Lipoprotein (a) as a cause of cardiovascular disease: insights from epidemiology, genetics, and biology

Lipoprotein(a) in atherosclerotic cardiovascular disease and proprotein convertase subtilisin/kexin-type 9 inhibitors

High plasma lipoprotein(a) (Lp(a)) levels increase the cardiovascular risk in populations with atherosclerotic cardiovascular disease (ASCVD). Apolipoprotein (a) [apo(a)], a unique protein component of Lp(a), plays an important role in the pathogenesis of atherosclerosis. Statins, the primary medication in managing ASCVD, lower low-density lipoprotein cholesterol (LDL-C) but concurrently elevate plasma Lp(a) levels, contributing to an increased residual cardiovascular risk. In turn, proprotein convertase subtilisin/kexin-type 9 (PCSK9) inhibitors, a novel class of LDL-C lowering drugs, effectively reduce plasma Lp(a) levels, which is believed to decrease residual cardiovascular risk. However, the mechanism by which PCSK9 inhibitors reduce Lp(a) levels remains unknown. In addition, there are some clinical limitations of PCSK9 inhibitors. Here, we systematically review the past, present, and prospects of studies pertaining to Lp(a), PCSK9 inhibitors, and ASCVD.

Association Between Lipoprotein(a) and Dilatation of Different Aortic Segments in Hypertensive Patients

PURPOSE

There are limited reports on the potential link between Lp(a) and ARDM. Thus, we examined the relationship between Lp(a) and ARDM among hypertensive patients.

METHODS

We used echocardiography to measure ARDM in 513 consecutively hospitalized patients. namely, the aortic valve annulus (Ava), sinuses of Valsalva (SV), sinotubular junction (STJ), and ascending aorta (AA) in 513 consecutive inpatients. We also examined the Lp(a), and other laboratory profiles of all participants.

RESULTS

Lp(a) exhibited a positive and independent relationship with the SV diameter (coefficient [β] = 0.330, p = 0.002) and STJ (coefficient [β] = 0.253, p = 0.023), regardless of age, sex, height, or other clinical factors among hypertensive, but not nonhypertensive patients. We also demonstrated that a marked rise in Lp(a) levels was independently associated with SV dilatation (SVD) (OR: 1.006, 95% CI: 1.002-1.009, p = 0.002) and AA dilatation (AAD) (OR: 1.006, 95% CI: 1.000-1.011, p = 0.035) in patients with hypertension. In the subgroup analysis, elevated Lp(a) levels were significantly associated with SV dilatation in all subgroups, and with AAD in males and patients aged 65 years or younger (p < 0.05). The restricted cubic spline analysis indicated a linear association between Lp(a) levels and the risk of both SV and AAD (p < 0.05).

CONCLUSIONS

Herein, we were the first to report that among hypertensive patients, elevated Lp(a) concentrations were intricately linked to the ARDMs at SV and STJ. Moreover, we revealed that the Lp(a) level was a stand-alone indicator of SVD and AAD.

Advances in the pharmacological management of hyperlipidemia through the use of combination therapies

INTRODUCTION

Lipid-lowering therapies are well established for the treatment of cardiovascular disease (CVD). Historically monotherapy studies have been performed, but the introduction of statins has led to these drugs being recognized as baseline therapies and to the investigation of combination therapy of both older and newer medications with them.

AREAS COVERED

Surrogate marker studies have shown additive effects on LDL-C, triglycerides and HDL-C of combination therapies with statins and these have extended to lipoprotein (a). Imaging studies have often shown benefits paralleling lipid studies. However, outcome studies have failed to show added benefits with niacin or fibrates while confirming the benefits of ezetimibe, bempedoic acid and proprotein convertase subtilisin kexin-9 (PCSK-9) inhibitors and icosapent ethyl.

EXPERT OPINION

Combination therapy for LDL-C in dual combinations is well validated. Data for intervention on triglycerides is limited to icosapent ethyl, but this may exert effects independent of lipids. New drugs targeting triglycerides through apolipoprotein C3 and angiopoietin-like peptides are in development. Studies on combination therapy raising HDL-C have generally disappointed, though cholesterol ester transfer protein (CETP) inhibition remains a target. Lipoprotein (a) is recognized as a CVD risk factor and effective therapies are in development but results on CVD events are lacking.

Causal effect of lipoprotein(a) level on chronic kidney disease of European ancestry: a two-sample Mendelian randomization study

INTRODUCTION

Chronic kidney disease is a growing health issue, and the options of prevention and therapy remain limited. Although a number of observational studies have linked higher Lp(a) [lipoprotein(a)] levels to the kidney impairment, the causal relationship remains to be determined. The purpose of this study was to assess the causal association between Lp(a) levels and CKD.

METHODS

We selected eight single-nucleotide polymorphisms (SNPs) significantly associated with Lp(a) levels as instrumental variables. Genome-wide association study (GWAS) from CKDGen consortium yielded the summary data information for CKD. We designed the bidirectional two-sample Mendelian randomization (MR) analyses. The estimates were computed using inverse-variance weighted (IVW), simple median, weighted median, and maximum likelihood. MR-Egger regression was used to detect pleiotropy.

RESULTS

Fixed-effect IVW analysis indicated that genetically predicted Lp(a) levels were associated with CKD significantly (odds ratio, 1.039; 95% CI, 1.009-1.069; p = 0.010). The SNPs showed no pleiotropy according to result of MR-Egger test. Results from sensitivity analyses were consistent. In the inverse MR analysis, random-effect IVW method showed CKD had no causal effect on the elevated Lp(a) (odds ratio, 1.154; 95% CI, 0.845-1.576; p = 0.367).

CONCLUSION

In this bidirectional two-sample MR analysis, the causal deteriorating effects of genetically predicted plasma Lp(a) levels on the risk of CKD were identified. On the contrary, there is no evidence to support a causal effect of CKD on Lp(a) levels.

Lipoprotein(a) as an Independent Predictor of Elevated SYNTAX Score

Background/Objectives: Increased lipoprotein(a) [Lp(a)] level is associated with elevated possibility of atherosclerosis progression. SYNTAX score enables to grade the anatomy of coronary arteries. To identify the impact of increased Lp(a) level on SYNTAX score in individuals with acute myocardial infarction (AMI). Methods: In our analysis, we enrolled 173 consecutive adult patients hospitalized for AMI in a tertiary cardiology center from December 2022 to August 2023. Patient characteristics were compared for patients with SYNTAX score ≥ 23 (64 patients) and SYNTAX score < 23 (109 patients). The SYNTAX score was estimated based on the results of coronary angiography. Logistic regression analyses were performed to evaluate the factors associated with SYNTAX score. Results: Individuals with the SYNTAX score ≥ 23 were more likely to have arterial hypertension, diabetes mellitus, significant stenosis in the left main coronary artery, and higher Lp(a) levels than those with SYNTAX < 23 (all p < 0.05). On univariate analysis, age (OR 1.05, 95% CI 1.02-1.08, p = 0.001), Lp(a) levels (OR 1.04, 95% CI 1.01-1.06, p = 0.001), and arterial hypertension (OR 2.69, 95% CI 1.26-5.74, p = 0.011) were associated with SYNTAX score ≥ 23. Multivariable determinants of SYNTAX score ≥ 23 were as follows: Lp(a) levels (OR 1.03, 95% CI 1.01-1.08, p = 0.029), and age (OR 1.04, 95% CI 1.01-1.07, p = 0.005). The cut-off value for Lp(a) 166.16 nmol/L identifies patients with SYNTAX score ≥ 23 with 97% sensitivity and 44% specificity (area under curve 0.78, p < 0.001). Conclusions: Elevated Lp(a) concentration is associated with a higher SYNTAX score. A cut-off value of Lp(a) above 166.16 nmol/L allows us to identify subjects with SYNTAX score ≥ 23 with good specificity and sensitivity.

Lipid nanoparticle delivery of TALEN mRNA targeting LPA causes gene disruption and plasma lipoprotein(a) reduction in transgenic mice

Lipoprotein(a), or Lp(a), is encoded by the LPA gene and is a causal genetic risk factor for cardiovascular disease. Individuals with high Lp(a) are at risk for cardiovascular morbidity and are refractory to standard lipid-lowering agents. Lp(a)-lowering therapies currently in clinical development require repetitive dosing, while a gene editing approach presents an opportunity for a single-dose treatment. In this study, mRNAs encoding transcription activator-like effector nucleases (TALENs) were designed to target human LPA for gene disruption and permanent Lp(a) reduction. TALEN mRNAs were screened in vitro and found to cause on-target gene editing and target protein reduction with minimal off-target editing. TALEN mRNAs were then encapsulated with LUNAR, a proprietary lipid nanoparticle (LNP), and administered to transgenic mice that expressed a human LPA transgene. A single dose of TALEN mRNA-LNPs reduced plasma Lp(a) levels in mice by over 80%, which was sustained for at least 5 weeks. Moreover, both standard and long-read next-generation sequencing confirmed the presence of gene-inactivating deletions at LPA transgene loci. Overall, this study serves as a proof-of-concept for using TALEN-mediated gene editing to disrupt LPA in vivo, paving the way for the development of a feasible gene editing therapy for patients with high Lp(a).

