Lipoprotein(a) and inflammation- pathophysiological links and clinical implications for cardiovascular disease

Association Between Lipoprotein(a) and Arterial Stiffness in Young Adults with Familial Hypercholesterolemia

Background and Aims: Elevated lipoprotein(a) [Lp(a)] and familial hypercholesterolemia (FH) are both inherited dyslipidemias that are independently associated with cardiovascular disease. Surrogate markers to assess signs of atherosclerosis, such as arterial stiffness, might be useful to evaluate the cardiovascular risk in young patients. The aim of this study is to evaluate the contribution of Lp(a) to arterial stiffness, as measured by carotid pulse wave velocity (cPWV) in young adults with FH. Methods: For this cross-sectional study, 214 children with FH who participated in a randomized controlled trial between 1997 and 1999 on the efficacy and safety of pravastatin were eligible. After 20 years, these patients were invited for a hospital visit, including cPWV assessment (by 4D flow MRI) and Lp(a) measurement. Linear mixed-effects models were used to evaluate the association between Lp(a) and cPWV. Results: We included 143 patients (mean [standard deviation] age: 31.8 [3.2] years) from 108 families. Median (interquartile range) cPWV was 1.62 (1.31-2.06) m/s. Both the unadjusted (ß = -0.0014 m/s per 1 mg/dL increase in Lp(a), 95% CI: -0.0052 to 0.0023, p = 0.455) and adjusted model (ß = -0.0005 m/s per 1 mg/dL increase in Lp(a), 95% CI: -0.0042 to 0.0032, p = 0.785) showed no significant association between Lp(a) and cPWV. Conclusions: Our findings indicate that Lp(a) levels are not associated with carotid arterial stiffness in young adults with FH. Possibly, High Lp(a) might cause atherosclerosis by mechanisms beyond arterial stiffness in young adults. Other surrogate markers of early signs of atherosclerosis may be more suitable to evaluate the Lp(a)-mediated contribution to atherosclerosis in young FH patients.

Inflammation, Lp(a) and cardiovascular mortality: results from the LURIC study

OBJECTIVE

Lipoprotein(a) [Lp(a)] concentrations have been associated with cardiovascular risk. Recent studies suggested an interaction between systemic inflammation assessed via high-sensitivity C-reactive protein (hsCRP) and Lp(a). This study aimed to evaluate whether Lp(a), hsCRP, and interleukin-6 (IL-6) levels are associated with cardiovascular mortality in a German hospital-based cohort.

METHODS

Data were drawn from the Ludwigshafen Risk and Cardiovascular Health (LURIC) study, including 3,316 patients undergoing coronary angiography. Lp(a) was measured by immunoturbidimetry and categorized into three strata (< 50 mg/dL, n = 2668; 50-100 mg/dL, n = 482; > 100 mg/dL, n = 163). HsCRP was measured by immunonephelometry and categorized by intervals (1st < 1 mg/L, 2nd 1-2 mg/L and 3rd interval > 2 mg/L). IL-6 was measured by ELISA and categorized into two groups (1st < 3.2 ng/L, 2nd ≥ 3.2 ng/L). The primary outcome was cardiovascular disease (CVD) mortality, analyzed using Cox proportional hazards models and logistic regression.

RESULTS

Participants were predominantly male, with a mean age of 62.6 years. Extremely high Lp(a) (> 100 mg/dL) was associated with increased cardiovascular mortality (HR 1.5, 95% CI 1.06-2.12) compared to Lp(a) < 50 mg/dl. Both hsCRP (> 2 mg/L, HR 1.39, 95% CI 1.08-1.79 third vs. first interval) and more so IL-6 (HR 1.92, 95% CI 1.64-2.23, upper vs. lower half), were independently associated with higher CVD mortality. While hsCRP did not increase the Lp(a)-CVD mortality in stratified analysis, high IL-6 conferred an increased risk at Lp(a) levels > 100 mg/dL (HR 1.25, 95% CI 1.09-1.44).

