Lipoprotein(a): A missing culprit in the management of athero-thrombosis?

Lipoprotein(a)'s Role in Atherosclerosis and Aortic Stenosis: A Contemporary Literature Review

Lipoprotein(a), or Lp(a), is a distinctive lipoprotein particle linked to various cardiovascular diseases, notably atherosclerosis and aortic stenosis. Much like plasminogen, Lp(a) hinders normal fibrinolysis, leading to increased thrombosis and slower clearance of fibrin debris. It also causes inflammation, oxidative stress, and endothelial dysfunction, contributing to the formation of atherosclerotic lesions. Epidemiological studies have consistently shown that even slight increases in Lp(a) levels correlate with a heightened risk of cardiovascular events. Furthermore, Lp(a) plays a role in aortic stenosis by binding to leaflet valves, accumulating within them, and triggering calcium deposition and nodule formation. These calcium deposits gradually narrow the arteries, impeding blood flow. By raising inflammation and oxidative stress in the valve, Lp(a) accelerates tissue damage and calcium deposition. Traditional lipid-lowering therapies have limited efficacy in reducing Lp(a) levels. However, new treatments using RNA interference and antisense oligonucleotides to decrease Lp(a) production in the liver offer promising prospects for mitigating the risks and managing atherosclerosis and aortic stenosis associated with high Lp(a) levels. As Lp(a) screening becomes more common in healthcare, physicians will be better equipped to assess patients' risk levels and provide tailored treatments. This review aims to examine the role of Lp(a) in the development of aortic stenosis and atherosclerosis.

Impact of lipoprotein(a) and fibrinogen on prognosis in patients with coronary artery disease: A retrospective cohort study

BACKGROUND

Despite the considerable progress made in preventative methods, medication, and interventional therapies, it remains evident that cardiovascular events (CVEs) continue to be the primary cause of both death and morbidity among individuals diagnosed with coronary artery disease (CAD).

OBJECTIVE

To compare the connection between lipoprotein a (Lp[a]), fibrinogen (Fib), and both parameters combined with all-cause mortality to detect their value as prognostic biomarkers.

METHODS

This is a retrospective study. Patients diagnosed with CAD between January 2007 and December 2020 at the Guangdong Provincial People's Hospital (China) were involved in the study. 43,367 patients met the eligibility criteria. The Lp(a) and Fib levels were distributed into three tertile groups (low, medium, and high). All of the patients included in the study were followed up for all-cause mortality. Kaplan-Meier and Cox regression were performed to determine the relationship between Lp(a), Fib, and all-cause mortality. A concordance statistics model was developed to detect the impact of Fib and Lp(a) in terms of anticipating poor outcomes in patients with CAD.

RESULTS

Throughout a median follow-up of 67.0 months, 6,883 (15.9%) patients died. Participants with high Lp(a) (above 27.60 mg/dL) levels had a significantly higher risk for all-cause mortality than individuals with low Lp(a) levels (below 11.13 mg/dL; adjusted hazard ratio [aHR] 1.219, 95% confidence interval [CI]: 1.141-1.304, p< 0.001). Similarly, patients with high Fib levels (above 4.32 g/L) had a significantly greater risk of developing all-cause mortality compared with those with reduced Fib levels (below 3.41 g/L; aHR 1.415, 95% CI: 1.323-1.514, p< 0.001). Patients with raised Lp(a) and Fib levels had the maximum risk for all-cause mortality (aHR 1.702; 95% CI: 1.558-1.859, p< 0.001). When considered together, Lp(a) and Fib caused a significant elevation of the concordance statistic by 0.009 (p< 0.05), suggesting a higher value for predicting mortality when combining the two indicators.

CONCLUSION

High Lp(a) and Fib levels could be used as predictive biomarkers for all-cause mortality in individuals with CAD. The prediction accuracy for all-cause mortality improved after combining the two parameters.

The Essence of Lipoproteins in Cardiovascular Health and Diseases Treated by Photodynamic Therapy

Lipids, together with lipoprotein particles, are the cause of atherosclerosis, which is a pathology of the cardiovascular system. In addition, it affects inflammatory processes and affects the vessels and heart. In pharmaceutical answer to this, statins are considered a first-stage treatment method to block cholesterol synthesis. Many times, additional drugs are also used with this method to lower lipid concentrations in order to achieve certain values of low-density lipoprotein (LDL) cholesterol. Recent advances in photodynamic therapy (PDT) as a new cancer treatment have gained the therapy much attention as a minimally invasive and highly selective method. Photodynamic therapy has been proven more effective than chemotherapy, radiotherapy, and immunotherapy alone in numerous studies. Consequently, photodynamic therapy research has expanded in many fields of medicine due to its increased therapeutic effects and reduced side effects. Currently, PDT is the most commonly used therapy for treating age-related macular degeneration, as well as inflammatory diseases, and skin infections. The effectiveness of photodynamic therapy against a number of pathogens has also been demonstrated in various studies. Also, PDT has been used in the treatment of cardiovascular diseases, such as atherosclerosis and hyperplasia of the arterial intima. This review evaluates the effectiveness and usefulness of photodynamic therapy in cardiovascular diseases. According to the analysis, photodynamic therapy is a promising approach for treating cardiovascular diseases and may lead to new clinical trials and management standards. Our review addresses the used therapeutic strategies and also describes new therapeutic strategies to reduce the cardiovascular burden that is induced by lipids.

The ins and outs of lipoprotein(a) assay methods

Pathophysiological, epidemiological and genetic studies convincingly showed lipoprotein(a) (Lp(a)) to be a causal mediator of atherosclerotic cardiovascular disease (ASCVD). This happens through a myriad of mechanisms including activation of innate immune cells, endothelial cells as well as platelets. Although these certainties whether or not Lp(a) is ready for prime-time clinical use remain debated. Thus, remit of the present review is to provide an overview of different methods that have been employed for the measurement of Lp(a). The methods include dynamic light scattering, multi-angle light scattering analysis, near-field imaging, sedimentation, gel filtration, and electron microscopy. The development of multiple Lp(a) detection methods is vital for improved prediction of ASCVD risk.

Tale of two systems: the intertwining duality of fibrinolysis and lipoprotein metabolism

Fibrinolysis is an enzymatic process that breaks down fibrin clots, while dyslipidemia refers to abnormal levels of lipids and lipoproteins in the blood. Both fibrinolysis and lipoprotein metabolism are critical mechanisms that regulate a myriad of functions in the body, and the imbalance of these mechanisms is linked to the development of pathologic conditions, such as thrombotic complications in atherosclerotic cardiovascular diseases. Accumulated evidence indicates the close relationship between the 2 seemingly distinct and complicated systems-fibrinolysis and lipoprotein metabolism. Observational studies in humans found that dyslipidemia, characterized by increased blood apoB-lipoprotein and decreased high-density lipoprotein, is associated with lower fibrinolytic potential. Genetic variants of some fibrinolytic regulators are associated with blood lipid levels, supporting a causal relationship between these regulators and lipoprotein metabolism. Mechanistic studies have elucidated many pathways that link the fibrinolytic system and lipoprotein metabolism. Moreover, profibrinolytic therapies improve lipid panels toward an overall cardiometabolic healthier phenotype, while some lipid-lowering treatments increase fibrinolytic potential. The complex relationship between lipoprotein and fibrinolysis warrants further research to improve our understanding of the bidirectional regulation between the mediators of fibrinolysis and lipoprotein metabolism.

Treatment of Lp(a): Is It the Future or Are We Ready Today?

PURPOSE OF REVIEW

The goal of this review is to present the pharmacodynamic effectiveness as well as the clinical efficacy and safety of investigational antisense oligonucleotides (ASOs) and small interference RNAs (siRNAs) drugs that specifically target lipoprotein(a) (Lp(a)). The review will discuss whether the existing lipid-lowering therapies are adequate to treat high Lp(a) levels or whether it is necessary to use the emerging new therapeutic approaches which are based on the current RNA technologies.

RECENT FINDINGS

Lipoprotein(a) (Lp(a)) is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD), independent of other conventional risk factors. High Lp(a) levels are also independently associated with an increased risk of aortic stenosis progression rate. Plasma Lp(a) levels are primarily genetically determined by variation in the LPA gene coding for apo(a). All secondary prevention trials have demonstrated that the existing hypolipidemic therapies are not adequate to reduce Lp(a) levels to such an extent that could lead to a substantial reduction of ASCVD risk. This has led to the development of new drugs that target the mRNA transcript of LPA and efficiently inhibit Lp(a) synthesis leading to potent Lp(a) reduction. These new drugs are the ASO pelacarsen and the siRNAs olpasiran and SLN360. Recent pharmacodynamic studies showed that all these drugs potently reduce Lp(a) up to 98%, in a dose-dependent manner. Ongoing clinical trials will determine the Lp(a)-lowering efficacy, tolerability, and safety of these drugs as well as their potential effectiveness in reducing the ASCVD risk attributed to high plasma Lp(a) levels. We are not ready today to significantly reduce plasma Lp(a). Emerging therapies potently decrease Lp(a) and ongoing clinical trials will determine their effectiveness in reducing ASCVD risk in subjects with high Lp(a) levels.

