Association of Lipoprotein(a) With Atherosclerotic Plaque Progression

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.

Application of Quantitative Assessment of Coronary Atherosclerosis by Coronary Computed Tomographic Angiography

Coronary computed tomography angiography (CCTA) has emerged as a pivotal tool for diagnosing and risk-stratifying patients with suspected coronary artery disease (CAD). Recent advancements in image analysis and artificial intelligence (AI) techniques have enabled the comprehensive quantitative analysis of coronary atherosclerosis. Fully quantitative assessments of coronary stenosis and lumen attenuation have improved the accuracy of assessing stenosis severity and predicting hemodynamically significant lesions. In addition to stenosis evaluation, quantitative plaque analysis plays a crucial role in predicting and monitoring CAD progression. Studies have demonstrated that the quantitative assessment of plaque subtypes based on CT attenuation provides a nuanced understanding of plaque characteristics and their association with cardiovascular events. Quantitative analysis of serial CCTA scans offers a unique perspective on the impact of medical therapies on plaque modification. However, challenges such as time-intensive analyses and variability in software platforms still need to be addressed for broader clinical implementation. The paradigm of CCTA has shifted towards comprehensive quantitative plaque analysis facilitated by technological advancements. As these methods continue to evolve, their integration into routine clinical practice has the potential to enhance risk assessment and guide individualized patient management. This article reviews the evolving landscape of quantitative plaque analysis in CCTA and explores its applications and limitations.

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).

Lipoprotein(a): Emerging insights and therapeutics

The strong association between lipoprotein (a) [Lp(a)] and atherosclerotic cardiovascular disease has led to considerations of Lp(a) being a potential target for mitigating residual cardiovascular risk. While approximately 20 % of the population has an Lp(a) level greater than 50 mg/dL, there are no currently available pharmacological lipid-lowering therapies that have demonstrated substantial reduction in Lp(a). Novel therapies to lower Lp(a) include antisense oligonucleotides and small-interfering ribonucleic acid molecules and have shown promising results in phase 2 trials. Phase 3 trials are currently underway and will test the causal relationship between Lp(a) and ASCVD and whether lowering Lp(a) reduces cardiovascular outcomes. In this review, we summarize emerging insights related to Lp(a)'s role as a risk-enhancing factor for ASCVD, association with calcific aortic stenosis, effects of existing therapies on Lp(a) levels, and variations amongst patient populations. The evolving therapeutic landscape of emerging therapeutics is further discussed.

Nonobstructive epicardial coronary artery disease: an evolving concept in need of diagnostic and therapeutic guidance

For decades, we have been treating patients presenting with angina and concerning electrocardiographic changes indicative of ischemia or injury, in whom no culprit epicardial coronary stenosis was found during diagnostic coronary angiography. Unfortunately, the clinical outcomes of these patients were not better than those with recognized obstructive coronary disease. Improvements in technology have allowed us to better characterize these patients. Consequently, an increasing number of patients with ischemia and no obstructive coronary artery disease (INOCA) or myocardial infarction in the absence of coronary artery disease (MINOCA) have now gained formal recognition and are more commonly encountered in clinical practice. Although both entities might share functional similarities at their core, they pose significant diagnostic and therapeutic challenges. Unless we become more proficient in identifying these patients, particularly those at higher risk, morbidity and mortality outcomes will not improve. Though this field remains in constant flux, data continue to become available. Therefore, we thought it would be useful to highlight important milestones that have been recognized so we can all learn about these clinical entities. Despite all the progress made regarding INOCA and MINOCA, many important knowledge gaps continue to exist. For the time being, prompt identification and early diagnosis remain crucial in managing these patients. Even though we are still not clear whether intensive medical therapy alters clinical outcomes, we remain vigilant and wait for more data.

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.

Association of Lipoprotein(a) Levels With Myocardial Infarction in Patients With Low-Attenuation Plaque

BACKGROUND

Lipoprotein(a) (Lp[a]) is associated with an increased risk of myocardial infarction (MI). However, the mechanism underlying this association has yet to be fully elucidated.

OBJECTIVES

This multicenter study aimed to investigate whether association between Lp(a) and MI risk is reinforced by the presence of low-attenuation plaque (LAP) identified by coronary computed tomography angiography (CCTA).

METHODS

In a derivation cohort, a total of 5,607 patients with stable chest pain suspected of coronary artery disease who underwent CCTA and Lp(a) measurement were prospectively enrolled. In validation cohort, 1,122 patients were retrospectively collected during the same period. High Lp(a) was defined as Lp(a) ≥50 mg/dL. The primary endpoint was a composite of time to fatal or nonfatal MI. Associations were estimated using multivariable Cox proportional hazard models.

RESULTS

During a median follow-up of 8.2 years (Q1-Q3: 7.2-9.3 years), the elevated Lp(a) levels were associated with MI risk (adjusted HR [aHR]: 1.91; 95% CI: 1.46-2.49; P < 0.001). There was a significant interaction between Lp(a) and LAP (Pinteraction <0.001) in relation to MI risk. When stratified by the presence or absence of LAP, Lp(a) was associated with MI in patients with LAP (aHR: 3.03; 95% CI: 1.92-4.76; P < 0.001). Mediation analysis revealed that LAP mediated 73.3% (P < 0.001) for the relationship between Lp(a) and MI. The principal findings remained unchanged in the validation cohort.

CONCLUSIONS

Elevated Lp(a) augmented the risk of MI during 8 years of follow-up, especially in patients with LAP identified by CCTA. The presence of LAP could reinforce the relationship between Lp(a) and future MI occurrence.

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).

Uncovering atherosclerotic cardiovascular disease by PET imaging

Assessing atherosclerosis severity is essential for precise patient stratification. Specifically, there is a need to identify patients with residual inflammation because these patients remain at high risk of cardiovascular events despite optimal management of cardiovascular risk factors. Molecular imaging techniques, such as PET, can have an essential role in this context. PET imaging can indicate tissue-based disease status, detect early molecular changes and provide whole-body information. Advances in molecular biology and bioinformatics continue to help to decipher the complex pathogenesis of atherosclerosis and inform the development of imaging tracers. Concomitant advances in tracer synthesis methods and PET imaging technology provide future possibilities for atherosclerosis imaging. In this Review, we summarize the latest developments in PET imaging techniques and technologies for assessment of atherosclerotic cardiovascular disease and discuss the relationship between imaging readouts and transcriptomics-based plaque phenotyping.

Novel Therapies for Lipoprotein(a): Update in Cardiovascular Risk Estimation and Treatment

PURPOSE OF REVIEW

Lipoprotein(a) is an important causal risk factor for cardiovascular disease but currently no available medication effectively reduces lipoprotein(a). This review discusses recent findings regarding lipoprotein(a) as a causal risk factor and therapeutic target in cardiovascular disease, it reviews current clinical recommendations, and summarizes new lipoprotein(a) lowering drugs.

RECENT FINDINGS

Epidemiological and genetic studies have established lipoprotein(a) as a causal risk factor for cardiovascular disease and mortality. Guidelines worldwide now recommend lipoprotein(a) to be measured once in a lifetime, to offer patients with high lipoprotein(a) lifestyle advise and initiate other cardiovascular medications. Clinical trials including antisense oligonucleotides, small interfering RNAs, and an oral lipoprotein(a) inhibitor have shown great effect on lowering lipoprotein(a) with reductions up to 106%, without any major adverse effects. Recent clinical phase 1 and 2 trials show encouraging results and ongoing phase 3 trials will hopefully result in the introduction of specific lipoprotein(a) lowering drugs to lower the risk of cardiovascular disease.

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.

Effects of low-tube voltage coronary CT angiography on plaque and pericoronary fat assessment: intraindividual comparison

OBJECTIVES

To investigate the effects of low tube voltage on coronary plaques and pericoronary fat assessment, and to compare their extent among various levels of low voltage.