CONCLUSION

HsCRP and IL-6 are associated with cardiovascular mortality. Markedly elevated Lp(a) is associated with an increased risk of cardiovascular mortality in the context of high systemic inflammation. Anti-inflammatory treatments may provide additional therapeutic benefits for individuals with high Lp(a).

Relevance of Lipoprotein Composition in Endothelial Dysfunction and the Development of Hypertension

Endothelial dysfunction and chronic inflammation are determining factors in the development and progression of chronic degenerative diseases, such as hypertension and atherosclerosis. Among the shared pathophysiological characteristics of these two diseases is a metabolic disorder of lipids and lipoproteins. Therefore, the contents and quality of the lipids and proteins of lipoproteins become the targets of therapeutic objective. One of the stages of lipoprotein formation occurs through the incorporation of dietary lipids by enterocytes into the chylomicrons. Consequently, the composition, structure, and especially the properties of lipoproteins could be modified through the intake of bioactive compounds. The objective of this review is to describe the roles of the different lipid and protein components of lipoproteins and their receptors in endothelial dysfunction and the development of hypertension. In addition, we review the use of some non-pharmacological treatments that could improve endothelial function and/or prevent endothelial damage. The reviewed information contributes to the understanding of lipoproteins as vehicles of regulatory factors involved in the modulation of inflammatory and hemostatic processes, the attenuation of oxidative stress, and the neutralization of toxins, rather than only cholesterol and phospholipid transporters. For this review, a bibliographic search was carried out in different online metabases.

Association of Lipoprotein(a) With Major Adverse Cardiovascular Events Across hs-CRP: A Systematic Review and Meta-Analysis

Background

Lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic cardiovascular disease. The relationship between Lp(a) and major adverse cardiovascular events (MACE) in the context of high-sensitivity C-reactive protein (hs-CRP) levels remains controversial due to conflicting results from previous studies.

Objectives

This systematic review and meta-analysis aimed to clarify the association between Lp(a) and risk of MACE across different hs-CRP levels in both primary and secondary prevention settings.

Methods

We performed a systematic review by searching MEDLINE (PubMed), Embase (Ovid), Cochrane CENTRAL (Wiley), and Web of Science (Clarivate) from their inception to February 2024. Eligible studies reported the association of Lp(a) with MACE stratified by hs-CRP level. Data extraction and quality assessment were systematically conducted. Meta-analyses used random-effects models to compute pooled HRs for individuals with low (<2 mg/L) and high (≥2 mg/L) hs-CRP levels. Subgroup analyses were performed in primary and secondary prevention populations.

Results

Nine publications encompassing 11 studies that involved 562,301 participants met the inclusion criteria. The mean proportion of females was 39.9% and the weighted mean age for the entire cohort was 61.2 years. Elevated Lp(a) was significantly associated with MACE risk in both low and high hs-CRP groups, with pooled HR of 1.26 (95% CI: 1.11-1.42) and 1.33 (95% CI: 1.20-1.47), respectively. In the primary prevention group, the pooled HR for low and high hs-CRP groups was 1.33 (95% CI: 1.06-1.66) and 1.43 (95% CI: 1.13-1.82), respectively (subgroup difference, P = 0.65). The corresponding HRs for the secondary prevention population were 1.13 (95% CI: 1.00-1.27) and 1.31 (95% CI: 1.12-1.52), respectively (subgroup difference P = 0.13).

Conclusion

Elevated Lp(a) is associated with an increased risk of MACE independent of hs-CRP levels in both primary and secondary prevention populations.

Lipoprotein(a) and the atherosclerotic burden - Should we wait for clinical trial evidence before taking action?

