Lp(a) (Lipoprotein [a]) and Risk for Incident Atrial Fibrillation: Multi-Ethnic Study of Atherosclerosis

Associations of lipids and lipid-modifying drug target genes with atrial fibrillation risk based on genomic data

BACKGROUND

The causal associations of lipids and the drug target genes with atrial fibrillation (AF) risk remain obscure. We aimed to investigate the causal associations using genetic evidence.

METHODS

Mendelian randomization (MR) analyses were conducted using summary-level genome-wide association studies (GWASs) in European and East Asian populations. Lipid profiles (low-density lipoprotein cholesterol, triglyceride, and lipoprotein[a]) and lipid-modifying drug target genes (3-hydroxy-3-methylglutaryl-CoA reductase, proprotein convertase subtilisin/kexin type 9, NPC1-like intracellular cholesterol transporter 1, apolipoprotein C3, angiopoietin-like 3, and lipoprotein[a]) were used as exposures. AF was used as an outcome. The inverse variance weighted method was applied as the primary method. Summary-data-based Mendelian randomization analyses were performed for further validation using expression quantitative trait loci data. Mediation analyses were conducted to explore the indirect effect of coronary heart disease.

RESULTS

In the European population, MR analyses demonstrated that elevated levels of lipoprotein(a) increased AF risk. Moreover, analyses focusing on drug targets revealed that the genetically proxied target gene LPA, which simulates the effects of drug intervention by reducing lipoprotein(a), exhibited an association with AF risk. This association was validated in independent datasets. There were no consistent and significant associations observed for other traits when analyzed in different datasets. This finding was also corroborated by Summary-data-based Mendelian randomization analyses between LPA and AF. Mediation analyses revealed that coronary heart disease plays a mediating role in this association. However, in the East Asian population, no statistically significant evidence was observed to support these associations.

CONCLUSIONS

This study provided genetic evidence that Lp(a) may be a causal factor for AF and that LPA may represent a promising pharmacological target for preventing AF in the European population.

Recommendations of the Experts of the Polish Cardiac Society (PCS) and the Polish Lipid Association (PoLA) on the diagnosis and management of elevated lipoprotein(a) levels

Lipoprotein(a) [Lp(a)] is made up of a low-density lipoprotein (LDL) particle and a specific apolipoprotein(a). The blood concentration of Lp(a) is approximately 90% genetically determined, and the main genetic factor determining Lp(a) levels is the size of the apo(a) isoform, which is determined by the number of KIV2 domain repeats. The size of the apo(a) isoform is inversely proportional to the blood concentration of Lp(a). Lp(a) is a strong and independent cardiovascular risk factor. Elevated Lp(a) levels ≥ 50 mg/dl (≥ 125 nmol/l) are estimated to occur in more than 1.5 billion people worldwide. However, determination of Lp(a) levels is performed far too rarely, including Poland, where, in fact, it is only since the 2021 guidelines of the Polish Lipid Association (PoLA) and five other scientific societies that Lp(a) measurements have begun to be performed. Determination of Lp(a) concentrations is not easy due to, among other things, the different sizes of the apo(a) isoforms; however, the currently available certified tests make it possible to distinguish between people with low and high cardiovascular risk with a high degree of precision. In 2022, the first guidelines for the management of patients with elevated lipoprotein(a) levels were published by the European Atherosclerosis Society (EAS) and the American Heart Association (AHA). The first Polish guidelines are the result of the work of experts from the two scientific societies and their aim is to provide clear, practical recommendations for the determination and management of elevated Lp(a) levels.