MATERIALS AND METHODS

Patients were recommended for high-pitch low-tube voltage coronary computed tomography angiography (CCTA), and they were included if they had poor image quality and were referred to a conventional CCTA. The patients were classified into a low-voltage group (with 70-kV, 80-kV, and 90-kV subgroups) and a conventional group (100/120 kV). Their total plaque and subcomponent volumes and pericoronary fat attenuation index (FAI) were measured.

RESULTS

A total of 1002 image slices (from 65 patients and 74 plaques) were included, including 21, 31, 13, 4, and 61 patients in the 70-kV, 80-kV, 90-kV, 100-kV, and 120-kV groups respectively. The CT values of noncalcified plaques in the conventional and low-voltage groups were 54.6 ± 21.3 HU and 31.5 ± 22.6 HU, respectively (p < 0.05). Compared with the conventional group, the necrotic core and calcification volume were increased, and the fibrolipid volume, periplaque, and right coronary artery FAI were decreased in the low-voltage group and its subgroups (p < 0.001). The magnitude of changes in fibrous and calcification volumes increased in the 70-kV subgroup compared with that in the 90-kV subgroup (p < 0.05).

CONCLUSION

Low tube voltages, particularly of 70 kV, have a significant effect on coronary plaque and FAI. The effect of low voltage on plaque composition is characterized by a polarization pattern, i.e., a decrease in fibrolipid (medium density) and an increase in necrotic core (low density) and calcification (high density).

CLINICAL RELEVANCE STATEMENT

Our results highlight the comparability and repeatability of plaque and pericoronary fat assessments facilitated by the same or a similar tube voltage. It is necessary to carry out studies on the specificity threshold of low tube voltage at each level.

KEY POINTS

• Low tube voltage had a significant effect on coronary plaque and pericoronary fat, particularly 70 kV. • The effect of low tube voltage on plaque composition shows the shift from medium-density mixed components to low- and high-density components. • It is necessary to correct the specificity threshold or attenuation difference for low tube voltage at each level.

Impact of High Lipoprotein(a) on Long-Term Survival Following Coronary Artery Bypass Grafting

BACKGROUND

Lipoprotein(a) is a possible causal risk factor for atherosclerosis and related complications. The distribution and prognostic implication of lipoprotein(a) in patients undergoing coronary artery bypass grafting remain unknown. This study aimed to assess the impact of high lipoprotein(a) on the long-term prognosis of patients undergoing coronary artery bypass grafting.

METHODS AND RESULTS

Consecutive patients with stable coronary artery disease who underwent isolated coronary artery bypass grafting from January 2013 to December 2018 from a single-center cohort were included. The primary outcome was all-cause death. The secondary outcome was a composite of major adverse cardiovascular and cerebrovascular events. Of the 18 544 patients, 4072 (22.0%) were identified as the high-lipoprotein(a) group (≥50 mg/dL). During a median follow-up of 3.2 years, primary outcomes occurred in 587 patients. High lipoprotein(a) was associated with increased risk of all-cause death (high lipoprotein(a) versus low lipoprotein(a): adjusted hazard ratio [aHR], 1.31 [95% CI, 1.09-1.59]; P=0.005; lipoprotein(a) per 1-mg/dL increase: aHR, 1.003 [95% CI, 1.001-1.006]; P=0.011) and major adverse cardiovascular and cerebrovascular events (high lipoprotein(a) versus low lipoprotein(a): aHR, 1.18 [95% CI, 1.06-1.33]; P=0.004; lipoprotein(a) per 1-mg/dL increase: aHR, 1.002 [95% CI, 1.001-1.004]; P=0.002). The lipoprotein(a)-related risk was greater in patients with European System for Cardiac Operative Risk Evaluation <3, and tended to attenuate in patients receiving arterial grafts.

CONCLUSIONS

More than 1 in 5 patients with stable coronary artery disease who underwent coronary artery bypass grafting were exposed to high lipoprotein(a), which is associated with higher risks of death and major adverse cardiovascular and cerebrovascular events. The adverse effects of lipoprotein(a) were more pronounced in patients with clinically low-risk profiles or not receiving arterial grafts.

Photodynamic Therapy for Atherosclerosis

Atherosclerosis, which currently contributes to 31% of deaths globally, is of critical cardiovascular concern. Current diagnostic tools and biomarkers are limited, emphasizing the need for early detection. Lifestyle modifications and medications form the basis of treatment, and emerging therapies such as photodynamic therapy are being developed. Photodynamic therapy involves a photosensitizer selectively targeting components of atherosclerotic plaques. When activated by specific light wavelengths, it induces localized oxidative stress aiming to stabilize plaques and reduce inflammation. The key advantage lies in its selective targeting, sparing healthy tissues. While preclinical studies are encouraging, ongoing research and clinical trials are crucial for optimizing protocols and ensuring long-term safety and efficacy. The potential combination with other therapies makes photodynamic therapy a versatile and promising avenue for addressing atherosclerosis and associated cardiovascular disease. The investigations underscore the possibility of utilizing photodynamic therapy as a valuable treatment choice for atherosclerosis. As advancements in research continue, photodynamic therapy might become more seamlessly incorporated into clinical approaches for managing atherosclerosis, providing a blend of efficacy and limited invasiveness.

Lipoprotein(a): An important piece of the ASCVD risk factor puzzle across diverse populations

Elevated lipoprotein(a) (Lp[a]) is an independent, genetic risk factor for atherosclerotic cardiovascular disease (ASCVD) that impacts ~1.4 billion people globally. Generally, Lp(a) levels remain stable over time; thus, most individuals need only undergo Lp(a) testing through a non-fasting blood draw once in their lifetime, unless elevated Lp(a) is identified. Despite the convenience of the test for clinicians and patients, routine Lp(a) testing has not been widely adopted. This review provides a guide to the benefits of Lp(a) testing and solutions for overcoming common barriers in practice, including access to testing and lack of awareness. Lp(a) testing provides the opportunity to reclassify ASCVD risk and drive intensive cardiovascular risk factor management in individuals with elevated Lp(a), and to identify patients potentially less likely to respond to statins. Moreover, cascade screening can help to identify elevated Lp(a) in relatives of individuals with a personal or family history of premature ASCVD. Overall, given the profound impact of elevated Lp(a) on cardiovascular risk, Lp(a) testing should be an essential component of risk assessment by primary and specialty care providers.

Atherosclerotic plaque stabilization and regression: a review of clinical evidence

Atherosclerotic plaque results from a complex interplay between lipid deposition, inflammatory changes, cell migration and arterial wall injury. Over the past two decades, clinical trials utilizing invasive arterial imaging modalities, such as intravascular ultrasonography, have shown that reducing levels of atherogenic lipoproteins, mainly serum LDL-cholesterol (LDL-C), to very low levels can safely reduce overall atherosclerotic plaque burden and favourably modify plaque composition. Classically, this outcome has been achieved with intensive statin therapy. Since 2016, newer and potent lipid-lowering strategies, such as proprotein convertase subtilisin-kexin type 9 inhibition, have shown incremental effects on plaque regression and risk of clinical events. Despite maximal reduction in plasma LDL-C levels, considerable residual cardiovascular risk remains in some patients. Therefore, there is a need to study therapeutic approaches that address residual risk beyond LDL-C reduction to promote plaque stabilization or regression. Contemporary imaging modalities, such as coronary computed tomography angiography, enable non-invasive assessment of the overall atherosclerotic plaque burden as well as of certain local plaque characteristics. This technology could allow further study of plaque stabilization and regression using novel therapeutic approaches. Non-invasive plaque assessment might also offer the potential to guide personalized management strategies if validated for this purpose.

