Arterial hypertension and diastolic blood pressure associate with aortic stenosis

The Role of NOTCH Pathway Genes in the Inherited Susceptibility to Aortic Stenosis

The NOTCH-signaling pathway is responsible for intercellular interactions and cell fate commitment. Recently, NOTCH pathway genes were demonstrated to play an important role in aortic valve development, leading to an increased calcified aortic valve disease (CAVD) later in life. Here, we further investigate the association between genetic variants in the NOTCH pathway genes and aortic stenosis in a case-control study of 90 CAVD cases and 4723 controls using target panel sequencing of full-length 20 genes from a NOTCH-related pathway (DVL2, DTX2, MFNG, NUMBL, LFNG, DVL1, DTX4, APH1A, DTX1, APH1B, NOTCH1, ADAM17, DVL3, NCSTN, DTX3L, ILK, RFNG, DTX3, NOTCH4, PSENEN). We identified a common intronic variant in NOTCH1, protecting against CAVD development (rs3812603), as well as several rare and unique new variants in NOTCH-pathway genes (DTX4, NOTCH1, DTX1, DVL2, NOTCH1, DTX3L, DVL3), with a prominent effect of the protein structure and function.

The association between Alu hypomethylation and the severity of hypertension

Introduction

Epigenetic changes that cause genomic instability may be the basis of pathogenic processes of age-associated noncommunicable diseases (NCDs). Essential hypertension is one of the most common NCDs. Alu hypomethylation is an epigenetic event that is commonly found in elderly individuals. Epigenomic alterations are also found in age-associated NCDs such as osteoporosis and diabetes mellitus. Alu methylation prevents DNA from being damaged. Therefore, Alu hypomethylated DNA accumulates DNA damage and, as a result, causes organ function deterioration. Here, we report that Alu hypomethylation is a biomarker for essential hypertension.

Results

We investigated Alu methylation levels in white blood cells from normal controls, patients with prehypertension, and patients with hypertension. The hypertension group possessed the lowest Alu methylation level when classified by systolic blood pressure and diastolic blood pressure (P = 0.0002 and P = 0.0088, respectively). In the hypertension group, a higher diastolic blood pressure and a lower Alu methylation level were observed (r = -0.6278). Moreover, we found that changes in Alu hypomethylation in the four years of follow-up in the same person were directly correlated with increased diastolic blood pressure.

Conclusions

Similar to other age-associated NCDs, Alu hypomethylation is found in essential hypertension and is directly correlated with severity, particularly with diastolic blood pressure. Therefore, Alu hypomethylation may be linked with the molecular pathogenesis of high blood pressure and can be used for monitoring the clinical outcome of this disease.

Interventions in Adults With Repaired Coarctation of the Aorta

Background

Coarctation of the aorta coexists with other cardiac anomalies and has long‐term complications, including recoarctation, which may require intervention after the primary coarctation repair. This study aims to clarify the prevalence of and risk factors for interventions related to the coarctation complex as well as late mortality in a large contemporary patient population.

Methods and Results

The Swedish National Register of Congenital Heart Disease was used, which comprised 683 adults with repaired coarctation of the aorta. Analysis was performed on freedom from intervention thereafter at the coarctation site, aortic valve, left ventricular outflow tract, or ascending aorta. One hundred ninety‐six (29%) patients had at least 1 of these interventions. Estimated freedom from either of these interventions was 60% after 50 years. The risk of undergoing such an intervention was higher among men (hazard ratio, 1.6 [95% CI, 1.2–2.2]). Estimated freedom from another intervention at the coarctation site was 75% after 50 years. In women, there was an increase in interventions at the coarctation site after 45 years. Patients who underwent one of the previously mentioned interventions after the primary coarctation repair had poorer left ventricular function. Eighteen patients (3%) died during follow‐up in the register. The standardized mortality ratio was 2.9 (95% CI, 1.7–4.3).

Conclusions

Interventions are common after coarctation repair. The risk for and time of interventions are affected by sex. Our results have implications for planning follow‐up and giving appropriate medical advice to the growing population of adults with repaired coarctation of the aorta.

Observational and Genetic Associations of Modifiable Risk Factors with Aortic Valve Stenosis: A Prospective Cohort Study of 0.5 Million Participants

Background: Observational studies have shown that modifiable risk factors are associated with aortic valve stenosis (AVS). However, the causality behind these associations remains largely unknown. Objectives: To explore the associations of modifiable risk factors, including metabolic factors, biochemical measures, education, and lifestyles with AVS and their potential causal associations. Methods: We enrolled 361,930 British white people with genetic data in the UK biobank. Cox proportional risk regression models were used to estimate the hazard ratios between 28 modifiable risk factors and AVS. We used genetic instruments for modifiable risk factors to determine the potential causal relationships using a one-sample Mendelian randomization (MR) approach. Results: A total of 1602 participants developed AVS during an 8.4-year follow-up. Observational analyses showed higher adiposity, blood pressure, heart rate, low-density lipoprotein, urate, C-reactive protein, creatinine, albumin, and glycated hemoglobin, but lower serum vitamin D, and education, unhealthy lifestyle, and poor sleep quality were related to a higher risk of AVS after adjusting for the Bonferroni correction (p < 0.0013). Genetically predicted 1-SD higher levels of body mass index [HR: 1.09, 95% CI: 1.03 to 1.16], body fat percentage (1.17, 1.03 to 1.33), triglyceride (TG) [1.08, 1.00 to 1.16], low-density lipoprotein (LDL) (1.15, 1.08 to 1.21) and serum total cholesterol (TC) (1.13, 1.02 to 1.25) were associated with a higher risk of AVS, respectively. Genetically determined per category higher insomnia (1.32, 1.13 to 1.55) was also associated with AVS. The abovementioned genetic associations with the incident AVS showed an increasing relationship pattern. Conclusions: This study provides strong evidence for the potential causal roles of cardiometabolic factors in developing AVS, highlighting that an idea of metabolic status through a healthy lifestyle may help prevent AVS.