Association Between Lipoprotein (a) and Risk of Atrial Fibrillation: A Systematic Review and Meta-analysis of Mendelian Randomization Studies

Lipoprotein (a) (Lp[a]) is an established risk factor for atherosclerotic cardiovascular disease (ASCVD). However, data on association of Lp(a) with risk of atrial fibrillation (AF) is still limited. We searched PubMed/Medline, Scopus, and EMBASE for studies evaluating the association of Lp(a) with the occurrence of AF until July 2023. Random effects models and I2 statistics were used for pooled odds ratios (OR), and heterogeneity assessments. A subgroup analysis was performed based on the cohort population, and a one-out sensitivity analysis was performed. This meta-analysis comprised 275,647 AF cases and 2,100,172 Lp(a) participants. An increase in Lp(a) was associated with an increased risk of AF in mendelian randomization (MR) studies (OR 1.024, 95% CI: 1.007-1.042, I2 = 87.72%, P < 0.001). Leave-one-out sensitivity analysis confirmed equivalent results in MR studies. Subgroup analysis of MR studies revealed a higher risk of AF in the European cohort (OR 1.023, 95% CI: 1.007-1.040, I2 = 89.05%, P < 0.001) and a low risk (OR 0.940, 95% CI: 0.893-0.990) in the Chinese population. Meta-analysis of the MR data suggested higher levels of Lp(a) were associated with increased risk of AF. Future robust prospective studies are warranted to validate these findings.

Association of lipoprotein(a) with left ventricular hypertrophy assessed by electrocardiogram in adults: a large cross-sectional study

Background and aims

Increasing evidence supports a causal relationship between lipoprotein(a) [Lp(a)] and atherosclerotic cardiovascular disease, yet its association with left ventricular hypertrophy (LVH) assessed by electrocardiogram (ECG) remains unknown. The aim of this study was to explore the relationship between Lp(a) and LVH assessed by ECG in general population.

Methods and results

In this cross-sectional study, we screened 4,052 adults from the participants of the third National Health and Nutrition Examination Survey for analysis. Lp(a) was regarded as an exposure variable. LVH defined by the left ventricular mass index estimated from ECG was considered as an outcome variable. Multivariate logistic regression and restricted cubic spline (RCS) were used to assess the relationship between Lp(a) and LVH. Individuals with LVH had higher Lp(a) compared to individuals without LVH (P< 0.001). In the fully adjusted model, Lp(a) was strongly associated with LVH when as a continuous variable (per 1-unit increment, OR: 1.366, 95% CI: 1.043-1.789, P = 0.024), and higher Lp(a) remained independently associated with a higher risk of LVH when participants were divided into four groups according to quartiles of Lp(a) (Q4 vs Q1, OR: 1.508, 95% CI: 1.185-1.918, P = 0.001). And in subgroup analysis, this association remained significant among participants< 60 years, ≥ 60 years, male, with body mass index< 30 kg/m2, with hypertension and without diabetes (P< 0.05). In addition, we did not observe a nonlinear and threshold effect of Lp(a) with LVH in the RCS analysis (P for nonlinearity = 0.113).

Conclusion

Lp(a) was closely associated with LVH assessed by ECG in general population.

Lipoprotein(a) and heart failure: a systematic review

The role of lipoprotein(a) [Lp(a)] as a possible causal risk factor for atherosclerotic artery disease and aortic valve stenosis has been well established. However, the information on the association between Lp(a) levels and heart failure (HF) is limited and controversial. The main objective of the present study was to assess the association between Lp(a) levels and HF. This systematic review was performed according to PRISMA guidelines. A literature search was performed to detect studies that evaluated the association between Lp(a) levels and HF. Eight studies, including 73,410 patients, were eligible for this research. Seven prospective or retrospective cohorts and one cross-sectional study were analyzed. Five studies analyzed populations without HF; another three included patients with HF or left ventricular dysfunction. The endpoints evaluated varied according to the study analyzed, including incident HF, HF hospitalizations, and decreased left ventricular ejection fraction. Lp(a) levels were also analyzed in different ways, including analysis of Lp(a) as a continuous or categorical variable (distinct cut-off points or percentiles). Globally, the studies included in this review found predominantly positive results. Data on some relevant subgroups, such as HF of ischemic or non-ischemic etiology or HF with or without left ventricular dysfunction, was poorly reported. This systematic review suggests that there would be a positive relationship between Lp(a) levels and HF. Given the complexity and heterogeneity of HF, new studies should be developed to clarify this topic.