The fact that lipoprotein(a) levels should be regarded as a causal residual risk factor in the atherosclerotic cardiovascular diseases (ASCVD) is now a no-brainer. This review article aims to summarize the latest evidence supporting the causal role of lipoprotein(a) in ASCVD and the potential strategies to reduce the lipoprotein(a) burden until clinical trial results are available. Epidemiological and genetic data demonstrate the causal link between lipoprotein(a) and increased ASCVD risk. That being said, a specific question comes to mind: "must we wait for outcome trials in order to take action?". Given that lipoprotein(a) levels predict incident ASCVD in both primary and secondary prevention contexts, with a linear risk gradient across its distribution, measuring lipoprotein(a) can unequivocally help identify patients who may later benefit from specific lipoprotein(a)-lowering therapies. This understanding has led various National Societies to recommend dosing lipoprotein(a) in high-risk individuals and to support the recommendation of measuring lipoprotein(a) levels at least once in every adult for risk stratification.

Expression of Monocytes Subsets in Patients Diagnosed With Coronary Artery Atherosclerosis and Their Impact on Disease Severity

Introduction Many studies have supported inflammation as a mediator of lipoprotein (a) (Lp(a)) induced increase in cardiovascular disease risk, as it has pro-inflammatory effects on endothelial cells and monocytes. Aim This study aims to correlate Lp(a) level with different monocyte subsets in coronary atherosclerotic patients with different severity. Method The study included 60 patients with a mean age of 53.1 ± 10.5 diagnosed as coronary atherosclerotic patients by coronary angiography. Lp levels were measured using enzyme-linked immunosorbent assay (ELISA), while blood counts and monocyte subsets were analyzed by flow cytometry, and 30 apparently healthy individuals were included as the control group. Results Patients showed significantly higher median monocytic %, Lp(a), and higher C-reactive protein (CRP) values than the control group. Patients were subdivided into two groups: normal Lp(a) < 6.2 mg/dL (n = 24) and hyperlipoproteinemia(a) (hyper Lp(a)) ≥ 6.2 mg/dL (n = 36). Patients with hyper Lp(a) had higher non-classical monocytes (31.5% vs. 20%). Coronary atherosclerosis severity was associated with higher Lp(a) levels as well as non-classical monocytes; patients with mild atherosclerosis showed the highest classical and intermediate subset levels. While for a non-classical subset, patients with severe atherosclerosis showed the highest median level. A significant moderate positive correlation between Lp(a) and monocyte counts, as well as monocyte-lymphocyte (M/L) index and non-classical monocytes, was found. Conclusions Hyper Lp(a) and increased count of non-classical monocytes are significantly increased with disease progression (triple-vessel coronary disease risk). These results suggest that the expansion of non-classical monocytes is a cardiovascular disease (CVD) risk and predictor for disease severity. Strategies targeting inflammatory monocytes may slow CVD progression.

Discrimination and net-reclassification of cardiovascular disease risk with lipoprotein(a) levels: The ATTICA study (2002-2022)

BACKGROUND

Lipoprotein(a) [Lp(a)] is recognized as a risk factor for atherosclerotic cardiovascular disease (ASCVD). However, its influence on clinical risk evaluations remains unclear.

OBJECTIVE

This study aimed to determine whether Lp(a) improves CVD risk prediction among apparently healthy adults from the general population.

METHODS

In 2002, n = 3,042 adults free of CVD, residing in the Athens metropolitan area, in Greece, were recruited. A 20-year follow-up was conducted in 2022, comprising n = 2,169 participants, of which n = 1,988 had complete data for CVD incidence.

RESULTS

Lp(a) levels were significantly associated with 20-year ASCVD incidence in the crude model (hazard ratio per 1 mg/dL: 1.004, p = 0.048), but not in multi-adjusted models considering demographic, lifestyle, and clinical factors. Adding Lp(a) to the Reynolds Risk Score (RRS) and Framingham Risk Score (FRS) variables resulted in positive net reclassification improvement (NRI) values (0.159 and 0.160 respectively), indicating improved risk classification. Mediation analysis suggested that C-reactive protein, interleukin-6, and fibrinogen mediate the relationship between Lp(a) and ASCVD. No significant interaction was observed between Lp(a) and potential moderators.

