Frequent questions and responses on the 2022 lipoprotein(a) consensus statement of the European Atherosclerosis Society

Lipoprotein(a) concentrations and cardiovascular disease in patients with chronic kidney disease: Results from the German Chronic Kidney Disease study

BACKGROUND

Lipoprotein(a) (Lp(a)) is a causal, genetically determined risk factor for cardiovascular disease (CVD) in the general population. Patients with chronic kidney disease (CKD) have an increased CVD risk and elevated Lp(a) concentrations. Only a few studies on Lp(a) were performed in persons with mild-to-moderate CKD; none of them used genetic variants to explore potential causal associations.

OBJECTIVES

This study aims to investigate the association of measured and genetically predicted Lp(a) concentrations on prevalent and incident CVD events in the German Chronic Kidney Disease (GCKD) study.

METHODS

The study included 5043 participants of European ancestry with an estimated glomerular filtration rate (eGFR) between 30 and 60 mL/min/1.73 m2 or an eGFR >60 mL/min/1.73 m2 in the presence of overt albuminuria with a follow-up of 6.5 years.

RESULTS

With each 10 mg/dL higher Lp(a) concentration, odds for prevalent CVD (1290 events) increased 1.065-fold (95%CI: 1.042-1.088, p < 0.001). The risk was significantly higher in patients with Lp(a) ≥50 mg/dL but most pronounced in Lp(a) ≥70 mg/dL (odds ratio = 1.775 [1.409-2.231], p < 0.001) compared to Lp(a) <30 mg/dL. Each 10 mg/dL higher Lp(a) concentration and Lp(a) ≥70 mg/dL increased the risk for incident 3-point major adverse cardiovascular events (MACEs) (474 events): hazard ratio [HR] = 1.037 [1.009-1.067], p = 0.009 and HR = 1.335 [1.001-1.781], p = 0.050), respectively. Similar results were obtained for 4-point MACE (653 events). Analyses based on apo(a) isoforms and genetically predicted Lp(a) concentrations led to even stronger associations.

CONCLUSIONS

In patients with mild-to-severe CKD, elevated Lp(a) concentrations and genetic determinants of Lp(a) concentrations are significantly associated with CVD at baseline and during follow-up, independent of traditional risk factors.

Temporal variability of Lp(a) in clinically stable patients: Implications for cardiovascular risk assessment

OBJECTIVES

Lipoprotein(a) [Lp(a)] is a significant risk factor for cardiovascular disease, yet it is often overlooked in routine clinical assessments. As a primarily genetically determined risk factor, the traditional recommendation is to assess its level once in a lifetime, as the variability of Lp(a) over time is considered to be minimal. This study aims to evaluate the potential variability of Lp(a) in clinically stable patients and investigate factors contributing to the lack of stable levels.

METHODS

A retrospective analysis was conducted on a sample of adult patients attending a lipid clinic. Participants with at least two Lp(a) measurements taken with a minimum interval of four months were included. Lp(a) measurements were performed using the immunoturbidimetric assay. Variability in Lp(a) values was calculated as a percentage change from baseline, with participants exceeding a 25% change classified as having hypervariable Lp(a) levels. Additional clinical and biochemical variables were assessed.

RESULTS

61 participants with 171 Lp(a) determinations were included. Thirty-four percent exhibited a variability of 25% or higher (hypervariable). Men showed slightly greater variability than women. Changes in Lp(a) categories were observed among hypervariable patients, with some participants experiencing an increase while others showed a decrease. Menopause was present in all the women with hypervariable levels.

CONCLUSION

Our study suggests reconsidering the reliance on a single Lp(a) measurement for assessing cardiovascular risk. Repeat measurements, particularly in borderline cases, may be beneficial.

Lipoprotein(a) is a highly atherogenic lipoprotein: pathophysiological basis and clinical implications

PURPOSE OF REVIEW

Lipoprotein(a) has been identified as a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and aortic valve stenosis. However, as reviewed here, there is ongoing debate as to the key pathogenic features of Lp(a) particles and the degree of Lp(a) atherogenicity relative to low-density lipoprotein (LDL).