Non-Conventional Risk Factors: "Fact" or "Fake" in Cardiovascular Disease Prevention?

Cardiovascular diseases (CVDs), such as arterial hypertension, myocardial infarction, stroke, heart failure, atrial fibrillation, etc., still represent the main cause of morbidity and mortality worldwide. They significantly modify the patients' quality of life with a tremendous economic impact. It is well established that cardiovascular risk factors increase the probability of fatal and non-fatal cardiac events. These risk factors are classified into modifiable (smoking, arterial hypertension, hypercholesterolemia, low HDL cholesterol, diabetes, excessive alcohol consumption, high-fat and high-calorie diet, reduced physical activity) and non-modifiable (sex, age, family history, of previous cardiovascular disease). Hence, CVD prevention is based on early identification and management of modifiable risk factors whose impact on the CV outcome is now performed by the use of CV risk assessment models, such as the Framingham Risk Score, Pooled Cohort Equations, or the SCORE2. However, in recent years, emerging, non-traditional factors (metabolic and non-metabolic) seem to significantly affect this assessment. In this article, we aim at defining these emerging factors and describe the potential mechanisms by which they might contribute to the development of CVD.

Predictors of functional and morphological arterial wall properties in coronary artery disease patients with increased lipoprotein (a) levels before and after treatment with proprotein convertase subtilisin-kexin type 9 inhibitors

BACKGROUND

In addition to proatherogenic properties, lipoprotein (a) (Lp(a)) has also pro-inflammatory, antifibrinolytic and prothrombogenic features. The aim of the current study was to identify the predictors of functional and morphological properties of the arterial wall in patients after myocardial infarction and increased Lp(a) levels at the beginning and after treatment with proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors.

METHODS

Seventy-six post-myocardial infarction patients with high Lp(a) levels were included in the study. Ultrasound measurements of flow-mediated dilation of brachial artery (FMD), carotid intima-media thickness (c-IMT) and pulse wave velocity (PWV) were performed initially and after 6 months of treatment. At the same time points lipids, Lp(a), inflammatory and hemostasis markers were measured in blood samples.

RESULTS

In linear regression model FMD significantly correlated with age at first myocardial infarction (β = 0.689; p = 0.022), high-sensitivity C-reactive protein (β = -1.200; p = 0.009), vascular cell adhesion protein 1 (VCAM-1) (β = -0.992; p = 0.006), overall coagulation potential (β = 1.428; p = 0.014) and overall hemostasis potential (β = -1.473; p = 0.008). c-IMT significantly correlated with age at first myocardial infarction (β = 0.574; p = 0.033) and Lp(a) (β = 0.524; p = 0.040). PWV significantly correlated with systolic blood pressure (β = 0.332; p = 0.002), tumor necrosis factor alpha (β = 0.406; p = 0.002), interleukin-8 (β = -0.315; p = 0.015) and plasminogen activator inhibitor 1 (β = 0.229; p = 0.031). After treatment FMD reached statistical significance only in univariant analysis with systolic blood pressure (r = -0.286; p = 0.004) and VCAM-1 (r = -0.229; p = 0.024). PWV and c-IMT correlated with age (r = 0.334; p = 0.001 and r = 0.486; p < 0.0001, respectively) and systolic blood pressure (r = 0.556; p < 0.0001 and r = 0.233; p = 0.021, respectively).

CONCLUSIONS

Our results suggest that age, systolic blood pressure, Lp(a) levels and other biochemical markers associated with Lp(a) are predictors of functional and morphological properties of the arterial vessel wall in post-myocardial patients with high Lp(a) levels initially. However, after 6 months of treatment with PCSK9 inhibitors only age and systolic blood pressure seem to be predictors of these properties.

TRIAL REGISTRATION

The protocol for this study was registered with clinicaltrials.gov on November, 3 2020 under registration number NCT04613167.

Lipoprotein (a) and myocardial infarction: impact on long-term mortality

BACKGROUND AND AIMS

Lipoprotein (a) [Lp(a)] is a genetically regulated lipoprotein particle that is an independent risk factor for coronary atherosclerotic heart disease. However, the correlation between Lp(a) and left ventricular ejection fraction (LVEF) in patients with myocardial infarction (MI) has been poorly studied. The present study investigated the correlation between Lp(a) and LVEF, as well as the impact of Lp(a) on long-term mortality in patients with MI.

METHODS

Patients who underwent coronary angiography resulting in MI diagnosis between May 2018 and March 2020 at the First Affiliated Hospital of Anhui Medical University were included in this study. The patients were divided into groups based on the Lp(a) concentration and LVEF (reduced ejection fraction group: < 50%; normal ejection fraction group: ≥ 50%). Then, correlations between the Lp(a) level and LVEF, as well as the impact of Lp(a) on mortality, were assessed.

RESULTS

This study included 436 patients with MI. The Lp(a) level and LVEF were significantly and negatively correlated (r = -0.407, β = -0.349, P < 0.001). The area under the receiver operating characteristic curve (ROC) indicated that an Lp(a) concentration > 455 mg/L was the best predictive value for reduced ejection fraction (AUC: 0.7694, P < 0.0001). The clinical endpoints did not differ based on the Lp(a) concentration. However, all-cause mortality and cardiac mortality differed based on LVEF.

CONCLUSIONS

These results suggest that an elevated Lp(a) concentration predicts reduced ejection fraction and that LVEF predicts all-cause mortality and cardiac mortality in patients with MI.

Lipoprotein(a) Does Not Predict Thrombotic Events and In-Hospital Outcomes in Patients with COVID-19

The prothrombotic and proinflammatory properties of lipoprotein(a) (Lp(a)) have been hypothesized to play a role in the pathogenesis of severe COVID-19; however, the prognostic impact of Lp(a) on the clinical course of COVID-19 remains controversial. This study aimed to investigate whether Lp(a) may be associated with biomarkers of thrombo-inflammation and the occurrence of thrombotic events or adverse clinical outcomes in patients hospitalized for COVID-19. We consecutively enrolled a cohort of patients hospitalized for COVID-19 and collected blood samples for Lp(a) assessment at hospital admission. A prothrombotic state was evaluated through D-dimer levels, whereas a proinflammatory state was evaluated through C-reactive protein (CRP), procalcitonin, and white blood cell (WBC) levels. Thrombotic events were marked by the diagnosis of deep or superficial vein thrombosis (DVT or SVT), pulmonary embolism (PE), stroke, transient ischemic attack (TIA), acute coronary syndrome (ACS), and critical limb ischemia (CLI). The composite clinical end point of intensive care unit (ICU) admission/in-hospital death was used to evaluate adverse clinical outcomes. Among 564 patients (290 (51%) men, mean age of 74 ± 17 years) the median Lp(a) value at hospital admission was 13 (10-27) mg/dL. During hospitalization, 64 (11%) patients were diagnosed with at least one thrombotic event and 83 (15%) patients met the composite clinical end point. Lp(a), as either a continuous or categorical variable, was not associated with D-dimer, CRP, procalcitonin, and WBC levels (p > 0.05 for all correlation analyses). In addition, Lp(a) was not associated with a risk of thrombotic events (p > 0.05 for multi-adjusted odds ratios) nor with a risk of adverse clinical outcomes (p > 0.05 for multi-adjusted hazard ratios). In conclusion, Lp(a) does not influence biomarkers of plasma thrombotic activity and systemic inflammation nor has any impact on thrombotic events and adverse clinical outcomes in patients hospitalized for COVID-19.

Lipoprotein(a) and stroke: a two-sample Mendelian randomization study

Background

To evaluate the causal relationship between lipoprotein(a) Lp(a) and stroke risk.

Method

Adopting two grand scale genome-wide association study (GWAS) databases, the instrumental variables were selected on the basis that the genetic loci met the criteria of being independent of each other and closely related to Lp(a). Summary-level data for outcomes, ischemic stroke and its subtypes were acquired from the UK Biobank and MEGASTROKE consortium databases. Two-sample MR analyses were achieved using inverse variance-weighted (IVW) meta-analysis (primary analysis), weighted median analysis, and the MR Egger regression method. Multivariable-adjusted Cox regression models were also used for observational analysis.

Result

Genetically predicted Lp(a) was marginally related with higher odds of total stroke (odds ratio (OR) [95% confidence intervals (CI)]: 1.003 [1.001-1.006], p = 0.010), ischemic stroke (OR [95% CI]: 1.004[1.001-1.007], p = 0.004), and large-artery atherosclerotic stroke (OR [95% CI]: 1.012 [1.004-1.019], p = 0.002) when the IVW estimator was used on the MEGASTROKE data. The associations of Lp(a) with stroke and ischemic stroke were also remarkable in the primary analysis using the UK Biobank data. Higher Lp(a) levels were also related with increased total stroke and ischemic stroke risk in the observational research data in the UK Biobank database.