High lipoprotein(a) is a risk factor for peripheral artery disease, abdominal aortic aneurysms, and major adverse limb events

PURPOSE OF REVIEW

To summarize evidence from recent studies of high lipoprotein(a) as a risk factor for peripheral artery disease (PAD), abdominal aortic aneurysms (AAA), and major adverse limb events (MALE). Additionally, provide clinicians with 10-year absolute risk charts enabling risk prediction of PAD and AAA by lipoprotein(a) levels and conventional risk factors.

RECENT FINDINGS

Numerous studies support high lipoprotein(a) as an independent risk factor for PAD, AAA, and MALE. The strongest evidence is from the Copenhagen General Population Study (CGPS) and the UK Biobank, two large general population-based cohorts. In the CGPS, a 50 mg/dl higher genetically determined lipoprotein(a) associated with hazard ratios of 1.39 (1.24-1.56) for PAD and 1.21 (1.01-1.44) for AAA. Corresponding hazard ratio in the UK Biobank were 1.38 (1.30-1.46) and 1.42 (1.28-1.59). In CGPS participants with levels at least 99th (≥143 mg/dl) vs, less than 50th percentile (≤9 mg/dl), hazard ratios were 2.99 (2.09-4.30) for PAD and 2.22 (1.21-4.07) for AAA, with a corresponding incidence rate ratio for MALE of 3.04 (1.55-5.98) in participants with PAD.

SUMMARY

Evidence from both observational and genetic studies support high lipoprotein(a) as a causal risk factor for PAD, AAA, and MALE, and highlight the potential of future lipoprotein(a)-lowering therapy to reduce the substantial morbidity and mortality associated with these diseases.

The functions of apolipoproteins and lipoproteins in health and disease

Lipoproteins and apolipoproteins are crucial in lipid metabolism, functioning as essential mediators in the transport of cholesterol and triglycerides and being closely related to the pathogenesis of multiple systems, including cardiovascular. Lipoproteins a (Lp(a)), as a unique subclass of lipoproteins, is a low-density lipoprotein(LDL)-like particle with pro-atherosclerotic and pro-inflammatory properties, displaying high heritability. More and more strong evidence points to a possible link between high amounts of Lp(a) and cardiac conditions like atherosclerotic cardiovascular disease (ASCVD) and aortic stenosis (AS), making it a risk factor for heart diseases. In recent years, Lp(a)'s role in other diseases, including neurological disorders and cancer, has been increasingly recognized. Although therapies aimed at low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) have achieved significant success, elevated Lp(a) levels remain a significant clinical management problem. Despite the limited efficacy of current lipid-lowering therapies, major clinical advances in new Lp(a)-lowering therapies have significantly advanced the field. This review, grounded in the pathophysiology of lipoproteins, seeks to summarize the wide-ranging connections between lipoproteins (such as LDL-C and HDL-C) and various diseases, alongside the latest clinical developments, special emphasis is placed on the pivotal role of Lp(a) in cardiovascular disease, while also examining its future potential and mechanisms in other conditions. Furthermore, this review discusses Lp(a)-lowering therapies and highlights significant recent advances in emerging treatments, advocates for further exploration into Lp(a)'s pathogenic mechanisms and its potential as a therapeutic target, proposing new secondary prevention strategies for high-risk individuals.

Effect of ertugliflozin on left ventricular function in type 2 diabetes and pre-heart failure: the Ertu-GLS randomized clinical trial

BACKGROUND

The therapeutic effects of ertugliflozin, a sodium-glucose cotransporter 2 inhibitor, on cardiovascular outcome are not fully understood. This study aimed to evaluate the efficacy and safety of ertugliflozin on cardiac function in people with type 2 diabetes and pre-heart failure.

METHODS

We conducted a 24-week randomized, double-blind, placebo-controlled trial involving individuals with type 2 diabetes inadequately controlled with antidiabetic medications. Participants with left ventricular hypertrophy, E/e' >15, or impaired left ventricular global longitudinal strain (LVGLS) were randomized 1:1 to receive either ertugliflozin (5 mg once daily) or a placebo. The primary outcome was the change in LVGLS. Secondary outcomes included changes in left ventricular mass index (LVMI) and left ventricular ejection fraction (LVEF). Prespecified exploratory outcomes, including angiotensin-converting enzyme 2 (ACE2) and angiotensin (1-7) levels, were also assessed.

RESULTS

A total of 102 individuals (mean age, 63.9 ± 9.2 years; 38% women) were included. The ertugliflozin group showed a significant improvement in LVGLS (- 15.5 ± 3.1% to - 16.6 ± 2.8%, P = 0.004) compared to the placebo group (- 16.7 ± 2.7% to - 16.4 ± 2.6%, P = 0.509), with a significant between-group difference (P = 0.013). Improvements in LVMI and LVEF were also observed. Additionally, significant reductions in HbA1c, systolic blood pressure, whole-body and visceral fat, uric acid, proteinuria, N-terminal pro-B-type natriuretic peptide, and lipoprotein(a) were noted. ACE2 and angiotensin (1-7) levels significantly increased in the ertugliflozin group compared to the placebo group and correlated with changes in LVGLS [r = 0.456, P < 0.001 for ACE2; r = 0.541, P < 0.001 for angiotensin (1-7)]. Adverse events were similar between the two groups.

CONCLUSIONS

This study demonstrated that ertugliflozin has beneficial effects on left ventricular function in individuals with type 2 diabetes and pre-heart failure, and it provided insights into potential underlying mechanisms.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03717194.

Lack of association between Lp(a) and retinal vein occlusion in a single institution and US national database

OBJECTIVE

This study examines associations between lipoprotein(a) (Lp[a]), a low-density-like lipoprotein, and renal vein occlusion (RVO) in US cohorts to characterize its prognostic role in the setting of RVO.

DESIGN

A two-phase retrospective cohort study.

METHODS

In the first phase, patients with RVO and a Lp(a) quantitative laboratory value at a single tertiary centre were reviewed. Lp(a) status was assessed in association with age of RVO diagnosis, visual acuity, time to development of RVO, and central subfield thickness. In the second phase, the TriNetX US Collaborative Network, a large national database, also was queried for the presence of high or low Lp(a) values and diagnoses of RVO.

RESULTS

The single tertiary care centre identified 45 patients with RVO and a laboratory value of Lp(a), finding no significant associations with respect to Lp(a) status and age of RVO onset, time from the laboratory draw to the development of RVO, visual acuity, and central subfield thickness (p > 0.05 for all). The TriNetX national database identified 35,687 patients with a high Lp(a) value (>30 mg/dL or 61 nmol/L) and 51,692 with a low Lp(a) value. An elevated Lp(a) value was not associated with higher odds of central (odds ratio [OR] = 1.15; 95% CI, 0.88-1.50) or branch RVO (OR = 1.01; 95% CI, 0.76-1.36).

CONCLUSION

Taken together, this analysis suggests a lack of association between Lp(a) value and risk of RVO. This study highlights the benefit of large national databases in the validation of laboratory value predictors identified through small-cohort observational studies.

LDL-C and hs-CRP Jointly Modify the Effect of Lp(a) on 5-Year Death in Patients With Percutaneous Coronary Intervention

BACKGROUND

Recent studies have suggested that adverse events associated with lipoprotein(a) [Lp(a)] might be modified by low-density lipoprotein cholesterol (LDL-C) or high-sensitivity C-reactive protein (hs-CRP) levels, but whether LDL-C and hs-CRP jointly mediate the outcome of Lp(a) remains unknown in patients with coronary artery disease.

