MicroRNAs involve in bicuspid aortic aneurysm: pathogenesis and biomarkers

Single-cell RNA sequencing and ATAC sequencing identify novel biomarkers for bicuspid aortic valve-associated thoracic aortic aneurysm

Introduction

Bicuspid aortic valve (BAV) is the most prevalent congenital cardiovascular defect and known to cause thoracic aortic aneurysms (TAAs). To improve our understanding of BAV pathogenesis, we characterized the cellular composition of BAV tissues and identified molecular changes in each cell population.

Methods

Tissue samples from two patients with BAV and two heart transplant donors were analyzed using single-cell RNA sequencing, assay for transposase-accessible chromatin using sequencing, and weighted gene coexpression network analysis for differential gene analysis. TAA-related changes were evaluated by comparing the proportion of each cell type and gene expression profiles between TAA and control tissues. Further, by combining our single-cell RNA sequencing data with publicly available data from genome-wide association studies, we determined critical genes for BAV.

Results

We found 20 cell subpopulations in TAA tissues, including multiple subtypes of smooth muscle cells, fibroblasts, macrophages, and T lymphocytes. This result suggested that these cells play multiple functional roles in BAV development. Several differentially expressed genes, including CD9, FHL1y, HSP90AA1, GAS6, PALLD, and ACTA2, were identified.

Discussion

We believe that this comprehensive assessment of the cellular composition of TAA tissues and the insights into altered gene expression patterns can facilitate identification of novel diagnostic biomarkers and therapeutic targets for BAV-associated TAA.

Effect of transcatheter aortic valve replacement on ascending aorta dilatation rate in patients with tricuspid and bicuspid aortic stenosis

Objectives

The aim of the present study was to assess the differences between BAV and TAV patients with chronic moderate to severe or severe AS regarding presentation, incidence of TAVR, survival, ascending aorta diameter and dilatation rate before and after TAVR.

Methods

The study included 667 consecutive patients with chronic moderate to severe or severe AS from January 2012 and December 2022. Outcomes included all-cause mortality, incidence of TAVR, and ascending aorta diameter and dilatation rate.

Results

There were 185 BAV-AS and 482 TAV-AS patients, and BAV-AS patients were younger (67 vs 78 years, P = 0.027). Total follow-up was 4.5 years (IQR: 2.7-8.9 years), 290 patients underwent TAVR, and 165 patients died. The 8-year TAVR incidence was higher in BAV-AS (55% ± 4%) vs TAV-AS (41% ± 5%; P = 0.02). The 8-year survival was higher in BAV-AS (85% ± 6%) vs TAV-AS (71% ± 6%; P < 0.0001) and became insignificant after age adjustment (P = 0.33). The dilatation rate of ascending aorta was significantly faster in BAV-AS patients compared with TAV-AS patients before TAVR. However, the ascending aorta dilatation rate for BAV-AS and TAV-AS patients was not significantly different after TAVR.

Conclusions

Compared with TAV-AS, BAV-AS patients were younger and underwent TAVR more frequently, resulting in a considerable survival advantage. After TAVR, ascending aorta dilatation rates were similar in BAV-AS and TAV-AS patients, suggesting an important role of hemodynamics on ascending aorta dilatation in BAV-AS.

Evaluation of microRNA Expression Features in Patients with Various Types of Arterial Damage: Thoracic Aortic Aneurysm and Coronary Atherosclerosis

Circulating serum miRNA are increasingly used as biomarkers and potential treatment targets in several clinical scenarios, including cardiovascular diseases. However, the current data on circulating miRNA in thoracic aorta aneurism (TAA) patients are inconclusive. The aim of the present study is to compare the levels of several circulating miRNA in patients with degenerative TAA, coronary artery disease (CAD), and controls for special profile identification. We have identified several candidates for the role of new biomarkers: miR-143-3p, miR-181-5p, miR-126-3p, miR-126-5p, miR-145-5p, miR-150-5p, and miR-195-5p.

MATERIALS AND METHODS

Serum samples of 100 patients were analyzed, including 388 TAA patients scheduled for elective surgery, 67 patients with stable CAD and 17 controls, were used for miRNA isolation and identification.

RESULTS

More specific for TAA with very high predictive ability in ROC analysis was an increase in the levels of miR-21-5p, miR-29b-5p, miR-126-5p/-3p, miR-181b-5p, and miR-92a-3p, with the latter microRNA being investigated as a novel potential marker of TAA for the first time.

CONCLUSION

TAA and CAD patients demonstrated a significant increase in the levels of circulating miR-126-5p/-3p, miR-181b-5p, and miR-29b-3p. More specific for TAA with very high predictive ability in ROC analysis was an increase in the levels of miR-21-5p, -29b-5p, -126-5p/-3p, 181b-5p, and -92a-3p, with the latter microRNA being investigated as a potential marker of TAA for the first time.

Patients with Bicuspid Aortopathy and Aortic Dilatation

(1) Background: Bicuspid aortic valve (BAV) is the most frequent congenital cardiac disease. Alteration of ascending aorta diameter is a consequence of shear stress alterations due to haemodynamic abnormalities developed from inadequate valve cusp coaptation. (2) Objective: This narrative review aims to discuss anatomical, pathophysiological, genetical, ultrasound, and radiological aspects of BAV disease, focusing on BAV classification related to imaging patterns and flux models involved in the onset and developing vessel dilatation. (3) Methods: A comprehensive search strategy was implemented in PubMed from January to May 2022. English language articles were selected independently by two authors and screened according to the following criteria. (4) Key Contents and Findings: Ultrasound scan is the primary step in the diagnostic flowchart identifying structural and doppler patterns of the valve. Computed tomography determines aortic vessel dimensions according to the anatomo-pathology of the valve. Magnetic resonance identifies hemodynamic alterations. New classifications and surgical indications derive from these diagnostic features. Currently, indications correlate morphological results, dissection risk factors, and genetic alterations. Surgical options vary from aortic valve and aortic vessel substitution to aortic valve repair according to the morphology of the valve. In selected patients, transcatheter aortic valve replacement has an even more impact on the treatment choice. (5) Conclusions: Different imaging approaches are an essential part of BAV diagnosis. Morphological classifications influence the surgical outcome.