RECENT FINDINGS

Genetic analyses have revealed that Lp(a) on a per-particle basis is markedly (about six-fold) more atherogenic than LDL. Oxidized phospholipids carried on Lp(a) have been found to have substantial pro-inflammatory properties triggering pathways that may contribute to atherogenesis. Whether the strength of association of Lp(a) with ASCVD risk is dependent on inflammatory status is a matter of current debate and is critical to implementing intervention strategies. Contradictory reports continue to appear, but most recent studies in large cohorts indicate that the relationship of Lp(a) to risk is independent of C-reactive protein level.

SUMMARY

Lp(a) is a highly atherogenic lipoprotein and a viable target for intervention in a significant proportion of the general population. Better understanding the basis of its enhanced atherogenicity is important for risk assessment and interpreting intervention trials.

Aspirin use in patients with elevated lipoprotein(a): Impact on cardiovascular events and bleeding

The role of aspirin in cardiovascular primary prevention remains controversial. There are physiological reasons to explore its potential benefits in patients with high levels of lipoprotein(a) [Lp(a)], mainly due to its antifibrinolytic properties and interactions with platelets. The primary objective of this systematic review was to evaluate the cardiovascular benefits and bleeding risks associated with aspirin use in patients who have elevated Lp(a) levels but no history of cardiovascular disease. This systematic review was conducted following PRISMA guidelines. We performed a literature search to identify studies assessing the cardiovascular benefits and bleeding risks of aspirin use in patients with elevated Lp(a) levels (or a related genetic variant) who have no history of cardiovascular disease. Five studies (49,871 individuals) were considered for this systematic review. Three studies assessed the impact of aspirin use in relation to genetic variants associated with elevated Lp(a) levels (SNP rs379822), while the remaining two studies directly measured plasma levels of Lp(a). The endpoints evaluated varied among the studies. Overall, the findings consistently show that carriers of the apolipoprotein(a) variant or patients with Lp(a) levels > 50 mg/dL experience a reduction in cardiovascular risk with aspirin use. No significant bleeding issues were observed, although such events were reported in only two studies. This systematic review suggests that aspirin use in patients with elevated Lp(a) levels and no prior cardiovascular history may reduce cardiovascular risk. The available data on bleeding risk is insufficient.

The functions of apolipoproteins and lipoproteins in health and disease

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

Statins in the Cause and Prevention of Cancer: Confounding by Indication and Mediation by Rhabdomyolysis and Phosphate Toxicity

Statins are drugs used in cardiovascular pharmacotherapy to decrease hypercholesterolemia and lower the risk of atherosclerosis. Statins also increase the risk of rhabdomyolysis, which is often minimized in comparison with large relative risk reductions of cardiovascular disease reported in clinical trials. By contrast, absolute risk reductions of cardiovascular disease are often clinically insignificant and unreported in statin clinical trials. Additionally, cytotoxic effects of statins inhibit cancer cell proliferation and reduce cancer risk, but other studies found that statins are carcinogenic. Due to an inverse association between incidence of cancer and atherosclerosis, the indication to prescribe statins likely biases the association of statins with cancer prevention. Dietary patterns associated with atherosclerosis and cancer contain inverse amounts of cholesterol and phosphate, an essential mineral that stimulates tumorigenesis. Accordingly, lower cancer risk is associated with high dietary cholesterol intake and increased risk of atherosclerosis. Furthermore, serum is exposed to excessive inorganic phosphate that could increase cancer risk as rhabdomyolysis induced by statins releases phosphate from skeletal muscle breakdown. Increased risk of comorbid conditions associated with statins may share the mediating factor of phosphate toxicity. More research is warranted on statins in the cause and prevention of cancer.

