Anatomical characteristics of aortic valve diseases: Implications for transcatheter aortic valve replacement.

Background: The etiology of aortic stenosis (AS) significantly impacts transcatheter heart valve (THV) implantation, with rheumatic etiology posing challenges. The concept of valve anchoring during transcatheter aortic valve replacement (TAVR) for patients with aortic regurgitation (AR) remains unclear. Objective: This study aims to investigate the clinical and CT anatomical characteristics of various aortic valve diseases. Methods: A retrospective analysis was conducted on consecutive patients who underwent CT for severe aortic diseases between April 2019 and February 2023. CT analysis was performed in eight anatomical landmarks: left ventricular outflow tract (LVOT), aortic annulus, sinus of Valsalva (SOV), sinotubular junction (STJ), ascending aorta (AAO), coronary height, aortic angle, and aortic valve calcification volume. Results: 121 patients with severe aortic valve disease were included, divided into AS (71 cases, 59%) and AR (50 cases, 41%) groups. In patients with AR, the absolute diameters of the annulus, LVOT, SOV, STJ, and AAO, as well as the heights of SOV and STJ and the cardiac angle, are larger than those in patients with AS (all P < 0.05). In normalized aortic root dimensions, the AR group had a higher SOV and STJ diameter-to-annulus ratio than the AS group (STJ-SOV-annulus: 1.51-1.44-1.00 vs 1.33-1.28-1.00). The bicuspid and rheumatic AS groups had smaller sinuses (STJ-SOV-annulus:1.27-1.35-1.00, 1.17-1.30-1.00, respectively), necessitating the downsizing of the THV. For 74% of AR patients, the sinotubular junction could not be used as a second anchoring zone, and anchoring relied primarily on the annulus. Conclusions: Patients with rheumatic etiology require smaller valves, and anchoring in AR patients depends on the valve annulus. These structural characteristics will influence TAVR selection.

Mechanism Analysis of Vascular Calcification Based on Fluid Dynamics.

Vascular calcification is the abnormal deposition of calcium phosphate complexes in blood vessels, which is regarded as the pathological basis of multiple cardiovascular diseases. The flowing blood exerts a frictional force called shear stress on the vascular wall. Blood vessels have different hydrodynamic properties due to discrepancies in geometric and mechanical properties. The disturbance of the blood flow in the bending area and the branch point of the arterial tree produces a shear stress lower than the physiological magnitude of the laminar shear stress, which can induce the occurrence of vascular calcification. Endothelial cells sense the fluid dynamics of blood and transmit electrical and chemical signals to the full-thickness of blood vessels. Through crosstalk with endothelial cells, smooth muscle cells trigger osteogenic transformation, involved in mediating vascular intima and media calcification. In addition, based on the detection of fluid dynamics parameters, emerging imaging technologies such as 4D Flow MRI and computational fluid dynamics have greatly improved the early diagnosis ability of cardiovascular diseases, showing extremely high clinical application prospects.

Screening of immune-related secretory proteins linking chronic kidney disease with calcific aortic valve disease based on comprehensive bioinformatics analysis and machine learning.

BACKGROUND: Chronic kidney disease (CKD) is one of the most significant cardiovascular risk factors, playing vital roles in various cardiovascular diseases such as calcific aortic valve disease (CAVD). We aim to explore the CKD-associated genes potentially involving CAVD pathogenesis, and to discover candidate biomarkers for the diagnosis of CKD with CAVD. METHODS: Three CAVD, one CKD-PBMC and one CKD-Kidney datasets of expression profiles were obtained from the GEO database. Firstly, to detect CAVD key genes and CKD-associated secretory proteins, differentially expressed analysis and WGCNA were carried out. Protein-protein interaction (PPI), functional enrichment and cMAP analyses were employed to reveal CKD-related pathogenic genes and underlying mechanisms in CKD-related CAVD as well as the potential drugs for CAVD treatment. Then, machine learning algorithms including LASSO regression and random forest were adopted for screening candidate biomarkers and constructing diagnostic nomogram for predicting CKD-related CAVD. Moreover, ROC curve, calibration curve and decision curve analyses were applied to evaluate the diagnostic performance of nomogram. Finally, the CIBERSORT algorithm was used to explore immune cell infiltration in CAVD. RESULTS: The integrated CAVD dataset identified 124 CAVD key genes by intersecting differential expression and WGCNA analyses. Totally 983 CKD-associated secretory proteins were screened by differential expression analysis of CKD-PBMC/Kidney datasets. PPI analysis identified two key modules containing 76 nodes, regarded as CKD-related pathogenic genes in CAVD, which were mostly enriched in inflammatory and immune regulation by enrichment analysis. The cMAP analysis exposed metyrapone as a more potential drug for CAVD treatment. 17 genes were overlapped between CAVD key genes and CKD-associated secretory proteins, and two hub genes were chosen as candidate biomarkers for developing nomogram with ideal diagnostic performance through machine learning. Furthermore, SLPI/MMP9 expression patterns were confirmed in our external cohort and the nomogram could serve as novel diagnosis models for distinguishing CAVD. Finally, immune cell infiltration results uncovered immune dysregulation in CAVD, and SLPI/MMP9 were significantly associated with invasive immune cells. CONCLUSIONS: We revealed the inflammatory-immune pathways underlying CKD-related CAVD, and developed SLPI/MMP9-based CAVD diagnostic nomogram, which offered novel insights into future serum-based diagnosis and therapeutic intervention of CKD with CAVD.

