The re-emergence of lipoprotein(a) in a broader clinical arena

Lipoprotein(a) and peripheral artery disease: contemporary evidence and therapeutic advances

PURPOSE OF REVIEW

Peripheral artery disease (PAD) is a major cause of global health burden, including amputation and impaired quality of life. This review examines the evidence implicating lipoprotein(a) [Lp(a)] in PAD, which is timely as novel therapies lowering Lp(a) are currently being tested in several clinical trials.

RECENT FINDINGS

Human observational studies demonstrate strong associations between elevated Lp(a) levels and increased risk of PAD incidence, severity of chronic limb-threatening ischemia, and major adverse limb events. Emerging therapies including small interfering RNA, antisense oligonucleotides, proprotein convertase subtilisin-kexin type 9 inhibitors and lipoprotein apheresis demonstrate significant Lp(a)-lowering effects. However, whether these treatments benefit patients with PAD is currently unknown.

SUMMARY

Lp(a) may be involved in PAD pathogenesis. Lp(a)-lowering therapies may significantly reduce PAD-related events and improve outcomes. Future studies are needed to test Lp(a)-lowering therapies in people with PAD and to explore how the association of Lp(a) varies in different sexes and ethnicities and understand mechanisms by which Lp(a) may contribute to limb ischemia.

Genetic study of the causal effect of lipid profiles on insomnia risk: a Mendelian randomization trial

OBJECTIVES

In response to the controversy surrounding observational studies of the association between lipid profiles and the risk of insomnia, the aim of this study was to analyze lipid profiles, including triglycerides (TG), apolipoprotein A-1 (ApoA-1), apolipoprotein B (ApoB) and lipoprotein A (LPA), in a European population to further assess the causal relationship between these lipid types and insomnia.

MATERIALS AND METHODS

This study explores the causal effect of lipid profiles on insomnia based on a genome-wide association study (GWAS)-derived public dataset using two-sample and multivariate Mendelian randomization (MVMR) analysis. The main MR analyses used inverse variance weighting (IVW) odds ratio (OR), and the sensitivity analyses included weighted median (WM) and MR‒Egger.

RESULTS

Both MR and MVMR showed that lowering ApoA-1 and LPA levels had causal effects on the risk of insomnia [MR: per 10 units, ApoA-1: OR: 0.7546, 95% CI: 0.6075-0.9372, P = 0.011; LPA: OR: 0.8392, 95% CI: 0.7202-0.9778, P = 0.025; MVMR: per 10 units, ApoA-1: OR: 0.7600, 95% CI: 0.6362-0.9079, P = 0.002; LPA, OR: 0.903, 95% CI: 0.8283-0.9845, P = 0.021]. There were no causal effects of TG or ApoB on insomnia (all P > 0.05). The MR‒Egger intercept test, funnel plot, and IVW methods all suggested an absence of strong directional pleiotropy, and leave-one-out permutation analysis did not detect any single single-nucleotide polymorphism that had a strong influence on the results.

CONCLUSION

Elevated levels of ApoA-1 and LPA were independently and causally associated with the risk of insomnia, suggesting that elevated ApoA-1 and LPA levels may contribute to a reduced risk of insomnia.

High residual cardiovascular risk after lipid-lowering: prime time for Predictive, Preventive, Personalized, Participatory, and Psycho-cognitive medicine

As time has come to translate trial results into individualized medical diagnosis and therapy, we analyzed how to minimize residual risk of cardiovascular disease (CVD) by reviewing papers on "residual cardiovascular disease risk". During this review process we found 989 papers that started off with residual CVD risk after initiating statin therapy, continued with papers on residual CVD risk after initiating therapy to increase high-density lipoprotein-cholesterol (HDL-C), followed by papers on residual CVD risk after initiating therapy to decrease triglyceride (TG) levels. Later on, papers dealing with elevated levels of lipoprotein remnants and lipoprotein(a) [Lp(a)] reported new risk factors of residual CVD risk. And as new risk factors are being discovered and new therapies are being tested, residual CVD risk will be reduced further. As we move from CVD risk reduction to improvement of patient management, a paradigm shift from a reductionistic approach towards a holistic approach is required. To that purpose, a personalized treatment dependent on the individual's CVD risk factors including lipid profile abnormalities should be configured, along the line of P5 medicine for each individual patient, i.e., with Predictive, Preventive, Personalized, Participatory, and Psycho-cognitive approaches.