Lipid-Lowering Treatment Gaps in Patients after Acute Myocardial Infarction: Using Global Database TriNetX

Background and Objectives: Patients with previous acute myocardial infarction are at significantly higher risk of recurrent events. Early and intensive lipid-lowering therapy targeting low-density lipoprotein cholesterol is a key strategy for reducing cardiovascular risk in post-acute myocardial infarction patients worldwide. This study aimed to assess patients' real-life lipid-lowering treatment gaps after acute myocardial infarction using a global network, TriNetX, of anonymous, real-time patient data. The uniqueness of the study was the use of the novel, evolving, and constantly improving TriNetX platform and the evaluation of its feasibility for clinical research. Materials and Methods: A retrospective study was conducted on global repository patients in 2020, diagnosed with acute myocardial infarction, with a three-year follow-up. Results: After acute myocardial infarction, the prescribing rate of lipid-lowering medication (statins, ezetimibe and PCSK9I) was insufficient to reach target LDL-C values. The mean LDL-C level decreased from 2.7 mmol/L (103 mg/dL) as measured on the day of AMI to 1.97 mmol/L (76 mg/dL) between 31D and 3M. During the second and third years, the mean LDL-C value was stable (around 2.0 mmol/L (78 mg/dL)). LDL-C goals were not sufficiently reached, as only 7-12% of patients were reported to have LDL-C values < 55 mg/dL (1.4 mmol/L) and 13-20% of patients were reported to have LDL-C values < 70 mg/dL (1.8 mmol/L) during the follow-up periods. This means that a substantial number of patients remain at a very high risk for CV complications and mortality. Most cardiovascular complications happen within three months after acute myocardial infarction. Conclusions: Gaps remain between the recommendations for managing LDL-C in guidelines and what occurs in real life. The TriNetX platform is an innovative platform with significant potential and should be further developed for clinical research, as it enables the use of valuable interinstitutional data.

Prediction of 10-year cardiovascular disease risk by diabetes status and lipoprotein-a levels; the HellenicSCORE II

BACKGROUND

The aim of this study was to develop an updated model to predict 10-year cardiovascular disease (CVD) risk for Greek adults, i.e., the HellenicSCORE II+, based on smoking, systolic blood pressure (SBP), total and high-density-lipoprotein (HDL) cholesterol levels, and stratified by age group, sex, history of diabetes, and lipoprotein (Lp)-a levels.

METHODS

Individual CVD risk scores were calculated through logit-function models using the beta coefficients derived from SCORE2. The Attica study data were used for the calibration (3,042 participants, aged 45 (14) years; 49.1% men). Discrimination ability of the HellenicSCORE II+ was assessed using C-index (range 0-1), adjusted for competing risks.

RESULTS

The mean HellenicSCORE II+ score was 6.3% (95% confidence interval (CI) 5.9% to 6.6%) for men and 3.7% (95% CI 3.5% to 4.0%) for women (p < 0.001), and were higher compared to the relevant SCORE2; 23.5% of men were classified as low risk, 40.2% as moderate, and 36.3% as high risk, whereas the corresponding percentages for women were 56.2%, 18.6%, and 25.2%. C-statistic index was 0.88 for women and 0.79 for men when the HellenicSCORE II+ was applied to the Attica study data, suggesting very good accuracy. Stratified analysis by Lp(a) levels led to a 4% improvement in correct classification among participants with high Lp(a).

CONCLUSION

HellenicSCORE II+ values were higher than SCORE2, confirming that the Greek population is at moderate-to-high CVD risk. Stratification by Lp(a) levels may assist in better identifying individuals at high CVD risk.

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.

Early health technology assessment of gene silencing therapies for lowering lipoprotein(a) in the secondary prevention of coronary heart disease

BACKGROUND

Olpasiran and pelacarsen are gene-silencing therapies that lower lipoprotein(a). Cardiovascular outcome trials are ongoing. Mendelian randomisation studies estimated clinical benefits from lipoprotein(a) lowering.

OBJECTIVE

Our study estimated prices at which olpasiran and pelacarsen, in addition to standard-of-care, would be deemed cost-effective in reducing risk of recurrent coronary heart disease (CHD) events in the Australian healthcare system.