CONCLUSION

Lp(a) levels can predict 20-year CVD outcomes and improve CVD risk prediction within the general population, possibly via the intricate relationship between Lp(a), systemic inflammation, atherothrombosis.

The association between lipoprotein(a) levels and ischemic stroke in children: A case-control study

BACKGROUND

Pediatric arterial ischemic stroke (AIS) is a rare disorder, associated with severe morbidity. In adults, elevated lipoprotein(a) (Lp(a)), a cholesterol-like particle, is associated with ischemic stroke. However, data on Lp(a) and pediatric AIS are scarce. Therefore, we evaluated the association between Lp(a) levels and pediatric AIS.

METHODS

We included children who suffered an AIS (≤18 years) and were treated in a tertiary center in Amsterdam, the Netherlands. Two groups of children with AIS were identified: (i) neonates and (ii) children older than 29 days. A case-control study was performed, with the latter group as cases and children without AIS as control group. Cases and controls were matched for age of Lp(a) testing and sex. Multivariable logistic regression models were used.

RESULTS

Thirteen neonates and 23 children were included. Mean (SD) age of AIS was 0.6 (2.0) days and 9.2 (6.3) years, respectively. Children with AIS were matched to 62 controls. Lp(a) levels of greater than 50 mg/dL were more prevalent in children with AIS compared to controls (21.7% vs. 3.2%, p = .02). A significant association was found between Lp(a) and AIS (odds ratio [OR] adjusted for age at Lp(a) testing, body mass index [BMI], measurement assay: 1.36 per 10 mg/dL increase of Lp(a), 95% confidence interval [CI]: 1.02-1.82, p = .041).

CONCLUSIONS

In this study, Lp(a) levels were positively associated with the risk of AIS in children, suggesting that high Lp(a) might be an independent risk factor for AIS. This underlines the importance of Lp(a) measurement in children with AIS.

Lipoprotein (a)-Related Inflammatory Imbalance: A Novel Horizon for the Development of Atherosclerosis

PURPOSE OF REVIEW

The primary objective of this review is to explore the pathophysiological roles and clinical implications of lipoprotein(a) [Lp(a)] in the context of atherosclerotic cardiovascular disease (ASCVD). We seek to understand how Lp(a) contributes to inflammation and arteriosclerosis, aiming to provide new insights into the mechanisms of ASCVD progression.

RECENT FINDINGS

Recent research highlights Lp(a) as an independent risk factor for ASCVD. Studies show that Lp(a) not only promotes the inflammatory processes but also interacts with various cellular components, leading to endothelial dysfunction and smooth muscle cell proliferation. The dual role of Lp(a) in both instigating and, under certain conditions, mitigating inflammation is particularly noteworthy. This review finds that Lp(a) plays a complex role in the development of ASCVD through its involvement in inflammatory pathways. The interplay between Lp(a) levels and inflammatory responses highlights its potential as a target for therapeutic intervention. These insights could pave the way for novel approaches in managing and preventing ASCVD, urging further investigation into Lp(a) as a therapeutic target.

Association between hepatic steatosis and lipoprotein(a) levels in non-alcoholic patients: A systematic review

BACKGROUND AND OBJECTIVES

It is well known that lipid abnormalities exist in the context of non-alcoholic fatty liver disease (NAFLD). The association between lipoprotein(a) [Lp(a)] levels and NAFLD is poorly understood. The main objective of the present study was to assess the association between Lp(a) levels and NAFLD.

METHODS

This systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO CRD42023392526). A literature search was performed to detect studies that evaluated the association between Lp(a) levels, NAFLD and steatohepatitis (NASH).

RESULTS

Ten observational studies, including 40,045 patients, were identified and considered eligible for this systematic review. There were 9266 subjects in the NAFLD groups and 30,779 individuals in the respective control groups. Five studies evaluated patients with NAFLD (hepatic steatosis was associated with lower Lp(a) levels in four studies, while the remaining showed opposite results). Two studies evaluating NASH patients showed that Lp(a) levels were not different compared to controls. However, the increment of Lp(a) levels was correlated with liver fibrosis in one of them. In addition, one study analyzed simultaneously patients with NAFLD and NASH, showing a neutral result in NAFLD patients and a positive relationship in NASH patients. Two studies that included patients with the new definition of metabolic-associated fatty liver disease (MAFLD) also showed neutral results.

