMP13 (-77A/G; rs2252070), and the presence of large AAAs. Multiple logistic regression analysis revealed AAA family history ( P = .028), hypercholesterolemia ( P < .001), and current smoking ( P < .001) as AAA risk factors. Statistical difference was reached in genotype ( P = .047) and allele ( P = .037) frequencies for rs2252070, but the results did not remain significant after correction for multiple testing. No significant differences in genotype or allele frequencies for rs3918242 were detected. In summary, AAA family history, hypercholesterolemia, and current smoking were found to be risk factors for large AAAs.

Negative association of diabetes with rupture of abdominal aortic aneurysm

PURPOSE

To summarize the association of diabetes with abdominal aortic aneurysm rupture, we reviewed currently available studies with a systematic literature search and meta-analytic evaluation.

METHODS

To identify all studies reporting the association of diabetes with abdominal aortic aneurysm rupture, MEDLINE and EMBASE were searched through July 2015. For each study, data regarding diabetes prevalence in both the ruptured and non-ruptured groups were used to generate an unadjusted odds ratio for abdominal aortic aneurysm rupture and 95% confidence intervals. Alternatively, an unadjusted or adjusted odds ratio, or hazard ratio for abdominal aortic aneurysm rupture with 95% confidence interval was directly abstracted (as available) from each individual study.

RESULTS

Our search identified 11 eligible studies. A primary meta-analysis of nine studies reporting data on ruptured (not including non-ruptured symptomatic) abdominal aortic aneurysm demonstrated that diabetes was associated with significantly lower prevalence/incidence of abdominal aortic aneurysm rupture (odds ratio/hazard ratio, 0.71; 95% confidence interval, 0.56 to 0.89; p = 0.003). A secondary meta-analysis of all 11 studies (adding two studies in which non-ruptured symptomatic abdominal aortic aneurysm was included in the rupture group) also demonstrated that diabetes was associated with significantly lower prevalence/incidence of abdominal aortic aneurysm rupture (odds ratio/hazard ratio, 0.77; 95% confidence interval, 0.63 to 0.95; p = 0.01).

CONCLUSION

Diabetes is negatively associated with abdominal aortic aneurysm rupture.