METHODS

We developed a decision tree and lifetime Markov model. For olpasiran, participants had CHD and lipoprotein(a) 260 nmol/L at baseline and three-monthly injections, profiled on OCEAN(a) Outcomes trial (NCT05581303). Baseline risks of CHD, costs and utilities were obtained from published sources. Clinical trial data were used to derive reductions in lipoprotein(a) from treatment. Mendelian randomisation study data were used to estimate downstream clinical benefits. Annual discounting was 5 %. For pelacarsen, participants had CHD and lipoprotein(a) 226 nmol/L at baseline and one- monthly injections, profiled on Lp(a) HORIZON (NCT04023552) trial.

RESULTS

Olpasiran in addition to standard-of-care saved 0.87 discounted quality-adjusted life years (QALYs) per person. Olpasiran in addition to standard-of-care would be cost- effective at annual prices of AU$1867 (AU$467 per dose) at threshold AU$28,000 per QALY. Pelacarsen would be cost-effective at annual prices of AU$984 (AU$82 per dose). For ICER threshold AU$50,000 per QALY, olpasiran and pelacarsen would be cost-effective at annual prices AU$4207 and AU$2464 respectively.

CONCLUSION

This early health technology assessment model used inclusion criteria from clinical trials. Olpasiran and pelacarsen would be cost-effective if annual treatment prices were AU$1867 and AU$984 respectively, from the Australian healthcare perspective.

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.

Impact of Lipoprotein(a) Levels on Cardiovascular Risk Estimation

INTRODUCTION

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Association between lipoprotein(a) and premature atherosclerotic cardiovascular disease: a systematic review and meta-analysis

Aims

High lipoprotein(a) [Lp(a)] level has been demonstrated as an important risk factor for atherosclerotic cardiovascular diseases (ASCVD) amongst the older populations, whereas its effects in the younger population remain unclear. This study evaluated the associations between Lp(a) and the risk of premature ASCVD.

Method and results

PubMed and Embase were searched for related studies until 12 November 2023. Fifty-one studies including 100 540 participants were included. Mean age of patients ranged from 35.3 to 62.3 years. The proportion of male participants ranged from 0% to 100%. The mean follow-up was provided in five studies ranging from 1 year to 40 years. The definition of elevated Lp(a) varied among studies, such as >30 mg/dL, >50 mg/dL, the top tertiles, the top quartiles, the top quintiles, and so on. Higher Lp(a) was significantly associated with the composite ASCVD [odds ratio (OR): 2.15, 95% confidence interval (95% CI): 1.53-3.02, P < 0.001], especially for coronary artery disease (OR: 2.44, 95% CI: 2.06-2.90, P < 0.001) and peripheral arterial disease (OR: 2.56, 95% CI: 1.56-4.21, P < 0.001). This association remained significant in familial hypercholesterolaemia (FH) (OR: 3.11, 95% CI: 1.63-5.96, P < 0.001) and type 2 diabetes mellitus (T2DM) patients (OR: 2.23; 95% CI: 1.54-3.23, P < 0.001).Significant results were observed in South Asians (OR: 3.71, 95% CI: 2.31-5.96, P < 0.001), Caucasians (OR: 3.17, 95% CI: 2.22-4.52, P < 0.001), and patients with baseline low-density lipoprotein cholesterol (LDL-c) level ≥ 2.6 mmol/L.

Conclusion

Elevated Lp(a) predicts the risk of the composite or individual ASCVD in young, regardless of study design, gender, population characteristics (community or hospitalized), different premature definitions, and various Lp(a) measurement approaches. This association was important in South Asians, Caucasians, FH patients, T2DM patients, and patients with baseline LDL-c level ≥ 2.6 mmol/L.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Lipoprotein(a): from Causality to Treatment

PURPOSE OF REVIEW

This paper reviews the evidence why lipoprotein(a) (Lp(a)) is a causal risk factor for cardiovascular disease and how high Lp(a) concentrations should be managed now and with an outlook to the future.

