Current pharmacological management of aortic aneurysm

Identification of the CeRNA axis of circ_0000006/miR-483-5p/KDM2B in the progression of aortic aneurysm to aorta dissection

BACKGROUND

Aortic aneurysm (AA) and aortic dissection (AD) are serious cardiovascular disorders with a high risk of mortality. The molecular mechanisms underlying the progression from AA to AD are not well understood. This study aimed to identify the key circular RNA (circRNA)-microRNA (miRNA)-messenger RNA (mRNA) regulatory axis involved in this disease progression.

METHODS

CircRNA microarray, miRNA microarray, and mRNA sequencing were performed on plasma samples from healthy controls, AA patients, and AD patients. Bioinformatics analysis integrated the expression profiles to identify dysregulated circRNA-miRNA-mRNA networks. Key molecules were validated in vascular smooth muscle cells (VSMCs) and an AD mouse model. Cell proliferation, migration, and phenotypic transition assays were conducted after modulating the identified circRNA. The impact on AD progression was evaluated in mice upon circRNA knockdown.

RESULTS

A total of 12 circRNAs were found upregulated in AD compared to AA samples. miR-483-5p was downregulated while its targets KDM2B and circ_0000006 were upregulated in AD. Silencing circ_0000006 in VSMCs inhibited PDGF-induced phenotypic switching, proliferation, and migration by increasing miR-483-5p and decreasing KDM2B levels. In the AD mouse model, knockdown of circ_0000006 alleviated disease progression with similar molecular changes.

CONCLUSION

The study identified a novel circ_0000006/miR-483-5p/KDM2B axis dysregulated during AD progression. Targeting this axis, especially circ_0000006, could be a potential strategy to mitigate the transition from AA to AD by modulating VSMC phenotype and function.

Causal relationship between immune cells and aortic aneurysms: a Mendelian randomization study

OBJECTIVES

The causal association between immune cell traits and aortic aneurysm remains unknown.

METHODS

We performed a bidirectional two-sample Mendelian randomization analysis to explore the causality between 731 immune cell characteristics and the risk of abdominal aortic aneurysm and thoracic aortic aneurysms through publicly available genetic data, respectively. To examine heterogeneity and horizontal pleiotropy, Cochran's Q test and MR-Egger intercept were utilized. Additionally, multivariable Mendelian randomization analysis and meta-analysis were performed in further analysis.

RESULTS

We found that 20 immune phenotypes had a suggestive causality on abdominal aortic aneurysm, and 15 immune phenotypes had a suggestive causal effect on thoracic aortic aneurysm. After further false discovery rate adjustment (q value <0.1), CD20 on IgD+ CD38- B cell (q = 0.053) and CD127 on CD28+ CD4+ T cell (q = 0.096) were associated with an increased risk of abdominal aortic aneurysm, respectively, indicating a significant causality between them. After adjusting for smoking, there is still statistical significance between CD127 on CD28+ CD4+ T cell and abdominal aortic aneurysm. However, after adjusting for lipids, no statistical significance can be observed between CD127 on CD28+ CD4+ T cells and abdominal aortic aneurysm. Furthermore, there is still statistical significance between CD20 on IgD+ CD38- B cells and abdominal aortic aneurysm after adjusting for lipids and smoking, which was further identified by meta-analysis.

CONCLUSIONS

We found a causal association between immune cell traits and aortic aneurysm by genetic methods, thus providing new avenues for future mechanism studies.

Impact of frailty on adverse outcomes in patients with abdominal aortic aneurysm undergoing surgery: a systematic review and meta-analysis

OBJECTIVE

To explore the prognostic role of frailty in patients with abdominal aortic aneurysm (AAA) by conducting this systematic review and meta-analysis METHODS: We conducted an extensive literature search on PubMed, Web of Sciences, and Embase databases to identify studies that reported the association of frailty with postoperative complications, reintervention, or all-cause mortality in patients with AAA after surgery. Short-term mortality was defined by a combination of in-hospital and 30-day death.

RESULTS

Seven cohort studies reporting on 9 articles with 323,788 AAA patients were included. The reported prevalence of frailty in AAA patients ranged between 2.3% and 34.6%. Pooling the results revealed that frailty was significantly associated with a higher risk of short-term all-cause mortality (adjusted risk ratios [RR] 3.20; 95% confidence intervals [CI] 1.95-5.26), long-term all-cause mortality (adjusted RR 2.86; 95% CI 2.57-3.17), and postoperative complications (adjusted RR 2.19; 95% CI 1.50-3.20) compared to non-frail individuals. However, there was no clear association between frailty and reintervention (HR 1.44; 95% CI 0.97-2.16).

CONCLUSIONS

Frailty independently predicts the short and long-term survival as well as postoperative complications in patients with AAA undergoing surgery. Assessing frail status may potentially enhance surgical decision-making for these patients.

Sarcopenia defined by the psoas muscle mass or quality is associated with poor survival in patients with aortic aneurysm undergoing surgery: A meta-analysis

BACKGROUND

The impact of sarcopenia estimated by the skeletal muscle mass or quality on survival remains controversial in patients with aortic aneurysm. This meta-analysis aimed to assess the association between sarcopenia defined by the psoas muscle mass or quality and all-cause mortality in patients with aortic aneurysm.

METHODS

We comprehensively searched PubMed, Web of Science, and Embase databases until December 31, 2022. Studies investigating the association of CT-derived psoas muscle mass (psoas muscle area [PSA] and psoas muscle index [PMI]) or quality (lean PSA [LPSA]) with all-cause mortality in patients with aortic aneurysm undergoing surgery were included.

RESULTS

Eighteen studies reporting on 19 articles, enrolling 4767 patients were identified. A comparison of the bottom with the top psoas muscle mass, the pooled adjusted hazard ratios (HR) of all-cause mortality was 2.34 (95% confidence intervals [CI] 1.58-3.47). Low psoas muscle mass was associated with an increased risk of all-cause mortality when defined by the PSA (HR 2.01; 95% CI 1.42-2.75) or PMI (HR 2.37; 95% CI 1.24-4.55). Per 1 cm2 PMA increase conferred a 10% reduction in all-cause mortality. Patients with bottom LPMA had an increased risk of all-cause mortality (HR 3.27; 95% CI 1.90-5.60). Each 100 cm2 × HU LPMA increase conferred a 15% reduction in all-cause mortality.

CONCLUSIONS

Sarcopenia defined by the low psoas muscle mass or quality independently predicts all-cause mortality in patients with aortic aneurysm. However, the overall certainty of evidence for the categorical analysis of psoas muscle mass was downgraded by the presence of publication bias and significant heterogeneity.