Conclusion

Genetically predicted higher Lp(a) perhaps rise the risk of total stroke, ischemic stroke, and large-artery atherosclerotic stroke.

Prognostic impact of lipoprotein(a) in patients undergoing percutaneous coronary intervention modified by low density lipoprotein cholesterol

BACKGROUND

It is well established that lipoprotein(a)[Lp(a)] and low-density lipoprotein cholesterol (LDL-C) play a vital role in atherosclerosis. We investigated the prevalence and prognostic implications of increased Lp(a) in patients undergoing percutaneous coronary intervention (PCI) according to different LDL-C concentrations.

METHODS

A total of 9,190 patients with CAD after PCI were consecutively enrolled in the study and subsequently divided into three groups according to baseline LDL-C at cut-off of 70 and 100 mg/dl. Increased Lp(a) was defined as > 30 mg/dl. The primary endpoint was all-cause death. Second endpoint was cardiac death. Cox regression, Kaplan-Meier and Sensitivity analysis were performed.

RESULTS

During an average of 5.0 y of follow-up, 354 (3.9 %) patients experienced all-cause death with 213(2.3 %) of whom from cardiac death. Increased Lp(a) was present in 25.7 %, 34.2 %, and 40.6 % across the LDL-C < 70, 70-100 and≧100 mg/dl groups, respectively. After multivariate adjustment, Lp(a) elevation remained significantly associated with 5-y all-cause death (adjusted HR, 1.243; 95 % CI 1.001-1.544; p = 0.048) in the total cohort and only in those with LDL-C ≥ 100 mg/dl (adjusted HR, 1.642; 95 % CI 1.139-2.367; p = 0.008) when analyzed within each LDL-C category. Consistently with the results of associations between Lp(a) and cardiac death (adjusted HR, 1.534; 95 % CI 1.164-2.021; p = 0.002 for total cohort and adjusted HR, 2.404; 95 % CI 1.439-3.872; p < 0.001 for LDL-C ≥ 100 mg/dl). And this relationship holds after adjusting for LDL-Ccorr additionally. These findings are confirmed again in sensitivity analyses that excluded patients with Lp(a) concentrations in the top or the bottom 5 %.

CONCLUSIONS

We confirmed that increased Lp(a) was associated with increased risk of long-term outcomes, and such an association was modified by the baseline LDL-C concentrations. Screening of high Lp(a) in individuals with elevations of LDL-C may enables risk stratification for poor prognosis.

Absence of High Lipoprotein(a) Levels Is an Independent Predictor of Acute Myocardial Infarction without Coronary Lesions

The pathophysiological mechanisms underlying Myocardial Infarction with Non-Obstructive Coronary Artery Disease (MINOCA) are still under debate. Lipoprotein (a) [Lp(a)] has proinflammatory and prothrombotic actions and has been involved in the pathogenesis of atherosclerosis. However, no previous studies have linked Lp(a) levels with the probability of developing MINOCA. Moreover, the relationship between MINOCA and the plasma levels of other proatherogenic and proinflammatory molecules such as Interleukin-18 (IL18) and proprotein convertase subtilisin/kexin type 9 (PCSK9) has not been studied. We conducted a prospective, multicenter study involving 1042 patients with acute myocardial infarction (AMI). Seventy-six patients had no significant coronary lesions. All patients underwent plasma analysis on admission. MINOCA patients were younger (57 (47-68) vs. 61 (52-72) years; p = 0.010), more frequently female (44.7% vs. 21.0%; p < 0.001), and had lower rates of diabetes and of Lp(a) > 60 mg/dL (9.2% vs. 19.8%; p = 0.037) than those with coronary lesions; moreover, High Density Lipoprotein cholesterol (HDL-c) levels were higher in MINOCA patients. The absence of Lp(a) > 60 mg/dL and of diabetes were independent predictors of MINOCA, as well as female sex, high HDL-c levels, and younger age. IL-18 and PCSK9 levels were not predictors of MINOCA. During a follow-up of 5.23 (2.89, 7.37) years, the independent predictors of the primary outcome (acute ischemic events or death) in the whole sample were Lp(a) > 60 mg/dL, older age, low estimated Glomerular Filtration rate (eGFR), hypertension, previous heart failure (HF), coronary artery bypass graft, use of insulin, and no therapy with acetylsalicylic acid. In conclusion, in AMI patients, the absence of high Lp(a) levels, as well high HDL-c levels, were independent predictors of the inexistence of coronary artery disease. High Lp (a) levels were also an independent predictor of ischemic events or death.

Lipoprotein(a) in Atherosclerotic Diseases: From Pathophysiology to Diagnosis and Treatment

Lipoprotein(a) (Lp(a)) is a low-density lipoprotein (LDL) cholesterol-like particle bound to apolipoprotein(a). Increased Lp(a) levels are an independent, heritable causal risk factor for atherosclerotic cardiovascular disease (ASCVD) as they are largely determined by variations in the Lp(a) gene (LPA) locus encoding apo(a). Lp(a) is the preferential lipoprotein carrier for oxidized phospholipids (OxPL), and its role adversely affects vascular inflammation, atherosclerotic lesions, endothelial function and thrombogenicity, which pathophysiologically leads to cardiovascular (CV) events. Despite this crucial role of Lp(a), its measurement lacks a globally unified method, and, between different laboratories, results need standardization. Standard antilipidemic therapies, such as statins, fibrates and ezetimibe, have a mediocre effect on Lp(a) levels, although it is not yet clear whether such treatments can affect CV events and prognosis. This narrative review aims to summarize knowledge regarding the mechanisms mediating the effect of Lp(a) on inflammation, atherosclerosis and thrombosis and discuss current diagnostic and therapeutic potentials.

Impact of anti-oestrogen therapy on lipoprotein(a) in postmenopausal women: a systematic review and meta-analysis of double-blind placebo-controlled clinical studies

PURPOSE

The potential mechanisms of endocrine therapy for thrombosis remain currently unclear, and more studies are warranted for further investigation and elucidation. However, high plasma concentration of lipoprotein(a) (Lp(a)) is a recognized prothrombotic factor. The aim of our study was to systematically evaluate the effect of different anti-oestrogen therapy on plasma Lp(a) level in postmenopausal women.

METHODS

A systematic literature search was conducted in multiple electronic databases to identify the randomized, double-blind, placebo-controlled clinical studies on this topic. Effect size for changes in Lp(a) was expressed as mean difference (MD) and 95% confidence intervals (CI).

RESULTS

Data were pooled from 10 clinical trials comprising 24 treatment arms, which included 2049 women (1128 women in the active-treated arms and 921 women in the control arms). Meta-analysis of data suggested that anti-oestrogen therapy in women significantly reduced Lp(a) [MD = -5.92% (95%CI: -9.05%,-2.8%)].

CONCLUSIONS

This observation is of both clinical and pathophysiological relevance, also in view that the identification of molecular determinants and cellular pathways implicated in Lp(a) synthesis and metabolism is still of concern as a critical issue in lipidology and CV prevention.

Association between lipoprotein(a) and thromboembolism in patients with non-valvular atrial fibrillation: a cross-sectional study

BACKGROUND

Lipoprotein(a) [Lp(a)] is a recognized risk factor for ischemic stroke (IS); however, its role in thromboembolism in patients with non-valvular atrial fibrillation (NVAF) remains controversial. We aimed to assess the association of Lp(a) and IS and systemic embolism (SEE) in NVAF patients.

METHODS

In total, 16,357 patients with NVAF were recruited from the First Affiliated Hospital of Xinjiang Medical University from January 1, 2009, to December 31, 2021, and were divided into groups based on Lp(a) quartiles. Logistic regression models analyzed the association between Lp(a), IS, and SEE. The restriction cubic spline was used to assess the potential nonlinear relationship between Lp(a), IS, and SEE. We conducted subgroup analyses and estimated the multiplicative interaction between the stratified variables and Lp(a) to investigate whether the association between Lp(a) and IS and SEE was affected by age, sex, anticoagulants, and CHA₂DS₂-VASc score.

RESULTS

We identified 1319 IS and 133 SEE events. After correcting for CHA₂DS₂-VASc score and other potential confounders, each 1-standard deviation (SD) increase in log-Lp(a) was related to a 23% increased risk of IS (odds ratios [OR], 1.23; 95% confidence intervals [CI], 1.07-1.41). NVAF patients in the highest Lp(a) quartile were 1.23-fold more likely to have IS than those in the lowest quartile (OR, 1.23; 95% CI, 1.04-1.45). A positive linear relationship between Lp(a) and IS risk was observed (P for nonlinear = 0.341). In the fully adjusted model, subjects had a 1.78-fold increased risk of SEE for each 1-SD increase in log-Lp(a) (OR, 2.78; 95% CI, 1.78-4.36). Subjects in the highest Lp(a) quartile had a 2.38-fold elevated risk of SEE (OR, 3.38; 95% CI, 1.85-6.19) compared with the lowest quartile. Furthermore, Lp(a) had a nonlinear relationship with the risk of SEE (P for nonlinear = 0.005).