CONCLUSION

Although there could be an association between Lp(a) levels and hepatic steatosis, the results of the studies published to date are contradictory and not definitive.

Effectiveness of anthocyanin-containing foods and nutraceuticals in mitigating oxidative stress, inflammation, and cardiovascular health-related biomarkers: a systematic review of animal and human interventions

Cardiovascular diseases (CVDs) are a group of chronic health disorders prevalent worldwide that claim millions of lives yearly. Inflammation and oxidative stress are intricately associated with myocardial tissue damage, endothelial dysfunction, and increased odds of heart failure. Thus, dietary strategies aimed at decreasing the odds of CVDs are paramount. In this regard, the consumption of anthocyanins, natural pigments found in edible flowers, fruits, and vegetables, has attracted attention due to their potential to promote cardiovascular health. The main mechanisms of action linked with their protective effects on antioxidant and anti-inflammatory activities, serum lipid profile modulation, and other cardiovascular health parameters are explained and exemplified. However, little is known about the dose-dependency nature of the effects, which anthocyanin has better efficiency, and whether anthocyanin-containing foods display better in vivo efficacy than nutraceuticals (i.e., concentrated extracts containing higher levels of anthocyanins than foods). Thus, this systematic review focused on determining the effects of anthocyanin-containing foods and nutraceuticals on biomarkers associated with CVDs using animal studies and human interventions supported by in vitro mechanistic insights. Overall, the results showed that the regular consumption of anthocyanin-containing foods and nutraceuticals improved vascular function, lipid profile, and antioxidant and anti-inflammatory effects. The daily dosage, the participants' health status, and the duration of the intervention also significantly influenced the results.

Lipoprotein(a), C-Reactive Protein, and Cardiovascular Risk in Primary and Secondary Prevention Populations

Importance

Elevated lipoprotein(a) (Lp[a]) is a putative causal risk factor for atherosclerotic cardiovascular disease (ASCVD). There are conflicting data as to whether Lp(a) may increase cardiovascular risk only in the presence of concomitant inflammation.

Objective

To investigate whether Lp(a) is associated with cardiovascular risk independent of high-sensitivity C-reactive protein (hs-CRP) in both primary and secondary prevention populations.

Design, Setting, and Participants

This cohort study uses data from 3 distinct cohorts, 1 population-based cohort and 2 randomized clinical trials. Participants included individuals from the UK Biobank (data from 2006-2010) without prevalent ASCVD, participants in the FOURIER (TIMI 59) trial (data from 2013-2017) who had baseline Lp(a) and hs-CRP data, and participants in the SAVOR-TIMI 53 trial (data from 2010-2013) who had prevalent ASCVD and baseline values for Lp(a) and hs-CRP. The data analysis took place from November 2022 to November 2023.

Exposure

Baseline plasma Lp(a), considered either as a continuous variable or dichotomized at 125 nmol/L.

Main Outcomes and Measures

Risk of major adverse cardiovascular events (MACE) (composite of cardiovascular death, myocardial infarction [MI], or ischemic stroke), the individual MACE components, and peripheral artery disease (PAD).