Lipoprotein(a)-60 Years Later-What Do We Know?

Lipoprotein(a) (Lp(a)) molecule includes two protein components: apolipoprotein(a) and apoB100. The molecule is the main transporter of oxidized phospholipids (OxPL) in plasma. The concentration of this strongly atherogenic lipoprotein is predominantly regulated by the LPA gene expression. Lp(a) is regarded as a risk factor for several cardiovascular diseases. Numerous epidemiological, clinical and in vitro studies showed a strong association between increased Lp(a) and atherosclerotic cardiovascular disease (ASCVD), calcific aortic valve disease/aortic stenosis (CAVD/AS), stroke, heart failure or peripheral arterial disease (PAD). Although there are acknowledged contributions of Lp(a) to the mentioned diseases, clinicians struggle with many inconveniences such as a lack of well-established treatment lowering Lp(a), and common guidelines for diagnosing or assessing cardiovascular risk among both adult and pediatric patients. Lp(a) levels are different with regard to a particular race or ethnicity and might fluctuate during childhood. Furthermore, the lack of standardization of assays is an additional impediment. The review presents the recent knowledge on Lp(a) based on clinical and scientific research, but also highlights relevant aspects of future study directions that would approach more suitable and effective managing risk associated with increased Lp(a), as well as control the Lp(a) levels.

The Role of Biochemical Cardiac Markers in Atrial Fibrillation

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia. Proteins are a component of cardiac biomarkers containing cell structures that are released into the circulation when a myocardial injury occurs. They are essential in the diagnosis, risk assessment, and treatment of patients who have chest pain, are thought to have acute coronary syndrome, or are experiencing acute heart failure exacerbations. There are numerous biochemical cardiac markers, but this article summarizes the basic role of major biochemical cardiac markers, including cardiac natriuretic peptides, cardiac troponins, C-reactive protein (CRP), creatine kinase-MB, heart-type fatty acid-binding protein, ischemia-modified albumin, lipoprotein (a), osteopontin (OPN), and soluble suppression of tumorigenicity 2 (sST2), in AF. Atrial natriuretic peptide may serve as an indicator of atrial integrity, which may help to select appropriate treatment approaches for AF. Higher levels of N-terminal pro-B-type natriuretic peptide and brain natriuretic peptide are predictive of incidental AF. Increased troponin T release may indicate better clinical results following AF ablation. Similarly, CRP increases the risk of the AF-increasing calcium (Ca) influx in atrial myocytes, but not because of atrial fibrosis. Patients with postoperative AF have lower FABP3 gene expression in the atrium. Lipoprotein (a) (Lp[a]) may play a causative role in the onset of AF and impact various cardiac tissues. Clinical trials for Lp(a)-lowering drugs should assess their impact on preventing AF. Also, OPN was highly expressed in the circulation of AF patients and further increased with the progression of AF. sST2 was a reliable predictor of new-onset AF and can improve the accuracy of the AF risk model. There is a greater chance that these cardiac biomarkers might be employed to enhance clinical risk stratification in AF.

Elevated Lipoprotein(a) Levels and Atrial Fibrillation: A Systematic Review

Objective

The role of lipoprotein(a) (Lp[a]) as a possibly causal risk factor for atherosclerotic cardiovascular disease has been well established. However, the clinical evidence regarding the association between Lp(a) levels and atrial fibrillation (AF) remains limited and inconsistent. This study aimed to analyze the association between elevated Lp(a) levels or single-nucleotide polymorphisms (SNPs) related to high levels of Lp(a) and AF.

Methods

This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A literature search was performed to identify studies that evaluated the association between Lp(a) levels or SNPs related to high levels of Lp(a) and AF. Observational studies with a cross-sectional, case-control, or cohort design were included in this systematic review, without limitations according to language, country, or publication type.