METHODS AND RESULTS

A prospective study was conducted, enrolling consecutive 10 724 patients with percutaneous coronary intervention (PCI) in 2013. The endpoint event was all-cause death. A total of 10 000 patients with complete baseline data were finally included. During a median follow-up of 5.1 years, Lp(a) ≥ 30 mg/dL was an independent risk factor of all-cause death in the overall population, LDL-C ≥ 70 mg/dL, and hs-CRP ≥ 2 mg/L population, respectively. According to concurrent LDL-C (70 mg/dL) and hs-CRP (2 mg/L) levels, further analysis revealed that when LDL-C < 70 mg/dL regardless of hs-CRP levels, Lp(a) ≥ 30 mg/dL was not an independent predictor of all-cause death. However, when LDL-C ≥ 70 mg/dL, Lp(a) ≥ 30 mg/dL was independently associated with a higher risk of all-cause death in hs-CRP ≥ 2 mg/L (HR: 1.488, 95% CI: 1.059‒2.092), but not in hs-CRP < 2 mg/L (HR: 1.303, 95% CI: 0.914‒1.856).

CONCLUSION

Among PCI patients, Lp(a)-associated outcome was jointly affected by LDL-C and hs-CRP. As long as LDL-C is well controlled, the adverse effects of increased Lp(a) on cardiovascular risk seem to be weakened, and only when LDL-C and hs-CRP increase at the same time, elevated Lp(a) is associated with poorer long-term outcome.

Lipoprotein(a) and cardiovascular disease

One in five people are at high risk for atherosclerotic cardiovascular disease and aortic valve stenosis due to high lipoprotein(a). Lipoprotein(a) concentrations are lowest in people from east Asia, Europe, and southeast Asia, intermediate in people from south Asia, the Middle East, and Latin America, and highest in people from Africa. Concentrations are more than 90% genetically determined and 17% higher in post-menopausal women than in men. Individuals at a higher cardiovascular risk should have lipoprotein(a) concentrations measured once in their lifetime to inform those with high concentrations to adhere to a healthy lifestyle and receive medication to lower other cardiovascular risk factors. With no approved drugs to lower lipoprotein(a) concentrations, it is promising that at least five drugs in development lower concentrations by 65-98%, with three currently being tested in large cardiovascular endpoint trials. This Review covers historical perspectives, physiology and pathophysiology, genetic evidence of causality, epidemiology, role in familial hypercholesterolaemia and diabetes, management, screening, diagnosis, measurement, prevention, and future lipoprotein(a)-lowering drugs.

The Relationship between Lipoprotein A and the Prevalence of Multivessel Coronary Artery Disease in Young Patients with Acute Myocardial Infarction: An Observational Study

Introduction: Cardiovascular diseases are the leading cause of mortality worldwide, with a significant impact on socioeconomic aspects. Various biomarkers have been studied in relation to the diagnosis, progression, and prognosis of atherosclerotic disease, with lipoprotein (a) [Lp (a)] standing out as an important predictor of cardiovascular risk. This observational study aimed to clarify the association between Lp (a) levels and the severity of significant multivessel coronary lesions in acute myocardial infarction (AMI) patients. Materials and Methods: Conducted at the Clinical Emergency County Hospital of Craiova, Romania, the study involved 256 young patients divided into two groups based on Lp (a) levels: Group A (Lp (a) < 30 mg/dL) and Group B (Lp (a) ≥ 30 mg/dL). Patients included young adults up to 55 years for males and 60 years for females, excluding those with familial hypercholesterolemia. Results: The study revealed a significant association between elevated Lp (a) levels and the presence of multivessel coronary lesions. Patients with Lp (a) concentrations ≥ 30 mg/dL exhibited a higher prevalence of multivessel disease compared to those with lower levels. Discussion: The findings suggest that elevated Lp (a) levels are a crucial biomarker for the risk of coronary artery disease, particularly in young patients with AMI. The study emphasizes the need for aggressive lipid management strategies and personalized treatment approaches, considering the significant role of Lp (a) in atherosclerosis and AMI. Conclusions: Lipoprotein A levels above 30 mg/dL are associated with a higher prevalence of multivessel coronary lesions. Multivariate analysis revealed that higher Lp (a) levels and lower HDL levels are linked to an increased risk of multivessel coronary lesions.

Real-world impact of transitioning from one lipoprotein(a) assay to another in a clinical setting

Background and aims

Different lipoprotein(a) [Lp(a)] assays may affect risk stratification of individuals and thus clinical decision-making. We aimed to investigate how transitioning between Lp(a) assays at a large central laboratory affected the proportion of individuals with Lp(a) result above clinical thresholds.

Methods

We studied nationwide clinical laboratory data including 185,493 unique individuals (47.7 % women) aged 18-50 years with 272,463 Lp(a) measurements using Roche (2000-2009) and Siemens Lp(a) assay (2009-2019).

Results

While the majority of individuals (66-75 %) had low levels of Lp(a) (<30 mg/dL) independent of the assay used, the Roche assay detected 20 % more individuals with Lp(a) >50 mg/dL, 40 % more individuals with Lp(a) >100 mg/dL and 80 % more individuals with Lp(a) > 180 mg/dL than the currently used Siemens assay, likely due to calibration differences.

Conclusion

Transitioning from one Lp(a) immunoassay to another had significant impact on Lp(a) results, particularly in individuals approaching clinically relevant Lp(a) thresholds.

Lipoprotein (a) is a predictor of non-achievement of LDL-C goals in patients with chronic heart disease

INTRODUCTION AND OBJECTIVES

Lipoprotein (a) [Lp(a)] concentration influences serum low-density lipoprotein cholesterol (LDL-C) levels. How it influences the achievement of LDL-C targets established in the guidelines is not well studied. Our aim was to know the prevalence of elevated Lp(a) levels in patients with coronary artery disease, and to assess its influence on the achievement of LDL-C targets.

METHOD

We conducted a cross-sectional study in a cardiology department in Spain. A total of 870 patients with stable coronary artery disease had their lipid profile determined, including Lp(a). Patients were stratified into 2 groups according to Lp(a)>50mg/dL and Lp(a)≤50mg/dL. The association of Lp(a)>50mg/dL with achievement of LDL-C targets was assessed by logistic regression analysis.

RESULTS

The prevalence of Lp(a)>50mg/dL was 30.8%. Patients with Lp(a)>50mg/dL had higher baseline (142.30±47.54 vs. 130.47±40.75mg/dL; p=0.0001) and current (72.91±26.44 vs. 64.72±25.30mg/dL; p=0.0001), despite the fact that they were treated with more high-potency statins (77.2 vs. 70.9%; p=0.058) and more combination lipid-lowering therapy (37.7 vs. 25.7%; p=0.001). The proportion of patients achieving target LDL-C was lower in those with Lp(a)>50mg/dL. Independent predictors of having elevated Lp(a) levels>50mg/dL were the use of high-potency statins (OR 1.5; 95% CI 1.08-2.14), combination lipid-lowering therapy with ezetimibe (OR 2.0; 95% CI 1.45-2.73) and failure to achieve a LDL-C ≤55mg/dL (OR 2.3; 95% CI 1.63-3.23).

CONCLUSIONS

Elevated Lp(a) levels influence LDL-C levels and hinder the achievement of targets in patients at very high cardiovascular risk. New drugs that act directly on Lp(a) are needed in these patients.

New insights into the therapeutic options to lower lipoprotein(a)

BACKGROUND

Elevated levels of lipoprotein(a) [Lp(a)] represent a risk factor for cardiovascular disease including aortic valve stenosis, myocardial infarction and stroke. While the patho-physiological mechanisms linking Lp(a) with atherosclerosis are not fully understood, from genetic studies that lower Lp(a) levels protect from CVD independently of other risk factors including lipids and lipoproteins. Hereby, Lp(a) has been considered an appealing pharmacological target.

RESULTS

However, approved lipid lowering therapies such as statins, ezetimibe or PCSK9 inhibitors have a neutral to modest effect on Lp(a) levels, thus prompting the development of new strategies selectively targeting Lp(a). These include antisense oligonucleotides and small interfering RNAs (siRNAs) directed towards apolipoprotein(a) [Apo(a)], which are in advanced phase of clinical development. More recently, additional approaches including inhibitors of Apo(a) and gene editing approaches via CRISPR-Cas9 technology entered early clinical development.

CONCLUSION

If the results from the cardiovascular outcome trials, designed to demonstrate whether the reduction of Lp(a) of more than 80% as observed with pelacarsen, olpasiran or lepodisiran translates into the decrease of cardiovascular mortality and major adverse cardiovascular events, will be positive, lowering Lp(a) will become a new additional target in the management of patients with elevated cardiovascular risk.