A Review of the Clinical Pharmacology of Pelacarsen: A Lipoprotein(a)-Lowering Agent

Patients with genetically associated elevated lipoprotein(a) [Lp(a)] levels are at greater risk for coronary artery disease, heart attack, stroke, and peripheral arterial disease. To date, there are no US FDA-approved drug therapies that are designed to target Lp(a) with the goal of lowering the Lp(a) level in patients who have increased risk. The American College of Cardiology (ACC) has provided guidelines on how to use traditional lipid profiles to assess the risk of atherosclerotic cardiovascular disease (ASCVD); however, even with the emergence of statin add-on therapies such as ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, some populations with elevated Lp(a) biomarkers remain at an increased risk for cardiovascular (CV) disease. Residual CV risk has led researchers to inquire about how lowering Lp(a) can be used as a potential preventative therapy in reducing CV events. This review aims to present and discuss the current clinical and scientific evidence pertaining to pelacarsen.

Lipoprotein(a): Knowns, unknowns and uncertainties

Over the last 10 years, there have been advances on several aspects of lipoprotein(a) which are reviewed in the present article. Since the standard immunoassays for measuring lipoprotein(a) are not fully apo(a) isoform-insensitive, the application of an LC-MS/MS method for assaying molar concentrations of lipoprotein(a) has been advocated. Genome wide association, epidemiological, and clinical studies have established high lipoprotein(a) as a causal risk factor for atherosclerotic cardiovascular diseases (ASCVD). However, the relative importance of molar concentration, apo(a) isoform size or variants within the LPA gene is still controversial. Lipoprotein(a)-raising single nucleotide polymorphisms has not been shown to add on value in predicting ASCVD beyond lipoprotein(a) concentrations. Although hyperlipoproteinemia(a) represents an important confounder in the diagnosis of familial hypercholesterolemia (FH), it enhances the risk of ASCVD in these patients. Thus, identification of new cases of hyperlipoproteinemia(a) during cascade testing can increase the identification of high-risk individuals. However, it remains unclear whether FH itself increases lipoprotein(a). The ASCVD risk associated with lipoprotein(a) seems to follow a linear gradient across the distribution, regardless of racial subgroups and other risk factors. The inverse association with the risk of developing type 2 diabetes needs consideration as effective lipoprotein(a) lowering therapies are progressing towards the market. Considering that Mendelian randomization analyses have identified the degree of lipoprotein(a)-lowering that is required to achieve ASCVD benefit, the findings of the ongoing outcome trial with pelacarsen will clarify whether dramatically lowering lipoprotein(a) levels can reduce the risk of ASCVD.

Longitudinal Assessment of Lipoprotein(a) Levels in Perinatally HIV-Infected Children and Adolescents

HIV is an independent risk factor of cardiovascular disease (CVD); therefore, perinatally HIV-infected (PHIV) children potentially have a greater CVD risk at older age. Lipoprotein(a) (Lp(a)) is an established risk factor for CVD in the general population. To evaluate a potential increased CVD risk for PHIV children, we determined their lipid profiles including Lp(a). In the first substudy, we assessed the lipid profiles of 36 PHIV children visiting the outpatient clinic in Amsterdam between 2012 and 2020. In the second substudy, we enrolled 21 PHIV adolescents and 23 controls matched for age, sex and ethnic background on two occasions with a mean follow-up time of 4.6 years. We assessed trends of lipid profiles and their determinants, including patient and disease characteristics, using mixed models. In the first substudy, the majority of PHIV children were Black (92%) with a median age of 8.0y (5.7–10.8) at first assessment. Persistent elevated Lp(a) levels were present in 21/36 (58%) children (median: 374 mg/L (209–747); cut off = 300). In the second substudy, the median age of PHIV adolescents was 17.5y (15.5–20.7) and of matched controls 16.4y (15.8–19.5) at the second assessment. We found comparable lipid profiles between groups. In both studies, increases in LDL-cholesterol and total cholesterol were associated with higher Lp(a) levels. A majority of PHIV children and adolescents exhibited elevated Lp(a) levels, probably associated with ethnic background. Nonetheless, these elevated Lp(a) levels may additionally contribute to an increased CVD risk.

