Calcific aortic valve damage as a risk factor for cardiovascular events

Th1 cells reduce the osteoblast-like phenotype in valvular interstitial cells by inhibiting NLRP3 inflammasome activation in macrophages

BACKGROUND AND AIMS

Inflammation is initiates the propagation phase of aortic valve calcification. The activation of NLRP3 signaling in macrophages plays a crucial role in the progression of calcific aortic valve stenosis (CAVS). IFN-γ regulates NLRP3 activity in macrophages. This study aimed to explore the mechanism of IFN-γ regulation and its impact on CAVS progression and valve interstitial cell transdifferentiation.

METHODS AND RESULTS

The number of Th1 cells and the expression of IFN-γ and STAT1 in the aortic valve, spleen and peripheral blood increased significantly as CAVS progressed. To explore the mechanisms underlying the roles of Th1 cells and IFN-γ, we treated CAVS mice with IFN-γ-AAV9 or an anti-IFN-γ neutralizing antibody. While IFN-γ promoted aortic valve calcification and dysfunction, it significantly decreased NLRP3 signaling in splenic macrophages and Ly6C+ monocytes. In vitro coculture showed that Th1 cells inhibited NLPR3 activation in ox-LDL-treated macrophages through the IFN-γR1/IFN-γR2-STAT1 pathway. Compared with untreated medium, conditioned medium from Th1-treated bone marrow-derived macrophages reduced the osteogenic calcification of valvular interstitial cells.

CONCLUSION

Inhibition of the NLRP3 inflammasome by Th1 cells protects against valvular interstitial cell calcification as a negative feedback mechanism of adaptive immunity toward innate immunity. This study provides a precision medicine strategy for CAVS based on the targeting of anti-inflammatory mechanisms.

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.

Prediction of Coronary Calcification and Stenosis: Role of Radiomics From Low-Dose CT

RATIONALE AND OBJECTIVES

We aimed to assess relationship between single-click, whole heart radiomics from low-dose computed tomography (LDCT) for lung cancer screening with coronary artery calcification and stenosis.

MATERIALS AND METHODS

The institutional review board-approved, retrospective study included all 106 patients (68 men, 38 women, mean age 64 ± 7 years) who underwent both LDCT for lung cancer screening and had calcium scoring and coronary computed tomography angiography in our institution. We recorded the clinical variables including patients' demographics, smoking history, family history, and lipid profiles. Coronary calcium scores and grading of coronary stenosis were recorded from the radiology information system. We calculated the multiethnic scores for atherosclerosis risk scores to obtain 10-year coronary heart disease (MESA 10-Y CHD) risk of cardiovascular disease for all patients. Deidentified LDCT exams were exported to a Radiomics prototype for automatic heart segmentation, and derivation of radiomics. Data were analyzed using multiple logistic regression and kernel Fisher discriminant analyses.

RESULTS

Whole heart radiomics were better than the clinical variables for differentiating subjects with different Agatston scores (≤400 and >400) (area under the curve [AUC] 0.92 vs 0.69). Prediction of coronary stenosis and MESA 10-Y CHD risk was better on whole heart radiomics (AUC:0.86-0.87) than with clinical variables (AUC:0.69-0.79). Addition of clinical variables or visual assessment of coronary calcification from LDCT to whole heart radiomics resulted in a modest change in the AUC.

CONCLUSION

Single-click, whole heart radiomics obtained from LDCT for lung cancer screening can differentiate patients with different Agatston and MESA risk scores for cardiovascular diseases.

Extracellular Nucleotides Regulate Arterial Calcification by Activating Both Independent and Dependent Purinergic Receptor Signaling Pathways

Arterial calcification, the deposition of calcium-phosphate crystals in the extracellular matrix, resembles physiological bone mineralization. It is well-known that extracellular nucleotides regulate bone homeostasis raising an emerging interest in the role of these molecules on arterial calcification. The purinergic independent pathway involves the enzymes ecto-nucleotide pyrophosphatase/phosphodiesterases (NPPs), ecto-nucleoside triphosphate diphosphohydrolases (NTPDases), 5′-nucleotidase and alkaline phosphatase. These regulate the production and breakdown of the calcification inhibitor—pyrophosphate and the calcification stimulator—inorganic phosphate, from extracellular nucleotides. Maintaining ecto-nucleotidase activities in a well-defined range is indispensable as enzymatic hyper- and hypo-expression has been linked to arterial calcification. The purinergic signaling dependent pathway focusses on the activation of purinergic receptors (P1, P2X and P2Y) by extracellular nucleotides. These receptors influence arterial calcification by interfering with the key molecular mechanisms underlying this pathology, including the osteogenic switch and apoptosis of vascular cells and possibly, by favoring the phenotypic switch of vascular cells towards an adipogenic phenotype, a recent, novel hypothesis explaining the systemic prevention of arterial calcification. Selective compounds influencing the activity of ecto-nucleotidases and purinergic receptors, have recently been developed to treat arterial calcification. However, adverse side-effects on bone mineralization are possible as these compounds reasonably could interfere with physiological bone mineralization.