Lipoprotein(a) in children and adolescents with genetically confirmed familial hypercholesterolemia followed up at a specialized lipid clinic

Background and aim

Many children with an FH mutation also exhibit elevated lipoprotein(a) levels, which is an independent risk factor for atherosclerotic cardiovascular disease. Studies have reported higher levels of lipoprotein(a) in adult and middle-aged women than men. There is limited knowledge on the concentration and change of lipoprotein(a) levels in children with genetic FH, and therefore we investigated sex-differences in lipoprotein(a) level and change in lipoprotein(a) in girls and boys with genetically confirmed FH.

Methods

Medical records were reviewed retrospectively in 438 subjects with heterozygous FH that started follow-up below the age of 19 years at the Lipid Clinic, Oslo University Hospital in Norway, and of these we included 386 subjects with at least one Lp(a) measurement.

Results

Mean (SD) age at baseline was 13.8 (7.3) years and the age was similar between sexes. Girls had a higher lipoprotein(a) level than boys at baseline: median (25-75 percentile) 223 (108-487) vs. 154 (78-360) mg/L, respectively (p < 0.01). From baseline to follow-up measurement (mean [SD] 8.9 [6.1] years apart), the mean (95 % CI) absolute and percentage change in Lp(a) level in girls was 151.4 (54.9-247.8) mg/L and 44.8 (16.4-73.1) %, respectively, and in boys it was 66.8 (22.9-110.8) mg/L and 50.5 (8.8-92.3) %, respectively (both p > 0.05).

Conclusions

We found an increase in Lp(a) levels in children with genetic FH with age, and higher levels in girls than boys, which could impact risk assessment and future ASCVD. Further research is needed to elucidate whether subjects with FH could benefit from lipoprotein(a)-lowering therapies that are under current investigations.

Do genetically determined very high and very low LDL levels contribute to Lp(a) plasma concentration?

BACKGROUND AND AIMS

Lipoprotein(a) [Lp(a)] is a well-recognized risk factor for atherosclerotic cardiovascular disease (ASCVD). Few data are available on the distribution of Lp(a) levels among subjects at different cardiovascular risk and in subjects with monogenic and polygenic dyslipidemias (familial hypercholesterolemia, FH and familial hypobetalipoproteinemia type 1, FHBL1). The aim of this study was to investigate the distribution of Lp(a) plasma levels in subjects with high and low LDL-C levels (FH and FHBL1) and in the general population.

METHODS AND RESULTS

The study cohorts included 356 hypercholesterolemic patients, 212 carrying a FH causative mutation, 144 with clinical FH (mutation negative - FHneg), 52 FHBL1 and 797 free-living subjects. Lp(a) levels were significantly higher in FH subjects (both FH and FHneg) (median 12.46 mg/dl and 14.0 mg/dl, respectively) compared with FHBL1 and free-living subjects (7.68 mg/dl and 7.18 mg/dl, respectively). More, Lp(a) levels were similar in FH subjects carrying LDLR defective and null mutations and FHneg. Subjects at high and very high CV risk exhibited significant higher Lp(a) levels (median 10.68 mg/dl and 9.20 mg/dl, respectively) compared with low and moderate CV risk (median 5.72 mg/dl and 7.80 mg/dl, respectively) (p < 0.0008).

CONCLUSIONS

FH subjects exhibit higher Lp(a) levels than FHBL1 and general population. Lp(a) slightly contribute to hypercholesterolemia in FH patients. Subjects at high and very high CV risk exhibited significant higher Lp(a) levels compared with low and moderate CV risk. Combined evaluation of Lp(a) levels in FH subjects with other traditional risk factors could identify very high-risk individuals who may benefit from early aggressive treatments to avoid premature CV events.

The levels of serum lipoprotein(a) on clinical outcomes in Chinese hospitalized patients with cardiovascular diseases

OBJECTIVE

Serum lipoprotein(a) [Lp(a)] is a risk factor of cardiovascular diseases. However, the relationship between the serum Lp(a) and clinical outcomes has been seldom studied in Chinese hospitalized patients with cardiovascular diseases.

METHODS

We retrospectively collected the clinical data of hospitalized patients with cardiovascular diseases in the Cardiovascular Department of Dongguan People's Hospital from 2016 to 2021 through the electronic case system. Patients were divided into 4 groups based on Lp(a) quartiles: Quartile1 (≤ 80.00 mg/L), Quartile 2 (80.01 ~ 160.90 mg/L), Quartile 3 (160.91 ~ 336.41 mg/L), Quartile 4 (> 336.41 mg/L). Cox proportional hazard regression models were constructed to examine the relationship between Lp(a) and cardiovascular events.

RESULTS

A total of 8382 patients were included in this study. After an average follow-up of 619 (320 to 1061) days, 1361 (16.2%) patients developed major adverse cardiovascular events, and 125 (1.5%) all-cause death were collected. The incidence of MACEs was 7.65, 8.24, 9.73 and 10.75 per 100 person-years in each Lp(a) quartile, respectively; the all-cause mortality was 0.48, 0.69, 0.64 and 1.18 per 100 person-years in each Lp(a) quartile, respectively. The multivariate Cox regression analysis suggested that high Lp(a) level was an independent risk factor for MACEs (HR: 1.189, [95% CI: 1.045 to 1.353], P = 0.030) and all-cause death (HR: 1.573, [95% CI: 1.009 to 2.452], P = 0.046).

CONCLUSION

In addition to traditional lipid indicators, higher Lp(a) exhibited higher risks of adverse cardiovascular events and death, indicated worse prognosis. Lp(a) may be a new target for the prevention of atherosclerotic diseases.

Lipoprotein(a) in Children and Adolescents: Risk or Causal Factor for Cardiovascular Disease? A Narrative Review

The evaluation of serum Lp(a) values in childhood and adolescence has been widely debated, and in the last few years, many authors have tried to better define Lp(a) role in atherosclerosis pathogenesis, starting from childhood. In our narrative review, we have evaluated the main historical stages of Lp(a) studies in childhood, trying to focus on pathogenic mechanisms linked to elevated serum Lp(a) values, starting from ischemic stroke and vascular damage, and to its possible direct involvement in premature atherosclerosis from childhood onwards. Historic manuscripts on Lp(a) in pediatric patients have mainly focused on serum Lp(a) values and increased stroke risk. More recently, many studies have evaluated Lp(a) as a coronary vascular disease (CVD) risk factor starting from childhood, especially related to a positive family history of premature CVD. Finally, only a few studies evaluated the role of Lp(a) in premature atherosclerotic processes and endothelial and vascular damage in pediatric patients. Lastly, we have hypothesized a future perspective, with the hope that plasma Lp(a) levels will be treated with a tailored pharmacologic approach, and Lp(a) will become a precocious therapeutic target to control the atherosclerotic pathways from the first years of life.

Therapeutic Gene Editing in Dyslipidemias

Dyslipidemia, characterized by abnormal lipid levels in the blood, significantly escalates the risk of atherosclerotic cardiovascular disease and requires effective treatment strategies. While existing therapies can be effective, long-term adherence is often challenging. There has been an interest in developing enduring and more efficient solutions. In this context, gene editing, particularly clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technology, emerges as a groundbreaking approach, offering potential long-term control of dyslipidemia by directly modifying gene expression. This review delves into the mechanistic insights of various gene-editing tools. We comprehensively analyze various pre-clinical and clinical studies, evaluating the safety, efficacy, and therapeutic implications of gene editing in dyslipidemia management. Key genetic targets, such as low-density lipoprotein receptor (LDLR), proprotein convertase subtilisin/kexin type 9 (PCSK9), angiopoietin-like protein 3 (ANGPTL3), apolipoprotein C3 (APOC3), and lipoprotein (a) (Lp(a)), known for their pivotal roles in lipid metabolism, are scrutinized. The paper highlights the promising outcomes of gene editing in achieving sustained lipid homeostasis, discusses the challenges and ethical considerations in genome editing, and envisions the future of gene therapy in revolutionizing dyslipidemia treatment and cardiovascular risk reduction.

Elevated lipoprotein(a) levels: A crucial determinant of cardiovascular disease risk and target for emerging therapies

Cardiovascular disease (CVD) remains a significant global health challenge despite advancements in prevention and treatment. Elevated Lipoprotein(a) [Lp(a)] levels have emerged as a crucial risk factor for CVD and aortic stenosis, affecting approximately 20 of the global population. Research over the last decade has established Lp(a) as an independent genetic contributor to CVD and aortic stenosis, beginning with Kare Berg's discovery in 1963. This has led to extensive exploration of its molecular structure and pathogenic roles. Despite the unknown physiological function of Lp(a), studies have shed light on its metabolism, genetics, and involvement in atherosclerosis, inflammation, and thrombosis. Epidemiological evidence highlights the link between high Lp(a) levels and increased cardiovascular morbidity and mortality. Newly emerging therapies, including pelacarsen, zerlasiran, olpasiran, muvalaplin, and lepodisiran, show promise in significantly lowering Lp(a) levels, potentially transforming the management of cardiovascular disease. However, further research is essential to assess these novel therapies' long-term efficacy and safety, heralding a new era in cardiovascular disease prevention and treatment and providing hope for at-risk patients.

