Lipoprotein(a) Is Markedly More Atherogenic Than LDL: An Apolipoprotein B-Based Genetic Analysis

Lipoprotein (a) is associated with increased risk of Abdominal Aortic Aneurysm

Introduction

Lipoprotein(a) (Lp(a)) is a circulating apolipoprotein B (ApoB) containing particle that has been observationally linked to atherosclerotic cardiovascular disease and is the target of emerging therapeutics. Recent work has highlighted the role of circulating lipoproteins in abdominal aortic aneurysm (AAA). We sought to triangulate human observational and genetic evidence to evaluate the role of Lp(a) in AAA.

Methods

We tested the association between circulating levels of Lp(a) and clinically diagnosed abdominal aortic aneurysms while controlling for traditional AAA risk factors and levels of ApoB using logistic regression among 795 individuals with and 374,772 individuals without AAA in the UK Biobank (UKB). Multivariable Mendelian randomization (MVMR) was used to test for putatively causal associations between Lp(a) and AAA controlling for ApoB. Genetic instruments for Lp(a) and ApoB were created from genome-wide association studies (GWAS) of Lp(a) and ApoB comprising 335,796 and 418,505 UKB participants, respectively. The instruments were tested for association with AAA using data from a GWAS of 39,221 individuals with and 1,086,107 without AAA.

Results

Elevated Lp(a) levels were observationally associated with an increased risk of AAA (OR 1.04 per 10 nmol/L Lp(a); 95%CI 1.02-1.05; P<0.01). Clinically elevated Lp(a) levels (>150nmol/L) were likewise associated with an increased risk of AAA (OR 1.47; 95% CI 1.15-1.88; P < 0.01) when compared to individuals with Lp(a) levels <150nmol/L. MVMR confirmed a significant, ApoB-independent association between increased Lp(a) and increased risk of AAA (OR 1.13 per SD increase in Lp(a); 95%CI 1.02-1.24; P<0.02).

Conclusion

Both observational and genetic analyses support an association between increased Lp(a) and AAA risk that is independent of ApoB. These findings suggest that Lp(a) may be a therapeutic target for AAA and drive the inclusion of AAA as an outcome in clinical trials of Lp(a) antagonists.

Attitudes and barriers to lipoprotein(a) testing: A survey of providers at the University of Pennsylvania Health System

Guidelines recommend checking lipoprotein(a) [Lp(a)] levels in patients at high-risk for cardiovascular disease, with more recent recommendations advocating for universal screening in all adults. A brief electronic survey was distributed to select groups of University of Pennsylvania Health System (UPHS) providers, including Internal Medicine and Cardiology physicians and advance practice providers, to understand the current attitudes and barriers to testing for Lp(a). Of the 126 survey respondents, only 31% answered that they test for Lp(a) regularly in their practice. Presence of ASCVD and a family history of ASCVD were the most common reasons for testing. Most survey respondents (69%) replied that they do not currently check Lp(a) levels in patients. The most common reasons provided included lack of familiarity with Lp(a), insurance/ billing concerns, lack of clinical trial outcomes data, and lack of available pharmaceutical interventions. Results from ongoing clinical trials of novel Lp(a)-lowering therapies, if successful, may address provider hesitation toward Lp(a)-testing, but there remains a large gap to fill in awareness of Lp(a).

Recent Advances in Targeted Management of Inflammation In Atherosclerosis: A Narrative Review

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of morbidity and mortality despite effective low-density lipoprotein cholesterol-targeted therapies. This review explores the crucial role of inflammation in the residual risk of ASCVD, emphasizing its impact on atherosclerosis progression and plaque stability. Evidence suggests that high-sensitivity C-reactive protein (hsCRP), and potentially other inflammatory biomarkers, can be used to identify the inflammatory residual ASCVD risk phenotype and may serve as future targets for the development of more efficacious therapeutic approaches. We review the biological basis for the association of inflammation with ASCVD, propose new therapeutic strategies for the use of inflammation-targeted treatments, and discuss current challenges in the implementation of this new treatment paradigm for ASCVD.