CONCLUSIONS

Elevated Lp(a) concentration was significantly associated with IS and SEE, suggesting that Lp(a) may be an emerging biomarker that can help clinicians identify patients at high risk of thromboembolism in this population.

The Effect of Bariatric Surgery on Circulating Levels of Lipoprotein (a): A Meta-analysis

Background

Obesity, especially severe obesity, is associated with a higher risk of atherosclerotic cardiovascular disease (ASCVD) morbidity and mortality. Bariatric surgery is a durable and effective weight loss therapy for patients with severe obesity and weight-related comorbidities. Elevated plasma levels of lipoprotein (a) (Lp(a)) are causally associated with ASCVD. The aim of this meta-analysis was to analyze whether bariatric surgery is associated with Lp(a) concentrations.

Methods

A literature search in PubMed, Scopus, Embase, and Web of Science was performed from inception to May 1st, 2021. A random-effects model and the generic inverse variance weighting method were used to compensate for the heterogeneity of studies in terms of study design, treatment duration, and the characteristics of the studied populations. A random-effects metaregression model was used to explore the association with an estimated effect size. Evaluation of funnel plot, Begg's rank correlation, and Egger's weighted regression tests were used to assess the presence of publication bias in the meta-analysis.

Results

Meta-analysis of 13 studies including 1551 patients showed a significant decrease of circulating Lp(a) after bariatric surgery (SMD: -0.438, 95% CI: -0.702, -0.174, p < 0.001, I²: 94.05%). The results of the metaregression did not indicate any significant association between the changes in Lp(a) and duration of follow-up after surgery, reduction in body mass index, or baseline Lp(a) concentration. The reduction in circulating Lp(a) was robust in the leave-one-out sensitivity analysis.

Conclusion

Bariatric surgery significantly decreases circulating Lp(a) concentrations. This decrease may have a positive effect on ASCVD in obese patients.

Non-Lipid Effects of PCSK9 Monoclonal Antibodies on Vessel Wall

Elevated low density lipoprotein (LDL) cholesterol and lipoprotein(a) (Lp(a)) levels have an important role in the development and progression of atherosclerosis, followed by cardiovascular events. Besides statins and other lipid-modifying drugs, PCSK9 monoclonal antibodies are known to reduce hyperlipidemia. PCSK9 monoclonal antibodies decrease LDL cholesterol levels through inducing the upregulation of the LDL receptors and moderately decrease Lp(a) levels. In addition, PCSK9 monoclonal antibodies have shown non-lipid effects. PCSK9 monoclonal antibodies reduce platelet aggregation and activation, and increase platelet responsiveness to acetylsalicylic acid. Evolocumab as well as alirocumab decrease an incidence of venous thromboembolism, which is associated with the decrease of Lp(a) values. Besides interweaving in haemostasis, PCSK9 monoclonal antibodies play an important role in reducing the inflammation and improving the endothelial function. The aim of this review is to present the mechanisms of PCSK9 monoclonal antibodies on the aforementioned risk factors.

Assessment of Associations Between Serum Lipoprotein (a) Levels and Atherosclerotic Vascular Diseases in Hungarian Patients With Familial Hypercholesterolemia Using Data Mining and Machine Learning

Background and aims: Premature mortality due to atherosclerotic vascular disease is very high in Hungary in comparison with international prevalence rates, though the estimated prevalence of familial hypercholesterolemia (FH) is in line with the data of other European countries. Previous studies have shown that high lipoprotein(a)- Lp(a) levels are associated with an increased risk of atherosclerotic vascular diseases in patients with FH. We aimed to assess the associations of serum Lp(a) levels and such vascular diseases in FH using data mining methods and machine learning techniques in the Northern Great Plain region of Hungary.

Methods: Medical records of 590,500 patients were included in our study. Based on the data from previously diagnosed FH patients using the Dutch Lipid Clinic Network scores (≥7 was evaluated as probable or definite FH), we trained machine learning models to identify FH patients.

Results: We identified 459 patients with FH and 221 of them had data available on Lp(a). Patients with FH had significantly higher Lp(a) levels compared to non-FH subjects [236 (92.5; 698.5) vs. 167 (80.2; 431.5) mg/L, p < .01]. Also 35.3% of FH patients had Lp(a) levels >500 mg/L. Atherosclerotic complications were significantly more frequent in FH patients compared to patients without FH (46.6 vs. 13.9%). However, contrary to several other previous studies, we could not find significant associations between serum Lp(a) levels and atherosclerotic vascular diseases in the studied Hungarian FH patient group.

Conclusion: The extremely high burden of vascular disease is mainly explained by the unhealthy lifestyle of our patients (i.e., high prevalence of smoking, unhealthy diet and physical inactivity resulting in obesity and hypertension). The lack of associations between serum Lp(a) levels and atherosclerotic vascular diseases in Hungarian FH patients may be due to the high prevalence of these risk factors, that mask the deleterious effect of Lp(a).

Association between new markers of cardiovascular risk and hepatic insulin resistance in those at high risk of developing type 2 diabetes

AIM/HYPOTHESIS

Hepatic insulin resistance (HIR) is considered to be an independent predictor of metabolic disorders and plays an important role in systemic inflammation, which contributes to abnormalities in cardiovascular disease (CVD) risk factors. The aim of this study was to investigate the relationship between HIR and new markers of cardiovascular risks, including leptin/adiponectin ratio (L/A), lipoprotein(a) [Lp(a)], and tumor necrosis factor alpha (TNF-α), at comparable whole body insulin sensitivity in non-diabetic individuals with or without CVD and at high risk of developing type 2 diabetes.

METHODS

The HIR index, L/A, Lp(a), and TNF-α were measured in 50 participants with CVD and in 200 without CVD (1:4 ratio). These were also matched for the homeostatic model assessment for insulin resistance (HOMA-IR) and Matsuda-insulin sensitivity index (ISI) in an observational study design.

RESULTS

The HIR index (1.52 ± 0.14 vs. 1.45 ± 0.17, p < 0.02), L/A (3.22 ± 3.10 vs. 2.09 ± 2.27, p < 0.004), and levels of Lp(a) (66.6 ± 49.5 vs. 37.9 ± 3 6.8 mg/dL, p < 0.0001) and TNF-α (18.9 ± 21.8 vs. 5.4 ± 7.1 pg/mL, p < 0.0001) were higher in those with CVD than those without CVD. HOMA-IR and ISI were not significantly different (p = 0.88 and p = 0.35, respectively). The HIR index was directly correlated with L/A (r = 0.41, p < 0.0001), Lp(a) (r = 0.20, p < 0.002), TNF- α (r = 0.14, p < 0.03), and diastolic blood pressure (DBP) (r = 0.13, p < 0.03). The stepwise model analysis showed that L/A, Lp(a), and TNF-α explained about 20% of the variation in the HIR indices of all the participants (p < 0.02).

CONCLUSIONS/INTERPRETATIONS

Our results suggest a positive association between HIR and new markers of cardiovascular risk [L/A, Lp(a), and TNF- α] at comparable whole body insulin sensitivity in those with or without CVD and at high risk of developing type 2 diabetes.

Lipoprotein(a) and aortic valve stenosis: A casual or causal association?

AIMS

This review aims to provide an update of available methods for imaging calcification activity and potential therapeutic options.

DATA SYNTHESIS

Aortic valve calcification represents the most common heart valve condition requiring treatment among adults in Western societies. No medical therapies are proven to be effective in treating symptoms or reducing disease progression. Therefore, surgical or transcatheter aortic valve replacement remains the only available treatment option. Elevated circulating concentrations of lipoprotein(a) is strongly associated with degenerative aortic stenosis. This relationship was first observed in prospective observational studies, and the causal relationship was confirmed in genetic studies.

CONCLUSIONS

New therapeutic targets have been identified and new imaging techniques could be used to test the effectiveness of new agents and further clarify the pathophysiology of AVS. No therapy that specifically lowers Lp (a) levels has been approved for clinical use.

Lipoprotein(a)—The Crossroads of Atherosclerosis, Atherothrombosis and Inflammation

Increased lipoprotein(a) (Lp(a)) levels are an independent predictor of coronary artery disease (CAD), degenerative aortic stenosis (DAS), and heart failure independent of CAD and DAS. Lp(a) levels are genetically determinated in an autosomal dominant mode, with great intra- and inter-ethnic diversity. Most variations in Lp(a) levels arise from genetic variations of the gene that encodes the apolipoprotein(a) component of Lp(a), the LPA gene. LPA is located on the long arm of chromosome 6, within region 6q2.6–2.7. Lp(a) levels increase cardiovascular risk through several unrelated mechanisms. Lp(a) quantitatively carries all of the atherogenic risk of low-density lipoprotein cholesterol, although it is even more prone to oxidation and penetration through endothelia to promote the production of foam cells. The thrombogenic properties of Lp(a) result from the homology between apolipoprotein(a) and plasminogen, which compete for the same binding sites on endothelial cells to inhibit fibrinolysis and promote intravascular thrombosis. LPA has up to 70% homology with the human plasminogen gene. Oxidized phospholipids promote differentiation of pro-inflammatory macrophages that secrete pro-inflammatory cytokines (e. g., interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α). The aim of this review is to define which of these mechanisms of Lp(a) is predominant in different groups of patients.