Uncoupling the Vicious Cycle of Mechanical Stress and Inflammation in Calcific Aortic Valve Disease

Calcific aortic valve disease (CAVD) is a common acquired valvulopathy, which carries a high burden of mortality. Chronic inflammation has been postulated as the predominant pathophysiological process underlying CAVD. So far, no effective medical therapies exist to halt the progression of CAVD. This review aims to outline the known pathways of inflammation and calcification in CAVD, focussing on the critical roles of mechanical stress and mechanosensing in the perpetuation of valvular inflammation. Following initiation of valvular inflammation, dysregulation of proinflammatory and osteoregulatory signalling pathways stimulates endothelial-mesenchymal transition of valvular endothelial cells (VECs) and differentiation of valvular interstitial cells (VICs) into active myofibroblastic and osteoblastic phenotypes, which in turn mediate valvular extracellular matrix remodelling and calcification. Mechanosensitive signalling pathways convert mechanical forces experienced by valve leaflets and circulating cells into biochemical signals and may provide the positive feedback loop that promotes acceleration of disease progression in the advanced stages of CAVD. Mechanosensing is implicated in multiple aspects of CAVD pathophysiology. The mechanosensitive RhoA/ROCK and YAP/TAZ systems are implicated in aortic valve leaflet mineralisation in response to increased substrate stiffness. Exposure of aortic valve leaflets, endothelial cells and platelets to high shear stress results in increased expression of mediators of VIC differentiation. Upregulation of the Piezo1 mechanoreceptor has been demonstrated to promote inflammation in CAVD, which normalises following transcatheter valve replacement. Genetic variants and inhibition of Notch signalling accentuate VIC responses to altered mechanical stresses. The study of mechanosensing pathways has revealed promising insights into the mechanisms that perpetuate inflammation and calcification in CAVD. Mechanotransduction of altered mechanical stresses may provide the sought-after coupling link that drives a vicious cycle of chronic inflammation in CAVD. Mechanosensing pathways may yield promising targets for therapeutic interventions and prognostic biomarkers with the potential to improve the management of CAVD.

Cumulative incidence and predictors of acquired aortic stenosis in a large population of men followed for up to 43 years

Background

Acquired aortic stenosis (AS) increases with age and has high mortality without intervention. Factors predicting its development are unclear, although atherosclerotic factors are assumed to be involved. Our aim in this study is to estimate the lifetime cumulative incidence and predictors of AS in middle-aged men.

Methods

We included a random sample of men (n = 9998) born 1915–1925 in Gothenburg, Sweden. From them, 7,494 were examined and followed until a diagnosis of AS or death (maximum follow-up time 42.8 years). We identified AS diagnosis from the Swedish National Patient Registry and deaths from the Swedish Cause of Death Registry by using International Classification of Disease (ICD) diagnostic criteria. To study time-dependent relationships between AS and risk factors with death as the competing risk, we divided the cohort into three overlapping follow-up groups: 25–43, 30–43 and 35–43 years. We used age-adjusted Cox proportional hazards model to identify predictors of AS.

Results

The lifelong cumulative incidence of AS was 3.2%. At baseline, participants in the third group had a healthier lifestyle, lower body mass index (BMI), blood pressure, and serum cholesterol levels. Higher BMI, obesity, cholesterol, hypertension, atrial fibrillation, smoking and heredity for stroke were associated with AS. With BMI of 20–22.5 as a reference, hazard ratios of being diagnosed with AS for men with a baseline BMI of 25–27.5 kg/m², 27.5–30 kg/m² and > 30 kg/m² were 1.99 (95% CI 1.12–3.55), 2.98 (95% CI 1.65–5.40) and 3.55 (95% CI 1.84–6.87), respectively.

Conclusions

The lifetime cumulative incidence of AS in middle-aged male population was 3.2%. Multiple atherosclerotic risk factors, particularly high BMI might be associated with a higher risk of developing AS.

Aortic Valve Calcification Score in Patients with Arterial Hypertension Environmentally Exposed to Tobacco Smoke

The objective of our study was to determine the relationship between exposure to environmental tobacco smoke (ETS) and the value of the aortic valve calcification score (AVCS) in people suffering from arterial hypertension (AH). 107 non-smokers with AH (mean age 67.16 ± 8.48 years) were qualified for the study. The degree of exposure to ETS was assessed using the Second-hand Smoke Exposure Scale (SHSES) questionnaire. Study group was divided depending on ETS exposure: A—no exposure, B—low, C—medium and D—high. AVCS was measured based on the aortic valve plane multiplanar reconstruction from the non-contrast phase of the cardiac computed tomography. The Agatston algorithm was used, in which calcifications were considered changes with a density exceeding 130 HU. The mean AVCS value in the study group of patients was 213.59 ± 304.86. The AVCS was significantly lower in subgroup A than in subgroups C and D. In subgroup A, the lack of aortic valve calcification (AVCS = 0) was observed significantly more frequently than in subgroups C and D. There was a positive correlation between the number of SHSES points and the AVCS value (r = 0.37, p < 0.05). Based on the ROC curve, the SHSES value was determined as the optimal cut-off point for the prediction of AVCS = 0, amounting to 3 points. The accuracy of SHSES < 3 as the predictor of AVCS = 0 was set at 62.18%. Hypertensive patients have an unfavourable relationship between the amount of exposure to ETS, determined on the SHSES scale, and the AVCS value.