Risk stratification of ST-segment elevation myocardial infarction (STEMI) patients using machine learning based on lipid profiles

BACKGROUND

Numerous studies have revealed the relationship between lipid expression and increased cardiovascular risk in ST-segment elevation myocardial infarction (STEMI) patients. Nevertheless, few investigations have focused on the risk stratification of STEMI patients using machine learning algorithms.

METHODS

A total of 1355 STEMI patients who underwent percutaneous coronary intervention were enrolled in this study during 2015-2018. Unsupervised machine learning (consensus clustering) was applied to the present cohort to classify patients into different lipid expression phenogroups, without the guidance of clinical outcomes. Kaplan-Meier curves were implemented to show prognosis during a 904-day median follow-up (interquartile range: 587-1316). In the adjusted Cox model, the association of cluster membership with all adverse events including all-cause mortality, all-cause rehospitalization, and cardiac rehospitalization was evaluated.

RESULTS

All patients were classified into three phenogroups, 1, 2, and 3. Patients in phenogroup 1 with the highest Lp(a) and the lowest HDL-C and apoA1 were recognized as the statin-modified cardiovascular risk group. Patients in phenogroup 2 had the highest HDL-C and apoA1 and the lowest TG, TC, LDL-C and apoB. Conversely, patients in phenogroup 3 had the highest TG, TC, LDL-C and apoB and the lowest Lp(a). Additionally, phenogroup 1 had the worst prognosis. Furthermore, a multivariate Cox analysis revealed that patients in phenogroup 1 were at significantly higher risk for all adverse outcomes.

CONCLUSION

Machine learning-based cluster analysis indicated that STEMI patients with increased concentrations of Lp(a) and decreased concentrations of HDL-C and apoA1 are likely to have adverse clinical outcomes due to statin-modified cardiovascular risks.

TRIAL REGISTRATION

ChiCTR1900028516 ( http://www.chictr.org.cn/index.aspx ).

Relation of First and Total Recurrent Atherosclerotic Cardiovascular Disease Events to Increased Lipoprotein(a) Levels Among Statin Treated Adults With Cardiovascular Disease

The relation between elevated lipoprotein(a) and total atherosclerotic cardiovascular disease (ASCVD) residual risk in persons with known cardiovascular disease on statin therapy is not well-established. We examined first and total recurrent ASCVD event risk in statin-treated adults with prior ASCVD. We studied 3,359 adults (mean age 63.6 years, 85.1% male) with prior ASCVD on statin therapy from the AIM-HIGH clinical trial cohort. The first and total ASCVD event rates were calculated by lipoprotein(a) [Lp(a)] categories. Cox regression and Prentice, Williams and Peterson (PWP) models provided hazard ratios (HRs) for ASCVD events over a mean follow-up of 3.3 years, adjusted for age, gender, trial treatment, LDL-C, and other risk factors. A total of 747 events occurred during follow-up, among which 544 were first events. First and total ASCVD event rates were greater with higher Lp(a) levels. Compared with Lp(a)<15 mg/dL, HRs (95% CIs) for subsequent total ASCVD events among Lp(a) levels of 15-<30, 30-<50, 50-<70, and ≥70 mg/dL were 1.04 (0.82 to 1.32), 1.15 (0.88 to 1.49), 1.27 (1.00 to 1.63) and 1.51 (1.25 to 1.84). Moreover, a continuous relation for total events was observed (HR=1.08 [1.04 to 1.12] per 20 mg/dL greater Lp(a). Findings for first ASCVD events and in those with LDL-C ≥70 mg/dL versus <70 mg/dL and with and without diabetes were similar. The risk of first and total ASCVD events is increased with Lp(a) levels of ≥70 mg/dL and ≥50 mg/dL, respectively, among adults with known CVD on statin therapy.

Conceptualization of Heterogeneity of Chronic Diseases and Atherosclerosis as a Pathway to Precision Medicine: Endophenotype, Endotype, and Residual Cardiovascular Risk

The article discusses modern approaches to the conceptualization of pathogenetic heterogeneity in various branches of medical science. The concepts of endophenotype, endotype, and residual cardiovascular risk and the scope of their application in internal medicine and cardiology are considered. Based on the latest results of studies of the genetic architecture of atherosclerosis, five endotypes of atherosclerosis have been proposed. Each of the presented endotypes represents one or another pathophysiological mechanism of atherogenesis, having an established genetic substrate, a characteristic panel of biomarkers, and a number of clinical features. Clinical implications and perspectives for the study of endotypes of atherosclerosis are briefly reviewed.