Results

Among 357 220 individuals in the UK Biobank without prevalent ASCVD, 232 699 (65%) had low hs-CRP (<2 mg/L), and 124 521 (35%) had high hs-CRP (≥2 mg/L) values. In a Cox proportional hazard model adjusted for ASCVD risk factors, higher Lp(a) was associated with increased cardiovascular risk regardless of baseline hs-CRP value for MACE (hs-CRP ≥2 mg/L: hazard ratio [HR] per 50-nmol/L higher Lp[a], 1.05; 95% CI, 1.04-1.07; P < .001; for hs-CRP <2 mg/L: HR, 1.05; 95% CI, 1.04-1.07; P < .001; P = .80 for interaction), as well as MI, ischemic stroke, and PAD individually. Among 34 020 individuals in the FOURIER and SAVOR trials with baseline cardiometabolic disease, there were 17 643 (52%) with low and 16 377 (48%) with high baseline hs-CRP values. In Cox proportional hazard models using aggregated data from FOURIER and SAVOR, higher baseline Lp(a) was associated with increased cardiovascular risk regardless of baseline hs-CRP for MACE (hs-CRP ≥2 mg/L: HR per 50-nmol/L higher Lp[a], 1.02; 95% CI, 1.00-1.05; P = .04; hs-CRP <2 mg/L: HR, 1.05; 95% CI, 1.02-1.08; P < .001; P = .16 for interaction), MI, and PAD.

Conclusions and Relevance

In this study, higher levels of Lp(a) were associated with MACE, MI, and PAD in both primary and secondary prevention populations regardless of baseline hs-CRP value.

Lipoprotein apheresis affects the concentration of extracellular vesicles in patients with elevated lipoprotein (a)

Lipoprotein apheresis (LA) is a therapeutic option for hyperlipoproteinemia(a) (hyper-Lp(a)) and atherosclerotic cardiovascular disease (ASCVD). LA improves blood rheology, reduces oxidative stress parameters and improves endothelial function. The underlying molecular mechanisms of LA beneficial effects are unknown, but it has been suggested that LA exhibits multiple activities beyond simply removing lipoproteins. We hypothesized that LA removes not only lipoproteins, but also extracellular vesicles (EVs). To test this hypothesis, we performed a prospective study in 22 patients undergoing LA for hyper-Lp(a) and ASCVD. Different EVs subtypes were measured before and directly after LA, and after 7 days. We used calibrated flow cytometry to detect total particle concentration (diameter >  ~ 100 nm), total lipoproteins concentration (diameter > 200 nm, RI > 1.51), total EV concentration (diameter > 200 nm, RI < 1.41), concentrations of EVs derived from erythrocytes (CD235a+; diameter > 200 nm, RI < 1.41), leukocytes (CD45+; diameter > 200 nm, RI < 1.41) and platelets (CD61+, PEVs; diameter > 200 nm, RI < 1.41). LA reduced the concentrations of all investigated EVs subtypes and lipoproteins. Lp(a) concentration was lowered by 64.5% [(58% - 71%); p < 0.001]. Plasma concentrations of EVs > 200 nm in diameter derived from platelets (CD61 +), leukocytes (CD45+) and erythrocytes (CD235a+) decreased after single LA procedure by 42.7% [(12.8-54.7); p = 0.005], 42.6% [(29.7-54.1); p = 0.030] and 26.7% [(1.0-62.7); p = 0.018], respectively, compared to baseline. All EV subtypes returned to the baseline concentrations in blood plasma after 7 days. To conclude, LA removes not only Lp(a), but also cell-derived EVs, which may contribute to LA beneficial effects.

Effects of proprotein convertase subtilisin-kexin type 9 inhibitors on inflammatory and hemostatic parameters in post myocardial infarction patients