Lipoprotein (a) and lipid-lowering treatment from the perspective of a cardiac surgeon. An impact on the prognosis in patients with aortic valve replacement and after heart transplantation

Lipoprotein(a) is a recognized risk factor for ASCVD. There is still no targeted therapy for Lp(a), however, drugs such as pelacarsen, olpasiran, zerlasiran, lepodisiran and muvalaplin are in clinical trials and have been shown to be effective in significantly reducing Lp(a) levels. Moreover, elevated Lp(a) levels significantly affect the prognosis of patients after aortic valve replacement (AVR) and heart transplantation (HTx). Therefore, the assessment of Lp(a) concentration in these patients will allow for a more accurate stratification of their cardiovascular risk, and the possibility of lowering Lp(a) will allow for the optimization of this risk. In this article, we summarized the most important information regarding the role of Lp(a) and lipid-lowering treatment in patients after AVR and HTx.

Atherogenic lipid profile in patients with statin treatment after acute coronary syndrome: a real-world analysis from Chinese cardiovascular association database

BACKGROUND

Adverse atherogenic lipid profile is associated with an increased risk of major adverse cardiac events in patients after acute coronary syndrome (ACS). Knowledge regarding the impact of statins on lipid profile remains limited.

METHODS

We retrospectively analysed multicenter, real-world data from the Chinese Cardiovascular Association Database-iHeart Project. Patients with a primary diagnosis of ACS from 2014 to 2021 during index hospitalisation and having at least one lipid panel record after discharge within 12 months were enrolled. We analysed target achievement of atherogenic lipid profile, including apolipoprotein B (< 80 mg/dL), low-density lipoprotein cholesterol (LDL-C) (< 1.8 mmol/L), lipoprotein(a) [Lp(a)] (< 30 mg/dL), triglycerides (< 1.7 mmol/L), remnant cholesterol (RC) (< 0.78 mmol/L), non-high-density lipoprotein cholesterol (< 2.6 mmol/L) at baseline and follow-up. Multivariate Cox regression models were employed to investigate the association between patient characteristics and target achievement.

RESULTS

Among 4861 patients, the mean age was 64.9 years. Only 7.8% of patients had all atherogenic lipids within the target range at follow-up. The proportion of target achievement was for LDL-C 42.7%, Lp(a) 73.3%, and RC 78.5%. Patients with female sex, younger age, myocardial infarction, hypertension, and hypercholesteremia were less likely to control LDL-C, Lp(a), and RC. An increase in the burden of comorbidities was negatively associated with LDL-C and Lp(a) achievements but not with RC.

CONCLUSIONS

A substantial gap exists between lipid control and the targets recommended by contemporary guidelines. Novel therapeutics targeting the whole atherogenic lipid profile will be warranted to improve cardiovascular outcomes.

Lipoprotein(a) in interventional cardiology: identifying patients at highest risk of recurrent cardiovascular events through early recognition - a case based review

INTRODUCTION

Lipoprotein(a) [Lp(a)] is linked to higher risks of atherosclerotic cardiovascular disease (ASCVD). Current guideline recommendations are quite liberal on measuring Lp(a) (Class IIa, Level C), and may lead to underuse among (interventional) cardiologists.

AREAS COVERED

This case-based narrative review outlines four clinical cases of patients with elevated Lp(a) to illustrate its pathophysiological impact on coronary artery disease (CAD). The expert consensus statements from the American Heart Association (AHA) and European Atherosclerosis Society (EAS) served as the basis of this review. More recent publications, from 2023 to 2024, were accessed through the MEDLINE online library.

EXPERT OPINION

We highlighted the importance of routine Lp(a) measurement in identifying patients at high risk for atherosclerosis, necessitating potent risk mitigation. Measuring Lp(a) helps clinicians identify which patients are at highest residual risk, who require potent pharmacological treatment and special attention during catheter interventions. As noninvasive and advanced intravascular imaging modalities evolve, future catheterization laboratories will integrate advanced imaging, diagnostics, and treatment, facilitating tailored patient care. Knowing Lp(a) levels is crucial in this context. While Lp(a)-lowering drugs are currently investigated in clinical trials, it is of paramount importance to know Lp(a) levels and strive toward aggressive management of other modifiable risk factors in patients with elevated Lp(a) and established symptomatic CAD being diagnosed or treated in catheterization laboratories.