The association of lipoprotein (a) with coronary artery calcification: A systematic review and meta-analysis

BACKGROUND AND AIMS

Coronary artery calcification (CAC) is a crucial pathophysiological characteristic of atherosclerosis. The association between lipoprotein (a) [Lp(a)] and CAC is inconsistent. We aimed to assess the relationship between Lp(a) and CAC by exploring the association between elevated Lp(a) and CAC prevalence, the relationship between Lp(a) level and CAC prevalence, and the correlation between elevated Lp(a) and CAC progression.

METHODS

We searched the PubMed, Web of Science, and EMBASE databases up to November 01, 2023. Studies exploring the association between serum Lp(a) and CAC (quantified using the Agatston score) were included. Association between Lp(a) level or elevated Lp(a) (higher than the cutoff values of 30 mg/dL, 50 mg/dL, or the highest quartile ranging from 33 to 38.64 mg/dL) and prevalence [CAC score >0 or >100, log (CAC score+1) >0] or progression (an increase in CAC score >0 or ≥100) of CAC were analysed. Odds ratios and 95% confidence intervals were calculated using a random-effects model.

RESULTS

40,073 individuals from 17 studies were included. Elevated Lp(a) was associated with a higher prevalence of CAC (OR, 1.31; 95% CI, 1.06 to 1.61; p = 0.01). As a continuous variable, Lp(a) level was positively correlated with the prevalence of CAC (OR, 1.05; 95% CI, 1.02 to 1.08; p = 0.003). Furthermore, elevated Lp(a) was associated with greater CAC progression (OR, 1.54; 95% CI, 1.23 to 1.92; p = 0.0002).

CONCLUSIONS

This meta-analysis suggested that Lp(a) is associated with prevalence and progression of CAC. Further studies are required to explore whether Lp(a)-lowering therapy could prevent or inhibit CAC, ultimately reducing coronary artery disease risk.

Noninvasive Coronary Atherosclerotic Plaque Imaging

Coronary artery disease is the leading cause of morbidity and mortality worldwide. Despite remarkable advances in the management of coronary artery disease, the prediction of adverse coronary events remains challenging. Over the preceding decades, considerable effort has been made to improve risk stratification using noninvasive imaging. Recently, these efforts have increasingly focused on the direct imaging of coronary atherosclerotic plaque. Modern imaging now allows imaging of coronary plaque burden, plaque type, atherosclerotic plaque activity, and plaque thrombosis, which have major potential to refine patient risk stratification, aid decision making, and advance future clinical practice.

High levels of lipoprotein(a) in transgenic mice exacerbate atherosclerosis and promote vulnerable plaque features in a sex-specific manner

BACKGROUND AND AIMS

Despite increased clinical interest in lipoprotein(a) (Lp(a)), many questions remain about the molecular mechanisms by which it contributes to atherosclerotic cardiovascular disease. Existing murine transgenic (Tg) Lp(a) models are limited by low plasma levels of Lp(a) and have not consistently shown a pro-atherosclerotic effect of Lp(a).

METHODS

We generated Tg mice expressing both human apolipoprotein(a) (apo(a)) and human apoB-100, with pathogenic levels of plasma Lp(a) (range 87-250 mg/dL). Female and male Lp(a) Tg mice (Tg(LPA+/0;APOB+/0)) and human apoB-100-only controls (Tg(APOB+/0)) (n = 10-13/group) were fed a high-fat, high-cholesterol diet for 12 weeks, with Ldlr knocked down using an antisense oligonucleotide. FPLC was used to characterize plasma lipoprotein profiles. Plaque area and necrotic core size were quantified and immunohistochemical assessment of lesions using a variety of cellular and protein markers was performed.

RESULTS

Male and female Tg(LPA+/0;APOB+/0) and Tg(APOB+/0) mice exhibited proatherogenic lipoprotein profiles with increased cholesterol-rich VLDL and LDL-sized particles and no difference in plasma total cholesterol between genotypes. Complex lesions developed in the aortic sinus of all mice. Plaque area (+22%), necrotic core size (+25%), and calcified area (+65%) were all significantly increased in female Tg(LPA+/0;APOB+/0) mice compared to female Tg(APOB+/0) mice. Immunohistochemistry of lesions demonstrated that apo(a) deposited in a similar pattern as apoB-100 in Tg(LPA+/0;APOB+/0) mice. Furthermore, female Tg(LPA+/0;APOB+/0) mice exhibited less organized collagen deposition as well as 42% higher staining for oxidized phospholipids (OxPL) compared to female Tg(APOB+/0) mice. Tg(LPA+/0;APOB+/0) mice had dramatically higher levels of plasma OxPL-apo(a) and OxPL-apoB compared to Tg(APOB+/0) mice, and female Tg(LPA+/0;APOB+/0) mice had higher plasma levels of the proinflammatory cytokine MCP-1 (+3.1-fold) compared to female Tg(APOB+/0) mice.

CONCLUSIONS

These data suggest a pro-inflammatory phenotype exhibited by female Tg mice expressing Lp(a) that appears to contribute to the development of more severe lesions with greater vulnerable features.

Cardiometabolic predictors of high-risk CCTA phenotype in a diverse patient population

Introduction

Low-attenuation non-calcified plaque (LAP) burden and vascular inflammation by pericoronary adipose tissue (PCAT) measured from coronary CT angiography (CCTA) have shown to be predictors of cardiovascular outcomes. We aimed to investigate the relationships of cardiometabolic risk factors including lipoprotein(a) and epicardial adipose tissue (EAT) with CCTA high-risk imaging biomarkers, LAP and vascular inflammation.

Methods

The patient population consisted of consecutive patients who underwent CCTA for stable chest pain and had a complete cardiometabolic panel including lipoprotein(a). Plaque, PCAT and EAT were measured from CT using semiautomated software. Elevated LAP burden and PCAT attenuation were defined as ≥4% and ≥70.5 HU, respectively. The primary clinical end-point was a composite of myocardial infarction, revascularization or cardiovascular death.

Results

A total of 364 consecutive patients were included (median age 56 years, 64% female); the majority of patients were of Hispanic (60%), and the rest were of non-Hispanic Black (21%), non-Hispanic White (6%) and non-Hispanic Asian (4%) race/ethnicity. The prevalence of elevated LAP burden and PCAT attenuation was 31 and 18%, respectively, while only 8% had obstructive stenosis. There were significant differences in plaque characteristics among different racial/ethnic groups (p<0.001). Lipoprotein(a) correlated with LAP burden in Hispanic patients. Patients with elevated LAP were older, more likely to be have diabetes, hypertension, hyperlipidemia and smoke with higher CAC and EAT volume (all P<0.05). Patients with elevated LAP were more likely to develop the primary clinical outcome (p<0.001) but those with elevated PCAT were not (p=0.797).

Conclusion

The prevalence of LAP and PCAT attenuation were 31 and 18%, respectively. Lipoprotein(a) levels correlated with LAP burden in Hispanic patients. Age, male sex, hypertension and hyperlipidemia increased the odds of elevated LAP, which showed prognostic significance.

Correlation of neck circumference, coronary calcification severity and cardiovascular events in Chinese elderly patients with acute coronary syndromes

BACKGROUND AND AIMS

We aimed to investigate whether neck circumference (NC) can predict metabolic syndrome (MetS), coronary calcification and lesion, and major adverse cardiovascular events (MACEs).

METHODS

A total of 867 patients with acute coronary syndrome (ACS) over 60 years old from the Second Hospital of Shandong University, who had undergone coronary computed tomography, were randomly selected for a retrospective analysis. The subjects were divided into male and female groups, NC quartile 1-4 groups (Q1-Q4 groups), non-multivessel coronary disease (non-MVCD) and multi-vessel coronary disease (MVCD) groups.