Results

Eleven observational studies including 1,246,817 patients were eligible for this systematic review. Two cross-sectional studies, 5 prospective/retrospective cohort studies, and 4 Mendelian randomization studies were analyzed. Two cross-sectional studies that compared Lp(a) levels between patients with and without AF showed conflicting results. Cohort studies that evaluated the incidence of AF according to Lp(a) levels showed different results: no association (3 studies), a positive association (1 study), and an inverse relationship (1 study). Finally, Mendelian randomization studies also showed heterogeneous results (positive association: 2 studies; inverse association: 1 study; no association: 1 study).

Conclusion

Although there could be an association between Lp(a) levels and AF, the results of the studies published to date are contradictory and not yet definitive. Therefore, further research should clarify this issue.

The association between lipoprotein(a) and atrial fibrillation: A systemic review and meta-analysis

Lipoprotein(a) (Lp[a]) is a particle consisting of a low-density lipoprotein (LDL)-like core connected to an apolipoprotein(a) chain, which is an established risk factor for cardiovascular disease. However, studies addressing the relationship between atrial fibrillation (AF) and Lp(a) demonstrated conflicted results. Thus, we sought to evaluate this relationship by conducting this systemic review and meta-analysis. We performed a comprehensive systematic search of health science databases, including PubMed, Embase, Cochrane Library, Web of Science, MEDLINE, and ScienceDirect, to identify all relevant literature from their inception to March 1, 2023. We identified nine related articles, which were eventually included in this study. Our study showed no association between Lp(a) with new-onset AF (HR = 1.45, 95% confidence interval [CI]: 0.57-3.67, p = .432). In addition, genetically elevated Lp(a) was not associated with the risk of atrial fibrillation (OR = 1.00, 95% CI: 1.00-1.00, p = .461). Different stratification of Lp(a) levels may have different outcomes. Also, higher Lp(a) levels may be inversely associated with the risk of developing AF compared to those with lower levels. Lp(a) levels were not associated with incident AF. Further research is needed to identify the mechanism underlying these results and better understand Lp(a) stratification for AF and the possible inverse association between Lp(a) and AF.

Lipoprotein(a): Cardiovascular Disease, Aortic Stenosis and New Therapeutic Option

Atherosclerosis is a chronic and progressive inflammatory process beginning early in life with late clinical manifestation. This slow pathological trend underlines the importance to early identify high-risk patients and to treat intensively risk factors to prevent the onset and/or the progression of atherosclerotic lesions. In addition to the common Cardiovascular (CV) risk factors, new markers able to increase the risk of CV disease have been identified. Among them, high levels of Lipoprotein(a)-Lp(a)-lead to very high risk of future CV diseases; this relationship has been well demonstrated in epidemiological, mendelian randomization and genome-wide association studies as well as in meta-analyses. Recently, new aspects have been identified, such as its association with aortic stenosis. Although till recent years it has been considered an unmodifiable risk factor, specific drugs have been developed with a strong efficacy in reducing the circulating levels of Lp(a) and their capacity to reduce subsequent CV events is under testing in ongoing trials. In this paper we will review all these aspects: from the synthesis, clearance and measurement of Lp(a), through the findings that examine its association with CV diseases and aortic stenosis to the new therapeutic options that will be available in the next years.

Association of lipoprotein(a) with all-cause and cause-specific mortality: A prospective cohort study

BACKGROUND

A growing number of studies have demonstrated a causal association between lipoprotein(a) [Lp(a)] and atherosclerotic cardiovascular diseases (ASCVDs), but its association with all-cause and cause-specific mortality remains unclear. Therefore, this study aimed to explore the association of Lp(a) with all-cause and cause-specific mortality.

METHODS

This prospective cohort study included 8,525 participants from the third National Health and Nutrition Examination Survey. Lp(a) was considered an exposure variable, all-cause and cause-specific mortality were used as outcome variables, and all participants were followed from the interview date until death or December 31, 2015. COX proportional hazards regression models, stratified analysis, sensitivity analysis, restricted cubic spline plots and Kaplan-Meier survival curves were used to analyze the association of Lp(a) with all-cause and cause-specific mortality.