Vascular and valvular calcification biomarkers

Vascular and valvular calcification constitutes a major health problem with serious clinical consequences. It is important for medical laboratorians to improve their knowledge on this topic and to know which biological markers may have a potential interest and might be useful for diagnosis and for management of ectopic calcifications. This review focuses on the pathophysiological mechanisms of vascular and valvular calcification, with emphasis on the mechanisms that are different for the two types of events, which underscore the need for differentiated healthcare, and explain different response to therapy. Available imaging and scoring tools used to assess both vascular and valvular calcification, together with the more studied and reliable biological markers emerging in this field (e.g., Fetuin A and matrix Gla protein), are discussed. Recently proposed functional assays, measuring the propensity of human serum to calcify, appear promising for vascular calcification assessment and are described. Further advancement through omic technologies and statistical tools is also reported. Clinical chemistry and laboratory medicine practitioners overlook this new era that will engage them in the near future, where a close cooperation of professionals with different competencies, including laboratorists, is required. This innovative approach may truly revolutionize practice of laboratory and of whole medicine attitude, making progression in knowledge of pathways relevant to health, as the complex calcification-related pathways, and adding value to patient care, through a precision medicine strategy.

Familial hypercholesterolemia and elevated lipoprotein(a): double heritable risk and new therapeutic opportunities

There is compelling evidence that the elevated plasma lipoprotein(a) [Lp(a)] levels increase the risk of atherosclerotic cardiovascular disease (ASCVD) in the general population. Like low-density lipoprotein (LDL) particles, Lp(a) particles contain cholesterol and promote atherosclerosis. In addition, Lp(a) particles contain strongly proinflammatory oxidized phospholipids and a unique apoprotein, apo(a), which promotes the growth of an arterial thrombus. At least one in 250 individuals worldwide suffer from the heterozygous form of familial hypercholesterolemia (HeFH), a condition in which LDL-cholesterol (LDL-C) is significantly elevated since birth. FH-causing mutations in the LDL receptor gene demonstrate a clear gene-dosage effect on Lp(a) plasma concentrations and elevated Lp(a) levels are present in 30-50% of patients with HeFH. The cumulative burden of two genetically determined pro-atherogenic lipoproteins, LDL and Lp(a), is a potent driver of ASCVD in HeFH patients. Statins are the cornerstone of treatment of HeFH, but they do not lower the plasma concentrations of Lp(a). Emerging therapies effectively lower Lp(a) by as much as 90% using RNA-based approaches that target the transcriptional product of the LPA gene. We are now approaching the dawn of an era, in which permanent and significant lowering of the high cholesterol burden of HeFH patients can be achieved. If outcome trials of novel Lp(a)-lowering therapies prove to be safe and cost-effective, they will provide additional risk reduction needed to effectively treat HeFH and potentially lower the CVD risk in these high-risk patients even more than currently achieved with LDL-C lowering alone.

A modified algorithm with lipoprotein(a) added for diagnosis of familial hypercholesterolemia

BACKGROUND

Previous studies have observed that high level of lipoprotein (a) [Lp(a)] was common in the phenotypic familial hypercholesterolemia (FH) and may explain part of the clinical diagnosis of FH.

HYPOTHESIS

We aim to develop a modified model including Lp(a) and compare its diagnostic performance with Dutch Lipid Clinic Network (DLCN) criteria.

METHODS

Data of 10 449 individuals were utilized for the model establishment (7806 for derivation and 2643 for validation) from January 2011 to March 2018. The novel score model was modified on the basis of DLCN. Furthermore, 718 patients were screened for LDLR, APOB, and PCSK9 gene mutations.

RESULTS

The novel modified model consisted of untreated low-density lipoprotein cholesterol (LDL-C) level, Lp(a), personal premature coronary heart disease (CHD), tendon xanthomas and family history of CHD and/or hypercholesterolemia. It has shown high discrimination (area under curve [AUC] 0.991, 95% confidence interval [CI[ 0.988-0.994, P < .001) for distinguishing clinical FH from non-FH diagnosed using DLCN. Furthermore, a concordance analysis was performed to compare the modified model with DLCN and it showed a good agreement with DLCN (κ = 0.765). External validation of the novel model also showed good accordance (κ = 0.700). Further genetic analysis showed that the agreements between the new model and mutation improved a little compared to that between DLCN and mutation.