RESULTS

After adjusting for potential confounders, NC was associated with risk factors promoting coronary artery disease (CAD) and coronary artery calcification score (CACS). The severity of CAD increased by 0.202 times and 0.372 times for each unit of NC in male and female groups, respectively. Compared with the lower CACS group, the risk of coronary calcification increased by 0.139 times, and MVCD increased 0.268 times, with each unit increase of NC. Except for all-cause death, there were significant differences between the Q1-Q4 groups in the prevalence of all primary endpoints, cardiogenic death, unexpected re-hospitalization of heart failure, ACS recurrence or unplanned revascularization, and non-fatal stroke (p log-rank <0.01). In view of the overall trend, with the increase of NC quartiles, the prevalence of MACEs gradually increased (all p < 0.01).

CONCLUSIONS

NC is closely associated with MetS and its components, coronary calcification and lesion degree, and MACEs. NC could be used as surrogate of CACS to predict the coronary condition and prognosis of elderly patients with ACS.

Regression and stabilization of atherogenic plaques

Atherosclerotic plaque assessment has become a crucial element in the examination of cardiovascular diseases. Plaque may exhibit progression and could become unstable if not treated, making plaque regression and stabilization among the most important goals of any cardiovascular intervention in cardiovascular medicine. In this review, we explore the current understanding of plaque regression and stabilization, discuss imaging and measurement techniques, and examine the evidence for pharmacological interventions and other interventions aimed at addressing this condition.

The Association of Lipoprotein(a) and Neutrophil-to-Lymphocyte Ratio Combination with Atherosclerotic Cardiovascular Disease in Chinese Patients

Objective

The association of lipoprotein(a) [Lp(a)] with atherosclerotic cardiovascular disease (ASCVD) risk can be modified by chronic systemic inflammation. The neutrophil-to-lymphocyte ratio (NLR) is a reliable and easily available marker of immune response to various infectious and non-infectious stimuli. The purpose of this study was to assess the combined effects of Lp(a) and NLR in predicting the ASCVD risk and coronary artery plaque traits.

Methods

This study included 1618 patients who had coronary computed tomography angiography (CTA) with risk assessment of ASCVD. CTA was used to evaluate the traits of coronary atherosclerotic plaques, and the association of ASCVD with Lp(a) and NLR was assessed by multivariate logistic regression models.

Results

Plasma Lp(a) and NLR were significantly increased in patients having plaques. High Lp(a) was defined as the plasma Lp(a) level > 75 nmol/L and high NLR as NLR > 1.686. The patients were grouped into four categories according to normal or high NLR and plasma Lp(a) as nLp(a)/NLR-, hLp(a)/NLR-, nLp(a)/NLR+ and hLp(a)/NLR+. The patients in the latter three groups had higher risk of ASCVD compared to the reference group nLp(a)/NLR-, with the highest ASCVD risk in the hLp(a)/NLR+ group (OR = 2.39, 95% CI = 1.49-3.83, P = 0.000). The occurrence of unstable plaques was 29.94% in the hLp(a)/NLR+ group, which was significantly higher than groups nLp(a)/NLR+, hLp(a)/NLR- and nLp(a)/NLR- with 20.83%, 26.54% and 22.58%, respectively, and there was a significantly increased risk of unstable plaque in the hLp(a)/NLR+ group compared to the nLp(a)/NLR- group (OR = 1.67, 95% CI = 1.04-2.68, P = 0.035). The risk of stable plaque was not significantly increased in the hLp(a)/NLR+ group compared to the nLp(a)/NLR- group (OR = 1.73, 95% CI = 0.96-3.10, P = 0.066).

Conclusion

The concomitant presence of elevated Lp(a) and higher NLR is associated with increased unstable coronary artery plaques in patients with ASCVD.

Lipoprotein(a) and the risk of recurrent coronary heart disease: the Dubbo Study

OBJECTIVE

Elevated Lipoprotein(a) [Lp(a)] has not been firmly established as a risk factor for recurrent coronary heart disease (CHD). The present analysis explored this relationship in senior citizens.

METHODS

This was a longitudinal study in 607 subjects, all with prevalent CHD, mean age 71 years, followed for 16 years. Baseline examinations of lipids and other CHD risk factors were conducted in 1988-89 in Dubbo, Australia. The independent contribution of Lp(a) to a further CHD event was examined in proportional hazards regression models.

RESULTS

There were 399 incident CHD cases. Median Lp(a) in CHD cases was 130 mg/L (Interquartile range 60-315) and in non-cases 105 mg/L (45-250) (p < .07, U-Test). 26% of CHD cases and 19% of non-cases had Lp(a) 300 + mg/L; 18% of CHD cases and 8% of non-cases had Lp(a) 500 + mg/L. Lp(a) in Quintile 5 of its distribution (355 + mg/L), using Lp(a) Quintile 1 (<50mg/L) as reference, significantly predicted recurrent CHD with Hazard Ratio 1.53 (95% CI 1.11-2.11, p = .01). Prediction was independent of other risk factors. Lp(a) 500 + mg/L versus lower, significantly predicted recurrent CHD with Hazard Ratio 1.59 (1.16-2.17, p < .01). Prediction was similarly significant for Lp(a) 300 + mg/L versus lower, with Hazard Ratio 1.37 (1.09-1.73, p < .01).

CONCLUSION

Elevated Lp(a) is an independent and significant predictor of recurrent CHD in senior citizens. Upper reference Lp(a) levels of 500 mg/L (≈125nmol/L) or 300 mg/L (≈75nmol/L) both appear to be appropriate. The clinical benefit of therapy to reduce elevated Lp(a) remains to be confirmed.

Lipoprotein(a) in clinical practice: A guide for the clinician

Cardiovascular disease (CVD) remains the leading cause of death worldwide. Serum lipoprotein(a) (Lp(a)) has been shown to be an independent and causative risk factor for atherosclerotic CVD and calcific aortic valvular disease. Lp(a) continues to be studied, with emerging insights into the epidemiology of CVD with respect to Lp(a), pathogenic mechanisms of Lp(a) and strategies to mitigate disease. There have been novel insights into genetic polymorphisms of the LPA gene, interactions between concomitant risk factors and Lp(a) based on real-world data, and metabolic pathway targets for Lp(a) reduction. This review highlights these recent advances in our understanding of Lp(a) and discusses management strategies as recommended by cardiovascular professional societies, emerging therapies for lowering Lp(a), and future directions in targeting Lp(a) to reduce CVD.

Lipoprotein(a) and coronary artery calcium in comparison with other lipid biomarkers: The multi-ethnic study of atherosclerosis

BACKGROUND

Coronary artery calcium (CAC) scoring is often used for atherosclerotic cardiovascular disease (ASCVD) risk stratification in individuals with elevated lipoprotein(a) [Lp(a)].

OBJECTIVE

To evaluate associations between Lp(a) and baseline CAC (volume/density) and CAC progression compared to other lipid biomarkers.

METHODS

We utilized data from the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort study of individuals without clinical ASCVD, excluding statin users. We evaluated the associations between Lp(a), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), triglycerides, total cholesterol, apolipoprotein B, and non-HDL-C with baseline CAC and annual CAC progression using multivariable ordinal regression with adjustment for ASCVD risk factors. Analyses were also stratified by median age.

RESULTS

In 5,597 participants (2,726 at median 9.5-year follow-up), Lp(a) was not associated with baseline CAC volume or density and was modestly associated with volume progression (OR 1.11, 95% CI 1.03-1.21). However, other biomarkers were positively associated with baseline volume and volume progression (LDL-C: OR 1.26, 95% CI: 1.19-1.33 and OR 1.22, 95% CI: 1.15-1.30, respectively), except HDL-C which was inversely associated. LDL-C, total cholesterol and non-HDL-C were inversely associated with baseline density. In participants <62 years of age, Lp(a) was modestly associated with baseline CAC volume (OR 1.10, 95% CI: 1.00-1.20) and volume progression (OR 1.16 95% CI: 1.04-1.30).