Lipoprotein(a) and diet: consuming sugar-sweetened beverages lowers lipoprotein(a) levels in obese and overweight adults

Lipoprotein(a) [Lp(a)] contributes to cardiovascular disease risk. A genetically determined size polymorphism in apolipoprotein(a) [apo(a)], determined by the number of Kringle (K) repeats, inversely regulates Lp(a) levels. Nongenetic factors including dietary saturated fat influence Lp(a) levels. However, less is known about the effects of carbohydrates including dietary sugars. In this double-blind, parallel arm study among 32 overweight/obese adults, we investigated the effect of consuming glucose- or fructose-sweetened beverages providing 25% of energy requirements for 10 weeks on Lp(a) level and assessed the role of the apo(a) size polymorphism. The mean (±SD) age of participants was 54 ± 8 years, 50% were women, and 75% were of European descent. Following the 10-week intervention, Lp(a) level was reduced by an average (±SEM) of -13.2% ± 4.3% in all participants (P = 0.005); -15.3% ± 7.8% in the 15 participants who consumed glucose (P = 0.07); and -11.3% ± 4.5% in the 17 participants who consumed fructose (P = 0.02), without any significant difference in the effect between the two sugar groups. Relative changes in Lp(a) levels were similar across subgroups of lower versus higher baseline Lp(a) level or carrier versus noncarrier of an atherogenic small (≤22K) apo(a) size. In contrast, LDL-C increased. In conclusion, in older, overweight/obese adults, consuming sugar-sweetened beverages reduced Lp(a) levels by ∼13% independently of apo(a) size variability and the type of sugar consumed. The Lp(a) response was opposite to that of LDL-C and triglyceride concentrations. These findings suggest that metabolic pathways might impact Lp(a) levels.

Advancements in risk stratification and management strategies in primary cardiovascular prevention

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of morbidity and mortality worldwide, highlighting the urgent need for advancements in risk assessment and management strategies. Although significant progress has been made recently, identifying and managing apparently healthy individuals at a higher risk of developing atherosclerosis and those with subclinical atherosclerosis still poses significant challenges. Traditional risk assessment tools have limitations in accurately predicting future events and fail to encompass the complexity of the atherosclerosis trajectory. In this review, we describe novel approaches in biomarkers, genetics, advanced imaging techniques, and artificial intelligence that have emerged to address this gap. Moreover, polygenic risk scores and imaging modalities such as coronary artery calcium scoring, and coronary computed tomography angiography offer promising avenues for enhancing primary cardiovascular risk stratification and personalised intervention strategies. On the other hand, interventions aiming against atherosclerosis development or promoting plaque regression have gained attention in primary ASCVD prevention. Therefore, the potential role of drugs like statins, ezetimibe, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, omega-3 fatty acids, antihypertensive agents, as well as glucose-lowering and anti-inflammatory drugs are also discussed. Since findings regarding the efficacy of these interventions vary, further research is still required to elucidate their mechanisms of action, optimize treatment regimens, and determine their long-term effects on ASCVD outcomes. In conclusion, advancements in strategies addressing atherosclerosis prevention and plaque regression present promising avenues for enhancing primary ASCVD prevention through personalised approaches tailored to individual risk profiles. Nevertheless, ongoing research efforts are imperative to refine these strategies further and maximise their effectiveness in safeguarding cardiovascular health.

Elderly patients with very high plasma lipoprotein(a) concentrations and few cardiovascular consequences: a case series

Lipoprotein(a) (Lp(a)) is an atherogenic low-density lipoprotein (LDL)-like particle that is currently regarded as a non-modifiable risk factor for atherosclerotic cardiovascular disease. The number of patients detected with elevated Lp(a) concentrations has been increasing in recent years, although the implication of this finding is unclear for patients and physicians. We screened our lipid clinic database for patients aged >65 years with very high Lp(a) concentrations, which were defined as >230 nmol/L, and cardiovascular outcomes were assessed. The patients' (n = 16) mean (±standard deviation) age was 72.2 ± 7.1 years and the mean Lp(a) concentration was 313 ± 68 nmol/L. After a cumulative 129.0 patient-year follow-up (mean: 8.1 ± 4.2 years), the mean age was 80.3 ± 7.0 years. We observed a low baseline prevalence of cardiovascular events, with only two patients having a history of cardiovascular events. Furthermore, zero incident adverse cardiovascular events were recorded over the follow-up. Therefore, very high Lp(a) concentrations and disease-free old age are not mutually exclusive. Our aggregated clinical experience is that there is only a modest association between elevated Lp(a) concentrations and adverse outcomes. Nonetheless, we still advise treating modifiable risk factors in these patients.