REVIEW FINDINGS

No optimal and widely available animal models exist to study the causality of the association between Lp(a) and cardiovascular disease. This has been a major handicap for the entire field. However, genetic studies turned the page. Already in the early 1990s, the principle of Mendelian randomization studies was applied for the first time ever (even if they were not named so at that time). Genetic variants of the LPA gene such as the apolipoprotein(a) isoform size, the number and sum of kringle IV repeats and later single nucleotide polymorphisms are strongly associated with life-long exposure to high Lp(a) concentrations as well as cardiovascular outcomes. This evidence provided a basis for the development of specific Lp(a)-lowering drugs that are currently in clinical testing phase. Lp(a) is one of the most important genetically determined risk factors for cardiovascular disease. With the specific Lp(a)-lowering therapies, we might get tools to fight this common risk factor in case the outcome trials will be positive.

An LC-MS-based designated comparison method with similar performance to the Lp(a) reference measurement procedure to guide molar Lp(a) standardization

BACKGROUND

The 2022 consensus statement of the European Atherosclerosis Society (EAS) on lipoprotein(a) (Lp(a)) recognizes the role of Lp(a) as a relevant genetically determined risk factor and recommends its measurement at least once in an individual's lifetime. It also strongly urges that Lp(a) test results are expressed as apolipoprotein (a) (apo(a)) amount of substance in molar units and no longer in confounded Lp(a) mass units (mg/dL or mg/L). Therefore, IVD manufacturers should transition to molar units. A prerequisite for this transition is the availability of an Lp(a) Reference Measurement Procedure (RMP) that allows unequivocal molecular detection and quantification of apo(a) in Lp(a). To that end an ISO 17511:2020 compliant LC-MS based and IFCC-endorsed RMP has been established that targets proteotypic peptides of apolipoprotein(a) (apo(a)) in Lp(a). The RMP is laborious and requires highly skilled operators. To guide IVD-manufacturers of immunoassay-based Lp(a) test kits in the transition from mass to molar units, a Designated Comparison Method (DCM) has been developed and evaluated.

METHODS

To assess whether the DCM provides equivalent results compared to the RMP, the procedural designs were compared and the analytical performance of DCM and RMP were first evaluated in a head-to-head comparison. Subsequently, apo(a) was quantified in 153 human clinical serum samples. Both DCM and RMP were calibrated using external native calibrators that produce results traceable to SRM2B. Measurement uncertainty (MU) was checked against predefined allowable MU.

RESULTS

The major difference in the design of the DCM for apo(a) is the use of only one enzymatic digestion step. The analytical performance of the DCM and RMP for apo(a) is highly similar. In a direct method comparison, equivalent results were obtained with a median regression slope 0.997 of and a median bias of - 0.2 nmol/L (- 0.2%); the intermediate imprecision of the test results was within total allowable error (TEa) (CVa of 10.2% at 90 nmol/L).

CONCLUSIONS

The semi-automated, higher throughput, LC-MS-based method for Lp(a) meets the predefined analytical performance specifications and allowable MU and is hence applicable as a higher order Designated Comparison Method, which is ideally suited to guide IVD manufacturers in the transition from Lp(a) mass to molar units.

Healthy lifestyle, lipoprotein (a) levels and the risk of coronary artery disease

BACKGROUND

Lipoprotein (a) [Lp(a)] is associated with coronary artery disease (CAD). However, the role of healthy lifestyle against the risk of CAD with consideration of high Lp(a) levels remains unclear.

METHODS

This study examined 4512 participants who underwent serum Lp(a) level assessment at Kanazawa University Hospital from 2008 to March 2016. Their lifestyle habits were examined based on four questionnaires regarding dietary pattern, exercise habits, smoking status and body weight. Logistic regression analyses were performed to identify the association between healthy lifestyle and CAD independent of Lp(a) levels.

RESULTS

The Lp(a) levels were significantly associated with CAD (odds ratio [OR]: 1.12, 95% confidence interval [CI]: 1.08-1.17, p = 1.3 × 10-7 per 10 mg/dL). Under these circumstances, the lifestyle risk score was also significantly associated with CAD (OR: 1.24, 95% CI: 1.12-1.36, p = 2.4 × 10-8 ). Compared with patients with a favourable lifestyle who have Lp(a) levels of <30 mg/dL, those with an intermediate or unfavourable lifestyle were at higher risk for CAD (OR: 1.11, 95% CI: 1.02-1.20, p = 0.003 and OR: 1.40, 95% CI: 1.16-1.54, p = 3.6 × 10-5 , respectively). Further, patients with a favourable, intermediate or unfavourable lifestyle who have Lp(a) levels of ≥30 mg/dL were at high risk for CAD (OR: 1.21, 95% CI: 1.08-1.34, p = 0.0014; OR: 1.31, 95% CI: 1.14-1.48, p = 1.2 × 10-4 ; and OR: 1.81, 95% CI: 1.44-2.18, p = 2.2 × 10-7 , respectively).