CONCLUSIONS

In contrast to other lipid biomarkers, Lp(a) was not associated with baseline CAC volume or density and was only modestly associated with volume progression. Our findings suggest that Lp(a) is not as robustly associated with CAC as other lipid biomarkers.

Current Management and Future Perspectives in the Treatment of Lp(a) with a Focus on the Prevention of Cardiovascular Diseases

Lipoprotein(a) [Lp(a)] is a lipid molecule with atherogenic, inflammatory, thrombotic, and antifibrinolytic effects, whose concentrations are predominantly genetically determined. The association between Lp(a) and cardiovascular diseases (CVDs) has been well-established in numerous studies, and the ability to measure Lp(a) levels is widely available in the community. As such, there has been increasing interest in Lp(a) as a therapeutic target for the prevention of CVD. The impact of the currently available lipid-modifying agents on Lp(a) is modest and heterogeneous, except for the monoclonal antibody proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i), which demonstrated a significant reduction in Lp(a) levels. However, the absolute reduction in Lp(a) to significantly decrease CVD outcomes has not been definitely established, and the magnitude of the effect of PCSK9i seems insufficient to directly reduce the Lp(a)-related CVD risk. Therefore, emerging therapies are being developed that specifically aim to lower Lp(a) levels and the risk of CVD, including RNA interference (RNAi) agents, which have the capacity for temporary and reversible downregulation of gene expression. This review article aims to summarize the effects of Lp(a) on CVD and to evaluate the available evidence on established and emerging therapies targeting Lp(a) levels, focusing on the potential reduction of CVD risk attributable to Lp(a) concentrations.

Evidence and Uncertainties on Lipoprotein(a) as a Marker of Cardiovascular Health Risk in Children and Adolescents

Lipoprotein(a) (Lp(a)) is made up of apoprotein(a) (apo(a)) and an LDL-like particle. The LPA gene encodes apo(a) and thus determines the characteristics and amount of apo(a) and Lp(a). The proportion of Lp(a) in each individual is genetically determined and is only minimally modifiable by the environment or diet. Lp(a) has important pro-atherosclerotic and pro-inflammatory effects. It has been hypothesized that Lp(a) also has pro-coagulant and antifibrinolytic actions. For these reasons, high Lp(a) values are an important independent risk factor for cardiovascular disease and calcific aortic valve stenosis. Numerous studies have been performed in adults about the pathophysiology and epidemiology of Lp(a) and research is under way for the development of drugs capable of reducing Lp(a) plasma values. Much less information is available regarding Lp(a) in children and adolescents. The present article reviews the evidence on this topic. The review addresses the issues of Lp(a) changes during growth, the correlation between Lp(a) values in children and those in their parents, and between Lp(a) levels in children, and the presence of cardiovascular disease in the family. Gaining information on these points is particularly important for deciding whether Lp(a) assay may be useful for defining the cardiovascular risk in children, in order to plan a prevention program early.

Serum lipoprotein(a) and bioprosthetic aortic valve degeneration

AIMS

Bioprosthetic aortic valve degeneration demonstrates pathological similarities to aortic stenosis. Lipoprotein(a) [Lp(a)] is a well-recognized risk factor for incident aortic stenosis and disease progression. The aim of this study is to investigate whether serum Lp(a) concentrations are associated with bioprosthetic aortic valve degeneration.

METHODS AND RESULTS

In a post hoc analysis of a prospective multimodality imaging study (NCT02304276), serum Lp(a) concentrations, echocardiography, contrast-enhanced computed tomography (CT) angiography, and 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) were assessed in patients with bioprosthetic aortic valves. Patients were also followed up for 2 years with serial echocardiography. Serum Lp(a) concentrations [median 19.9 (8.4-76.4) mg/dL] were available in 97 participants (mean age 75 ± 7 years, 54% men). There were no baseline differences across the tertiles of serum Lp(a) concentrations for disease severity assessed by echocardiography [median peak aortic valve velocity: highest tertile 2.5 (2.3-2.9) m/s vs. lower tertiles 2.7 (2.4-3.0) m/s, P = 0.204], or valve degeneration on CT angiography (highest tertile n = 8 vs. lower tertiles n = 12, P = 0.552) and 18F-NaF PET (median tissue-to-background ratio: highest tertile 1.13 (1.05-1.41) vs. lower tertiles 1.17 (1.06-1.53), P = 0.889]. After 2 years of follow-up, there were no differences in annualized change in bioprosthetic hemodynamic progression [change in peak aortic valve velocity: highest tertile [0.0 (-0.1-0.2) m/s/year vs. lower tertiles 0.1 (0.0-0.2) m/s/year, P = 0.528] or the development of structural valve degeneration.

CONCLUSION

Serum lipoprotein(a) concentrations do not appear to be a major determinant or mediator of bioprosthetic aortic valve degeneration.

Lipoprotein(a) Is Associated With the Progression and Vulnerability of New-Onset Carotid Atherosclerotic Plaque

BACKGROUND

Although important progress has been made in understanding Lp(a) (lipoprotein[a])-mediated stroke risk, the contribution of Lp(a) to the progression of vulnerable plaque features associated with stroke risk remains unclear. This study aims to evaluate whether Lp(a) is associated with carotid plaque progression, new-onset plaque features, and plaque vulnerability in a prospective community-based cohort study.

METHODS

Baseline Lp(a) levels were measured using latex-enhanced turbidimetric immunoassay among 804 participants aged 45 to 74 years and free of cardiovascular disease in the Chinese Multi-provincial Cohort Study-Beijing project. Carotid atherosclerosis was measured twice by B-mode ultrasonography over a 10-year interval during the 2002 and 2012 surveys to assess the progression of total, vulnerable and stable plaques, and plaque vulnerability. The total plaque area and plaque vulnerability score were calculated.

RESULTS

The median baseline Lp(a) level was 10.20 mg/dL (interquartile range, 6.20 to 17.18 mg/dL). Modified Poisson regression analysis showed that Lp(a) ≥50 mg/dL was significantly associated with 10-year progression of total carotid plaque (relative risk [RR], 1.41 [95% CI, 1.21-1.64]; E-value=2.17), vulnerable plaque (RR, 1.93 [95% CI, 1.54-2.41]), and stable plaque (RR, 1.51 [95% CI, 1.11-2.07]) compared with Lp(a) <50 mg/dL. Moreover, among participants without plaque at baseline, Lp(a) ≥50 mg/dL was related to an increased total plaque area (β=0.36 [95% CI, 0.06-0.65]; P=0.018) and increased plaque vulnerability score (β=0.30 [95% CI, 0.01-0.60]; P=0.045) in multivariable linear regression.

CONCLUSIONS

Elevated Lp(a) levels were associated with 10-year carotid plaque progression and plaque vulnerability, providing a basis for Lp(a) as a treatment target for stroke prevention.

Clinical Trial Design for Lipoprotein(a)-Lowering Therapies: JACC Focus Seminar 2/3

Lipoprotein(a) [Lp(a)] is a source of residual risk in patients with atherosclerotic cardiovascular disease (ASCVD). Clinical trials of fully human monoclonal antibodies targeting proprotein convertase subtilisin kexin 9 have shown that reductions in Lp(a) concentrations may be a predictor of event reduction with this class of cholesterol-lowering therapy. With the advent of selective therapies targeting Lp(a) such as antisense oligonucleotides, small-interfering RNA-based therapies, and gene editing, lowering of Lp(a) may lead to reduction in ASCVD. The phase 3 Lp(a)HORIZON (Assessing the Impact of Lipoprotein(a) Lowering with TQJ230 on Major Cardiovascular Events in Patients With CVD) outcomes trial is currently testing the effect of pelacarsen, an antisense oligonucleotide, on ASCVD risk. Olpasiran is a small-interfering RNA that is in a phase 3 clinical trial. As these therapies enter clinical trials, challenges in trial design will have to be addressed to optimize patient selection and outcomes.