RESULTS

After adjusting for traditional cardiovascular risk factors, Lp(a) remained strongly associated with all-cause and CVDs-related mortality (P for trend = 0.007 and < 0.001). Subgroup analyses showed that higher Lp(a) remained associated with higher risk of all-cause mortality in those > 60 years of age, with a BMI < 30 kg/m², and without diabetes, whereas the association between Lp(a) and CVDs-related mortality remained stable in participants ≤ 60 years of age, male, with a BMI < 30 kg/m², with hypertension, without diabetes, or without CVDs (P < 0.05). In sensitivity analyses, we found that the association of Lp(a) with all-cause and CVDs-related mortality remained robust after excluding individuals who died within one year of follow-up (P for trend = 0.041 and 0.002).

CONCLUSIONS

Lp(a) was associated with the risk of all-cause and CVDs-related mortality.

Low lipoprotein(a) concentration is associated with atrial fibrillation: a large retrospective cohort study

BACKGROUND AND AIMS

The role of serum lipoprotein(a) [Lp(a)] levels in atrial fibrillation (AF) is still uncertain, especially in the Chinese population. Here, we aimed to elucidate the potential relationship between Lp(a) quantiles and AF.

METHODS

All data were collected through inpatients with electronic health records from the Second Affiliated Hospital of Nanchang University, Jiangxi Province, China. The propensity score matching (PSM) method was used to match control and case groups. Interactions between AF, Lp(a) quantiles, and other clinical indices were analyzed by logistic regression and stratified analysis. Statistical analyses were performed with IBM SPSS statistical software and R software.

RESULTS

From 2017 to 2021, 4,511 patients with AF and 9,022 patients without AF were 1:2 matched by the propensity score matching method. A total of 46.9% of the study group was women, and the baseline mean age was 65 years. The AF group exhibited lower median Lp(a) than the non-AF group (15.95 vs. 16.90 mg/dL; P < 0.001). Based on the Lp(a) quantiles, the study population was divided into four groups: Q1 (≤ 8.71 mg/dL), Q2 (8.71-16.54 mg/dL), Q3 (16.54-32.42 mg/dL) and Q4 (> 32.42 mg/dL). The AF prevalence of each group decreased from 34.2% (Q1) to 30.9% (Q4) (P < 0.001). Lp(a) quantiles 1-3 significantly increased AF to 1.162-fold (1.049-1.286), 1.198-fold (1.083-1.327), and 1.111-fold (1.003-1.231) in the unadjusted logistic regression model, respectively. In the adjusted model, Lp(a) < 32.42 mg/dL still showed a significant inverse association with AF. In the stratified analysis, Lp(a) levels in female patients exhibited a significant negative correlation with AF (OR of Q1: 1.394[1.194-1.626], P = 0.001). Age and hypertension did not affect the adverse correlation.

CONCLUSION

Low circulating Lp(a) levels were associated with AF, especially in the female Han population, suggesting that Lp(a) may be useful for risk stratification of AF in female individuals.

Lipid Profile and Atrial Fibrillation: Is There Any Link?

Atrial fibrillation (AF) is the most common type of symptomatic arrhythmias, which was induced by multiple causes and dyslipidemia is a well-known causal factor for the atherosclerotic cardiovascular disease (ASCVD). Interestingly, emerging data has suggested that lipid disorder may be also associated with AF. Several previous studies have shown a link of the prevalence of AF with decreased concentration of low-density lipoproteins (LDL)-cholesterol, total cholesterol (TC), high-density lipoproteins (HDL)-cholesterol, and elevated lipoprotein(a) [Lp(a)]. In this manuscript, we try to summarize the current evidence regarding the relation of dyslipidemia to the incident AF, present the potential lipid-related mechanisms of AF development, which is involved in cell membrane properties, LDL-receptors reduction, reverse cholesterol transport, adiposity-induced inflammation, apoptosis, and autophagy. Such information may boost our understandings concerning the lipid disorder and AF, which may help future exploration in the link of dyslipidemia and AF.