High lipoprotein(a) is associated with major adverse limb events after femoral artery endarterectomy

BACKGROUNDS AND AIMS

Elevated lipoprotein(a) (Lp[a]) has been identified as a causal risk factor for cardiovascular disease including peripheral arterial disease (PAD). Although Lp(a) is associated with the diagnosis of PAD, it remains elusive whether there is an association of Lp(a) with cardiovascular and limb events in patients with severe PAD.

METHODS

Preoperative plasma Lp(a) levels were measured in 384 consecutive patients that underwent iliofemoral endarterectomy and were included in the Athero-Express biobank. Our primary objective was to assess the association of Lp(a) levels with Major Adverse Limb Events (MALE). Our secondary objective was to relate Lp(a) levels to Major Adverse Cardiovascular Events (MACE) and femoral plaque composition that was acquired from baseline surgery.

RESULTS

During a median follow-up time of 5.6 years, a total of 225 MALE were recorded in 132 patients. Multivariable analysis, including history of peripheral intervention, age, diabetes mellitus, end stage renal disease and PAD disease stages, showed that Lp(a) was independently associated with first (HR of 1.36 (95% CI 1.02-1.82) p = .036) and recurrent MALE (HR 1.36 (95% CI 1.10-1.67) p = .004). A total of 99 MACE were recorded but Lp(a) levels were not associated with MACE.sLp(a) levels were significantly associated with a higher presence of smooth muscle cells in the femoral plaque, although this was not associated with MALE or MACE.

CONCLUSIONS

Plasma Lp(a) is independently associated with first and consecutive MALE after iliofemoral endarterectomy. Hence, in patients who undergo iliofemoral endarterectomy, Lp(a) could be considered as a biomarker to enhance risk stratification for future MALE.

PoLA/CFPiP/PCS/PSLD/PSD/PSH guidelines on diagnosis and therapy of lipid disorders in Poland 2021

In Poland there are still nearly 20 million individuals with hypercholesterolaemia, most of them are unaware of their condition; that is also why only ca. 5% of patients with familial hypercholesterolaemia have been diagnosed; that is why other rare cholesterol metabolism disorders are so rarely diagnosed in Poland. Let us hope that these guidelines, being an effect of work of experts representing 6 main scientific societies, as well as the network of PoLA lipid centers being a part of the EAS lipid centers, certification of lipidologists by PoLA, or the growing number of centers for rare diseases, with a network planned by the Ministry of Health, improvements in coordinated care for patients after myocardial infarction (KOS-Zawał), reimbursement of innovative agents, as well as introduction in Poland of an effective primary prevention program, will make improvement in relation to these unmet needs in diagnostics and treatment of lipid disorders possible.

Principal predictors of major adverse limb events in diabetic peripheral artery disease: A narrative review

Background and aims

The increasing prevalence of diabetes mellitus is causing a massive growth of peripheral artery disease incidences, a disabling complication of diabetic atherosclerosis, which leads often to the amputation of the affected limb. Critical limb ischemia is the terminal disease stage, which requires a prompt intervention to relieve pain and save limbs. However, patients undergoing revascularization often suffer from cardiovascular, cerebrovascular and major adverse limb events with poor outcomes. Furthermore, the same procedure performed in apparently similar patients has various outcomes and lack of an outcome predictive support causes a high lower limb arterial revascularization rate with disastrous effects for patients. We collected the main risk factors of major adverse limb events in a more readable and immediate format of the topic, to propose an overview of parameters to manage effectively peripheral artery disease patients and to propose basics of a new predictive tool to prevent from disabling vascular complications of the disease.

Methods

Most recent and updated literature about the prevalence of major adverse limb events in peripheral artery disease was reviewed to identify possible main predictors.

Results

In this article, we summarized major risk factors of limb revascularization failure and disabling vascular complications collecting those parameters principally responsible for major adverse limb events, which provides physio-pathological explanation of their role in peripheral artery disease.

Conclusion

We evaluated and listed a panel of possible predictors of MALE (Major Adverse Limb Event) in order to contribute to the development of a predictive score, based on a summary of the main risk factors reported in scientific articles, which could improve the management of peripheral artery disease by preventing vascular accidents.

Prevalence of dyslipidemia and gene polymorphisms of ABCB1 and SLCO1B1 in Han, Uygur, Kazak, Hui, Tatar, Kirgiz, and Sibe populations with coronary heart disease in Xinjiang, China

Background

Dyslipidemia is a predisposing factor for coronary heart disease (CHD). High-intensity statin therapy is recommended as secondary prevention. ABCB1 and SLCO1B1 genes influence the efficacy and safety of statins. Xinjiang is a multi-ethnic area; however, little is known about the prevalence of dyslipidemia and gene polymorphisms of ABCB1 and SLCO1B1 in minority groups with CHD.

Objective

To measure levels of lipid and apolipoprotein and the prevalence of dyslipidemia and gene polymorphisms of ABCB1, SLCO1B1 in Han, Uygur, Kazak, Hui, Tatar, Kirgiz, and Sibe populations with CHD in Xinjiang.

Methods

This descriptive retrospective study compares lipid levels in ethnic groups using Kruskal-Wallis test or analysis of variance. The study compared gene polymorphisms and the prevalence of dyslipidemia among different ethnic groups using the chi-square test. The lipid profiles in plasma were measured before lipid-lowering therapy using commercially available kits. Genotyping of SLCO1B1 and ABCB1 variants was performed using sequencing by hybridization.

Results

A total of 2218 patients were successfully screened, including 1044 Han, 828 Uygur, 113 Kazak, 138 Hui, 39 Tatar, 36 Kirgiz, and 20 Sibe patients. The overall mean age was 61.8 ± 10.8 years, and 72.5% of participants were male. Dyslipidemia prevalence in these ethnic groups was 42.1, 49.8, 52.2, 40.6, 48.7, 41.7, and 45.0%, respectively. The prevalence of dyslipidemia, high total cholesterol (TC), high triglycerides (TG), and high low density lipoprotein cholesterol (LDL-C) differed significantly among the groups (P = 0.024; P < 0.001; P < 0.001; P < 0.001, respectively). For the Han group, high LDL-C, high TC, and high TG prevalence differed significantly by gender (P = 0.001, P = 0.022, P = 0.037, respectively). The prevalence of high TC, high TG, and low high density lipoprotein cholesterol (HDL-C) differed significantly by gender in the Uygur group (P = 0.006, P = 0.004, P < 0.001, respectively). The prevalence of high TC in Hui patients significantly differed by gender (P = 0.043). These findings suggest that polymorphisms in ABCB1 and C3435T differ significantly across ethnicities (P < 0.001).

Conclusions

The prevalences of dyslipidemia, high TC, high TG, and high LDL-C in Han, Uygur, Kazak, Hui, Tatar, Kirgiz, and Sibe CHD patients in Xinjiang differed concerning ethnicity. Ethnic, gender, and lifestyle were the key factors that affected the lipid levels of the population. The prevalence of polymorphisms of ABCB1 and C3435T significantly differed across ethnicities. These findings will aid the selection of precision lipid-lowering medications and prevention and treatment of CHD according to ethnicity in Xinjiang.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01544-3.

Targetting ferroptosis for blood cell-related diseases

Ferroptosis is an iron-dependent cell death pathway and participates in various diseases. Current evidence suggests that ferroptosis can obviously affect the function of blood cells. This paper aims to elaborate the role of ferroptosis in blood cells and related diseases. First, abnormal ferroptosis damages the developing red blood cells by breaking systemic iron homeostasis, leading to erythropoiesis suppression and anaemia. Ferroptosis mediates neutrophils recruitment and neutrophil extracellular trap formation (NETosis). In T-cells, ferroptosis induces a novel point of synergy between immunotherapy and radiotherapy. Additionally, ferroptosis may mediate B cells differentiation, antibody responses and lymphoma. Nevertheless, increased ferroptosis can ameliorate acute myeloid leukaemia and T-cell leukaemia/lymphoma by inducing iron-dependent cancer cells death. Besides, ferroptosis activates platelets by increasing P-selectin, thus causing thromboembolism. Ferroptosis mediates virus infection and parasite infection by driving T-cell death and preventing T-cell immunity. Interestingly, ferroptosis is also considered as a critical player in COVID-19 infections, while targetting ferroptosis may also improve thromboembolism and prognosis in patients with COVID-19 infection. Overall, the crucial role of ferroptosis in blood cells will show a new therapeutic potential in blood cell-related diseases.HighlightsFerroptosis shows a new therapeutic potential for blood cell-related diseases.Ferroptosis damages erythropoiesis and thus induces anaemia.Ferroptosis induces platelet activation and leads to thromboembolism.Ferroptosis regulates T-cell and B-cell immunity, which participant in infectious diseases.Inversely, ferroptosis ameliorates acute myeloid leukaemia and T-cell leukaemia.

