IL6 gene polymorphism association with calcific aortic valve stenosis and influence on serum levels of interleukin-6

Bibliometric analysis of treatment modalities in calcific aortic valve stenosis

Background

Calcific aortic valve stenosis (CAVS) is a common cardiovascular condition associated with significant adverse events and high mortality rates. Unfortunately, there are currently no effective pharmacological treatments to halt or prevent its progression. Through our analysis of global trends and treatment strategies, we have identified valuable insights and promising therapeutic possibilities. Additionally, by utilizing bibliometric and visualization techniques, we provide a comprehensive overview of the current research landscape in this field.

Method

According to our design idea, we used the Web of Science database to select publications on aortic stenosis and related treatments. Through our VOSviewer and CiteSpace analysis, a total of 787 articles have been analyzed by September 2024. We also summarize and explore the most prolific authors, the most prolific countries, and the journals and institutions that publish the most articles.

Results

A visual analysis of the collected articles reveals that Canada and the United States have the highest publication volumes in this field. Among institutions, Harvard University in the U.S. leads in publication count, followed by Laval University in Canada and the University of California in the U.S. The top three research hotspots are stenosis, calcification, and progression. The journal with the highest number of publications in this area is Frontiers in Cardiovascular Medicine, followed by Catheterization and Cardiovascular Interventions and Arteriosclerosis, Thrombosis and Vascular Biology. Furthermore, research on CAVS treatment spans various directions and focuses, including therapeutic approaches, pathogenesis, and diagnostic methods.

Conclusion

Research into CAVS treatment has advanced significantly over the years. While interventional and surgical valve replacement remains the mainstay treatments for aortic stenosis, they are insufficient to fully meet the needs of the patient. Emerging priorities now focus on improving diagnostics, exploring innovative therapies, uncovering disease mechanisms, and developing novel drugs. These findings highlight the evolving demands in this field and underscore the need for continued research to address these challenges.

Frailty in Older Adults with Severe Aortic Stenosis: The Role of Systemic Inflammation and Calcium Homeostasis

Background: Frailty and severe aortic stenosis (AoS) are critical conditions in older adults, both of which share pathophysiological mechanisms including chronic inflammation and calcium metabolism dysregulation, potentially influencing the development and progression of these conditions. This study aimed to analyze systemic inflammation and calcium homeostasis biomarkers and their associations with frailty in older adults with severe AoS. Methods: This prospective study included 191 patients aged ≥75 years with severe AoS who were candidates for aortic valve replacement and were evaluated at a Geriatrics Frailty Assessment and Intervention Clinic. Frailty was defined as a score ≤6 on the Short Physical Performance Battery (SPPB). Biomarkers analyzed included aortic valve calcium score, parathyroid hormone (PTH), calcidiol (vitamin D), calcium, phosphate, creatinine, interleukin-6 (IL-6), and the Systemic Immune-Inflammation Index. Multivariate logistic regression was performed to identify independent predictors of frailty. Results: Of the 191 patients studied, 53.9% were women, with a mean age of 84.1 ± 4.1 years. Frailty was identified in 28.3% of patients (mean SPPB score 7.6 ± 2.5). Statistically significant differences between frail and non-frail patients were observed for PTH (87.7 ± 61.1 pg/mL vs. 70 ± 44.4 pg/mL, p = 0.028) and IL-6 (10.4 ± 11.2 pg/mL vs. 7 ± 8.2 pg/mL, p = 0.049). Notably, in the multivariate model, IL-6 emerged as a significant independent predictor of frailty (OR 1.037; CI 1.001-1.074, p = 0.043). Conclusions: IL-6 was identified as a biomarker significantly associated with frailty in older adults with severe AoS. Evaluating IL-6 could enhance the precision of frailty assessments, complement functional measures, and support clinical decision-making in this population.

Genetics of Calcific Aortic Stenosis: A Systematic Review

Background: Calcific aortic stenosis is the most prevalent valvular abnormality in the Western world. Factors commonly associated with calcific aortic stenosis include advanced age, male sex, hypertension, diabetes and impaired renal function. This review synthesises the existing literature on genetic associations with calcific aortic stenosis. Methods: A systematic search was conducted in the PubMed, Ovid and Cochrane libraries from inception to 21 July 2024 to identify human studies investigating the genetic factors involved in calcific aortic stenosis. From an initial pool of 1392 articles, 78 were selected for full-text review and 31 were included in the final qualitative synthesis. The risk of bias in these studies was assessed using the Newcastle Ottawa Scale. Results: Multiple genes have been associated with calcific aortic stenosis. These genes are involved in different biological pathways, including the lipid metabolism pathway (PLA, LDL, APO, PCSK9, Lp-PLA2, PONS1), the inflammatory pathway (IL-6, IL-10), the calcification pathway (PALMD, TEX41) and the endocrine pathway (PTH, VIT D, RUNX2, CACNA1C, ALPL). Additional genes such as NOTCH1, NAV1 and FADS1/2 influence different pathways. Mechanistically, these genes may promote a pro-inflammatory and pro-calcific environment in the aortic valve itself, leading to increased osteoblastic activity and subsequent calcific degeneration of the valve. Conclusions: Numerous genetic associations contribute to calcific aortic stenosis. Recognition of these associations can enhance risk stratification for individuals and their first-degree relatives, facilitate family screening, and importantly, pave the way for targeted therapeutic interventions focusing on the identified genetic factors. Understanding these genetic factors can also lead to gene therapy to prevent calcific aortic stenosis in the future.