CONCLUSIONS

The novel modified model, including Lp(a), could provide new insights into FH diagnosis in Chinese population with more concerns on the patients with high level of Lp(a).

Plasma Lipoprotein(a) Concentration Is Associated With the Coronary Severity but Not With Events in Stable Coronary Artery Disease Patients: A Chinese Cohort Study

BACKGROUND

Although lipoprotein(a) (Lp(a)) has been regarded as an independent risk factor for atherosclerotic cardiovascular disease (ASCVD), its predictive role in outcomes in stable coronary artery disease (CAD) has been undetermined. The aim of the present study was to investigate the relations of Lp(a) to the coronary severity and events in Chinese patients with angiography-proven stable CAD.

METHODS

A total of 3,278 patients with stable CAD were consecutively enrolled and the coronary severity was evaluated by the Gensini Score (GS) system. Patients were divided into two groups according to the median of GS: high GS group (n=1,585) and low GS group (n=1,693). The associations of continuous Lp(a), Lp(a) ≥300mg/L, and tertiles of Lp(a) with GS and events were respectively evaluated.

RESULTS

Patients in the high GS group had significantly higher concentrations of Lp(a). In addition, the multivariate Cox regression analysis indicated that elevated Lp(a) (odds ratio: 1.164, 95% confidence interval: 1.005-1.349), Lp(a) ≥300mg/L (odds ratio: 1.200, 95% confidence interval: 1.028-1.401), and the highest tertile of Lp(a) (odds ratio: 1.205, 95% confidence interval: 1.010-1.438) were statistically associated with GS after adjusted for potential confounders. However, although 215 (6.56%) events were established during a median of follow-up over 10,170 patient-years, no relationship between Lp(a) and events was found.

CONCLUSIONS

In this Chinese cohort study on stable CAD with moderate sample size and follow-up duration, data showed that Lp(a) was significantly associated with the coronary severity while not with cardiovascular events, similar to several studies, suggesting that further study is needed regarding the role of Lp(a) in ASCVD.

Effect of Niacin on Carotid Atherosclerosis in Patients at Low-Density Lipoprotein-Cholesterol Goal but High Lipoprotein (a) Level: a 2-Year Follow-Up Study

Objective

To examine the effect of niacin on the progression of carotid intima-media thickness (IMT) in patients with high level of lipoprotein (Lp) (a).

Methods

Patients at low-density lipoprotein-cholesterol goal but with Lp (a) >25 mg/dL and mean carotid IMT >0.75 mm were included. Eligible patients were randomized at a 1:2 ratio into one of two groups for 24 months: control or 1,500 mg extended release niacin. The primary study outcomes were the percentage changes in mean and maximal carotid IMT. The percentage change in lipid profiles including Lp (a) was analyzed as a secondary study outcome.

Results

Among 96 randomized patients, 31 completed the study (mean age: 65 years; male: 44%). At follow-up, the percentage change in mean carotid IMT was not significantly different between the two groups (−1.4%±15.5% and −1.1%±7.3% in the control and niacin groups, respectively, p=0.95). The percentage change in maximal carotid IMT was also similar in the two groups (0.7%±16.5% and −4.4%±11.6%, respectively, p=0.35). Elevation of high-density lipoprotein-cholesterol tended to be higher in the niacin group (p=0.07), and there was a significant difference in the percentage change in hemoglobin A1c between the two groups (−1.9%±2.2% and 3.3%±6.7%, respectively, p=0.02). Reduction of Lp (a) was greater in the niacin-treated group compared to placebo, but the difference was not statistically significant.

Conclusion

Treatment with niacin for two years did not inhibit the progression of carotid intima-media thickening in patients with high Lp (a) level. However, this study may have been underpowered to evaluate the primary study outcome.