Despite progress in treatment, elevated levels of low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) (Lp(a)), represent a significant part of the residual risk. Both are associated with inflammation and the coagulation fibrinolytic system. The purpose of our research was to evaluate the effect of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) on lipid parameters and indicators of inflammation, coagulation and fibrinolysis. We included 100 post myocardial infarction (MI) patients with insufficiently controlled LDL-C values despite the maximum dose of statin, and highly elevated Lp(a). Patients received alirocumab or evolocumab (150 mg sc or 140 mg sc every two weeks, respectively), or placebo for 6 months. In patients receiving PCSK9i, a significant decrease in total cholesterol (TC), LDL-C, triglycerides (TG) and Lp(a), and an increase in high density lipoprotein cholesterol (p < 0.001 for all) was found. Before treatment, the concentrations of TC, LDL-C and TG correlated with the concentrations of thrombin activatable fibrinolysis inhibitor (r = 0.41, p < 0.001; r = 0.353, p < 0.001; r = 0.311, p = 0.003, respectively), and plasminogen activator inhibitor-1 (r = 0.302, p = 0.007; r = 0.218, p = 0.049; r = 0.278; p = 0.013, respectively). The concentrations of TC and LDL-C correlated with overall fibrinolytic potential (r = -0.220, p = 0.034; r = -0.207, p = 0.047, respectively). The concentration of TG was related to the concentration of interleukin 6 (r = 0.290, p = 0.004) and interleukin 8 (r = 0.332, p = 0.001). No correlations between Lp(a) and inflammatory or hemostatic variables were found. No associations were found after treatment. Our results show that inflammatory cytokines and fibrinolytic parameters are related to LDL-C and not Lp(a) in post-MI patients before and with neither of them following PCSK9i treatment. The trial registration number: NCT04613167, Date of registration: November 3, 2020.

Haplotype of the Lipoprotein(a) Gene Variants rs10455872 and rs3798220 Is Associated with Parameters of Coagulation, Fibrinolysis, and Inflammation in Patients after Myocardial Infarction and Highly Elevated Lipoprotein(a) Values

Lipoprotein(a) (Lp(a)) is an independent risk factor for future coronary events. Variants rs10455872 and rs3798220 in the gene encoding Lp(a) are associated with an increased Lp(a) concentration and risk of coronary artery disease. We aimed to determine whether in high-risk coronary artery disease patients these two genetic variants and the kringle IV type 2 (KIV-2) repeats are associated with impairment of inflammatory and hemostatic parameters. Patients after myocardial infarction with elevated Lp(a) levels were included. Blood samples underwent biochemical and genetic analyses. In carriers of the AC haplotype, the concentrations of tumor necrosis factor (TNF)-α (4.46 vs. 3.91 ng/L, p = 0.046) and plasminogen activator inhibitor-1 (PAI-1) (p = 0.026) were significantly higher compared to non-carriers. The number of KIV-2 repeats was significantly associated with the concentration of high-sensitivity C-reactive protein (ρ = 0.251, p = 0.038) and overall fibrinolytic potential (r = -0.253, p = 0.038). In our patients, a direct association between the AC haplotype and both TNF-α and PAI-1 levels was observed. Our study shows that the number of KIV-2 repeats not only affects proatherosclerotic and proinflammatory effects of Lp(a) but is also associated with its antifibrinolytic properties.

Lipoprotein(a) in patients with breast cancer after chemotherapy: exploring potential strategies for cardioprotection

Developments in neoadjuvant and adjuvant chemotherapy (CHT) have led to an increase in the number of breast cancer survivors. The determination of an appropriate follow-up for these patients is of increasing importance. Deaths due to cardiovascular disease (CVD) are an important part of mortality in patients with breast cancer.This review suggests that chemotherapeutic agents may influence lipoprotein(a) (Lp(a)) concentrations in breast cancer survivors after CHT based on many convincing evidence from epidemiologic and observational researches. Usually, the higher the Lp(a) concentration, the higher the median risk of developing CVD. However, more clinical trial results are needed in the future to provide clear evidence of a possible causal relationship. This review also discuss the existing and emerging therapies for lowering Lp(a) concentrations in the clinical setting. Hormone replacement therapy, statins, proprotein convertase subtilisin/kexin-type 9 (PCSK9) inhibitors, Antisense oligonucleotides, small interfering RNA, etc. may reduce circulating Lp(a) or decrease the incidence of CVD.

Plasma Lipoprotein(a) Levels in Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis

INTRODUCTION

The polycystic ovary syndrome (PCOS) may represent an important model of lipid alterations. Lipoprotein(a) [Lp(a)] has emerged as a new marker of cardiovascular risk.