Ancestry specific distribution of LPA Kringle IV-Type-2 genetic variants highlight associations to apo(a) copy number, glucose, and hypertension

Background

High Lp(a) levels contribute to atherosclerotic cardiovascular disease and are tightly regulated by the LPA gene . Lp(a) levels have an inverse correlation with LPA Kringle IV Type-2 (KIV-2) copy number (CN). Black (B) and Hispanic (H) individuals exhibit higher levels of Lp(a), and rates of CVD compared to non-Hispanic Whites (NHW). Therefore, we investigated genetic variations in the LPA KIV-2 region across three ancestries and their associations with metabolic risk factors.

Methods

Using published pipelines, we analyzed a multi-ethnic whole exome dataset comprising 3,817 participants from the Washington Heights and Inwood Columbia Aging Project (WHICAP): 886 [NHW (23%), 1,811 Caribbean (C) H (47%), and 1,120 B individuals (29%). Rare and common variants (alternative allele carrier frequency, CF < 0.01 or > 0.99 and 0.01 < CF < 0.99, respectively) were identified and KIV-2 CN estimated. The associations of variants and CN with history of heart disease, hypertension (HTN), stroke, lipid levels and clinical diagnosis of Alzheimer's disease (AD) was assessed. A small pilot provided in-silico validation of study findings.

Results

We report 1421 variants in the LPA KIV-2 repeat region, comprising 267 exonic and 1154 intronic variants. 61.4% of the exonic variants have not been previously described. Three novel exonic variants significantly increase the risk of HTN across all ethnic groups: 4785-C/A (frequency = 78%, odds ratio [OR] = 1.45, p = 0.032), 727-T/C (frequency = 96%, OR = 2.11, p = 0.032), and 723-A/G (frequency = 96%, OR = 1.97, p = 0.038). Additionally, six intronic variants showed associations with HTN: 166-G/A, 387-G/C, 402-G/A, 4527-A/T, 4541-G/A, and 4653-A/T. One intronic variant, 412-C/T, was associated with decreased blood glucose levels (frequency = 72%, β = -14.52, p = 0.02).Three of the associations were not affected after adjusting for LPA KIV-2 CN: 412-C/T (β = -14.2, p = 0.03), 166-G/A (OR = 1.41, p = 0.05), and 387-G/C (OR = 1.40, p = 0.05). KIV CN itself was significantly associated with 314 variants and was negatively correlated with plasma total cholesterol levels.

Conclusions

In three ancestry groups, we identify novel rare and common LPA KIV-2 region variants. We report new associations of variants with HTN and Glucose levels. These results underscore the genetic complexity of the LPA KIV-2 region in influencing cardiovascular and metabolic health, suggesting potential genetic regulation of pathways that can be studied for research and therapeutic interventions.

Impact of Lipoprotein(a) Level on Low-Density Lipoprotein Cholesterol- or Apolipoprotein B-Related Risk of Coronary Heart Disease

BACKGROUND

Conventional low-density lipoprotein cholesterol (LDL-C) quantification includes cholesterol attributable to lipoprotein(a) (Lp(a)-C) due to their overlapping densities.

OBJECTIVES

The purposes of this study were to compare the association between LDL-C and LDL-C corrected for Lp(a)-C (LDLLp(a)corr) with incident coronary heart disease (CHD) in the general population and to investigate whether concomitant Lp(a) values influence the association of LDL-C or apolipoprotein B (apoB) with coronary events.

METHODS

Among 68,748 CHD-free subjects at baseline LDLLp(a)corr was calculated as "LDL-C-Lp(a)-C," where Lp(a)-C was 30% or 17.3% of total Lp(a) mass. Fine and Gray competing risk-adjusted models were applied for the association between the outcome incident CHD and: 1) LDL-C and LDLLp(a)corr in the total sample; and 2) LDL-C and apoB after stratification by Lp(a) mass (≥/<90th percentile).