Effect of the Interaction between Obstructive Sleep Apnea and Lipoprotein(a) on Insulin Resistance: A Large-Scale Cross-Sectional Study

Both obstructive sleep apnea (OSA) and decreased serum lipoprotein(a) (Lp(a)) concentrations are associated with insulin resistance. However, their interaction effect on insulin resistance has never been investigated. Therefore, we performed a cross-sectional study on OSA-suspected Chinese Han participants. Laboratory-based polysomnographic variables, biochemical indicators, anthropometric measurements, and medical history were collected. Linear regression and binary logistic regression analyses with interaction terms were used to investigate the potential effects of the interaction between the severity of OSA (assessed by the apnea-hypopnea index (AHI)) and Lp(a) concentrations on insulin resistance (assessed by the homeostasis model assessment of insulin resistance (HOMA-IR)), after adjusting for potential confounders including age, gender, body mass index, waist-to-hip circumference ratio, mean arterial pressure, smoking status, drinking status, and lipid profiles. A total of 4,152 participants were enrolled. In the OSA-suspected population, AHI positively correlated with insulin resistance and serum Lp(a) concentrations independently and inversely correlated with insulin resistance. In addition, the interaction analysis showed that the linear association between lgAHI and lgHOMA-IR was much steeper and more significant in subjects with relatively low Lp(a) concentrations, suggesting a significant positive interaction between lgLp(a) and lgAHI on lgHOMA-IR (P = 0.013). Furthermore, the interaction on a multiplicative scale also demonstrated a significant positive interaction (P = 0.044). A stronger association between AHI quartiles and the presence of insulin resistance (defined as HOMA-IR > 3) could be observed for participants within lower Lp(a) quartiles. In conclusion, a significant positive interaction was observed between OSA and decreased Lp(a) with respect to insulin resistance. This association might be relevant to the assessment of metabolic or cardiovascular disease risk in OSA patients.

Elevated lipoprotein(a) and low-density lipoprotein cholesterol as predictors of the severity and complexity of angiographic lesions in patients with premature coronary artery disease

BACKGROUND

Elevated lipoprotein(a) (Lp[a]) and low-density lipoprotein (LDL) cholesterol are important inheritable risk factors for premature coronary artery disease (CAD). Lp(a) mediates cardiovascular risk through prothrombotic, proinflammatory, and proatherogenic properties. The association of Lp(a) and LDL cholesterol with angiographic disease severity and complexity in patients with premature CAD has yet to be established.

OBJECTIVE

To investigate the relationship of Lp(a) and LDL cholesterol with the severity and complexity of coronary artery lesions using the SYNergy between percutaneous coronary intervention with TAXUS and Cardiac Surgery (SYNTAX) and Gensini scores, in patients with premature CAD.

METHODS

Plasma Lp(a) levels were consecutively measured by an automated latex-enhanced immunoassay in 147 patients with premature coronary events (aged <60 years). Elevated Lp(a) was defined as >0.5 g/L, and elevated LDL cholesterol as an untreated LDL cholesterol of >5.0 mmol/L (>193 mg/dL). Demographical, biochemical, and clinical data were retrospectively collected from medical records. SYNTAX and Gensini scores were independently assessed by 2 investigators.

RESULTS

Patients were subdivided into tertiles using SYNTAX scores. The proportion of patients with elevated Lp(a) and elevated LDL cholesterol were significantly higher in patients with higher SYNTAX and Gensini scores (P < .05). In multivariate analysis (adjusting for age, diabetes, hypertension, and previous coronary event), elevated Lp(a) and elevated LDL cholesterol remained significant, independent predictors of higher SYNTAX and Gensini scores (P < .05). Patients with both elevated Lp(a) and elevated LDL cholesterol constituted most of the patients in the highest SYNTAX tertile, while patients with nonelevated Lp(a) and nonelevated LDL cholesterol were predominantly in the lowest SYNTAX tertile (P < .05).

CONCLUSION

In patients with premature CAD, elevated Lp(a) and LDL cholesterol (in a range consistent with familial hypercholesterolemia) were significant, independent predictors of the severity of CAD. Both lipid disorders should be routinely screened for in younger patients presenting to the coronary care unit.

Association between lipoprotein (a) and proprotein convertase substilisin/kexin type 9 in patients with heterozygous familial hypercholesterolemia: A case-control study

BACKGROUND

Recent data have suggested an important role of lipoprotein (a) [Lp(a)] and proprotein convertase substilisin/kexin type 9 (PCSK9) in the development of atherosclerotic cardiovascular disease (ASCVD) in both general population and family hypercholesterolemia (FH), while the relation of Lp(a) to PCSK9 has not been examined.

OBJECTIVE

The aim of the present study was to investigate the association between plasma PCSK9 and Lp(a)in patients with heterozygous FH (HeFH).

METHODS

Two hundred and fifty-five molecularly confirmed patients with HeFH were compared to 255 age- and gender-matched non-FH controls. Plasma PCSK9 and Lp(a) concentrations were measured using ELISA and immunoturbidimetric method respectively, and finally their association was assessed.