CONCLUSIONS

Healthy lifestyle was associated with a lower risk of CAD regardless of Lp(a) levels.

Lipoprotein(a), Interleukin-6 inhibitors, and atherosclerotic cardiovascular disease: Is there an association?

Background and aims

Lipoprotein(a) [Lp(a)] and interleuking-6 (IL-6), an inflammation biomarker, have been established as distinct targets of the residual atherosclerotic cardiovascular disease (ASCVD) risk. We aimed to investigate the association between them, and the potential clinical implications in ASCVD prevention.

Methods

A literature search was conducted in PubMed until December 31st, 2022, using relevant keywords.

Results

Elevated lipoprotein(a) [Lp(a)] levels constitute the most common inherited lipid disorder associated with ASCVD. Although Lp(a) levels are mostly determined genetically by the LPA gene locus, they may be altered by acute conditions of stress and chronic inflammatory diseases. Considering its resemblance with low-density lipoproteins, Lp(a) is involved in atherosclerosis, but it also exerts oxidative, thrombotic, antifibrinolytic and inflammatory properties. The cardiovascular efficacy of therapies lowering Lp(a) by >90% is currently investigated. On the other hand, interleukin (IL)-1b/IL-6 pathway also plays a pivotal role in atherosclerosis and residual ASCVD risk. IL-6 receptor inhibitors [IL-6(R)i] lower Lp(a) by 16-41%, whereas ongoing trials are investigating their potential anti-atherosclerotic effect. The Lp(a)-lowering effect of IL-6(R)i might be attributed to the inhibition of the IL-6 response elements in the promoter region of the LPA gene.

Conclusions

Although the effect of IL-6(R)i on Lp(a) levels is inferior to that of available Lp(a)-lowering therapies, the dual effect of the former on both inflammation and apolipoprotein (a) synthesis may prove of equal or even greater significance when it comes ASCVD outcomes. More trials are required to establish IL-6(R)i in ASCVD prevention and elucidate their interplay with Lp(a) as well as its clinical significance.

Highlights of Cardiovascular Disease Prevention Studies Presented at the 2023 European Society of Cardiology Congress

PURPOSE OF REVIEW

To summarize selected late-breaking science on cardiovascular (CV) disease prevention presented at the 2023 European Society of Cardiology (ESC) congress.

RECENT FINDINGS

The NATURE-PARADOX was a naturally randomized trial that used genetic data from the UK Biobank registry to create "cumulative exposure to low-density lipoprotein-cholesterol (LDL-C)" biomarker and evaluate its association with major CV events regardless of plasma LDL-C levels or age. Safety and efficacy data of inclisiran, a PCSK9-interfering mRNA (PCSK9i) administered subcutaneously twice annually, were presented. Data on two new PCSK9is were presented, recaticimab, an oral drug, and lerodalcibep, a subcutaneous drug with a slightly different architecture than currently available PSCK9is. A phase 1 trial on muvalaplin, an oral lipoprotein (a) inhibitor, was presented. An atherosclerotic CV disease (ASCVD) risk prediction algorithm for the Asian population using SCORE2 data was presented. Long-term follow-up of patients enrolled in the CLEAR outcomes trial showed sustained and more significant ASCVD risk reduction with bempedoic acid in high-risk patients. The late-breaking clinical science at the 2023 congress of the ESC extends the known safety and efficacy data of a PCSK9i with the introduction of new drugs in this class. Using cumulative exposure to LDL-C rather than a single value will help clinicians tailor the LDL-C reduction strategy to individual risk and is an important step towards personalized medicine.