Oscillatory fluid-induced mechanobiology in heart valves with parallels to the vasculature

Forces generated by blood flow are known to contribute to cardiovascular development and remodeling. These hemodynamic forces induce molecular signals that are communicated from the endothelium to various cell types. The cardiovascular system consists of the heart and the vasculature, and together they deliver nutrients throughout the body. While heart valves and blood vessels experience different environmental forces and differ in morphology as well as cell types, they both can undergo pathological remodeling and become susceptible to calcification. In addition, while the plaque morphology is similar in valvular and vascular diseases, therapeutic targets available for the latter condition are not effective in the management of heart valve calcification. Therefore, research in valvular and vascular pathologies and treatments have largely remained independent. Nonetheless, understanding the similarities and differences in development, calcific/fibrous pathologies and healthy remodeling events between the valvular and vascular systems can help us better identify future treatments for both types of tissues, particularly for heart valve pathologies which have been understudied in comparison to arterial diseases.

Conduction disturbances after transcatheter aortic valve implantation procedures - predictors and management

Transcatheter aortic valve implantation (TAVI) has become a safe and efficient alternative to cardiac surgery in patients with severe aortic stenosis. In many countries the number of performed TAVI procedures equals the number of surgical implantations. Indications for TAVI are becoming more liberal, allowing a wider spectrum of patients to benefit from the advantages of transcatheter therapy. Due to its invasive nature, TAVI is associated with some complications such as conduction disturbances. Although these disturbances are usually not lethal, they have a great influence on patients’ state and long term-survival. The most relevant and common are His’ bundle branch blocks, atrioventricular blocks, and need for permanent pacemaker implantation. With the frequency at 10% to even 50%, conduction abnormalities are among the most important TAVI-related adverse events. Risk factors for conduction disturbances include age, anatomy of the heart, periprocedural factors, type of implanted valve, and comorbidities. Severity of occurring complications varies; therefore selection of a proper treatment approach is required. Considered as the most effective management, permanent pacemaker implantation turned out to negatively influence both recovery and survival. Moreover, there is no expert consensus on use of resynchronization therapy after TAVI. In this paper, the authors present a comprehensive analysis of the most common conduction disturbances accompanying TAVI, factors related to their occurrence, and treatment approach.

Assessment of Risk Factors in Patients With Myocardial Infarction

Background:

Coronary artery diseases (CAD) are one of the important health problems in the world, although considerable progresses have been made to decrease the mortality, they are still the first cause of death in many countries. Hence, the necessity of examining effective factors and risk factors on CAD can be one of the most important health priorities in many countries like Iran.

Objective:

This study was performed to assess the risk factors in patients with myocardial infarction (MI) in Zahedan.

Materials and Methods:

This is a cross sectional study in which 213 patients were examined. They had been diagnosed to have heart failure. Data gathering took 18 months. Data gathering tool was a designed checklist which was filled up by an experienced nurse during interview. Obtained results were recorded in files and analyzed in SPSS 21.

Results:

Results showed that 70% of patients were women and only 30% were men. 48% of them were illiterate and patients mean age was 58.3. SD had been 12.6. The mean of pain onset time till referring to hospital was 11 hours with SD of 2.1. 17% of patients (coronary artery diseases history), 25.5% (hypertension history), 26% (diabetes history), 15.5% (cholesterol history), 13% (smoking) and 3% have reported CABG history. The majority of people who referred had inferior MI (40.4%). 67.1% normal rhythm, 2.8% atrial fibrillation and 16% had ventricular tachycardia. Statistical tests showed a significant correlation between sex and the mean of referring time (p<0.05) but the relation between age and referring time was not significant.

Conclusion:

Effective risk factors on MI were recognized in this study. Some of them such as age, sex and education cannot be modified but many are controllable such as hypertension, diabetes, cholesterol, and smoking and on time referring after pain onset. Having considered the results of this study health promotion for society and especially vulnerable people can be provided by omitting or reducing risk factors.