RESULTS

Similar risk estimates for incident CHD were found for LDL-C and LDL-CLp(a)corr30 or LDL-CLp(a)corr17.3 (subdistribution HR with 95% CI) were 2.73 (95% CI: 2.34-3.20) vs 2.51 (95% CI: 2.15-2.93) vs 2.64 (95% CI: 2.26-3.10), respectively (top vs bottom fifth; fully adjusted models). Categorization by Lp(a) mass resulted in higher subdistribution HRs for uncorrected LDL-C and incident CHD at Lp(a) ≥90th percentile (4.38 [95% CI: 2.08-9.22]) vs 2.60 [95% CI: 2.21-3.07]) at Lp(a) <90th percentile (top vs bottom fifth; Pinteraction0.39). In contrast, apoB risk estimates were lower in subjects with higher Lp(a) mass (2.43 [95% CI: 1.34-4.40]) than in Lp(a) <90th percentile (3.34 [95% CI: 2.78-4.01]) (Pinteraction0.49).

CONCLUSIONS

Correction of LDL-C for its Lp(a)-C content provided no meaningful information on CHD-risk estimation at the population level. Simple categorization of Lp(a) mass (≥/<90th percentile) influenced the association between LDL-C or apoB with future CHD mostly at higher Lp(a) levels.

Impact of Social Determinants of Health and Lifestyle on Association Between Lipoprotein(a) and Cardiovascular Events

Background

In European cohorts, healthier lifestyle either attenuated or associated with lower cardiovascular risk despite elevated lipoprotein(a) [Lp(a)].

Objectives

The purpose of this study was to test if social determinants of health (SDOH) and Life's Simple 7 (LS7) scores impact the association of Lp(a) with cardiovascular events in U.S. cohorts.

Methods

We performed a sequential multivariable Cox proportional hazard analysis using the ARIC (Atherosclerosis Risk In Communities) and MESA (Multi-Ethnic Study of Atherosclerosis) cohorts. We first adjusted for age, gender, non-high-density lipoprotein-cholesterol, race, and ethnicity, then sequentially added SDOH and LS7 scores. The primary outcomes were time until first myocardial infarction (MI) or stroke.

Results

ARIC (n = 15,072; median Lp(a) = 17.3 mg/dL) had 16.2 years and MESA (n = 6,822; median Lp(a) = 18.3 mg/dL) had 12.3 years of average follow-up. In age, gender, race, and ethnicity, and non-high-density lipoprotein-cholesterol adjusted analyses, Lp(a) was associated with MI in ARIC (HR: 1.10, P < 0.001) and MESA (HR: 1.11, P = 0.001), and stroke in ARIC (HR: 1.07, P < 0.001) but not MESA (HR: 0.97, P = 0.53). In models with SDOH and LS7, associations of Lp(a) remained similar with MI (ARIC, HR: 1.08, P < 0.001; MESA, HR: 1.10, P = 0.001) and stroke (ARIC, HR: 1.06, P = 0.002; MESA, HR: 0.96, P = 0.37). Each additional SDOH correlated positively with MI (ARIC, HR: 1.04, P = 0.01; MESA, HR: 1.08, P = 0.003) and stroke in ARIC (HR: 1.08, P = 0.00) but not MESA (HR: 1.03, P = 0.41). Each additional LS7 point correlated negatively with MI (ARIC, HR: 0.88, P < 0.001; MESA, HR: 0.85, P < 0.001) and stroke (ARIC, HR: 0.91, P < 0.001; MESA, HR: 0.86, P < 0.001).

Conclusions

SDOH and lifestyle factors associated with risk for MI and stroke but did not largely impact the association between Lp(a) and cardiovascular events.

Recent updates on therapeutic targeting of lipoprotein(a) with RNA interference

PURPOSE OF REVIEW

RNA interference (RNAi)-based therapies that target specific gene products have impacted clinical medicine with 16 FDA approved drugs. RNAi therapy focused on reducing plasma lipoprotein(a) [Lp(a)] levels are under evaluation.