A Polynesian-specific SLC22A3 variant associates with low plasma lipoprotein(a) concentrations independent of apo(a) isoform size in males

Lipoprotein(a) (Lp(a)) is a low-density lipoprotein (LDL)-like particle in which the apolipoprotein B component is covalently linked to apolipoprotein(a) (apo(a)). Lp(a) is a well-established independent risk factor for cardiovascular diseases. Plasma Lp(a) concentrations vary enormously between individuals and ethnic groups. Several nucleotide polymorphisms in the SLC22A3 gene associate with Lp(a) concentration in people of different ethnicities. We investigated the association of a Polynesian-specific (Māori and Pacific peoples) SLC22A3 gene coding variant p.Thr44Met) with the plasma concentration of Lp(a) in a cohort of 302 healthy Polynesian males. An apo(a)-size independent assay assessed plasma Lp(a) concentrations; all other lipid and apolipoprotein concentrations were measured using standard laboratory techniques. Quantitative real-time polymerase chain reaction was used to determine apo(a) isoforms. The range of metabolic (HbA1c, blood pressure, and blood lipids) and blood lipid variables were similar between the non-carriers and carriers in age, ethnicity and BMI adjusted models. However, rs8187715 SLC22A3 variant was significantly associated with lower Lp(a) concentrations. Median Lp(a) concentration was 10.60 nmol/L (IQR: 5.40-41.00) in non-carrier group, and was 7.60 nmol/L (IQR: 5.50-12.10) in variant carrier group (P<0.05). Lp(a) concentration inversely correlated with apo(a) isoform size. After correction for apo(a) isoform size, metabolic parameters and ethnicity, the association between the SLC22A3 variant and plasma Lp(a) concentration remained. The present study is the first to identify the association of this gene variant and low plasma Lp(a) concentrations. This provides evidence for better guidance on ethnic specific cut-offs when defining 'elevated' and 'normal' plasma Lp(a) concentrations in clinical applications.

Efficacy of Diagnostic Testing of Suspected Coronary Artery Disease: A Contemporary Review

BACKGROUND

Coronary artery disease (CAD) is a highly prevalent condition which can lead to myocardial ischemia as well as acute coronary syndrome. Early diagnosis of CAD can improve patient outcomes through guiding risk factor modification and treatment modalities.

SUMMARY

Testing for CAD comes with increased cost and risk; therefore, physicians must determine which patients require testing, and what testing modality will offer the most useful data to diagnose patients with CAD. Patients should have an initial risk stratification for pretest probability of CAD based on symptoms and available clinical data. Patients with a pretest probability less than 5% should receive no further testing, while patients with a high pretest probability should be considered for direct invasive coronary angiography. In patients with a pretest probability between 5 and 15%, coronary artery calcium score and or exercise electrocardiogram can be obtained to further risk stratify patients to low-risk versus intermediate-high-risk. Intermediate-high-risk patients should be tested with coronary computed tomography angiography (preferred) versus positron emission tomography or single photon emission computed tomography based on their individual patient characteristics and institutional availability.

KEY MESSAGES

This comprehensive review aimed to describe the available CAD testing modalities, detail their risks and benefits, and propose when each should be considered in the evaluation of a patient with suspected CAD.

Partitioning and aggregating cross-tissue and tissue-specific genetic effects to identify gene-trait associations

TWAS have shown great promise in extending GWAS loci to a functional understanding of disease mechanisms. In an effort to fully unleash the TWAS and GWAS information, we propose MTWAS, a statistical framework that partitions and aggregates cross-tissue and tissue-specific genetic effects in identifying gene-trait associations. We introduce a non-parametric imputation strategy to augment the inaccessible tissues, accommodating complex interactions and non-linear expression data structures across various tissues. We further classify eQTLs into cross-tissue eQTLs and tissue-specific eQTLs via a stepwise procedure based on the extended Bayesian information criterion, which is consistent under high-dimensional settings. We show that MTWAS significantly improves the prediction accuracy across all 47 tissues of the GTEx dataset, compared with other single-tissue and multi-tissue methods, such as PrediXcan, TIGAR, and UTMOST. Applying MTWAS to the DICE and OneK1K datasets with bulk and single-cell RNA sequencing data on immune cell types showcases consistent improvements in prediction accuracy. MTWAS also identifies more predictable genes, and the improvement can be replicated with independent studies. We apply MTWAS to 84 UK Biobank GWAS studies, which provides insights into disease etiology.

Associations of Circulating Biomarkers with Disease Risks: A Two-Sample Mendelian Randomization Study

Circulating biomarkers play a pivotal role in personalized medicine, offering potential for disease screening, prevention, and treatment. Despite established associations between numerous biomarkers and diseases, elucidating their causal relationships is challenging. Mendelian Randomization (MR) can address this issue by employing genetic instruments to discern causal links. Additionally, using multiple MR methods with overlapping results enhances the reliability of discovered relationships. Here, we report an MR study using multiple methods, including inverse variance weighted, simple mode, weighted mode, weighted median, and MR-Egger. We use the MR-base resource (v0.5.6) from Hemani et al. 2018 to evaluate causal relationships between 212 circulating biomarkers (curated from UK Biobank analyses by Neale lab and from Shin et al. 2014, Roederer et al. 2015, and Kettunen et al. 2016 and 99 complex diseases (curated from several consortia by MRC IEU and Biobank Japan). We report novel causal relationships found by four or more MR methods between glucose and bipolar disorder (Mean Effect Size estimate across methods: 0.39) and between cystatin C and bipolar disorder (Mean Effect Size: -0.31). Based on agreement in four or more methods, we also identify previously known links between urate with gout and creatine with chronic kidney disease, as well as biomarkers that may be causal of cardiovascular conditions: apolipoprotein B, cholesterol, LDL, lipoprotein A, and triglycerides in coronary heart disease, as well as lipoprotein A, LDL, cholesterol, and apolipoprotein B in myocardial infarction. This Mendelian Randomization study not only corroborates known causal relationships between circulating biomarkers and diseases but also uncovers two novel biomarkers associated with bipolar disorder that warrant further investigation. Our findings provide insight into understanding how biological processes reflecting circulating biomarkers and their associated effects may contribute to disease etiology, which can eventually help improve precision diagnostics and intervention.

Abdominal aortic aneurysm and cardiometabolic traits share strong genetic susceptibility to lipid metabolism and inflammation

Abdominal aortic aneurysm has a high heritability and often co-occurs with other cardiometabolic disorders, suggesting shared genetic susceptibility. We investigate this commonality leveraging recent GWAS studies of abdominal aortic aneurysm and 32 cardiometabolic traits. We find significant genetic correlations between abdominal aortic aneurysm and 21 of the cardiometabolic traits investigated, including causal relationships with coronary artery disease, hypertension, lipid traits, and blood pressure. For each trait pair, we identify shared causal variants, genes, and pathways, revealing that cholesterol metabolism and inflammation are shared most prominently. Additionally, we show the tissue and cell type specificity in the shared signals, with strong enrichment across traits in the liver, arteries, adipose tissues, macrophages, adipocytes, and fibroblasts. Finally, we leverage drug-gene databases to identify several lipid-lowering drugs and antioxidants with high potential to treat abdominal aortic aneurysm with comorbidities. Our study provides insight into the shared genetic mechanism between abdominal aortic aneurysm and cardiometabolic traits, and identifies potential targets for pharmacological intervention.

Consensus on lipoprotein(a) of the Spanish Society of Arteriosclerosis. Literature review and recommendations for clinical practice

The irruption of lipoprotein(a) (Lp(a)) in the study of cardiovascular risk factors is perhaps, together with the discovery and use of proprotein convertase subtilisin/kexin type 9 (iPCSK9) inhibitor drugs, the greatest novelty in the field for decades. Lp(a) concentration (especially very high levels) has an undeniable association with certain cardiovascular complications, such as atherosclerotic vascular disease (AVD) and aortic stenosis. However, there are several current limitations to both establishing epidemiological associations and specific pharmacological treatment. Firstly, the measurement of Lp(a) is highly dependent on the test used, mainly because of the characteristics of the molecule. Secondly, Lp(a) concentration is more than 80% genetically determined, so that, unlike other cardiovascular risk factors, it cannot be regulated by lifestyle changes. Finally, although there are many promising clinical trials with specific drugs to reduce Lp(a), currently only iPCSK9 (limited for use because of its cost) significantly reduces Lp(a). However, and in line with other scientific societies, the SEA considers that, with the aim of increasing knowledge about the contribution of Lp(a) to cardiovascular risk, it is relevant to produce a document containing the current status of the subject, recommendations for the control of global cardiovascular risk in people with elevated Lp(a) and recommendations on the therapeutic approach to patients with elevated Lp(a).