Prevalence of lipoprotein(a) measurement in patients with or at risk of cardiovascular disease

INTRODUCTION

Lipoprotein(a) [Lp(a)] is a genetically determined independent risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve disease. Despite recommendations from professional societies in the cardiovascular field, the awareness of elevated Lp(a) as a risk factor and screening for Lp(a) are suspected to be low.

METHODS

We conducted a retrospective, observational case control study of patient charts from January 1, 2017 to June 19, 2022. The primary aims were 1) to describe the proportion of patients at the healthcare network's primary care and cardiology clinics that met Lp(a) screening criteria and were tested; and 2) to describe the proportion of patients throughout the entire healthcare network that had Lp(a) measured.

RESULTS

Of the 2,412,020 patient charts in the health network, only 5,942 (0.25 %) had Lp(a) measured. Of the 84,581 patients in primary care or cardiology clinics who met screening criteria, only 1,311 (1.55 %) had Lp(a) measured. Patients with Lp(a) measured were more likely to be younger, non-Hispanic/Latinx, had a lipid panel measured, a cardiac computed tomography (CT) imaging study, and higher low-density lipoprotein-cholesterol. Patients with ASCVD, heart failure, ischemic heart disease, aortic stenosis, peripheral vascular disease, or a stroke did not feature highly among patients who received Lp(a) testing. Having an abnormal or risk-enhancing Lp(a) level was associated with being female and/or being Black/African American.

CONCLUSIONS

Despite increased awareness of Lp(a) and its contribution to cardiovascular disease there exists a paucity of testing. Increased Lp(a) testing can identify patients who have an increased cardiovascular risk underestimated by other metrics.

Lipoprotein(a) and the pooled cohort equations for ASCVD risk prediction: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD) but is not included in the Pooled Cohort Equations (PCE). We aimed to assess how well the PCE predict 10-year event rates in individuals with elevated Lp(a), and whether the addition of Lp(a) improves risk prediction.

METHODS

We compared observed versus PCE-predicted 10-year ASCVD event rates, stratified by Lp(a) level and ASCVD risk category using Poisson regression, and evaluated the association between Lp(a) > 50 mg/dL and ASCVD risk using Cox proportional hazards models in the Multi-Ethnic Study of Atherosclerosis (MESA). We evaluated the C-index and net reclassification improvement (NRI) with addition of Lp(a) to the PCE.

RESULTS

The study population included 6639 individuals (20%, n = 1325 with elevated Lp(a)). The PCE accurately predicted 10-year event rates for individuals with elevated Lp(a) with observed event rates falling within predicted limits. Elevated Lp(a) was associated with increased risk of CVD events overall (HR 1.27, 95% CI 1.00-1.60), particularly in low (HR 2.45, 95% CI 1.40-4.31), and high-risk (HR 1.41, 95% CI 1.02-1.96) individuals. Continuous NRI (95% CI) with the addition of Lp(a) to the PCE for CVD was 0.0963 (0.0158-0.1953) overall, and 0.2999 (0.0876, 0.5525) among low-risk individuals.

CONCLUSIONS

The PCE performs well for event rate prediction in individuals with elevated Lp(a). However, Lp(a) is associated with increased CVD risk, and the addition of Lp(a) to the PCE improves risk prediction, particularly among low-risk individuals. These results lend support for increasing use of Lp(a) testing for risk assessment.