RECENT FINDINGS

RNAi-based therapies have made significant progress over the past 2 decades and currently consist of antisense oligonucleotides (ASO) and small interfering RNA (siRNA). Chemical modification of the RNA backbone and conjugation of siRNA enables efficient gene silencing in hepatocytes allowing development of effective cholesterol lowering therapies. Multiple lines of evidence suggest a causative role for Lp(a) in atherosclerotic cardiovascular disease, and recent analyses indicate that Lp(a) is more atherogenic than low density lipoprotein- cholesterol (LDL-C). These findings have led to the 'Lp(a) hypothesis' that lowering Lp(a) may significantly improve cardiovascular outcomes. Four RNAi-based drugs have completed early phase clinical trials demonstrating >80% reduction in plasma Lp(a) levels. Phase 3 clinical trials examining clinical outcomes with these agents are currently underway.

SUMMARY

Currently, four RNAi-based drugs have been shown to be effective in significantly lowering plasma Lp(a) levels. Clinical outcome data from phase 3 trials will evaluate the Lp(a) hypothesis.

Therapeutic Potential of Lipoprotein(a) Inhibitors

Increasing evidence has implicated lipoprotein(a) [Lp(a)] in the causality of atherosclerosis and calcific aortic stenosis. This has stimulated immense interest in developing novel approaches to integrating Lp(a) into the setting of cardiovascular prevention. Current guidelines advocate universal measurement of Lp(a) levels, with the potential to influence cardiovascular risk assessment and triage of higher-risk patients to use of more intensive preventive therapies. In parallel, considerable activity has been undertaken to develop novel therapeutics with the potential to achieve selective and substantial reductions in Lp(a) levels. Early studies of antisense oligonucleotides (e.g., mipomersen, pelacarsen), RNA interference (e.g., olpasiran, zerlasiran, lepodisiran) and small molecule inhibitors (e.g., muvalaplin) have demonstrated effective Lp(a) lowering and good tolerability. These agents are moving forward in clinical development, in order to determine whether Lp(a) lowering reduces cardiovascular risk. The results of these studies have the potential to transform our approach to the prevention of cardiovascular disease.

In the Beginning, Lipoproteins Cross the Endothelial Barrier

Atherosclerosis begins with the infiltration of cholesterol-containing lipoproteins into the arterial wall. White blood cell (WBC)-associated inflammation follows. Despite decades of research using genetic and pharmacologic methods to alter WBC function, in humans, the most effective method to prevent the initiation and progression of disease remains low-density lipoprotein (LDL) reduction. However, additional approaches to reducing cardiovascular disease would be useful as residual risk of events continues even with currently effective LDL-reducing treatments. Some of this residual risk may be due to vascular toxicity of triglyceride-rich lipoproteins (TRLs). Another option is that LDL transcytosis continues, albeit at reduced rates due to lower circulating levels of this lipoprotein. This review will address these two topics. The evidence that TRLs promote atherosclerosis and the processes that allow LDL and TRLs to be taken up by endothelial cells leading to their accumulation with the subendothelial space.

High lipoprotein(a): Actionable strategies for risk assessment and mitigation

High levels of lipoprotein(a) [Lp(a)] are causal for atherosclerotic cardiovascular disease (ASCVD). Lp(a) is the most prevalent inherited dyslipidemia and strongest genetic ASCVD risk factor. This risk persists in the presence of at target, guideline-recommended, LDL-C levels and adherence to lifestyle modifications. Epidemiological and genetic evidence supporting its causal role in ASCVD and calcific aortic stenosis continues to accumulate, although various facets regarding Lp(a) biology (genetics, pathophysiology, and expression across race/ethnic groups) are not yet fully understood. The evolving nature of clinical guidelines and consensus statements recommending universal measurements of Lp(a) and the scientific data supporting its role in multiple disease states reinforce the clinical merit to start population screening for Lp(a) now. There is a current gap in the implementation of recommendations for primary and secondary cardiovascular disease (CVD) prevention in those with high Lp(a), in part due to a lack of protocols for management strategies. Importantly, targeted apolipoprotein(a) [apo(a)]-lowering therapies that reduce Lp(a) levels in patients with high Lp(a) are in phase 3 clinical development. This review focuses on the identification and clinical management of patients with high Lp(a). Specifically, we highlight the clinical value of measuring Lp(a) and its use in determining Lp(a)-associated CVD risk by providing actionable guidance, based on scientific knowledge, that can be utilized now to mitigate risk caused by high Lp(a).