Computed tomographic angiography in coronary artery disease

Coronary computed tomographic angiography (CCTA) is becoming the first-line investigation for establishing the presence of coronary artery disease and, with fractional flow reserve (FFRCT), its haemodynamic significance. In patients without significant epicardial obstruction, its role is either to rule out atherosclerosis or to detect subclinical plaque that should be monitored for plaque progression/regression following prevention therapy and provide risk classification. Ischaemic non-obstructive coronary arteries are also expected to be assessed by non-invasive imaging, including CCTA. In patients with significant epicardial obstruction, CCTA can assist in planning revascularisation by determining the disease complexity, vessel size, lesion length and tissue composition of the atherosclerotic plaque, as well as the best fluoroscopic viewing angle; it may also help in selecting adjunctive percutaneous devices (e.g., rotational atherectomy) and in determining the best landing zone for stents or bypass grafts.

Improving diagnostic assessments in the ever-changing landscape of atherosclerosis

As our understanding of atherosclerotic vascular injury continues to evolve, so should our diagnostic approaches. Emerging data have recently challenged our basic understanding in linking ischemia to its adverse outcomes as well as the need for invasive testing for both diagnosis and treatment. The advent of coronary computed tomography in providing improved visualization of coronary arteries has led to the identification of both subclinical atherosclerosis and high-risk coronary lesions. Recognition of asymptomatic coronary artery disease (CAD) with objective localization of subclinical coronary atherosclerosis improves atherosclerotic cardiovascular risk assessment and allows healthcare providers to take effective primary prevention measures. Therefore, reshaping the diagnostic landscape in proposing new testing modalities would be highly dependent on local resource availability and the reading expertise of each clinical practice and medical institution. The main objective of this Review is to propose a potentially new diagnostic approach of simply using noninvasive stress testing or coronary angiography in the routine assessment of CAD.

Does Coronary Plaque Morphology Matter Beyond Plaque Burden?

PURPOSE OF REVIEW

Imaging of adverse coronary plaque features by coronary computed tomography angiography (CCTA) has advanced greatly and at a fast pace. We aim to describe the evolution, present and future in plaque analysis, and its value in comparison to plaque burden.

RECENT FINDINGS

Recently, it has been demonstrated that in addition to plaque burden, quantitative and qualitative assessment of coronary plaque by CCTA can improve the prediction of future major adverse cardiovascular events in diverse coronary artery disease scenarios. The detection of high-risk non-obstructive coronary plaque can lead to higher use of preventive medical therapies such as statins and aspirin, help identify culprit plaque, and differentiate between myocardial infarction types. Even more, over traditional plaque burden, plaque analysis including pericoronary inflammation can potentially be useful tools for tracking disease progression and response to medical therapy. The identification of the higher risk phenotypes with plaque burden, plaque characteristics, or ideally both can allow the allocation of targeted therapies and potentially monitor response. Further observational data are now required to investigate these key issues in diverse populations, followed by rigorous randomized controlled trials.

Editor-in-Chief's Top Picks From 2022

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. This process has become a true labor of love due to the time they require, but I am motivated by the sheer number of listeners (16 million plus), and it has allowed me to familiarize myself with every paper that we publish. Thus, I have selected the top 100 papers (both Original Investigations and Review Articles) from distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as their Central Illustrations and podcasts. The highlights comprise the following sections: Basic & Translational Research, Cardiac Failure & Myocarditis, Cardiomyopathies & Genetics, Cardio-Oncology, Congenital Heart Disease, Coronary Disease & Interventions, Coronavirus, Hypertension, Imaging, Metabolic & Lipid Disorders, Neurovascular Disease & Dementia, Promoting Health & Prevention, Rhythm Disorders & Thromboembolism, and Valvular Heart Disease.^1-100.

Lipoprotein(a): Its Association with Calcific Aortic Valve Stenosis, the Emerging RNA-Related Treatments and the Hope for a New Era in “Treating” Aortic Valve Calcification

The treatment of patients with aortic valve calcification (AVC) and calcific aortic valve stenosis (CAVS) remains challenging as, until today, all non-invasive interventions have proven fruitless in preventing the disease’s onset and progression. Despite the similarities in the pathogenesis of AVC and atherosclerosis, statins failed to show a favorable effect in preventing AVC progression. The recognition of lipoprotein(a) [Lp(a)] as a strong and potentially modifiable risk factor for the development and, perhaps, the progression of AVC and CAVS and the evolution of novel agents leading in a robust Lp(a) reduction, have rekindled hope for a promising future in the treatment of those patients. Lp(a) seems to promote AVC via a ‘three hit’ mechanism including lipid deposition, inflammation and autotaxin transportation. All of these lead to valve interstitial cells transition into osteoblast-like cells and, thus, to parenchymal calcification. Currently available lipid-lowering therapies have shown a neutral or mild effect on Lp(a), which was proven insufficient to contribute to clinical benefits. The short-term safety and the efficacy of the emerging agents in reducing Lp(a) have been proven; nevertheless, their effect on cardiovascular risk is currently under investigation in phase 3 clinical trials. A positive result of these trials will probably be the spark to test the hypothesis of the modification of AVC’s natural history with the novel Lp(a)-lowering agents.

PCSK9 Inhibitors in Cancer Patients Treated with Immune-Checkpoint Inhibitors to Reduce Cardiovascular Events: New Frontiers in Cardioncology

Cancer patients treated with immune checkpoint inhibitors (ICIs) are exposed to a high risk of atherosclerosis and cardiometabolic diseases due to systemic inflammatory conditions and immune-related atheroma destabilization. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key protein involved in metabolism of low-density lipoprotein (LDL) cholesterol. PCSK9 blocking agents are clinically available and involve monoclonal antibodies, and SiRNA reduces LDL levels in high-risk patients and atherosclerotic cardiovascular disease events in multiple patient cohorts. Moreover, PCSK9 induces peripheral immune tolerance (inhibition of cancer cell- immune recognition), reduces cardiac mitochondrial metabolism, and enhances cancer cell survival. The present review summarizes the potential benefits of PCSK9 inhibition through selective blocking antibodies and siRNA in patients with cancer, especially in those treated with ICIs therapies, in order to reduce atherosclerotic cardiovascular events and potentially improve ICIs-related anticancer functions.

Imaging subclinical coronary atherosclerosis to guide lipid management, are we there yet?

Atherosclerotic cardiovascular disease risk (ASCVD) is an ongoing epidemic, and lipid abnormalities are its primordial cause. Most individuals suffering a first ASCVD event are previously asymptomatic and often do not receive preventative therapies. The cornerstone of primary prevention has been the identification of individuals at risk through risk calculators based on clinical and laboratory traditional risk factors plus risk enhancers. However, it is well accepted that a clinical risk calculator misclassifies a significant proportion of individuals leading to the prescription of a lipid-lowering medication with very little yield or a missed opportunity for lipid-lowering agents with a potentially preventable event. The development of coronary artery calcium scoring (CAC) and CT coronary angiography (CCTA) provide complementary tools to directly visualize coronary plaque and other risk-modifying imaging components that can potentially provide individualized lipid management. Understanding patient selection for CAC or potentially CCTA and the risk implications of the different parameters provided, such as CAC score, coronary stenosis, plaque characteristics and burden, epicardial adipose tissue, and pericoronary adipose tissue, have grown more complex as technologies evolve. These parameters directly affect the shared decision with patients to start or withhold lipid-lowering therapies, to adjust statin intensity or LDL cholesterol goals. Emerging lipid lowering studies with non-invasive imaging as a guide to patient selection and treatment efficacy, plus the evolution of lipid lowering therapies from statins to a diverse armament of newer high-cost agents have pushed these two fields forward with a complex interaction. This review will discuss existing risk estimators, and non-invasive imaging techniques for subclinical coronary atherosclerosis, traditionally studied using CAC and more recently CCTA with qualitative and quantitative measurements. We will also explore the current data, gaps of knowledge and future directions on the use of these techniques in the risk-stratification and guidance of lipid management.