AIM

The main objective of this meta-analysis was to analyze the available evidence on Lp(a) levels in patients with PCOS compared to a control group.

METHODS

This meta-analysis was performed according to PRISMA guidelines. A literature search was performed to detect studies that have quantified Lp(a) levels in women with PCOS compared to a control group. The primary outcome was Lp(a) levels expressed in mg/dL. Random effects models were used.

RESULTS

Twenty-three observational studies including 2,337 patients were identified and considered eligible for this meta-analysis. In the overall analysis, the quantitative analysis showed that patients with PCOS have a higher Lp(a) levels (SMD: 1.1 [95% CI: 0.7 to 1.4]; I²=93%) compared to the control group. The results were similar in the analysis of the subgroups of patients according to body mass index (normal weight group: SMD: 1.2 [95% CI: 0.5 to 1.9], I²=95%; overweight group: SMD: 1.2 [95% CI: 0.5 to 1.8], I²=89%). Sensitivity analysis showed that the results were robust.

CONCLUSIONS

This meta-analysis shows that women with PCOS had higher levels of Lp(a) compared to healthy women used as a control group. These findings were observed in both overweight and non-overweight women.

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), Inflammation, and Atherosclerosis

Growing evidence has shown that high levels of lipoprotein (a) (Lp(a)) and chronic inflammation may be responsible for the residual risk of cardiovascular events in patients managed with an optimal evidence-based approach. Clinical studies have demonstrated a correlation between higher Lp(a) levels and several atherosclerotic diseases including ischemic heart disease, stroke, and degenerative calcific aortic stenosis. The threshold value of Lp(a) serum concentrations associated with a significantly increased cardiovascular risk is >125 nmol/L (50 mg/dL). Current available lipid-lowering drugs have modest-to-no impact on Lp(a) levels. Chronic inflammation is a further condition potentially implicated in residual cardiovascular risk. Consistent evidence has shown an increased risk of cardiovascular events in patients with high sensitivity C reactive protein (>2 mg/dL), an inflammation biomarker. A number of anti-inflammatory drugs have been investigated in patients with or at risk of cardiovascular disease. Of these, canakinumab and colchicine have been found to be associated with cardiovascular risk reduction. Ongoing research aimed at improving risk stratification on the basis of Lp(a) and vessel inflammation assessment may help refine patient management. Furthermore, the identification of these conditions as cardiovascular risk factors has led to increased investigation into diagnostic and therapeutic strategies targeting them in order to reduce atherosclerotic cardiovascular disease burden.

Lipoprotein(a) as a Predictive Biomarker and Therapeutic Target for Acute Coronary Syndromes

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in Western societies, despite the significant advances that have improved primary and secondary prevention. Hence, several novel biomarkers have been identified as potential diagnostic and therapeutic targets which could improve outcomes even when traditional risk factors are well-controlled. Lipoprotein (a) [Lp(a)] has pro-atherogenic, pro-thrombotic, and pro-inflammatory properties, and its levels are relatively constant and genetically predetermined. Several epidemiological studies have associated high Lp(a) with increased risk for acute coronary syndromes (ACS) even when other CAD risk factors are included in the multivariate analysis. However, until recently, specific therapeutic options targeting Lp(a) were not associated, and thus, Lp(a) is currently used as a risk and treatment modifying biomarker with guidelines suggesting the intensified treatment of low-density lipoprotein in intermediate- to-high-risk patients with increased Lp(a) levels. Lately, specific treatment options targeting Lp(a) have become available and include antisense oligonucleotides and small-interfering RNA, which induce a robust reduction of Lp(a). Results of ongoing phase-3 trials will answer whether Lp(a) will become a biomarker specifically treated to reduce the burden of cardiovascular mortality. The scope of this review article is to present the current evidence regarding the use of Lp(a) as a biomarker, predictive of increased CAD risk, and to discuss the future perspectives on pharmaceutical reduction of Lp(a) as a therapeutic target in high-risk patients.