Lipid Toxicity in the Cardiovascular-Kidney-Metabolic Syndrome (CKMS)

Recent studies of Cardiovascular-Kidney-Metabolic Syndrome (CKMS) indicate that elevated concentrations of derivatives of phospholipids (ceramide, sphingosine), oxidized LDL, and lipoproteins (a, b) are toxic to kidney and heart function. Energy production for renal proximal tubule resorption of critical fuels and electrolytes is required for homeostasis. Cardiac energy for ventricular contraction/relaxation is preferentially supplied by long chain fatty acids. Metabolism of long chain fatty acids is accomplished within the cardiomyocyte cytoplasm and mitochondria by means of the glycolytic, tricarboxylic acid, and electron transport cycles. Toxic lipids and excessive lipid concentrations may inhibit cardiac function. Cardiac contraction requires calcium movement from the sarcoplasmic reticulum from a high to a low concentration at relatively low energy cost. Cardiac relaxation involves calcium return to the sarcoplasmic reticulum from a lower to a higher concentration and requires more energy consumption. Diastolic cardiac dysfunction occurs when cardiomyocyte energy conversion is inadequate. Diastolic dysfunction from diminished ATP availability occurs in the presence of inadequate blood pressure, glycemia, or lipid control and may lead to heart failure. Similar disruption of renal proximal tubular resorption of fuels/electrolytes has been found to be associated with phospholipid (sphingolipid) accumulation. Elevated concentrations of tissue oxidized low-density lipoprotein cholesterols are associated with loss of filtration efficiency at the level of the renal glomerular podocyte. Macroscopically excessive deposits of epicardial and intra-nephric adipose are associated with vascular pathology, fibrosis, and inhibition of essential functions in both heart and kidney. Chronic triglyceride accumulation is associated with fibrosis of the liver, cardiac and renal structures. Successful liver, kidney, or cardiac allograft of these vital organs does not eliminate the risk of lipid toxicity. Lipid lowering therapy may assist in protecting vital organ function before and after allograft transplantation.

Lipoprotein(a): A Review of Risk Factors, Measurements, and Novel Treatment Modalities

The study of lipoprotein(a) [Lp(a)] has long been a source of interest as a possible independent risk factor for atherosclerotic cardiovascular disease (ASCVD). The results of large sample observational studies, genome-wide association studies, and Mendelian randomization studies have been strong indicators supporting the link between ASCVD and Lp(a) despite early studies, with less sensitive assays, failing to show a connection. The recommendations for the indications and frequency of testing Lp(a) levels vary between US, Canadian, and European organizations due to the uncertain role of Lp(a) in ASCVD. The innovation of recent therapies, such as antisense oligonucleotides and small interfering RNA, designed to specifically target and reduce Lp(a) levels by targeting mRNA translation have once more thrust LP(a) into the spotlight of inquiry. These emerging modalities serve the dual purpose of definitively elucidating the connection between elevated Lp(a) levels and atherosclerotic cardiovascular risk, as well as the possibility of providing clinicians with the tools necessary to manage elevated Lp(a) levels in vulnerable populations. This review seeks to examine the mechanisms of atherogenicity of Lp(a) and explore the most current pharmacologic therapies currently in development.

The impact of baseline dietary fatty acid intake on the association between lipoprotein(a) and mortality in two US cohorts

Background

Lipoprotein(a) (Lp(a)) is an established casual risk factor for atherosclerotic cardiovascular disease. It remains unknown whether dietary fat modifies the association of Lp(a) with cardiovascular death.

Aim

To understand if dietary fat modifies the association between Lp(a) and cardiovascular death.

Methods

We utilized the Atherosclerotic Risk in Communities (ARIC) study and National Health and Nutrition Examination Survey (NHANES) III cohorts and used multivariate cox proportional hazard modeling to test the association between Lp(a), dietary fats, and cardiovascular death.

Results

The sample (n = 22,805) had average age 51.3 years and was mostly female (55.4%). Lp(a) ≥ 30 mg/dL was associated with CV death in both ARIC (1.36, p = 0.001) and NHANES (1.31, p = 0.03). In multivariate analysis, no categorical or individual fatty acids modified the association between Lp(a) and CV death.

Conclusion

There was no evidence that baseline dietary fat intake modified the association between Lp(a) and CV death.