Targeted Treatment against Lipoprotein (a): The Coming Breakthrough in Lipid Lowering Therapy

Atherosclerotic cardiovascular diseases (ASCVD) are a very important cause of premature death. The most important risk factor for ASCVD is lipid disorders. The incidence of lipid disorders and ASCVD is constantly increasing, which means that new methods of prevention and treatment of these diseases are still being searched for. In the management of patients with lipid disorders, the primary goal of therapy is to lower the serum LDL-C concentration. Despite the available effective lipid-lowering therapies, the risk of ASCVD is still increased in some patients. A high level of serum lipoprotein (a) (Lp(a)) is a risk factor for ASCVD independent of serum LDL-C concentration. About 20% of Europeans have elevated serum Lp(a) levels, requiring treatment to reduce serum Lp(a) concentrations in addition to LDL-C. Currently available lipid lowering drugs do not sufficiently reduce serum Lp(a) levels. Hence, drugs based on RNA technology, such as pelacarsen, olpasiran, SLN360 and LY3819469, are undergoing clinical trials. These drugs are very effective in lowering the serum Lp(a) concentration and have a satisfactory safety profile, which means that in the near future they will fill an important gap in the armamentarium of lipid-lowering drugs.

Lipoprotein (a) variability is associated with mean follow-up C-reactive protein in patients with coronary artery disease following percutaneous coronary intervention

BACKGROUND

Increased lipoprotein (a) [lp (a)] has proinflammatory effects, which increase the risk of coronary artery disease. However, the association between lp (a) variability and follow-up C-reactive protein (CRP) level in patients undergoing percutaneous coronary intervention (PCI) has not been investigated.

AIM

To explore the association between lp (a) variability and mean CRP levels within the 1^st year post-PCI.

METHODS

Results of lp (a) and CRP measurements from at least three follow-up visits of patients who had received PCI were retrospectively analyzed. Standard deviation (SD), coefficient of variation (CV), and variability independent of the mean (VIM) are presented for the variability for lp (a) and linear regression analysis was conducted to correlate lp (a) variability and mean follow-up CRP level. The relationship of lp (a) variability and inflammation status was analyzed by restricted cubic spline analysis. Finally, exploratory analysis was performed to test the consistency of results in different populations.

RESULTS

A total of 2712 patients were enrolled. Patients with higher variability of lp (a) had a higher level of mean follow-up CRP (P < 0.001). lp (a) variability was positively correlated with the mean follow-up CRP (SD: β = 0.023, P < 0.001; CV: β = 0.929, P < 0.001; VIM: β = 1.648, P < 0.001) by multivariable linear regression analysis. Exploratory analysis showed that the positive association remained consistent in most subpopulations.

CONCLUSION

Lp (a) variability correlated with mean follow-up CRP level and high variability could be considered an independent risk factor for increased post-PCI CRP level.

m6A 'writer' KIAA1429 regulates the proliferation and migration of endothelial cells in atherosclerosis

Increasing evidences have illustrated the important role of N⁶-methyladenosine (m⁶A) in atherosclerosis (AS). However, the role of m⁶A modification in AS pathophysiological process is still unknown. Here, the present work tried to investigate the expression and function of m⁶A methyltransferase KIAA1429 in AS pathology and explored its undergoing m⁶A-dependent molecular mechanism. Results indicated that KIAA1429 remarkedly up-regulated in oxidative low-density lipoprotein (ox-LDL)-treated human umbilical vein endothelial cells (HUVECs). KIAA1429 over-expression inhibited the proliferation/migration in ox-LDL-treated HUVECs, while, KIAA1429 knockdown up-regulated the proliferation and migration. Mechanistically, via m⁶A modification sites binding, ROCK2 mRNA was post-transcriptionally upregulated by KIAA1429 in response to Actinomycin D. Collectively, our study demonstrated the regulation of KIAA1429 on ox-LDL-induced HUVECs via m⁶A/ROCK2 pathway. These findings provide new insights for m⁶A-mediated epigenetics in AS.

Lipoprotein (a) levels and vulnerable characteristics in nonculprit plaque in patients with acute coronary syndrome

•

High Lp(a) level is associated with more TCFA in nonculprit plaque in ACS patients.

•

The association was significant among patients with plaque erosion.

•

Measurement of Lp(a) may be useful for risk stratification in ACS patients.

Background

High plasma levels of Lp(a) are associated with a worse prognosis in patients with coronary artery disease. The aim of the present study is to clarify the association between high lipoprotein a [Lp(a)] levels and vulnerable characteristics of nonculprit plaques in patients with acute coronary syndrome (ACS).

Methods

A total of 185 consecutive patients with ACS who underwent optical coherence tomography imaging of nonculprit plaques in the culprit vessels were enrolled. Patients were divided into the high Lp(a) group (≥30 mg/dL; 50 nonculprit plaques in 49 patients) or the low Lp(a) group (<30 mg/dL; 139 nonculprit plaques in 136 patients).

Results

The prevalence of thin-cap fibroatheroma (TCFA) was significantly higher in the high Lp(a) group than in the low Lp(a) group (38.0 vs. 21.6%, p = 0.034). Multivariate logistic analysis demonstrated that a high Lp(a) level was independently associated with the prevalence of TCFA (odds ratio, 1.18; 95% confidence interval, 1.01–1.36; p = 0.033). The prevalence of TCFA was significantly higher in the high Lp(a) group than in the low Lp(a) group among patients with plaque erosion (50.0 vs. 9.4%, respectively; p = 0.027), although the difference was not statistically significant between the two groups in patients with plaque rupture.

Conclusions

High Lp(a) levels were associated with a high prevalence of TCFA in nonculprit plaques among patients with ACS, particularly in patients with plaque erosion. The present results may partly explain the pathogenesis of worse clinical outcomes in patients with ACS and a high Lp(a) level as shown in clinical studies.

Association of Lipoprotein (a) With Coronary-Computed Tomography Angiography-Assessed High-Risk Coronary Disease Attributes and Cardiovascular Outcomes

BACKGROUND

Lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular events. This study evaluated the relationship between Lp(a) and high-risk attributes by coronary computed tomography angiography as well as their prognostic value.

METHODS

Lp(a) and coronary computed tomography angiography from 377 consecutive patients at Zhongshan Hospital (Shanghai, China) were evaluated. High-risk attributes were defined as high-risk morphological attributes (low attenuation plaque, positive remodeling, napkin-ring sign, spotty calcification, minimum lumen area <4 mm², or plaque burden [ratio between cross-sectional plaque area at the site of maximum stenosis and cross-sectional vessel area] ≥70%); inflammatory attribute represented by fat attenuation index; high-risk physiological attributes [lesion-specific ischemia defined by fractional flow reserve by coronary computed tomography angiography ≤0.8, physiologic diffuseness defined by fractional flow reserve by coronary computed tomography angiography pullback pressure gradient]. Total plaque volume in mm³ was also quantified. Quintiles or binary classification of Lp(a) levels were used to evaluate its relationships with plaque features and clinical outcomes with ANOVA, Cox models, and log-rank tests, as appropriate. The major adverse cardiovascular event included cardiovascular death, nonfatal myocardial infarction, and target vessel revascularization.

