Aortic valve sclerosis is an echocardiographic indicator of significant coronary disease in patients undergoing diagnostic coronary angiography

Upregulation of miR-664a-3p Ameliorates Calcific Aortic Valve Disease by Inhibiting the BMP2 Signaling Pathway

The development of calcific aortic valve disease (CAVD) is a complex process of ectopic calcification involving various factors that lead to aortic valve stenosis, hemodynamic changes, and, in severe cases, even sudden death. Currently, aortic valve replacement is the only effective method. The osteogenic differentiation of aortic valve interstitial cells (AVICs) is one of the key factors of valve calcification. Emerging evidence suggests that bone morphogenetic protein 2 (BMP2) can induce the proosteogenic activation of AVICs. However, the regulatory mechanism underlying this activation in AVICs is unclear. In the present study, we elucidated through high-throughput RNA sequencing and RT-qPCR that miR-664a-3p was evidently downregulated in the calcific aortic valve. We also proved that miR-664a-3p was involved in regulating osteogenic differentiation in AVICs. Target prediction analysis and dual-luciferase reporter gene assay confirmed that miR-664a-3p is preferentially bound to BMP2. Furthermore, the effect of the miR-664a-3p/BMP2 axis on osteogenic differentiation in AVICs was examined using the gain- and loss-of-function approach. Finally, we constructed a mouse CAVD model and verified the effect of the miR-664a-3p/BMP2 axis on the aortic valve calcification leaflets in vivo. In conclusion, miR-664a-3p regulates osteogenic differentiation in AVICs through negative regulation of BMP2, highlighting that miR-664a-3p may be a potential therapeutic target for CAVD.

Prevalence and modifiable risk factors of degenerative valvular heart disease among elderly population in southern China

Objective

To investigate the prevalence and modifiable risk factors of degenerative valvular heart disease (DVHD) among elderly population in southern China.

Methods

A stratified multistage sampling method was used to recruit subjects. The contents of the survey included the questionnaire, laboratory examination, echocardiography, and other auxiliary examinations. The possible risk factors of DVHD were analyzed by logistic regression analysis.

Results

A total of 3538 subjects ≥ 65 years of age were enrolled. One thousand three hundred and seven subjects (36.9%) were diagnosed with DVHD. Degenerative was the most common etiology of VHD. Prevalence of DVHD increased with advancing age. The prevalence of DVHD differed by living region (χ² = 45.594, P < 0.001), educational level ( χ² = 50.557, P < 0.001), and occupation ( χ² = 36.961, P < 0.001). Risk factors associated with DVHD included age (two-fold increased risk for each 10-year increase in age), elevated level C-reactive protein (OR = 1.346, 95% CI: 1.100−1.646), elevated level low density lipoprotein (OR = 1.243, 95% CI: 1.064−1.451), coronary artery disease (OR = 1.651, 95% CI: 1.085−2.513), smoking (OR = 1.341, 95% CI: 1.132−1.589), and hypertension (OR = 1.414, 95% CI: 1.221−1.638). Other significant risk factors included reduced or elevated level red blood cell (OR = 1.347, 95% CI: 1.031−1.761; OR = 1.599, 95% CI: 1.097−2.331; respectively), elevated level platelets (OR = 1.891, 95% CI: 1.118−3.198), elevated level uric acid (OR = 1.282, 95% CI: 1.112−1.479), and stroke (OR: 1.738, 95% CI = 1.085−2.513).

Conclusions

The survey characterized the baseline conditions of DVHD cohort of elderly population in Guangzhou city. The established and emerging risk factors for DVHD may represent challenges and opportunities for therapy.

Trace elements in patients with aortic valve sclerosis

Background:

Aortic valve sclerosis (AVSc) is defined as the thickening and calcification of aortic valve cusps, in the absence of obstruction of ventricular outflow. AVSc is linked with a clear imbalance in some trace elements.

Aims:

The objective of this study was to investigate the relationship between AVSc and serum levels of iron (Fe), zinc (Zn), selenium (Se), and copper (Cu). Additionally, this research aimed to explore the clinical significance of human serum zinc, selenium, copper, and iron concentrations as a potential new biomarker for AVSc patients and to clarify the pathophysiological role in individuals at risk of developing AVSc.