RESULTS

Both plasma PCSK9 and Lp(a) levels were significantly higher in patients with HeFH compared to control group (p<0.001). Besides, the Lp(a) concentration and percentage of Lp(a)≥300mg/L were increased by PCSK9 tertiles in HeFH group (both p<0.05) while not in control group. In partial correlation analysis, Lp(a) was associated with PCSK9 (r=0.254, p<0.001) in HeFH group but not in control, which were further confirmed by multivariable linear regression analysis. Furthermore, significant associations between Lp(a) and PCSK9 were also found in subgroups of HeFH group irrespective of definite or probable FH, with and without coronary artery disease (CAD), and with statin or not.

CONCLUSIONS

Plasma Lp(a) level was associated with PCSK9 in patients with HeFH alone, suggesting that much about the interaction of PCSK9 with Lp(a) in FH need further explorations.

Lipoprotein(a) and coronary atheroma progression rates during long-term high-intensity statin therapy: Insights from SATURN

BACKGROUND & AIMS

Lipoprotein(a) [Lp(a)] is a low-density lipoprotein (LDL)-like particle that associates with major adverse cardiovascular events (MACE). We examined relationships between Lp(a) measurements and changes in coronary atheroma volume following long-term maximally-intensive statin therapy in coronary artery disease patients.

METHODS

Study of coronary atheroma by intravascular ultrasound: Effect of Rosuvastatin Versus Atorvastatin (SATURN) used serial intravascular ultrasound measures of coronary atheroma volume in patients treated with rosuvastatin 40 mg or atorvastatin 80 mg for 24 months. Baseline and follow-up Lp(a) levels were measured in 915 of the 1039 SATURN participants, and were correlated with changes in percent atheroma volume (ΔPAV).

RESULTS

Mean age was 57.7 ± 8.6 years, 74% were men, 96% were Caucasian, with statin use prior to study enrolment occurring in 59.3% of participants. Baseline [median (IQR)] LDL-cholesterol (LDL-C) and measured Lp(a) levels (mg/dL) were 114 (99, 137) and 17.4 (7.6, 52.9) respectively; follow-up measures were 60 (47, 77), and 16.5 (6.7, 57.7) (change from baseline: p < 0.001, p = 0.31 respectively). At baseline, there were 676 patients with Lp(a) levels <50 mg/dL [median Lp(a) of 10.9 mg/dL], and 239 patients with Lp(a) levels ≥ 50 mg/dL [median Lp(a) of 83.2 mg/dL]. Quartiles of baseline and follow-up Lp(a) did not associate with ΔPAV. Irrespective of the achieved LDL-C (<vs. ≥70 mg/dL), neither baseline nor on-treatment (<vs. ≥median) Lp(a) levels significantly associated with ΔPAV. No significant differences were observed in ΔPAV in Lp(a) risers versus non-risers, nor in those patients with baseline or on-treatment Lp(a) levels <vs. > 50 mg/dL.

CONCLUSIONS

In coronary artery disease patients prescribed long-term maximally intensive statin therapy with low on-treatment LDL-C levels, measured Lp(a) levels (predominantly below the 50 mg/dL threshold) do not associate with coronary atheroma progression. Alternative biomarkers may thus associate with residual cardiovascular risk in such patients.

Lipoprotein(a): new insights from modern genomics

PURPOSE OF REVIEW

Lipoprotein(a) [Lp(a)] is the strongest independent genetic risk factor for both myocardial infarction and aortic stenosis. It has also been associated with other forms of atherosclerotic cardiovascular disease (CVD) including ischemic stroke. Its levels are genetically determined and remain fairly stable throughout life. Elevated Lp(a), above 50 mg/dl, affects one in five individuals worldwide.

RECENT FINDINGS

Herein, we review the recent epidemiologic and genetic evidence supporting the causal role of Lp(a) in CVD, highlight recommendations made by European and Canadian guidelines regarding Lp(a) and summarize the rapidly evolving field of Lp(a)-lowering therapies including antisense therapies and Proprotein Convertase Subtilisin/Kexin Type 9 inhibitors.

SUMMARY

With novel therapies on the horizon, Lp(a) is poised to gain significant clinical relevance and its lowering could have a significant impact on the burden of CVD. VIDEO ABSTRACT.