RESULTS

Lp(a) was significantly associated with total plaque volume (P=0.004), fat attenuation index (P=0.031), and fractional flow reserve by coronary computed tomography angiography pullback pressure gradient (P=0.038). Patients with a high Lp(a) level had a higher total plaque volume (393.3 mm³ versus 293.9 mm³, P<0.001), lower pullback pressure gradient (0.62 versus 0.69, P=0.023), higher fat attenuation index (-70.5HU versus -73.9HU, P=0.004), and higher incidence of major adverse cardiovascular event (14.5% versus 6.3%, adjusted hazard ratio: 2.52, 95% CI: 1.12-5.63, P=0.025). In a 4-group classification according to Lp(a) and high-risk attributes, patients with high Lp(a) and ≥3 high-risk attributes had the highest risk of major adverse cardiovascular event (25.9%; overall P<0.001). Causal mediation analysis revealed that around 40% of the prognostic effect of Lp(a) was mediated by high-risk attributes.

CONCLUSIONS

Lp(a) level is associated with coronary computed tomography angiography high-risk characteristics, including morphologic, physiologic, and inflammatory attributes as well as major adverse cardiovascular event. This effect is partly mediated by inflammation and vulnerable plaque.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05323227.

Noninvasive Plaque Imaging to Accelerate Coronary Artery Disease Drug Development

Coronary artery disease (CAD) remains the leading cause of adult mortality globally. Targeting known modifiable risk factors has had substantial benefit, but there remains a need for new approaches. Improvements in invasive and noninvasive imaging techniques have enabled an increasing recognition of distinct quantitative phenotypes of coronary atherosclerosis that are prognostically relevant. There are marked differences in plaque phenotype, from the high-risk, lipid-rich, thin-capped atheroma to the low-risk, quiescent, eccentric, nonobstructive calcified plaque. Such distinct phenotypes reflect different pathophysiologic pathways and are associated with different risks for acute ischemic events. Noninvasive coronary imaging techniques, such as computed tomography, positron emission tomography, and coronary magnetic resonance imaging, have major potential to accelerate cardiovascular drug development, which has been affected by the high costs and protracted timelines of cardiovascular outcome trials. This may be achieved through enrichment of high-risk phenotypes with higher event rates or as primary end points of drug efficacy, at least in phase 2 trials, in a manner historically performed through intravascular coronary imaging studies. Herein, we provide a comprehensive review of the current technology available and its application in clinical trials, including implications for sample size requirements, as well as potential limitations. In its effort to accelerate drug development, the US Food and Drug Administration has approved surrogate end points for 120 conditions, but not for CAD. There are robust data showing the beneficial effects of drugs, including statins, on CAD progression and plaque stabilization in a manner that correlates with established clinical end points of mortality and major adverse cardiovascular events. This, together with a clear mechanistic rationale for using imaging as a surrogate CAD end point, makes it timely for CAD imaging end points to be considered. We discuss the importance of global consensus on these imaging end points and protocols and partnership with regulatory bodies to build a more informed, sustainable staged pathway for novel therapies.

New Horizons: Revival of Lipoprotein (a) as a Risk Factor for Cardiovascular Disease

The status of lipoprotein (a) [Lp(a)] as a cardiovascular risk factor has been resurrected by advances in genetics. Mendelian randomization studies show a causal link of Lp(a) with coronary artery disease (CAD), peripheral artery disease (PAD), and calcific aortic valve stenosis (CAVS). The genetics of Lp(a) is complex and extends beyond the kringle-IV type 2, as it is also dependent on ancestry. The plasma concentration of Lp(a) is determined by the hepatic production of apolipoprotein(a) [apo(a)] component of Lp(a), supporting the use of nucleic acids that inhibit the messenger RNA (mRNA) gene transcript for apo(a). Analytical barriers to measurement of Lp(a) are being addressed using isoform independent assays and a traceable standard. The association of Lp(a) and atherosclerotic cardiovascular disease is higher for myocardial infarction than PAD and CAVS. Increased risk of type 2 diabetes mellitus associated with low Lp(a) levels is perplexing and requires further investigation. The greatest advancement in Lp(a)-lowering therapies is based on using RNA therapeutics that are now being investigated in clinical trials. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition lowers Lp(a) modestly, but whether cardiovascular benefit is independent of low-density lipoprotein lowering remains unclear. Opportunistic and selective testing for Lp(a) is supported by moderate evidence, with the case for universal screening premature. Modification of behavioral and clinical risk factors may be targeted to mitigate Lp(a)-mediated risk of cardiovascular disease. Clinical practice guidelines have been developed to address gaps in care of high Lp(a), but full implementation awaits the findings of clinical outcome trials using RNA-directed therapies currently underway.

Role of lipoprotein(a) in plaque progression

Identified by Berg in 1963, lipoprotein(a) represents a key contemporary residual risk pathway in atherosclerotic cardiovascular disease (ASCVD) secondary prevention. Indeed, epidemiological and genetic studies have undoubtedly demonstrated that lipoprotein(a) is one of the strongest causal risk factors of ASCVD. Although a risk threshold has been set between 30 and 50 mg/dL, depending on the ethnicity, a linear risk gradient across the distribution has been demonstrated. In the context of the atherosclerotic process, hyperlipoproteinaemia(a) contributes to the atherosclerotic plaque formation by deposition of cholesterol in the same manner as low-density lipoprotein (LDL) cholesterol, due to the LDL particle component of lipoprotein(a). Lipoprotein(a) accumulates in human coronary and carotid atherosclerotic lesions. High concentrations of lipoprotein(a) are associated with accelerated progression of the necrotic core, but not with coronary calcium score (CAC), although in the latter case, the evaluation of lipoprotein(a) can overcome the potential limitation of CAC to capture the totality of ASCVD risk in asymptomatic individuals. Finally, in the absence of a pharmacological approach to lower lipoprotein(a) to the extent required to achieve a cardiovascular benefit, implementation strategies that increase awareness among the population, patients, and healthcare providers on the importance of lipoprotein(a) in the development of ASCVD are eagerly needed.

Associations of lipid measures with total occlusion in patients with established coronary artery disease: a cross-sectional study

Background

Total occlusion is the most severe coronary lesion, indicating heavy ischemic burden and poor prognosis. The lipid profile is central to the development of atherosclerotic coronary lesions. Evidence on the optimal lipid measure to be monitored and managed in patients with established coronary artery disease (CAD) is inconclusive.

Methods

Total cholesterol (TC), total triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), nonhigh-density lipoprotein cholesterol (non-HDL-c), lipoprotein (a) [Lp(a)], apolipoprotein B (apoB), non-HDL-c/HDL-c, and apoB/apoA-1 were analyzed in quintiles and as continuous variables. The associations of lipid measures with total occlusion were tested using logistic regression models, visualized with restricted cubic splines, and compared by areas under the receiver operating characteristic curves (AUROC). Discordance analysis was performed when apoB/apoA-1 and non-HDL-c/HDL-c were not in concordance.

Results

The prospective cohort study included 10,003 patients (mean age: 58 years; women: 22.96%), with 1879 patients having total occlusion. The risks of total occlusion significantly increased with quintiles of Lp(a), non-HDL-c/HDL-c, and apoB/apoA-1 (all p for trend < 0.001). TG had no association with total occlusion. Restricted cubic splines indicate significant positive linear relations between the two ratios and total occlusion [odds ratio per 1-standard deviation increase (95% confidence interval): non-HDL-c/HDL-c: 1.135 (1.095–1.176), p < 0.001; apoB/apoA-1: 2.590 (2.049–3.274), p < 0.001]. The AUROCs of apoB/apoA-1 and non-HDL-c/HDL-c were significantly greater than those of single lipid measures. Elevation in the apoB/apoA-1 tertile significantly increased the risk of total occlusion at a given non-HDL-c/HDL-c tertile but not vice versa.

Conclusion

ApoB/apoA-1 confers better predictive power for total occlusion than non-HDL-c/HDL-c and single lipid measures in established CAD patients.