The effect of apolipoprotein E gene polymorphism and Lp(a) levels on coronary artery disease with atrial fibrillation

OBJECTIVE

To explore the influence of apolipoprotein E (APOE) genotypes and blood lipid metabolism on coronary artery disease (CAD) with atrial fibrillation (AF).

METHODS

Patients with suspected CAD were consecutively enrolled and divided into groups with or without CAD and/or AF. Blood lipid levels and APOE genotypes were determined and analysed for associations with CAD and AF.

RESULTS

A total of 2048 patients were included (400 patients without CAD or AF [controls], 126 patients without CAD but with AF, 1294 patients with CAD without AF, and 228 patients with CAD and AF). Age and lipoprotein (a) (Lp[a]) levels were significantly higher in patients with CAD and AF versus those with CAD without AF. Among patients with CAD, the E3/E3 genotype and ε3 allele frequencies were significantly lower in patients with AF than in those without AF, and the E4/E4 genotype and ε4 allele frequencies were significantly increased. Multivariate logistic regression revealed that increased Lp(a) levels and age were independent risk factors for AF in patients with CAD.

CONCLUSION

Among patients with CAD, those with AF had increased age, ε4 frequencies and Lp(a) levels. Age and Lp(a) levels may be independent risk factors for AF in patients with CAD.

Elevated Lipoprotein(a) and Risk of Atrial Fibrillation: An Observational and Mendelian Randomization Study

BACKGROUND

Atrial fibrillation (AF) is a cardiac arrhythmia associated with an elevated risk of stroke, heart failure, and mortality. However, preventative therapies are needed with ancillary benefits on its cardiovascular comorbidities. Lipoprotein(a) (Lp[a]) is a recognized risk factor for atherosclerotic cardiovascular disease (ASCVD), which itself increases AF risk, but it remains unknown whether Lp(a) is a causal mediator of AF independent of ASCVD.

OBJECTIVES

This study investigated the role of Lp(a) in AF and whether it is independent of ASCVD.

METHODS

Measured and genetically predicted Lp(a) levels were tested for association with 20,432 cases of incident AF in the UK Biobank (N = 435,579). Mendelian randomization analyses were performed by using summary-level data for AF from publicly available genome-wide association studies (N = 1,145,375).

RESULTS

In the UK Biobank, each 50 nmol/L (23 mg/dL) increase in Lp(a) was associated with an increased risk of incident AF using measured Lp(a) (HR: 1.03; 95% CI: 1.02-1.04 ; P = 1.65 × 10^-8) and genetically predicted Lp(a) (OR: 1.03; 95% CI: 1.02-1.05; P = 1.33 × 10^-5). Mendelian randomization analyses using independent data replicated the effect (OR: 1.04 per 50 nmol/L Lp[a] increase; 95% CI: 1.03-1.05 per 50 nmol/L Lp[a] increase; P = 9.23 × 10^-10). There was no evidence of risk-conferring effect from low-density lipoprotein cholesterol or triglycerides, and only 39% (95% CI: 27%-73%) of Lp(a) risk was mediated through ASCVD, suggesting that Lp(a) partly influences AF independent of its known effects on ASCVD.

CONCLUSIONS

Our findings implicate Lp(a) as a potential causal mediator in the development of AF which show that the effects of Lp(a) extend across myocardial tissues. Ongoing clinical trials for Lp(a)-lowering therapies should evaluate effects on AF prevention.