Lipids and Lipoproteins in Health and Disease: Focus on Targeting Atherosclerosis

Despite advances in pharmacotherapy, intervention devices and techniques, residual cardiovascular risks still cause a large burden on public health. Whilst most guidelines encourage achieving target levels of specific lipids and lipoproteins to reduce these risks, increasing evidence has shown that molecular modification of these lipoproteins also has a critical impact on their atherogenicity. Modification of low-density lipoprotein (LDL) by oxidation, glycation, peroxidation, apolipoprotein C-III adhesion, and the small dense subtype largely augment its atherogenicity. Post-translational modification by oxidation, carbamylation, glycation, and imbalance of molecular components can reduce the capacity of high-density lipoprotein (HDL) for reverse cholesterol transport. Elevated levels of triglycerides (TGs), apolipoprotein C-III and lipoprotein(a), and a decreased level of apolipoprotein A-I are closely associated with atherosclerotic cardiovascular disease. Pharmacotherapies aimed at reducing TGs, lipoprotein(a), and apolipoprotein C-III, and enhancing apolipoprotein A-1 are undergoing trials, and promising preliminary results have been reported. In this review, we aim to update the evidence on modifications of major lipid and lipoprotein components, including LDL, HDL, TG, apolipoprotein, and lipoprotein(a). We also discuss examples of translating findings from basic research to potential therapeutic targets for drug development.

Lipoprotein (a) level as a risk factor for stroke and its subtype: A systematic review and meta-analysis

The role of lipoprotein-A [Lp (a)] as a risk factor for stroke is less well documented than for coronary heart disease. Hence, we conducted a systematic review and meta-analysis for the published observational studies in order to investigate the association of Lp (a) levels with the risk of stroke and its subtypes. In our meta-analysis, 41 studies involving 7874 ischemic stroke (IS) patients and 32,138 controls; 13 studies for the IS subtypes based on TOAST classification and 7 studies with 871 Intracerebral hemorrhage (ICH) cases and 2865 control subjects were included. A significant association between increased levels of Lp (a) and risk of IS as compared to control subjects was observed (standardized mean difference (SMD) 0.76; 95% confidence interval (CIs) 0.53-0.99). Lp (a) levels were also found to be significantly associated with the risk of large artery atherosclerosis (LAA) subtype of IS (SMD 0.68; 95% CI 0.01-1.34) as well as significantly associated with the risk of ICH (SMD 0.65; 95% CI 0.13-1.17) as compared to controls. Increased Lp (a) levels could be considered as a predictive marker for identifying individuals who are at risk of developing IS, LAA and ICH.

Relationship between lipoproteins, thrombosis and atrial fibrillation

The prothrombotic state in atrial fibrillation (AF) occurs as a result of multifaceted interactions, known as Virchow’s triad of hypercoagulability, structural abnormalities, and blood stasis. More recently, there is emerging evidence that lipoproteins are implicated in this process, beyond their traditional role in atherosclerosis. In this review, we provide an overview of the various lipoproteins and explore the association between lipoproteins and AF, the effects of lipoproteins on haemostasis, and the potential contribution of lipoproteins to thrombogenesis in AF. There are several types of lipoproteins based on size, lipid composition, and apolipoprotein category, namely: chylomicrons, very low-density lipoprotein, low-density lipoprotein (LDL), intermediate-density lipoprotein, and high-density lipoprotein. Each of these lipoproteins may contain numerous lipid species and proteins with a variety of different functions. Furthermore, the lipoprotein particles may be oxidized causing an alteration in their structure and content. Of note, there is a paradoxical inverse relationship between total cholesterol and LDL cholesterol (LDL-C) levels, and incident AF. The mechanism by which this occurs may be related to the stabilizing effect of cholesterol on myocardial membranes, along with its role in inflammation. Overall, specific lipoproteins may interact with haemostatic pathways to promote excess platelet activation and thrombin generation, as well as inhibiting fibrinolysis. In this regard, LDL-C has been shown to be an independent risk factor for thromboembolic events in AF. The complex relationship between lipoproteins, thrombosis and AF warrants further research with an aim to improve our knowledge base and contribute to our overall understanding of lipoprotein-mediated thrombosis.

On the present and future role of Lp-PLA2 in atherosclerosis-related cardiovascular risk prediction and management

Circulating concentration and activity of secretory phospholipase A₂ (sPLA₂) and lipoprotein-associated phospholipase A₂ (Lp-PLA₂) have been proven as biomarkers of increased risk of atherosclerosis-related cardiovascular disease (ASCVD). Lp-PLA₂ might be part of the atherosclerotic process and may contribute to plaque destabilisation through inflammatory activity within atherosclerotic lesions. However, all attempts to translate the inhibition of phospholipase into clinically beneficial ASCVD risk reduction, including in randomised studies, by either non-specific inhibition of sPLA₂ (by varespladib) or specific Lp-PLA₂ inhibition by darapladib, unexpectedly failed. This gives us a strong imperative to continue research aimed at a better understanding of how Lp-PLA₂ and sPLA₂ regulate vascular inflammation and atherosclerotic plaque development. From the clinical viewpoint there is a need to establish and validate the existing and emerging novel anti-inflammatory therapeutic strategies to fight against ASCVD development, by using potentially better animal models and differently designed clinical trials in humans.

The cholesterol-lowering effect of unripe Rubus coreanus is associated with decreased oxidized LDL and apolipoprotein B levels in subjects with borderline-high cholesterol levels: a randomized controlled trial

BACKGROUND

Rubus coreanus (R. coreanus) possesses properties that may decrease cholesterol levels.

METHODS

The effects of unripe R. coreanus (uRC) consumption on low-density lipoprotein (LDL) and total cholesterol levels related to decreased circulating apolipoprotein (Apo) B and oxidized LDL levels were evaluated. This randomized, double-blind, placebo-controlled study included subjects with borderline-high cholesterol levels (between 200 and 239 mg/dL) who consumed one capsule daily containing 600 mg of freeze-dried uRC extract (n = 39) or the placebo (n = 38).

RESULTS

After 12 weeks, the uRC group showed reductions of 21.23 ± 4.36 mg/dL in total cholesterol levels (P = 0.007) and 15.61 ± 4.16 mg/dL in LDL cholesterol levels (P = 0.032). In addition, significantly greater reductions in Apo B levels were observed in the uRC group (- 3.48 ± 3.40 mg/dL), but Apo B levels were increased in the placebo group (6.21 ± 2.84 mg/dL; P = 0.032). Furthermore, a remarkably lower oxidized LDL level was detected in the uRC group (57.76 ± 2.07 U/L) than in the placebo group (66.09 ± 3.47 U/L) after 12 weeks of consumption (P = 0.044).

CONCLUSIONS

Because of its cholesterol-lowering effect, uRC shows great promise as a therapeutic agent for subjects with borderline-high total blood cholesterol levels.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03649620 (8/28/2018, retrospectively registered).

Lipoprotein(a) Lowering-From Lipoprotein Apheresis to Antisense Oligonucleotide Approach

It is well-known that elevated lipoprotein(a)—Lp(a)—levels are associated with a higher risk of cardiovascular (CV) mortality and all-cause mortality, although a standard pharmacotherapeutic approach is still undefined for patients with high CV risk dependent on hyperlipoproteinemia(a). Combined with high Lp(a) levels, familial hypercholesterolemia (FH) leads to a greater CVD risk. In suspected FH patients, the proportion of cases explained by a rise of Lp(a) levels ranges between 5% and 20%. In the absence of a specific pharmacological approach able to lower Lp(a) to the extent required to achieve CV benefits, the most effective strategy today is lipoprotein apheresis (LA). Although limited, a clear effect on Lp(a) is exerted by PCSK9 antagonists, with apparently different mechanisms when given with statins (raised catabolism) or as monotherapy (reduced production). In the era of RNA-based therapies, a new dawn is represented by the use of antisense oligonucleotides APO(a)L_rx, able to reduce Lp(a) from 35% to over 80%, with generally modest injection site reactions. The improved knowledge of Lp(a) atherogenicity and possible prevention will be of benefit for patients with residual CV risk remaining after the most effective available lipid-lowering agents.