Impact of Lipoprotein(a) Levels on Cardiovascular Risk Estimation

INTRODUCTION

A new cardiovascular risk (CVR) calculator that incorporates Lipoprotein(a) [Lp(a)] levels has recently been designed.

AIMS

To estimate CVR using the new score and to identify the reduction in low-density lipoprotein cholesterol (LDL-C) or systolic blood pressure (SBP) necessary to balance the risk attributable to Lp(a).

METHODS

CVR throughout life and at 10 years was estimated with the new score in patients in primary prevention, both considering and not considering the value of Lp(a). When the estimated risk considering Lp(a) levels exceeded the baseline risk, the reduction in LDL-C levels or SBP necessary to balance the risk attributable to Lp(a) was calculated.

RESULTS

In total, 671 patients (mean age 54.2 years, 47.2% women) were included. Globally, 22.7% of the population had high Lp(a) values (> 50 mg/dL or > 125 nmol/L). When calculating CVR throughout life and considering the Lp(a) value, the global risk increased in 66.7% of cases (median 19.3%). Similar results were observed when we assessed the 10-year risk. The risk associated with Lp(a) could be completely compensated by decreasing LDL-C (average 21 mg/dL) or SBP (average 6.3 mmHg) in 79.2% and 74.7% of cases, respectively.

CONCLUSION

When calculating the CVR with the new score, two-thirds and one-third of the population were bidirectionally recategorized as 'up' or 'down,' respectively. The decrease in LDL-C or SBP mitigated the increased risk caused by Lp(a) levels across a substantial proportion of patients.

Associations of Circulating Biomarkers with Disease Risks: a Two-Sample Mendelian Randomization Study

Background

Circulating biomarkers play a pivotal role in personalized medicine, offering potential for disease screening, prevention, and treatment. Despite established associations between numerous biomarkers and diseases, elucidating their causal relationships is challenging. Mendelian Randomization (MR) can address this issue by employing genetic instruments to discern causal links. Additionally, using multiple MR methods with overlapping results enhances the reliability of discovered relationships.

Methods

Here we report an MR study using multiple methods, including inverse variance weighted, simple mode, weighted mode, weighted median, and MR Egger. We use the MR-base resource (v0.5.6)1 to evaluate causal relationships between 212 circulating biomarkers (curated from UK Biobank analyses by Neale lab and from Shin et al. 2014, Roederer et al. 2015, and Kettunen et al. 2016)2-4 and 99 complex diseases (curated from several consortia by MRC IEU and Biobank Japan).

Results

We report novel causal relationships found by 4 or more MR methods between glucose and bipolar disorder (Mean Effect Size estimate across methods: 0.39) and between cystatin C and bipolar disorder (Mean Effect Size: -0.31). Based on agreement in 4 or more methods, we also identify previously known links between urate with gout and creatine with chronic kidney disease, as well as biomarkers that may be causal of cardiovascular conditions: apolipoprotein B, cholesterol, LDL, lipoprotein A, and triglycerides in coronary heart disease, as well as lipoprotein A, LDL, cholesterol, and apolipoprotein B in myocardial infarction.

Conclusions

This Mendelian Randomization study not only corroborates known causal relationships between circulating biomarkers and diseases but also uncovers two novel biomarkers associated with bipolar disorder that warrant further investigation. Our findings provide insight into understanding how biological processes reflecting circulating biomarkers and their associated effects may contribute to disease etiology, which can eventually help improve precision diagnostics and intervention.

SGLT2-inhibition increases total, LDL, and HDL cholesterol and lowers triglycerides: Meta-analyses of 60 randomized trials, overall and by dose, ethnicity, and drug type

BACKGROUND AND AIMS

Sodium glucose co-transporter 2 (SGLT2)-inhibitors were developed as glucose-lowering drugs. Surprisingly, SGLT2-inhibitors also reduced risk of cardiovascular disease. The impact of SGLT2-inhibitors on lipids and lipoproteins is unclear, but an effect might contribute to the observed lower cardiovascular risk. We conducted a meta-analysis to examine this, overall and by dose, ethnicity, and drug type.

METHODS

PubMed, EMBASE and Web of Science were searched for randomized controlled trials examining all available SGLT2-inhibitors. Studies with available lipid measurements were included. Quantitative data synthesis was performed using random and fixed effects models.

RESULTS

We identified 60 randomized trials, including 147,130 individuals. Overall, using random effects models, SGLT2-inhibitor treatment increased total cholesterol by 0.09 mmol/L (95% CI: 0.06, 0.13), low-density lipoprotein (LDL) cholesterol by 0.08 mmol/L (0.05, 0.10), and high-density lipoprotein (HDL) cholesterol by 0.06 mmol/L (0.05, 0.07), while it reduced triglycerides by 0.10 mmol/L (0.06, 0.14). Fixed effects estimates were similar but with smaller effect sizes for HDL cholesterol and triglycerides. For higher SGLT2-inhibitor doses, there was a nominally higher non-significant effect on lipids and lipoproteins. In Asian compared to non-Asian populations, a slightly larger increase in HDL cholesterol and a decrease in triglycerides were observed, but with similar results for total and LDL cholesterol. Treatment effects on lipids and lipoproteins were generally robust across different SGLT2-inhibitor drugs.

CONCLUSION

In meta-analyses, SGLT2-inhibition increased total, LDL, and HDL cholesterol and decreased triglycerides. Effect sizes varied slightly by drug dose and ethnicity but were generally robust by drug type.

A potentially underestimated predictor of coronary artery disease risk: The ApoB/ApoA1 ratio

Background

Cardiovascular disease (CVD) is the leading cause of death worldwide, and statin therapy is the cornerstone of atherosclerotic cardiovascular disease. However, clinical practice is unsatisfactory, and there is significant interest in the risk of residual cardiovascular events. Traditional study methods make it difficult to exclude the crosstalk of confounding factors, and we investigated the impact of the ApoB/ApoA1 ratio on CVD using two-sample Mendelian randomization (MR) and multivariate Mendelian randomization (MVMR) methods.

Methods

Two-sample MR and MVMR analyses were performed using pooled statistics from genome-wide association studies (GWAS) of ApoB/ApoA1 ratio (BAR), lipoprotein (a) (Lp(a)), and triglyceride (TG) in Europeans to assess the causal relationship between BAR, Lp(a), and TG with coronary artery disease (CAD).

Results

The genetic prediction of BAR was significantly correlated with CAD (Inverse variance weighted (IVW) beta = 0.255; OR = 1.291; 95 % CI = 1.061-1.571; P = 0.011) in a two-sample MR analysis. MVMR studies showed that BAR (beta = 0.373; OR = 1.452; 95 % CI = 1.305-1.615; P = 7.217e-12), Lp (a) (beta = 0.238; OR = 1.269; 95 % CI = 1.216-1.323; P = 2.990e-28), and TG (beta = 0.155; OR = 1.168; 95 % CI = 1.074-1.270; P = 2.829e-04) were significantly associated with CAD. After further colinearity analyses of LASSO regressions, the results of multivariate analyses were similar for IVW, MR-Egger, MR-Lasso, and median methods.

Conclusion

BAR is causally related to coronary artery disease. BAR is an independent predictor of CAD risk, independent of routine lipid measurements and other risk factors. TG and Lp(a) may be causally related to CAD, subject to verification in clinical practice.