Long-Term Abnormalities of Lipid Profile After a Single Episode of Sepsis

Background: Acute disturbances of the lipid profile are commonplace during acute sepsis episode. However, their long-term persistence has not to be investigated despite pivotal role of dyslipidemia in several comorbidities excessively noted in sepsis survivors (stroke, cardiomyopathy). Methods: A total of 9,861 individuals hospitalized for a singular episode of sepsis between 2009 and 2019 were identified from electronic medical records. Lab measurements of total cholesterol (Tchol), high-density lipoprotein (HDL-c), low-density lipoprotein (LDL-c), very low-density lipoprotein (VLDL), triglycerides (TG), lipoprotein(a) [Lp (a)], apolipoprotein B (ApoB), and C-reactive protein (CRP). The data were examined as baseline values before sepsis, during hospitalization, and <3 months, 3-6 months, 6-12 months, 1-2 years, and more than 2 years from initial sepsis. Results: Significant reductions in HDL-c (HDLbaseline = 44.06 vs. HDLsepsis = 28.2; U = -37.79, p < 0.0001, Cohen's d = 0.22) and LDL-c serum levels were observed during and up to three months post sepsis, with females much less affected. In contrast, male subjects had derangement in HDL present for up to two years after a singular septic episode. Total cholesterol levels were slightly yet significantly elevated for up to two years after sepsis. TG were elevated up to one year [TGbaseline = 128.26 vs. TGsepsis = 170.27, t(8255) = -21.33, p < 0.0001, Cohen's d = 0.49] and normalized. Lp(a) was elevated up to two years after initial episode [Lp(a)baseline = 24.6 ± 16.06; Lp(a)sepsis-2year = 8.25 ± 5.17; Lp(a)morethan2years = 61.4 ± 40.1; ANOVA F (2, 24) = 7.39; p = 0.0032]. Response to statin therapy was blunted in sepsis survivors for several years after sepsis resolution. Significant drop-out in prescription of statins and niacin after sepsis was observed. Serum high sensitivity C-reactive protein was elevated for up to five years after sepsis resolution (H [6;1685] = 502.2; p < 0.0001). Discussion: Lipid abnormalities persisted long after the initial septic insult suggesting potential role in accelerating atherosclerosis and other abnormalities. In addition, sepsis seems to blunt statin effectiveness. Additionally, a significant and unexplained drop in statin use was seen in post-septic period. Conclusions: Our study suggests that persistent derangements of lipid profile components for up to two years after sepsis may be associated with altered risk of atherosclerosis-related events among sepsis survivors.

Lipoprotein (a) and Cardiovascular Disease: A Missing Link for Premature Atherosclerotic Heart Disease and/or Residual Risk

ABSTRACT

Lipoprotein(a) or lipoprotein "little a" is an under-recognized causal risk factor for cardiovascular (CV) disease (CVD), including coronary atherosclerosis, aortic valvular stenosis, ischemic stroke, heart failure and peripheral arterial disease. Elevated plasma Lp(a) (≥50 mg/dL or ≥100 nmol/L) is commonly encountered in almost 1 in 5 individuals and confers a higher CV risk compared to those with normal Lp(a) levels, although such normal levels have not been generally agreed upon. Elevated Lp(a) is considered a cause of premature and accelerated atherosclerotic CVD. Thus, in patients with a positive family or personal history of premature coronary artery disease (CAD), Lp(a) should be measured. However, elevated Lp(a) may confer increased risk for incident CAD even in the absence of a family history of CAD, and even in those who have guideline-lowered LDL-cholesterol (<70 mg/dl) and continue to have a persisting CV residual risk. Thus, measurement of Lp(a) will have a significant clinical impact on the assessment of atherosclerotic CVD risk, and will assume a more important role in managing patients with CVD with the advent and clinical application of specific Lp(a)-lowering therapies. Conventional therapeutic approaches like lifestyle modification and statin therapy remain ineffective at lowering Lp(a). Newer treatment modalities, such as gene silencing via RNA interference with use of antisense oligonucleotide(s) or small interfering RNA molecules targeting Lp(a) seem very promising. These issues are herein reviewed, accumulated data are scrutinized, meta-analyses and current guidelines are tabulated and Lp(a)-related CVDs and newer therapeutic modalities are pictorially illustrated.

Association of Lipoprotein (a) variants with risk of cardiovascular disease: a Mendelian randomization study

Background

There is a well-documented empirical relationship between lipoprotein (a) [Lp(a)] and cardiovascular disease (CVD); however, causal evidence, especially from the Chinese population, is lacking. Therefore, this study aims to estimate the causal association between variants in genes affecting Lp(a) concentrations and CVD in people of Han Chinese ethnicity.