Daring to dream: Targeting lipoprotein(a) as a causal and risk-enhancing factor

Lipoprotein(a) [Lp(a)], a distinct lipoprotein class, has become a major focus for cardiovascular research. This review is written in light of the recent guideline and consensus statements on Lp(a) and focuses on 1) the causal association between Lp(a) and cardiovascular outcomes, 2) the potential mechanisms by which elevated Lp(a) contributes to cardiovascular diseases, 3) the metabolic insights on the production and clearance of Lp(a) and 4) the current and future therapeutic approaches to lower Lp(a) concentrations. The concentrations of Lp(a) are under strict genetic control. There exists a continuous relationship between the Lp(a) concentrations and risk for various endpoints of atherosclerotic cardiovascular disease (ASCVD). One in five people in the Caucasian population is considered to have increased Lp(a) concentrations; the prevalence of elevated Lp(a) is even higher in black populations. This makes Lp(a) a cardiovascular risk factor of major public health relevance. Besides the association between Lp(a) and myocardial infarction, the relationship with aortic valve stenosis has become a major focus of research during the last decade. Genetic studies provided strong support for a causal association between Lp(a) and cardiovascular outcomes: carriers of genetic variants associated with lifelong increased Lp(a) concentration are significantly more frequent in patients with ASCVD. This has triggered the development of drugs that can specifically lower Lp(a) concentrations: mRNA-targeting therapies such as anti-sense oligonucleotide (ASO) therapies and short interfering RNA (siRNA) therapies have opened new avenues to lower Lp(a) concentrations more than 95%. Ongoing Phase II and III clinical trials of these compounds are discussed in this review.

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.

Prognostic impacts of diabetes status and lipoprotein(a) levels in patients with ST-segment elevation myocardial infarction: a prospective cohort study

OBJECTS

This study aimed to investigate the impact of lipoprotein(a) [Lp(a)] levels on the prognosis of Chinese patients with ST-segment elevation myocardial infarction (STEMI), and to explore if the impact may differ in the diabetes mellitus (DM) and nonDM groups.

METHODS

Between March 2017 and January 2020, 1543 patients with STEMI who underwent emergency percutaneous coronary intervention (PCI) were prospectively recruited. The primary outcome was a composite of all-cause death, MI recurrence (reMI), and stroke, known as major adverse cardiovascular events (MACE). Analyses involving the Kaplan-Meier curve, Cox regression, and restricted cubic spline (RCS) were conducted.

RESULTS

During the 1446-day follow-up period, 275 patients (17.8%) experienced MACEs, including 141 with DM (20.8%) and 134 (15.5%) without DM. As for the DM group, patients with Lp(a) ≥ 50 mg/dL showed an apparently higher MACE risk compared to those with Lp(a) < 10 mg/dL (adjusted hazard ratio [HR]: 1.85, 95% confidence interval [CI]:1.10-3.11, P = 0.021). The RCS curve indicates that the HR for MACE appeared to increase linearly with Lp(a) levels exceeding 16.9 mg/dL. However, no similar associations were obtained in the nonDM group, with an adjusted HR value of 0.57 (Lp(a) ≥ 50 mg/dL vs. < 10 mg/dL: 95% CI 0.32-1.05, P = 0.071). Besides, compared to patients without DM and Lp(a) ≥ 30 mg/dL, the MACE risk of patients in the other three groups (nonDM with Lp(a) < 30 mg/dL, DM with Lp(a) < 30 mg/dL, and DM with Lp(a) ≥ 30 mg/dL) increased to 1.67-fold (95% CI 1.11-2.50, P = 0.013), 1.53-fold (95% CI 1.02-2.31, P = 0.041), and 2.08-fold (95% CI 1.33-3.26, P = 0.001), respectively.

CONCLUSIONS

In this contemporary STEMI population, high Lp(a) levels were linked to an increased MACE risk, and very high Lp(a) levels (≥ 50 mg/dL) significantly indicated poor outcomes in patients with DM, while not for those without DM.

TRIAL REGISTRATION

clinicaltrials.gov NCT: 03593928.

The role of atherogenic lipoproteins in diabetes: Molecular aspects and clinical significance

Dyslipidaemia plays a prominent role in the genesis of atherosclerotic plaque and the increased cardiovascular risk in diabetes. Macrophages readily take up atherogenic lipoproteins, transforming into foam cells and amplifying vascular damage in the presence of endothelial dysfunction. We discuss the importance of distinct lipoprotein subclasses in atherogenic diabetic dyslipidaemia as well as the effects of novel anti-diabetic agents on lipoprotein fractions and ultimately on cardiovascular risk prevention. In patients with diabetes, lipid abnormalities should be aggressively identified and treated in conjunction with therapeutical agents used to prevent cardiovascular disease. The use of drugs that improve diabetic dyslipidaemia plays a prominent role in conferring cardiovascular benefit in individuals with diabetes.