Increased APOE glycosylation plays a key role in the atherogenicity of L5 low-density lipoprotein

Low-density lipoprotein (LDL) is heterogeneous, composed of particles with variable atherogenicity. Electronegative L5 LDL exhibits atherogenic properties in vitro and in vivo, and its levels are elevated in patients with increased cardiovascular risk. Apolipoprotein E (APOE) content is increased in L5, but what role APOE plays in L5 function remains unclear. Here, we characterized the contributions of APOE posttranslational modification to L5's atherogenicity. Using two-dimensional electrophoresis and liquid chromatography-mass spectrometry, we studied APOE's posttranslational modification in L5 from human plasma. APOE structures with various glycan residues were predicted. Molecular docking and molecular dynamics simulation were performed to examine the functional changes of APOE resulting from glycosylation. We also examined the effects of L5 deglycosylation on endothelial cell apoptosis. The glycan sequence N-acetylgalactosamine, galactose, and sialic acid was consistently expressed on serine 94, threonine 194, and threonine 289 of APOE in L5 and was predicted to contribute to L5's negative surface charge and hydrophilicity. The electrostatic force between the negatively charged sialic acid-containing glycan residue of APOE and positively charged amino acids at the receptor-binding area suggested that glycosylation interferes with APOE's attraction to receptors, lipid-binding ability, and lipid transportation and metabolism functions. Importantly, L5 containing glycosylated APOE induced apoptosis in cultured endothelial cells through lectin-like oxidized LDL receptor-1 (LOX-1) signaling, and glycosylation removal from L5 attenuated L5-induced apoptosis. APOE glycosylation may contribute to the atherogenicity of L5 and be a useful biomarker for rapidly quantifying L5.

What do we know about the role of lipoprotein(a) in atherogenesis 57 years after its discovery?

Elevated circulating concentrations of lipoprotein(a) [Lp(a)] is strongly associated with increased risk of atherosclerotic cardiovascular disease (CVD) and degenerative aortic stenosis. This relationship was first observed in prospective observational studies, and the causal relationship was confirmed in genetic studies. Everybody should have their Lp(a) concentration measured once in their lifetime. CVD risk is elevated when Lp(a) concentrations are high i.e. > 50 mg/dL (≥100 mmol/L). Extremely high Lp(a) levels >180 mg/dL (≥430 mmol/L) are associated with CVD risk similar to that conferred by familial hypercholesterolemia. Elevated Lp(a) level was previously treated with niacin, which exerts a potent Lp(a)-lowering effect. However, niacin is currently not recommended because, despite the improvement in lipid profile, no improvements on clinical outcomes have been observed. Furthermore, niacin use has been associated with severe adverse effects. Post hoc analyses of clinical trials with proprotein convertase subtilisin/kexin type-9 (PCSK9) inhibitors have shown that these drugs exert clinical benefits by lowering Lp(a), independent of their potent reduction of low-density lipoprotein cholesterol (LDL-C). It is not yet known whether PCSK9 inhibitors will be of clinical use in patients with elevated Lp(a). Apheresis is a very effective approach to Lp(a) reduction, which reduces CVD risk but is invasive and time-consuming and is thus reserved for patients with very high Lp(a) levels and progressive CVD. Studies are ongoing on the practical application of genetic approaches to therapy, including antisense oligonucleotides against apolipoprotein(a) and small interfering RNA (siRNA) technology, to reduce the synthesis of Lp(a).

Association between lipoprotein(a) concentration and the risk of stroke in the Chinese Han population: a retrospective case-control study

Background

Lipoprotein(a) [Lp(a)] is a risk factor of coronary heart disease, however, its effects on stroke are less well-defined.

Methods

We performed a single-center, retrospective case-control study in 1,953 and 196 ischemic stroke and hemorrhagic stroke in-hospital patients, respectively. Controls were healthy individuals that were matched for sex and age (±5 years) for the ischemic (1:1 ratio) and hemorrhagic (1:2 ratio) stroke. Lp(a) concentration was measured using the latex agglutination turbidimetric method. Logarithmic transformation and quartile categorization were applied to adjust for the skewed distribution of Lp(a). Conditional logistic regression models were used to assess the association between Lp(a) and stroke risk.

Results

Median Lp(a) concentration was higher in stroke patients when compared with controls (12.2 vs. 8.60 mg/dL) and hemorrhagic strokes (14.40 vs. 13.40 mg/dL). The conditional multivariate analysis revealed a positive association between Lp(a) and ischemic stroke (OR =2.03, 2.36, and 2.03 for quartiles 2, 3 and 4, respectively, vs. quartile 1; P<0.001). In addition, elevated Lp(a) was also significantly associated with increased hemorrhagic stroke risk, after adjusted for potential covariates (OR =1.93, 3.24, and 2.19 for quartile 2, 3 and 4 respectively vs. quartile 1, P<0.05). The stratified analyses for ischemic and hemorrhagic stroke revealed significant association between elevated log-transformed Lp(a) and ischemic stroke in men. Furthermore, there was a trend towards a higher stroke risk for younger patients compared with older patients.

Conclusions

Elevated serum Lp(a) is significantly positively correlated with ischemic and hemorrhagic stroke risk in the Chinese Han population, especially among men and younger patients.

Calcific Aortic Valve Stenosis and Atherosclerotic Calcification

PURPOSE OF REVIEW

This review summarizes the pathophysiology of calcific aortic valve stenosis (CAVS) and surveys relevant clinical data and basic research that explain how CAVS arises.

RECENT FINDINGS

Lipoprotein(a) [Lp(a)], lipoprotein-associated phospholipase A2 (Lp-PLA2), oxidized phospholipids (OxPL), autotaxin, and genetic driving forces such as mutations in LPA gene and NOTCH gene seem to play a major role in the development of CAVS. These factors might well become targets of medical therapy in the coming years. CVAS seems to be a multifactorial disease that has much in common with coronary artery disease, mainly regarding lipidic accumulation and calcium deposition. No clinical trials conducted to date have managed to answer the key question of whether Lp(a) lowering and anti-calcific therapies confer a benefit in terms of reducing incidence or progression of CAVS, although additional outcome trials are ongoing.

Lipoprotein apheresis is an optimal therapeutic option to reduce increased Lp(a) levels

BACKGROUND

Lipoprotein(a) (Lp(a)) is a genetic risk factor for cardiovascular disease (CVD) and is associated with the induction and sustaining of atherosclerotic cardiovascular diseases (ASCVD). Since 2008 Lp(a) along with progressive CVD has been approved as an indication for regular lipoprotein apheresis (LA) in Germany. The German Lipoprotein Apheresis Registry (GLAR) has been initiated to provide statistical evidence for the assessment of extracorporeal procedures to treat dyslipidemia for both LDL-cholesterol (LDL-C) and Lp(a). The GLAR now allows prospective investigations over a 5-year period about annual incidence rates of cardiovascular events. Here Lp(a) patients (LDL-C < 100 mg/dl; Lp(a) > 60 mg/dl or >120 nmol/l) showed the same reduction of major coronary (83%) and non-coronary events (63%) as had been formerly shown in the Pro(a)LiFe study. However, Lp(a) is not only an apolipoprotein(a) (apo(a)) and LDL-C containing particle, which is covalently bound to a LDL-C core by a disulphide bridge. The composition of this particle, inter alia containing oxidized phospholipids, gives pro-atherosclerotic, pro-inflammatory, and pro-thrombotic properties, inducing atherosclerotic processes mainly in the arterial wall. However, recent investigations have shown that a reduction of inflammatory settings without LDL-C or Lp(a) reduction may reduce ASCVD events. Lipoprotein apheresis (LA) could not only reduce LDL-C and Lp(a) in parallel, but also different inflammatory and coagulation parameters. In summary lipoprotein apheresis is not only anti-atherosclerotic, but also anti-inflammatory and anti-thrombotic and therefore an ideal treatment option with respect to the shown reduction of major adverse coronary events (MACE) and major adverse non-coronary events (MANCE) by reducing Lp(a) levels.

Serum Lipoprotein (a) levels in acute coronary syndrome; Comparison of younger and elderly patients with healthy controls

Objective:

To compare and see the association of serum Lipoprotein (a) levels in younger and older patients suffering from acute coronary syndrome compared to healthy controls

Methods:

This case control study was conducted in department of cardiology, King Edward Medical University, Lahore from January to December 2015. Total 180 subjects (90 cases and 90 healthy controls, subdivided in 45 young and old in each group ≤/>45 years of age) were included in the study by non-probability purposive sampling. Patients presenting with acute coronary event and angiographically proven coronary vascular disease were considered cases while those with normal coronaries served as controls. Lp(a) was measured after ten hours fasting. Lp(a) >30 nmol/l) were considered as high. Data were entered and analyzed in SPSS 17. Independent sample t-test was used to compare the mean lipoprotein (a) in cases and controls.

Results:

The mean age of cases and controls was 48.02 ± 10.90 & 45.89±10.09 years respectively. Lipid profile was similar in both cases and controls except triglycerides that were higher in controls (p=0.024). The mean lipoprotein (a) in cases was 47.03 ± 45.47 and in controls was 29.69±23.10 (p-value 0.001). Mean Lp(a) level was significantly high in cases vs controls in young subjects, (50.15±55.62 vs 25.75±15.84, p= 0.006), while in old ones, difference was not statistically significant (43.92±32.69 vs 33.64±28.22, p= 0.114). The frequency of desirable, borderline high, high, and very high Lp(a) levels in cases was 23(25.6%), 12(13.3%), 27(30.0%) and 28(31.1%), while in controls, it was 26(28.9%), 31(34.4%), 17(18.9%) and 16(17.8%), (p-value 0.003). Chi-Square test showed significant association of high Lp(a) with coronary artery disease in younger cases vs controls (P=0.004) with OR 3.65 but not in older (p-value 0.358).