Pro-Calcifying Role of Enzymatically Modified LDL (eLDL) in Aortic Valve Sclerosis via Induction of IL-6 and IL-33

One of the contributors to atherogenesis is enzymatically modified LDL (eLDL). eLDL was detected in all stages of aortic valve sclerosis and was demonstrated to trigger the activation of p38 mitogen-activated protein kinase (p38 MAPK), which has been identified as a pro-inflammatory protein in atherosclerosis. In this study, we investigated the influence of eLDL on IL-6 and IL-33 induction, and also the impact of eLDL on calcification in aortic valve stenosis (AS). eLDL upregulated phosphate-induced calcification in valvular interstitial cells (VICs)/myofibroblasts isolated from diseased aortic valves, as demonstrated by alizarin red staining. Functional studies demonstrated activation of p38 MAPK as well as an altered gene expression of osteogenic genes known to be involved in vascular calcification. In parallel with the activation of p38 MAPK, eLDL also induced upregulation of the cytokines IL-6 and IL-33. The results suggest a pro-calcifying role of eLDL in AS via induction of IL-6 and IL-33.

Lipoprotein(a) and calcific aortic valve disease initiation and progression: a systematic review and meta-analysis

Although evidence indicates the association of lipoprotein(a) [Lp(a)] with atherosclerosis, the link with calcific aortic valve disease (CAVD) is unclear. This systematic review and meta-analysis explores the connection between Lp(a) and aortic valve calcification and stenosis (AVS). We included all relevant studies, indexed in eight databases, up to February 2023. A total of 44 studies (163 139 subjects) were included, with 16 of them being further meta-analysed. Despite considerable heterogeneity, most studies support the relationship between Lp(a) and CAVD, especially in younger populations, with evidence of early aortic valve micro-calcification in elevated-Lp(a) populations. The quantitative synthesis showed higher Lp(a) levels, by 22.63 nmol/L (95% CI: 9.98-35.27), for patients with AVS, while meta-regressing the data revealed smaller Lp(a) differences for older populations with a higher proportion of females. The meta-analysis of eight studies providing genetic data, revealed that the minor alleles of both rs10455872 and rs3798220 LPA gene loci were associated with higher risk for AVS (pooled odds ratio 1.42; 95% CI: 1.34-1.50 and 1.27; 95% CI: 1.09-1.48, respectively). Importantly, high-Lp(a) individuals displayed not only faster AVS progression, by a mean difference of 0.09 m/s/year (95% CI: 0.09-0.09), but also a higher risk of serious adverse outcomes, including death (pooled hazard ratio 1.39; 95% CI: 1.01-1.90). These summary findings highlight the effect of Lp(a) on CAVD initiation, progression and outcomes, and support the early onset of Lp(a)-related subclinical lesions before clinical evidence.

Lipoprotein(a) As a Potential Predictive Factor for Earlier Aortic Valve Replacement in Patients with Bicuspid Aortic Valve

Bicuspid aortic valve (BAV) affects 0.5-2% of the general population and constitutes the major cause of severe aortic valve stenosis (AVS) in individuals ≤70 years. The aim of the present study was to evaluate the parameters that may provide information about the risk of AVS developing in BAV patients, with particular emphasis on lipoprotein(a) (Lp(a)), which is a well-recognized risk factor for stenosis in the general population. We also analyzed the impact of autotaxin (ATX) and interleukin-6 (IL-6) as parameters potentially related to the pathomechanism of Lp(a) action. We found that high Lp(a) levels (>50 mg/dL) occurred significantly more frequently in patients with AVS than in patients without AVS, both in the group below and above 45 years of age (p = 0.036 and p = 0.033, respectively). Elevated Lp(a) levels were also strictly associated with the need for aortic valve replacement (AVR) at a younger age (p = 0.016). However, the Lp(a) concentration did not differ significantly between patients with and without AVS. Similarly, we observed no differences in ATX between the analyzed patient groups, and both ATX activity and concentration correlated significantly with Lp(a) level (R = 0.465, p < 0.001 and R = 0.599, p < 0.001, respectively). We revealed a significantly higher concentration of IL-6 in young patients with AVS. However, this observation was not confirmed in the group of patients over 45 years of age. We also did not observe a significant correlation between IL-6 and Lp(a) or between CRP and Lp(a) in any of the analyzed groups of BAV patients. Our results demonstrate that a high level of Lp(a), greater than 50 mg/dL, may be a significant predictive factor for earlier AVR. Lp(a)-related parameters, such as ATX and IL-6, may be valuable in providing information about the additional cardiovascular risks associated with developing AVS.

Genetics of aortic valve disease

PURPOSE OF REVIEW

Aortic valve disease is a leading global cause of morbidity and mortality, posing an increasing burden on society. Advances in next-generation technologies and disease models over the last decade have further delineated the genetic and molecular factors that might be exploited in development of therapeutics for affected patients. This review describes several advances in the molecular and genetic understanding of AVD, focusing on bicuspid aortic valve (BAV) and calcific aortic valve disease (CAVD).

RECENT FINDINGS

Genomic studies have identified a myriad of genes implicated in the development of BAV, including NOTCH1 , SMAD6 and ADAMTS19 , along with members of the GATA and ROBO gene families. Similarly, several genes associated with the initiation and progression of CAVD, including NOTCH1 , LPA , PALMD , IL6 and FADS1/2 , serve as the launching point for emerging clinical trials.

SUMMARY

These new insights into the genetic contributors of AVD have offered new avenues for translational disease investigation, bridging molecular discoveries to emergent pharmacotherapeutic options. Future studies aimed at uncovering new genetic associations and further defining implicated molecular pathways are fuelling the new wave of drug discovery.