Simultaneous quantitative LC-MS/MS analysis of 13 apolipoproteins and lipoprotein (a) in human plasma

Numerous studies have revealed a close correlation between the levels of apolipoproteins (Apos) (including lipoprotein(a) [Lp(a)]) and an increased risk of cardiovascular disease in recent decades. However, clinically, lipid profiling remains limited to the conventional plasma levels of cholesterol, triglyceride, ApoA1, and ApoB, which brings the necessity to quantify more apolipoproteins in human plasma. In this study, we simultaneously quantified 13 apolipoproteins and Lp(a) in 5 μL of human plasma using the LC-MS/MS platform. A method was developed for the precise detection of Lp(a), ApoA1, A2, A5, B, C1, C2, C3, D, E, H, L1, M, and J. Suitable peptides were selected and optimized to achieve clear separation of each peak. Method validation consisting of linearity, sensitivity, accuracy and precision, recovery, and matrix effects was evaluated. The intra-day CV ranged from 0.58% to 14.2% and the inter-day CV ranged from 0.51% to 13.3%. The recovery rates ranged from 89.8% to 113.7%, while matrix effects ranged from 85.4% to 113.9% for all apolipoproteins and Lp(a). Stability tests demonstrated that these apolipoproteins remained stable for 3 days at 4 °C and 7 days at -20 °C. This validated method was successfully applied to human plasma samples obtained from 45 volunteers. The quantitative results of ApoA1, ApoB, and Lp(a) exhibited a close correlation with the results from the immunity transmission turbidity assay. Collectively, we developed a robust assay that can be used for high-throughput quantification of apolipoproteins and Lp(a) simultaneously for investigating related risk factors in patients with dyslipidemia.

Impact of elevated lipoprotein(a) on coronary artery disease phenotype and severity

AIMS

A thorough characterization of the relationship between elevated lipoprotein(a) [Lp(a)] and coronary artery disease (CAD) is lacking. This study aimed to quantitatively assess the association of increasing Lp(a) levels and CAD severity in a real-world population.

METHODS AND RESULTS

This non-interventional, cross-sectional, LipidCardio study included patients aged ≥21 years undergoing angiography (October 2016-March 2018) at a tertiary cardiology centre, who have at least one Lp(a) measurement. The association between Lp(a) and CAD severity was determined by synergy between PCI with taxus and cardiac surgery (SYNTAX)-I and Gensini scores and angiographic characteristics. Overall, 975 patients (mean age: 69.5 years) were included; 70.1% were male, 97.5% had Caucasian ancestry, and 33.2% had a family history of premature atherosclerotic cardiovascular disease. Median baseline Lp(a) level was 19.3 nmol/L. Patients were stratified by baseline Lp(a): 72.9% had < 65 nmol/L, 21.0% had ≥100 nmol/L, 17.2% had ≥125 nmol/L, and 12.9% had ≥150 nmol/L. Compared with the normal (Lp(a) < 65 nmol/L) group, elevated Lp(a) groups (e.g. ≥ 150 nmol/L) had a higher proportion of patients with prior CAD (48.4% vs. 62.7%; P < 0.01), prior coronary revascularization (39.1% vs. 51.6%; P = 0.01), prior coronary artery bypass graft (6.0% vs. 15.1%; P < 0.01), vessel(s) with lesions (68.5% vs. 81.3%; P = 0.03), diffusely narrowed vessels (10.9% vs. 16.5%; P = 0.01) or chronic total occlusion lesions (14.3% vs. 25.2%; P < 0.01), and higher median SYNTAX-I (3.0 vs. 5.5; P = 0.01) and Gensini (10.0 vs. 16.0; P < 0.01) scores.

CONCLUSION

Elevated Lp(a) was associated with a more severe presentation of CAD. Awareness of Lp(a) levels in patients with CAD may have implications in their clinical management.

The current status of lipoprotein (a) measurement in clinical biochemistry laboratories in the UK: Results of a 2021 national survey

BACKGROUND

Lipoprotein(a) (Lp(a)) is now established as a causal risk factor for cardiovascular disease (CVD) and accurate laboratory measurement is of pivotal importance in reducing Lp(a) associated risk. The consensus statement by HEART UK in 2019 included recommendations to improve standardisation of clinical laboratory measurement and reporting of Lp(a).

METHODS

A 16 question, electronic audit survey was circulated to 190 accredited clinical biochemistry laboratories to assess the adoption of these recommendations in the UK.

RESULTS

Responses were received from 65 of 190 laboratories (34%). Only 5 (8%) did not offer Lp(a) measurement. Of those providing the test, 23% (n = 14) offered an in-house service (IHS), the remaining laboratories (77%; n = 46) used an external referral service (ERS). The majority (10 of 14 or 71%) of IHS laboratories responded with details of their method, stating whether it minimised sensitivity to the effect of Lp(a) isoform size and used calibrators certified for traceability to the WHO/IFCC reference material, however, only a minority ERS laboratories (13 of the 46 or 28%) were able to specify the method used by their referral laboratory. Of the laboratories who specified their reporting units, 6 of 10 IHS and 7 of 23 ERS laboratories reported in nmol/L. Among the 60 laboratories who responded, the HEART UK recommendations appear to have been adopted in full by only 3 IHS laboratories.

CONCLUSIONS

Further efforts are needed to standardise the measurement and reporting of Lp(a) so that results and interpretation are comparable across clinical biochemistry laboratories in the UK.

Association between Lipoprotein(a) concentration and adverse cardiac events in patients with coronary artery disease: An observational cohort study

This prospective study investigated the association between lipoprotein (a) [Lp(a)] levels and adverse cardiac events in patients undergoing percutaneous coronary intervention (PCI) for coronary artery disease. Among 600 patients, 79.16 % were male. Kaplan Meier analysis revealed significantly higher incidence rates of cardiac death, major adverse cardiac events, myocardial infarction, revascularization and stroke in patients with elevated Lp(a) (≥30 mg/dL). The Cox Regression model identified Lp(a) ≥30 mg/dL as a significant risk factor for adverse events (HR: 4.2920; 95%CI: 2.58-7.120; p < 0.05). Elevated Lp(a) levels were associated with an increased risk of adverse cardiac events in coronary artery disease patients undergoing PCI.

Impact of Elevated Lipoprotein A on Clinical Outcomes in Patients Undergoing Percutaneous Coronary Intervention: A Systematic Review and Meta-analysis

Lipoprotein(a) (Lp(a)) is an inherited lipoprotein particle associated with increased risk of atherosclerotic cardiovascular (CV) diseases. However, its impact on outcomes after percutaneous coronary intervention (PCI) remains unclear. The objective of this study was to assess the relationship between elevated Lp(a) levels and major adverse cardiovascular events (MACEs) and other outcomes in patients undergoing PCI. We systematically searched Embase, MEDLINE/PubMed, and Web of Science for studies published from 2015 to 2024 comparing CV outcomes between patients with elevated versus non-elevated Lp(a) levels after PCI. Primary outcome was MACE. Secondary outcomes included all-cause mortality, CV mortality, stroke, myocardial infarction, and revascularization. Risk ratios (RRs) were pooled using a random-effect model. Fifteen studies with 45,059 patients were included. Patients with elevated Lp(a) had a significantly higher risk of MACE (RR 1.38, 95% confidence interval (CI) 1.23-1.56). Elevated Lp(a) was also associated with increased risks of all-cause death (RR 1.26), CV death (RR 1.58), myocardial infarction (RR 1.44), revascularization (RR 1.38), and stroke (RR 1.18). Heterogeneity was considerable for some outcomes. This meta-analysis demonstrates that elevated Lp(a) levels are associated with worse CV outcomes, including higher rates of MACE, mortality, and recurrent ischemic events in patients undergoing PCI. Novel therapeutic approaches specifically targeting Lp(a) reduction may help mitigate residual CV risk in this high-risk population.

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.

Lipoprotein(a) Blood Levels and Cardiovascular Risk Reduction With Icosapent Ethyl

BACKGROUND

Elevated lipoprotein(a) (Lp[a]) concentrations are associated with increased cardiovascular event risk even in the presence of well-controlled low-density lipoprotein cholesterol levels, but few treatments are documented to reduce this residual risk.

OBJECTIVES

The aim of this post hoc analysis of REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial) was to explore the cardiovascular benefit of icosapent ethyl (IPE) across a range of Lp(a) levels.

METHODS

A total of 8,179 participants receiving statin therapy with established cardiovascular disease or age ≥50 years with diabetes and ≥1 additional risk factor, fasting triglyceride 1.69 to 5.63 mmol/L, and low-density lipoprotein cholesterol 1.06 to 2.59 mmol/L were randomized to receive 2 g twice daily of IPE or matching placebo. Relationships between continuous baseline Lp(a) mass concentration and risk for first and total (first and subsequent) major adverse cardiovascular events (MACE) were analyzed, along with the effects of IPE on first MACE among those with Lp(a) concentrations ≥50 or <50 mg/dL.