Patients and methods:

The study included 40 subjects with AVSc (25% male and 75% female) who were compared with a healthy control group with the same gender ratio. AVSc was based on comprehensive echocardiographic assessments. Blood samples were taken and Zn and Cu concentrations were determined through the use of atomic absorption spectroscopy. Se was measured using an inductively coupled plasma mass spectrometry device and Fe was measured using a Beckman Coulter instrument.

Results:

There was a significant difference in the prevalence of diabetes, blood pressure levels, and body mass index between the patients and the healthy subjects (p < 0.05). The differences between the serum Fe, Se, and Cu levels of the AVSc patients and the healthy subjects (p > 0.05) were recorded. The serum Zn of AVSc patients when compared was significantly lower compared with that of the control group (p < 0.01).

Conclusion:

Patients with AVSc had an imbalance in some of the trace elements in their blood. The patient group’s valves had higher serum Cu levels and lower serum Se, Zn, and Fe concentrations compared with the healthy group’s valves. In the valve patients as compared, AVSc had a high prevalence of obesity, hypertension, and diabetes.

Disturbed Flow Increases UBE2C (Ubiquitin E2 Ligase C) via Loss of miR-483-3p, Inducing Aortic Valve Calcification by the pVHL (von Hippel-Lindau Protein) and HIF-1α (Hypoxia-Inducible Factor-1α) Pathway in Endothelial Cells

Objective- Calcific aortic valve (AV) disease, characterized by AV sclerosis and calcification, is a major cause of death in the aging population; however, there are no effective medical therapies other than valve replacement. AV calcification preferentially occurs on the fibrosa side, exposed to disturbed flow (d-flow), whereas the ventricularis side exposed to predominantly stable flow remains protected by unclear mechanisms. Here, we tested the role of novel flow-sensitive UBE2C (ubiquitin E2 ligase C) and microRNA-483-3p (miR-483) in flow-dependent AV endothelial function and AV calcification. Approach and Results- Human AV endothelial cells and fresh porcine AV leaflets were exposed to stable flow or d-flow. We found that UBE2C was upregulated by d-flow in human AV endothelial cells in the miR-483-dependent manner. UBE2C mediated OS-induced endothelial inflammation and endothelial-mesenchymal transition by increasing the HIF-1α (hypoxia-inducible factor-1α) level. UBE2C increased HIF-1α by ubiquitinating and degrading its upstream regulator pVHL (von Hippel-Lindau protein). These in vitro findings were corroborated by immunostaining studies using diseased human AV leaflets. In addition, we found that reduction of miR-483 by d-flow led to increased UBE2C expression in human AV endothelial cells. The miR-483 mimic protected against endothelial inflammation and endothelial-mesenchymal transition in human AV endothelial cells and calcification of porcine AV leaflets by downregulating UBE2C. Moreover, treatment with the HIF-1α inhibitor (PX478) significantly reduced porcine AV calcification in static and d-flow conditions. Conclusions- These results suggest that miR-483 and UBE2C and pVHL are novel flow-sensitive anti- and pro-calcific AV disease molecules, respectively, that regulate the HIF-1α pathway in AV. The miR-483 mimic and HIF-1α pathway inhibitors may serve as potential therapeutics of calcific AV disease.

Cardiovascular morbidity and mortality in patients with aortic valve sclerosis: A systematic review and meta-analysis

AIMS

The association between aortic valve sclerosis (AVSc) and cardiovascular (CV) events is not consistent among different studies. We have performed a meta-analysis evaluating the association between AVSc and fatal and/or non-fatal CV and cerebrovascular events.

METHODS AND RESULTS

A systematic search was performed in the electronic databases (PubMed, Web of Science, Scopus, EMBASE). Studies evaluating coronary artery disease (CAD), stroke and CV mortality in AVSc patients and controls were included. Differences among cases and controls were expressed as Odds Ratio (OR) with pertinent 95% Confidence Intervals (CI). Thirty-one studies on 10,537 AVSc patients and 25,005 controls were included in the final analysis. The absolute risk of CAD was 45.8% (95% CI: 32.9-59.3) in AVSc patients and 29.4% (95% CI: 21.8-38.5) in controls with an OR of 2.02 (95% CI: 1.67-2.44) and an attributable risk of 35.8%. Moreover, stroke was reported in 11.8% (95% CI: 4.4-27.7) of AVSc patients and 7.9% (95% CI: 2.5-22.7) of controls (OR: 1.41, 95% CI: 1.16-1.71) with an attributable risk of 33.0%. CV mortality was 6.2% (95% CI: 2.7-13.5) in AVSc patients and 2.0% (95% CI: 0.5-7.9) in controls (OR: 2.70, 95% CI: 1.45-5.01), with an attributable risk of 67.7%. Results were confirmed when pooling together ORs for CAD, stroke and CV mortality obtained by means of multivariate analysis.