Methods

Two-sample Mendelian randomization analysis was used to assess the causal effect of Lp(a) concentrations on the risk of CVD. Summary statistics for Lp(a) variants were obtained from 1256 individuals in the Cohort Study on Chronic Disease of Communities Natural Population in Beijing, Tianjin and Hebei. Data on associations between single-nucleotide polymorphisms (SNPs) and CVD were obtained from recently published genome-wide association studies.

Results

Thirteen SNPs associated with Lp(a) levels in the Han Chinese population were used as instrumental variables. Genetically elevated Lp(a) was inversely associated with the risk of atrial fibrillation [odds ratio (OR), 0.94; 95% confidence interval (95%CI), 0.901–0.987; P = 0.012)], the risk of arrhythmia (OR, 0.96; 95%CI, 0.941–0.990; P = 0.005), the left ventricular mass index (OR, 0.97; 95%CI, 0.949–1.000; P = 0.048), and the left ventricular internal dimension in diastole (OR, 0.97; 95%CI, 0.950–0.997; P = 0.028) according to the inverse-variance weighted method. No significant association was observed for congestive heart failure (OR, 0.99; 95% CI, 0.950–1.038; P = 0.766), ischemic stroke (OR, 1.01; 95%CI, 0.981–1.046; P = 0.422), and left ventricular internal dimension in systole (OR, 0.98; 95%CI, 0.960–1.009; P = 0.214).

Conclusions

This study provided evidence that genetically elevated Lp(a) was inversely associated with atrial fibrillation, arrhythmia, the left ventricular mass index and the left ventricular internal dimension in diastole, but not with congestive heart failure, ischemic stroke, and the left ventricular internal dimension in systole in the Han Chinese population. Further research is needed to identify the mechanism underlying these results and determine whether genetically elevated Lp(a) increases the risk of coronary heart disease or other CVD subtypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01482-0.

Causal effects of plasma lipids on the risk of atrial fibrillation: A multivariable mendelian randomization study

BACKGROUND AND AIMS

Observational studies have suggested that plasma lipids contribute substantially to cardiovascular disease, but "cholesterol paradox" in atrial fibrillation (AF) remains. We sought to investigate the causal effects of lipid profiles on the risk of AF.

METHODS AND RESULTS

Two-sample Mendelian randomization (MR) framework was implemented to examine the causality of association. Summary estimations of genetic variants associated with low density lipoprotein (LDL)-cholesterol, high density lipoprotein (HDL)-cholesterol, total cholesterol, triglycerides, lipoprotein-a [Lp(a)], apolipoprotein A1 (ApoA 1), and apolipoprotein B (ApoB) were 81, 99, 96, 61, 30, 10, and 23 single nucleotide polymorphisms, respectively. Genetic association with AF were retrieved from a genome-wide association study that included 1,030,836 individuals. The complications for AF were predefined as cardioembolic stroke (CES) and heart failure (HF). In the multivariable MR, the odds ratios for AF per standard deviation (SD) increase were 1.030 (95% confidence interval (CI) 0.979-1.083; P = 0.257) for LDL-cholesterol, 0.986 (95% CI 0.931-1.044; P = 0.622) for HDL-cholesterol, 0.965 (95% CI 0.896-1.041; P = 0.359) for triglycerides, 1.001 (95% CI 1.000-1.003; P = 0.023) for Lp(a), 1.017 (95% CI 0.966-1.070; P = 0.518) for ApoA1, and 1.002 (95% CI 0.963-1.043; P = 0.923) for ApoB. There was no evidence that other lipid components were causally associated with AF, CES, or HF, other than for a marginal association between triglycerides and HF.

CONCLUSIONS

This MR study provides robust evidence that high Lp(a) increases the risk of AF, suggesting that interventions targeting Lp(a) may contribute to the primary prevention of AF.