RESULTS

Among 7,026 participants (86% of those randomized) with baseline Lp(a) assessments, the median concentration was 11.6 mg/dL (Q1-Q3: 5.0-37.4 mg/dL). Lp(a) had significant relationships with first and total MACE (P < 0.0001), while event reductions with IPE did not vary across the range of Lp(a) (interaction P > 0.10). IPE significantly reduced first MACE in subgroups with concentrations ≥50 and <50 mg/dL.

CONCLUSIONS

Baseline Lp(a) concentration was prognostic for MACE among participants with elevated triglyceride levels receiving statin therapy. Importantly, IPE consistently reduced MACE across a range of Lp(a) levels, including among those with clinically relevant elevations.

Lp(a) - an overlooked risk factor

Lipoprotein(a) (Lp(a)) is an increasingly discussed and studied risk factor for atherosclerotic cardiovascular disease and aortic valve stenosis. Many genetic and epidemiological studies support the important causal role that Lp(a) plays in the incidence of cardiovascular disease. Although dependent upon the threshold and unit of measurement of Lp(a), most estimates suggest between 20 and 30% of the world's population have elevated serum levels of Lp(a). Lp(a) levels are predominantly mediated by genetics and are not significantly modified by lifestyle interventions. Efforts are ongoing to develop effective pharmacotherapies to lower Lp(a) and to determine if lowering Lp(a) with these medications ultimately decreases the incidence of adverse cardiovascular events. In this review, the genetics and pathophysiological properties of Lp(a) will be discussed as well as the epidemiological data demonstrating its impact on the incidence of cardiovascular disease. Recommendations for screening and how to currently approach patients with elevated Lp(a) are also noted. Finally, the spectrum of pharmacotherapies under development for Lp(a) lowering is detailed.

Biomarkers of Cardiovascular Risk in Patients With Rheumatoid Arthritis: Results From the TARGET Trial

Cardiovascular disease remains an important comorbidity in patients with rheumatoid arthritis (RA), but traditional models do not accurately predict cardiovascular risk in patients with RA. The addition of biomarkers could improve prediction.

METHODS AND RESULTS

The TARGET (Treatments Against RA and Effect on FDG PET/CT) trial assessed whether different treatment strategies in RA differentially impact cardiovascular risk as measured by the change in arterial inflammation on arterial target to background ratio on fluorodeoxyglucose positron emission tomography/computed tomography scans conducted 24 weeks apart. A group of 24 candidate biomarkers supported by prior literature was assessed at baseline and 24 weeks later. Longitudinal analyses examined the association between baseline biomarker values, measured in plasma EDTA, and the change in arterial inflammation target to background ratio. Model fit was assessed for the candidate biomarkers only, clinical variables only, and models combining both. One hundred nine patients with median (interquartile range) age 58 years (53-65 years), RA duration 1.4 years (0.5-6.6 years), and 82% women had biomarkers assessed at baseline and follow-up. Because the main trial analyses demonstrated significant target to background ratio decreases with both treatment strategies but no difference across treatment groups, we analyzed all patients together. Baseline values of serum amyloid A, C-reactive protein, soluble tumor necrosis factor receptor 1, adiponectin, YKL-40, and osteoprotegerin were associated with significant change in target to background ratio. When selected candidate biomarkers were added to the clinical variables, the adjusted R2 improved from 0.20 to 0.33 (likelihood ratio P=0.0005).

CONCLUSIONS

A candidate biomarker approach identified several promising biomarkers that associate with baseline and treatment-associated changes in arterial inflammation in patients with RA. These will now be tested in an external validation cohort.

Nanoparticles and siRNA: A new era in therapeutics?

Since its discovery in 1998, the use of small interfering RNA (siRNA) has been increasing in biomedical studies because of its ability to very selectively inhibit the expression of any target gene. Thus, siRNAs can be used to generate therapeutic compounds for different diseases, including those that are currently 'undruggable'. This has led siRNA-based therapeutic compounds to break into clinical settings, with them holding the promise to potentially revolutionise therapeutic approaches. To date, the United States Food and Drug Administration (FDA) have approved 5 compounds for treating different diseases including hypercholesterolemia, transthyretin-mediated amyloidosis (which leads to polyneuropathy), hepatic porphyria, and hyperoxaluria. This current article presents an overview of the molecular mechanisms involved in the selective pharmacological actions of siRNA-based compounds. It also describes the ongoing clinical trials of siRNA-based therapeutic compounds for hepatic diseases, pulmonary diseases, atherosclerosis, hypertriglyceridemia, transthyretin-mediated amyloidosis, and hyperoxaluria, kidney diseases, and haemophilia, as well as providing a description of FDA-approved siRNA therapies. Because of space constraints and to provide an otherwise comprehensive review, siRNA-based compounds applied to cancer therapies have been excluded. Finally, we discuss how the use of lipid-based nanoparticles to deliver siRNAs holds promise for selectively targeting mRNA-encoding proteins associated with the genesis of different diseases. Thus, siRNAs can help reduce the cellular levels of these proteins, thereby contributing to disease treatment. As consequence, a marked increase in the number of marketed siRNA-based medicines is expected in the next two decades, which will likely open up a new era of therapeutics.

Consideration and Application of Lipoprotein(a) in the Risk Assessment of Atherosclerotic Cardiovascular Disease Risk in Adults

Lipoprotein(a) (Lp[a]) is an low-density lipoprotein (LDL)-like particle in which apolipoprotein (apo) B is covalently bound to a plasminogen-like molecule called apo(a). A High level of Lp(a) has been demonstrated to be an independent, causal, and prevalent risk factor for atherosclerotic cardiovascular disease (ASCVD), as well as aortic valve disease, through mechanisms that promote atherogenesis, inflammation, and thrombosis. With reliable and accessible assays, Lp(a) level has been established to be associated linearly with the risk for ASCVD. The 2021 Canadian Cardiovascular Society Dyslipidemia Guidelines recommend measuring an Lp(a) level once in a person's lifetime as part of the initial lipid screening. The aim of this review is to provide an update and overview of the utility and application of Lp(a) level in the assessment and treatment of adults at risk for ASCVD, consistent with this guideline recommendation.

Executive summary of the Hellenic Atherosclerosis Society guidelines for the diagnosis and treatment of dyslipidemias - 2023

Atherosclerotic cardiovascular disease (ASCVD) remains the main cause of death worldwide, and thus its prevention, early diagnosis and treatment is of paramount importance. Dyslipidemia represents a major ASCVD risk factor that should be adequately managed at different clinical settings. 2023 guidelines of the Hellenic Atherosclerosis Society focus on the assessment of ASCVD risk, laboratory evaluation of dyslipidemias, new and emerging lipid-lowering drugs, as well as diagnosis and treatment of lipid disorders in women, the elderly and in patients with familial hypercholesterolemia, acute coronary syndromes, heart failure, stroke, chronic kidney disease, diabetes, autoimmune diseases, and non-alcoholic fatty liver disease. Statin intolerance is also discussed.

Digital droplet PCR versus quantitative PCR for lipoprotein (a) kringle IV type 2 repeat polymorphism genetic characterization

BACKGROUND

Lipoprotein(a) [Lp(a)] level variability, related to atherothrombotic risk increase, is mainly attributed to LPA gene, encoding apolipoprotein(a), with kringle IV type 2 (KIV2) copy number variation (CNV) acting as the primary genetic determinant. Genetic characterization of Lp(a) is in continuous growth; nevertheless, the peculiar structural characteristics of this variant constitute a significant challenge to the development of effective detection methods. The aim of the study was to compare quantitative real-time PCR (qPCR) and digital droplet PCR (ddPCR) in the evaluation of KIV2 repeat polymorphism.

METHODS

We analysed 100 subjects tested for cardiovascular risk in which Lp(a) plasma levels were assessed.

RESULTS

Correlation analysis between CNV values obtained with the two methods was slightly significant (R = 0.413, p = 0.00002), because of the wider data dispersion in qPCR compared with ddPCR. Internal controls C1, C2 and C3 measurements throughout different experimental sessions revealed the superior stability of ddPCR, which was supported by a reduced intra/inter-assay coefficient of variation determined in this method compared to qPCR. A significant inverse correlation between Lp(a) levels and CNV values was confirmed for both techniques, but it was higher when evaluated by ddPCR than qPCR (R = -0.393, p = 0.000053 vs R = -0.220, p = 0.028, respectively). When dividing subjects into two groups according to 500 mg/L Lp(a) cut-off value, a significantly lower number of KIV2 repeats emerged among subjects with greater Lp(a) levels, with stronger evidence in ddPCR than in qPCR (p = 0.000013 and p = 0.001, respectively).

CONCLUSIONS

Data obtained support a better performance of ddPCR in the evaluation of KIV2 repeat polymorphism.