CONCLUSIONS

AVSc is associated with CAD, stroke and CV mortality. Taken together, these data suggest that patients with AVSc may benefit from a stricter CV risk monitoring and that AVSc screening may be included in the frame of CV risk stratification protocols.

Mechanosensitive microRNA-181b Regulates Aortic Valve Endothelial Matrix Degradation by Targeting TIMP3

Calcific aortic valve disease (CAVD) is a major cause of morbidity in the aging population, but the underlying mechanisms of its progression remain poorly understood. Aortic valve calcification preferentially occurs on the fibrosa, which is subjected to disturbed flow. The side-specific progression of the disease is characterized by inflammation, calcific lesions, and extracellular matrix (ECM) degradation. Here, we explored the role of mechanosensitive microRNA-181b and its downstream targets in human aortic valve endothelial cells (HAVECs). Mechanistically, miR-181b is upregulated in OS and fibrosa, and it targets TIMP3, SIRT1, and GATA6, correlated with increased gelatinase/MMP activity. Overexpression of miR-181b led to decreased TIMP3 and exacerbated MMP activity as shown by gelatinase assay, and miR-181b inhibition decreased gelatinase activity through the repression of TIMP3 levels. Luciferase assay showed specific binding of miR-181b to the TIMP3 gene. Overexpression of miR-181b in HAVECs subjected to either LS or OS increased MMP activity, and miR-181b inhibition abrogated shear-sensitive MMP activity. These studies suggest that targeting this shear-dependent miRNA may provide a novel noninvasive treatment for CAVD.

Shear-Sensitive Genes in Aortic Valve Endothelium

SIGNIFICANCE

Currently, calcific aortic valve disease (CAVD) is only treatable through surgical intervention because the specific mechanisms leading to the disease remain unclear. In this review, we explore the forces and structure of the valve, as well as the mechanosensors and downstream signaling in the valve endothelium known to contribute to inflammation and valve dysfunction.

RECENT ADVANCES

While the valvular structure enables adaptation to dynamic hemodynamic forces, these are impaired during CAVD, resulting in pathological systemic changes. Mechanosensing mechanisms-proteins, sugars, and membrane structures-at the surface of the valve endothelial cell relay mechanical signals to the nucleus. As a result, a large number of mechanosensitive genes are transcribed to alter cellular phenotype and, ultimately, induce inflammation and CAVD. Transforming growth factor-β signaling and Wnt/β-catenin have been widely studied in this context. Importantly, NADPH oxidase and reactive oxygen species/reactive nitrogen species signaling has increasingly been recognized to play a key role in the cellular response to mechanical stimuli. In addition, a number of valvular microRNAs are mechanosensitive and may regulate the progression of CAVD.

CRITICAL ISSUES

While numerous pathways have been described in the pathology of CAVD, no treatment options are available to avoid surgery for advanced stenosis and calcification of the aortic valve. More work must be focused on this issue to lead to successful therapies for the disease.

FUTURE DIRECTIONS

Ultimately, a more complete understanding of the mechanisms within the aortic valve endothelium will lead us to future therapies important for treatment of CAVD without the risks involved with valve replacement or repair. Antioxid. Redox Signal. 25, 401-414.

Association of Aortic Valve Sclerosis with Previous Coronary Artery Disease and Risk Factors

Background

Aortic valve sclerosis (AVS) is characterized by increased thickness, calcification and stiffness of the aortic leaflets without fusion of the commissures. Several studies show an association between AVS and presence of coronary artery disease.

Objective

The aim of this study is to investigate the association between presence of AVS with occurrence of previous coronary artery disease and classical risk factors.

Methods

The sample was composed of 2,493 individuals who underwent transthoracic echocardiography between August 2011 and December 2012. The mean age of the cohort was 67.5 ± 15.9 years, and 50.7% were female.

Results

The most frequent clinical indication for Doppler echocardiography was the presence of stroke (28.8%), and the most common risk factor was hypertension (60.8%). The most prevalent pathological findings on Doppler echocardiography were mitral valve sclerosis (37.1%) and AVS (36.7%). There was a statistically significant association between AVS with hypertension (p < 0.001), myocardial infarction (p = 0.007), diabetes (p = 0.006) and compromised left ventricular systolic function (p < 0.001). Conclusion: Patients with AVS have higher prevalences of hypertension, stroke, hypercholesterolemia, myocardial infarction, diabetes and compromised left ventricular systolic function when compared with patients without AVS. We conclude that there is an association between presence of AVS with previous coronary artery disease and classical risk factors.