Conclusion:

Serum lipoprotein(a) is strongly associated with coronary vascular disease especially in patients younger than 45 years of age despite comparable LDL and HDL between cases and controls, making Lp(a) likely independent risk factor for coronary vascular disease.

Effect of hormone replacement therapy on atherogenic lipid profile in postmenopausal women

BACKGROUND

Women develop cardiovascular disease (CVD) approximately 7-10 years later than men, but progress with similar risk after menopause. Recent studies suggest that hormone replacement therapy (HRT) is cardioprotective when initiated early after menopause, but the mechanisms involved are still unclear.

OBJECTIVE

In the current study, we aimed to examine the effects of HRT treatment on the plasma atherogenicity in postmenopausal women. We studied the total lipid profile in blood samples collected in a randomized, double-blinded, placebo controlled clinical trial of women with a history of venous thrombosis (VT), the EVTET study.

METHODS

One-hundred and forty postmenopausal women <70 years were included in EVTET and randomized either to active treatment (one tablet of 2 mg estradiol and 1 mg norethisterone acetate daily) (n = 71) or placebo (n = 69). Blood samples were taken at baseline and after 3 months and subjected to routine assessment of hemostatic factors and lipids.

RESULTS

Our study show that HRT compared to placebo significantly reduced plasma levels of Lp(a), ApoA1, ApoB, total cholesterol (TC), HDL-C, LDL-C, TC/HDL-C and LDL-C/HDL-C ratio at 3 months. No effect was observed on ApoB/ApoA1 ratio or triglycerides. The change in Lp(a) was significantly and inversely correlated with the change in estradiol (r = -0.32; P = 0.001) and positively correlated to the change in lipids, tissue factor pathway inhibitor activity and antigen, protein C and fibrinogen (r between 0.26 and 0.45, p < 0.01).

CONCLUSION

In sum, this study confirms a strong effect of HRT on atherogenic lipids with a large reduction in the pro-thrombotic Lp(a), suggesting an overall favorable effect on thrombogenicity after HRT replacement therapy in post-menopausal women at risk of VT.

Lipoprotein(a) Gene Polymorphism Increases a Risk Factor for Aortic Valve Calcification

Calcific aortic valve disease (CAVD) is a multifactorial condition. Both environmental and genetic factors play an important role in its etiology. CAVD exhibits a broad spectrum, varying from mild valve thickening to severe valve calcification and stenosis. Progression of the disease consists of chronic inflammation, lipoprotein deposition, and active leaflet calcification. It is a process similar to coronary artery disease. In this study, we investigated Lp(a) levels and gene polymorphisms associated with calcific aortic stenosis from blood samples after echocardiography in the evaluation of 75 patients diagnosed with CAVD and 77 controls. Blood tests were run in our laboratory to rule out certain risk factors before echocardiography examination. A significant association among smoking, elevated LDL level and creatinine, low albumin levels, Lp(a) level, rs10455872, and rs3798220 polymorphisms may be considered genetic risk factors for the development of calcific aortic stenosis.

Lipoprotein (a) interactions with cholesterol-containing lipids on angiographic coronary collateralization in type 2 diabetic patients with chronic total occlusion

Background

We investigated whether or to what extent the interaction of lipoprotein (a) [Lp(a)] with cholesterol-containing lipids was associated with angiographic coronary collateralization in type 2 diabetic patients with chronic total occlusion.

Methods

Serum levels of Lp(a), total cholesterol, low-density lipoprotein–cholesterol (LDL-C), high-density lipoprotein–cholesterol (HDL-C), and triglyceride were determined and non-HDL-C was calculated in 706 type 2 diabetic and 578 non-diabetic patients with stable coronary artery disease and angiographic total occlusion of at least one major coronary artery. The degree of collaterals supplying the distal aspect of a total occlusion from the contra-lateral vessel was graded as poor (Rentrop score of 0 or 1) or good coronary collateralization (Rentrop score of 2 or 3).

Results

For diabetic and non-diabetic patients, Lp(a), total cholesterol, LDL-C, and non-HDL-C levels were higher in patients with poor coronary collateralization than in those with good collateralization, whereas HDL-C and triglyceride levels were similar. After adjustment for potential confounding factors, tertiles of Lp(a), total cholesterol, LDL-C and non-HDL-C remained independent determinants for poor collateralization. A significant interaction between Lp(a) and total cholesterol, LDL-C or non-HDL-C was observed in diabetic patients (all P interaction < 0.001) but not in non-diabetics. At high tertile of total cholesterol (≥ 5.35 mmol/L), LDL-C (≥ 3.36 mmol/L) and non-HDL-C (≥ 4.38 mmol/L), diabetic patients with high tertile of Lp(a) (≥ 30.23 mg/dL) had an increased risk of poor collateralization compared with those with low tertile of Lp(a) (< 12.66 mg/dL) (adjusted OR = 4.300, 3.970 and 4.386, respectively, all P < 0.001).

Conclusions

Increased Lp(a) confers greater risk for poor coronary collateralization when total cholesterol, LDL-C or non-HDL-C are elevated especially for patients with type 2 diabetes.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0888-z) contains supplementary material, which is available to authorized users.

Tackling Residual Atherosclerotic Risk in Statin-Treated Adults: Focus on Emerging Drugs

Epidemiological studies and meta-analyses have consistently suggested the importance of lowering low-density lipoprotein cholesterol (LDL-C) to reduce cardiovascular (CV) events. However, these studies and mechanistic studies using intracoronary imaging modalities have reported patients who continue to experience CV events or disease progression despite optimal LDL-C levels on statins. These findings, including statin intolerance, have highlighted the importance of exploring additional potential therapeutic targets to reduce CV risk. Genomic insights have presented a number of additional novel targets in lipid metabolism. In particular, proprotein convertase subtilisin/kexin type 9 inhibitors have rapidly developed and recently demonstrated their beneficial impact on CV outcomes. Triglyceride (TG)-rich lipoproteins have been recently reported as a causal factor of atherosclerotic cardiovascular disease (ASCVD). Indeed, several promising TG-targeting therapies are being tested at various clinical stages. In this review, we present the evidence to support targeting atherogenic lipoproteins to target residual ASCVD risk in statin-treated patients.

Matrix Metalloproteinase 9 as a Predictor of Coronary Atherosclerotic Plaque Instability in Stable Coronary Heart Disease Patients with Elevated Lipoprotein(a) Levels

We sought to investigate whether levels of matrix metalloproteinases (MMPs) and their inhibitors predict coronary atherosclerotic plaque instability, as assessed by intravascular ultrasound (IVUS) virtual histology during coronary angiography. Blood samples were collected before angiography in 32 subjects (mean age 56 ± 8 years) with stable coronary heart disease (CHD) and elevated lipoprotein(a) (Lp(a), 94 ± 35 mg/dL). Levels of high-sensitivity C-reactive protein (hsCRP), apolipoprotein B100 (apoB100), MMP-7, MMP-9, tissue inhibitor of metalloproteinases (TIMP)-1, and TIMP-2 were determined using commercially available enzyme-linked immunosorbent assay kits. Results. The morphology of a total of sixty coronary lesions was assessed by virtual histology IVUS imaging. Eleven (18%) plaques in nine (28%) patients were classified as plaques with an unstable phenotype or a thin-cap fibroatheroma. Age, low-density lipoprotein cholesterol, apoB100, MMP-7, and MMP-9 levels were positively associated with necrotic core volume. Conversely, there was a negative relationship between MMP-7 and -9 levels and fibrous and fibro-fatty tissue volume. Multivariate regression analysis revealed that MMP-9 is a strong independent predictor of atherosclerotic plaque instability in stable CHD patients. In stable CHD patients with elevated Lp(a), MMP-9 levels are positively associated with the size of the necrotic core of coronary atherosclerotic plaques.

Dietary natural products as emerging lipoprotein(a)-lowering agents

Elevated plasma lipoprotein(a) (Lp(a)) levels are associated with an increased risk of cardiovascular disease (CVD). Hitherto, niacin has been the drug of choice to reduce elevated Lp(a) levels in hyperlipidemic patients but its efficacy in reducing CVD outcomes has been seriously questioned by recent clinical trials. Additional drugs may reduce to some extent plasma Lp(a) levels but the lack of a specific therapeutic indication for Lp(a)-lowering limits profoundly reduce their use. An attractive therapeutic option is natural products. In several preclinical and clinical studies as well as meta-analyses, natural products, including l-carnitine, coenzyme Q ₁₀ , and xuezhikang were shown to significantly decrease Lp(a) levels in patients with Lp(a) hyperlipoproteinemia. Other natural products, such as pectin, Ginkgo biloba, flaxseed, red wine, resveratrol and curcuminoids can also reduce elevated Lp(a) concentrations but to a lesser degree. In conclusion, aforementioned natural products may represent promising therapeutic agents for Lp(a) lowering.