The myth of aortic valve annulus changes in aortic valve disease.

Background: The characteristics of aortic annulus changes in aortic regurgitation (AR) patients are poorly understood, and predictive factors among aortic valve disease are yet to be established. Objective: This study seeks to elucidate the pattern of annular size fluctuations across different cardiac phases in AR patients and to identify predictors for annular enlargement during either systole or diastole in aortic valve diseases. Methods: A retrospective analysis was conducted on 55 patients with severe aortic valve diseases, including 26 patients with aortic stenosis (AS) and 29 with AR, to discern the two groups' contrasting and analogous patterns of annular changes. The patient sample was expanded to 107 to investigate the factors influencing the size of the annulus during different cardiac phases. Based on our findings, patients were then divided into two groups: those with an annulus that is larger during systole (83 patients) and those where the annulus is larger during diastole (24 patients). Results: Typically, AR patients exhibit a dynamic annulus, with both perimeter and area being largest during mid-systole. These dimensions diminish progressively and then increase again in early diastole, a pattern consistent with observations in AS patients. Among 107 patients, 21% had diastolic enlargement. Systolic measurements would lead to prosthesis undersizing in 17% of these. Male gender and lower systolic annulus minimum relative to body surface area (AnMin index) were predictors of diastolic enlargement, with ROC curve areas of 0.70 and 0.87 for AR and AS, respectively. Conclusions: Systolic measurements are recommended for AR patients. Gender and the AnMin index are significant predictors, particularly potent in AS patients.

Investigation into the role of Stmn2 in vascular smooth muscle phenotype transformation during vascular injury via RNA sequencing and experimental validation.

This study examined the effects of Stmn2 on phenotype transformation of vascular smooth muscle in vascular injury via RNA sequencing and experimental validation. Total RNA was extracted for RNA sequencing after 1, 3 and 5 days of injury to screen the differentially expressed genes (DEGs). Western blot was used to detect the protein expression of Stmn2 and its associated targets. The morphological changes of carotid arteries in rats were examined by hematoxylin and eosin (H&E) staining. The expression of vascular smooth muscle cell (VSMC) phenotype markers smooth muscle alpha-actin (α-SMA), vimentin and OPN were detected by immunohistochemistry. DEGs were related to the extracellular matrix and other cell components outside the plasma membrane. They were associated with protein binding, cytoskeleton protein binding, signal receptor binding and other molecular functions, actin cytoskeleton regulation and other Kyoto Encyclopedia of Genes and Genomes pathways. Stmn2 was identified as the hub gene of actin cytoskeleton pathway and vascular disease, and its expression followed the trend of decreasing initially and increasing afterwards during the progress of vascular injury. Western blot assay showed that the expression of Stmn2 and Tubulin decreased immediately after vascular injury; Stmn2 overexpression significantly up-regulated the expression of osteopontin and α-SMA and vimentin in VSMCs. The results of morphology analysis and immunostaining also showed that Stmn2 overexpression promoted the intima thickening and enhanced the proliferating cell nuclear antigen expression in the injured vascular tissues. In conclusion, our results implied that Stmn2 may play a potential role in vascular injury, which may be associated with VSMC phenotype transformation. Further studies are warranted to determine detailed molecular mechanisms of Stmn2 in vascular injury.

[The triglyceride-lowering effects of PCSK9 inhibitor differ in patients with different baseline triglyceride levels].

OBJECTIVE: To investigate the triglyceride (TG)-lowering effects of PCSK9 inhibitor in patients with in different baseline triglyceride levels. METHODS: Between February, 2019 and March, 2020, a total of 59 patients were treated with PCSK9 inhibitor (Evolocumab) in 5 hospitals, including Nanfang Hospital, Guangdong Provincial People's Hospital, First Affiliated Hospital of Sun Yat-sen University, Foshan Nanhai District People's Hospital and Yulin First People's Hospital. According to baseline triglyceride levels, the patients were divided into normal TG group (< 1.70 mmol/L, n=24), mild hypertriglyceridemia group (1.70-2.29 mmol/L, n=11), moderate hypertriglyceridemia group (2.30-5.63 mmol/L, n=13), and severe hypertriglyceridemia group (≥5.64 mmol/L, n=11), and the changes in TG level after the treatment were compared among the 4 groups. RESULTS: In the groups with normal and mildly elevated baseline TG level, the patients did not show significant changes in TG levels after the treatment. In patients with moderately and severely elevated baseline TG levels, treatment with PCSK9 inhibitor significantly reduced their TG levels (P < 0.005). CONCLUSIONS: PCSK9 inhibitor has a significant TG-lowering effect in patients with moderate to severe hypertriglyceridemia but not in patients with only mildly elevated baseline TG level.