Preferential activation of SMAD1/5/8 on the fibrosa endothelium in calcified human aortic valves--association with low BMP antagonists and SMAD6

Background

Aortic valve (AV) calcification preferentially occurs on the fibrosa side while the ventricularis side remains relatively unaffected. Here, we tested the hypothesis that side-dependent activation of bone morphogenic protein (BMP) pathway in the endothelium of the ventricularis and fibrosa is associated with human AV calcification.

Methods and Results

Human calcified AVs obtained from AV replacement surgeries and non-calcified AVs from heart transplantations were used for immunohistochemical studies. We found SMAD-1/5/8 phosphorylation (a canonical BMP pathway) was higher in the calcified fibrosa than the non-calcified fibrosa while SMAD-2/3 phosphorylation (a canonical TGFβ pathway) did not show any difference. Interestingly, we found that BMP-2/4/6 expression was significantly higher on the ventricularis endothelium compared to the fibrosa in both calcified and non-calcified AV cusps; however, BMP antagonists (crossvienless-2/BMPER and noggin) expression was significantly higher on the ventricularis endothelium compared to the fibrosa in both disease states. Moreover, significant expression of inhibitory SMAD-6 expression was found only in the non-calcified ventricularis endothelium.

Conclusions

SMAD-1/5/8 is preferentially activated in the calcified fibrosa endothelium of human AVs and it correlates with low expression of BMP antagonists and inhibitory SMAD6. These results suggest a dominant role of BMP antagonists in the side-dependent calcification of human AVs.

Aortic valve sclerosis: a marker of significant obstructive coronary artery disease in patients with chest pain?

BACKGROUND

Previous reports suggested a relationship between coronary artery disease (CAD) and aortic valve sclerosis (AVS). However, whether AVS can be used as a marker of obstructive CAD (obCAD) in patients with chest pain is unknown. We hypothesized that AVS is a predictive marker for obCAD in patients hospitalized for chest pain.

METHODS

We studied 93 consecutive patients with chest pain undergoing coronary angiography. All had negative cardiac enzymes and no previous diagnosis of cardiac ischemic disease. AVS was detected by transthoracic echocardiography. Resting electrocardiography, left ventricular systolic function, wall-motion abnormalities, and stress test results were considered. We calculated the diagnostic value for obCAD of AVS, stress test, and combination of the two methods.

RESULTS

ObCAD was present in 29 patients (31%). Patients with obCAD had a higher prevalence of AVS (38 vs 14%, P = .02) and positive stress test (67 vs 28%, P = .02). The odds ratio for obCAD in the presence of AVS was 3.7 (95% confidence interval 1.3-10.4, P = .01). AVS (P = .01) and a positive stress test (P = .002) were independent predictors for obCAD at the multivariate analysis. AVS had sensitivity of 38% and specificity of 86%. Stress test had sensitivity of 67% and specificity of 72%. When echocardiographic detection of AVS was combined with stress test, the sensitivity and negative predictive value improved to 93% and 96%, respectively.

CONCLUSIONS

AVS is an independent predictor for obCAD in patients with chest pain, thus, it should be considered in the risk stratification of these patients.

Aortic valve sclerosis: is it a cardiovascular risk factor or a cardiac disease marker?

BACKGROUND

Aortic valve sclerosis, without stenosis, has been associated with an increased cardiovascular mortality and morbidity due to myocardial infarction. However, it is unclear whether it is a cardiovascular risk factor or a cardiac disease marker. The goal of our study is to evaluate the difference in the prevalence of cardiovascular disease and risk factors among patients with or without aortic sclerosis.

METHODS

This observational study compared a group of 142 consecutive subjects with aortic valve sclerosis, assigned as group S, with a group of 101 subjects without aortic sclerosis, assigned as group C. Patients with bicuspid aortic valves and those with antegrade Doppler velocity across aortic valve leaflets exceeding 2.0 m/sec were excluded.

RESULTS

Mean ages of groups S and C were 71 +/- 8, and 68.8 +/- 6 years, respectively (P value = not significant). The prevalence of smoking, diabetes, hypercholesterolemia, hypertension, pulse pressure, left ventricular diastolic dysfunction, atrial fibrillation, and stroke was not significantly different between the two groups. However, there was a significantly higher prevalence of left ventricular hypertrophy (P = 0.05), ventricular arrhythmias (P = 0.02), myocardial infarction (P = 0.04), and systolic heart failure (P = 0.04) in aortic sclerosis group.

CONCLUSIONS

Aortic sclerosis is associated with a higher prevalence of left ventricular hypertrophy, ventricular arrhythmias, myocardial infarction, and systolic heart failure, while the prevalence of cardiovascular risk factors is not different between aortic sclerosis patients and controls. Hence, aortic sclerosis represents a cardiac disease marker useful for early identification of high-risk patients beyond cardiovascular risk factors rate.

C-reactive protein in predicting coronary artery disease in subjects with aortic valve sclerosis before diagnostic coronary angiography

BACKGROUND

Although previous studies have suggested that aortic valve sclerosis (AVS) shares common histologic features with atherosclerosis and is an indicator of significant coronary artery disease (CAD), many patients with aortic valve disease do not have coexisting coronary atherosclerotic disease and vice versa. It is important to find the subjects with AVS who are most likely to have concomitant CAD and require aggressive evaluation.

HYPOTHESIS

We hypothesized that the systemic inflammatory marker, high-sensitive C-reactive protein (hs-CRP), may be associated with AVS, and may be helpful before coronary angiography in identifying the presence of concomitant CAD in patients with AVS.

METHODS

This study included 227 patients with suspected CAD undergoing transthoracic echocardiography and coronary angiography. AVS was defined as a focal area of increased echogenicity and thickening of the aortic valve leaflets without restriction in motion. Data of atherosclerotic risk factors including hs-CRP were collected.

RESULTS

Technically satisfactory ultrasound recordings were obtained in 217 subjects (96% of enrolled patients). Patients with AVS were older (65+/-10 vs. 60+/-10 years old; P=0.0004), had higher serum creatinine levels (115.2+/-79.7 vs. 88.6 +/-35.4 micromol/L; P=0.04), and had greater prevalence of obstructive CAD (75% vs. 53%; P=0.001) than those with normal aortic valves. CRP levels were not associated with AVS, and failed to predict concomitant CAD in patients with AVS. Additionally, none of the established risk factors were independent predictors of the presence of CAD in AVS patients.

CONCLUSION

Hs-CRP levels appear to not be associated with AVS, and are of little value in terms of predicting the presence of concurrent CAD before coronary procedure.

Relationship between aortic valve sclerosis and the extent of coronary artery disease in patients undergoing diagnostic coronary angiography

BACKGROUND

Aortic valve sclerosis (AVS) is considered to be a manifestation of coronary atherosclerosis. Recent studies demonstrated an association between AVS and significant coronary artery disease (CAD).

AIM

We sought to determine the association between AVS and the extent of coronary atherosclerosis by means of the Gensini score system, which was calculated to yield a measure of the extent and severity of coronary atherosclerosis in patients referred for coronary angiography.

METHODS

A total of 160 consecutive patients referred for coronary angiography were subjected to echocardiography for screening of AVS and coronary risk assessment. Absence (group 1, n = 110) and presence of AVS (Group 2, n = 50) was established. The cardiac risk factors considered in this study were age, gender, family history of CAD, diabetes mellitus, hypertension, hypercholesterolemia and history of smoking. The body mass index was also measured. Atherosclerotic plaque burden was determined using the Gensini score. Significant CAD was defined as >50% reduction in the internal diameter of at least one coronary artery. Multivessel coronary disease was based on the presence of 2- or 3-vessel disease.

RESULTS

The AVS patients had a higher rate of 3-vessel disease (AVS group vs. non AVS: 40 vs. 13.6%; p < 0.001). No significant correlations were found between AVS and 1- and 2-vessel disease. Individuals with AVS were found to have a higher Gensini score (40.7 +/- 38.05 vs. 18 +/- 16.4; p < 0.001). Multivariate analysis identified age (p < 0.001), male sex (p = 0.01), triglycerides (p = 0.02), LDL cholesterol (p = 0.001) and Gensini score (p = 0.003) as independent predictors of AVS.

CONCLUSION

AVS is strongly interrelated with the coronary angiographic Gensini score. Echocardiographic detection of AVS in patients undergoing coronary angiography can provide a new surrogate marker of the extent of coronary atherosclerosis.