The relationship between Lp(a) and CVD outcomes: a systematic review

Management of Atherosclerotic Cardiovascular Risk in Inflammatory Bowel Disease: Current Perspectives

Inflammatory bowel disease (IBD) is a complex condition characterized by inflammation of the gastrointestinal system, encompassing Crohn's disease and ulcerative colitis. Patients diagnosed with IBD have an increased risk of atherosclerotic cardiovascular disease. This heightened risk can be attributed to a combination of mechanisms, including traditional risk factors, chronic inflammation, intestinal dysbiosis, increased risk of thrombosis, and the use of certain medications such as corticosteroids. There are significant gaps in current knowledge, particularly regarding the management of risk factors and the use of medications for cardiovascular disease prevention. Similarly, the cardiovascular effects of specific IBD therapies, particularly the newer ones, are not yet fully understood. This review focuses on the epidemiological evidence linking IBD with cardiovascular risk factors and cardiovascular disease. It describes the potential pathophysiological mechanisms underlying this association and examines the challenges involved in accurately assessing cardiovascular risk in these patients, including the utility of complementary tools such as subclinical atherosclerosis detection. Additionally, we consider the potential therapeutic implications for managing these patients. Finally, this review also underscores the importance of multidisciplinary collaboration. Effective teamwork among gastroenterologists, cardiologists, and general practitioners is essential for providing comprehensive care to patients with IBD.

Elevated serum lipoprotein(a) levels as a potential risk factor for diabetic retinopathy in type 2 diabetes: a meta-analysis

PURPOSE

This meta-analysis aimed to clarify the correlation between serum lipoprotein(a) [Lp(a)] levels and diabetic retinopathy (DR) in type 2 diabetes (T2D) individuals.

METHODS

We searched electronic databases, including PubMed, Web of Science, and Embase, for relevant observational studies evaluating the association between serum Lp(a) levels and the risk of DR. Odds ratios (ORs) with 95% confidence intervals (CIs) were summarized to indicate the association between a high Lp(a) and the risk of DR. Data were extracted and pooled using a random-effects model to account for variability among studies. Heterogeneity was assessed using the I2 statistic, and publication bias was evaluated through funnel plots and Egger's test.

RESULTS

Eleven observational studies were included. Compared to T2D patients of the lowest Lp(a) category, those of the highest Lp(a) category were associated with a higher risk of DR (OR: 2.05, 95% CI: 1.43-2.93, I2 = 83%, p < 0.001). Subgroup analyses suggested this association was predominantly observed in cross-sectional and case-control studies but not cohort studies (p for subgroup differences = 0.03). Additionally, the link between Lp(a) and DR was consistent across variables such as study country, Lp(a) cutoff values, analysis model (univariate or multivariate), and adjustment for concurrent medication use. A further meta-analysis suggested a significant relationship between elevated Lp(a) levels and proliferative DR (OR: 1.90, 95% CI: 1.03-3.48, I2 = 86%, p = 0.04).

CONCLUSION

Elevated serum Lp(a) levels are associated with an increased risk of DR in individuals with T2D.

A positive association between RDW and coronary heart disease in the rheumatoid arthritis population: A cross-sectional study from NHANES

Previous research has indicated that higher red blood cell distribution width (RDW) increases the risk of coronary heart disease. However, no studies have established a link between RDW and coronary heart disease in the rheumatoid arthritis population. This research aims to explore the association between RDW and coronary heart disease among individuals with rheumatoid arthritis. We selected demographic data, laboratory data, lifestyle, and medical history from the National Health and Nutrition Examination Survey (NHANES), specifically including age, gender, poverty, RDW, race, BMI, diabetes, education, coronary heart disease, hypertension, cholesterol, smoking, and drinking. RDW and coronary heart disease were found to have a positive association in the rheumatoid arthritis population (OR = 1.145, 95%CI: 1.036-1.266, P = .0098), even after adjusting for factors such as age, gender, race, education level, smoking, and drinking. Subgroup analysis showed a stronger positive association, particularly in individuals aged 55-66 years, males, and the Hispanic White population with diabetes or hypercholesterolemia. There is a significant correlation between RDW and coronary heart disease among individuals with rheumatoid arthritis.

Association between serum lipoprotein(a) and mildly reduced eGFR: a cross-sectional study

Lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease (CVD) and aortic stenosis. However, the data on the relationship between Lp(a) and mildly reduced estimated glomerular filtration rate (eGFR) has been disputed. This study was conducted to assess the relationship between Lp(a) concentrations and mildly reduced eGFR in healthy subjects.This community-based, cross-sectional study enrolled 1,064 volunteers aged ≥ 40 years who lived in Yonghong Community, Zhonglou District, Changzhou, China, between December 2016 and December 2017. A mildly reduced eGFR was defined as eGFR between 60 and 90 mL/min/1.73m2. A standardized questionnaire and biochemical measurements were used to gather information about participants. The serum concentration of Lp(a) was determined using the latex-enhanced immunoturbidimetric test. Of the total study population, 34.8% (n = 370) were men, and the mean age was 66.8 ± 8.5 years. A significant association existed between Lp(a) levels and the risk of mildly reduced eGFR. Individuals with the highest tertile of Lp(a) had higher odds of mildly reduced eGFR after adjusting for various confounders (adjusted odds ratio [OR]: 1.80, 95% confidence interval [CI]: 1.24-2.60, P = 0.0025) compared to those with the lowest tertile of Lp(a). Multivariable logistic regression of studies in which Lp(a) was presented as continuous variables showed consistent results (adjusted OR: 1.23 for 1-SD increment of Ln-Lp(a), 95% CI: 1.05-1.43). Subgroup analyses showed that study characteristics such as age, sex, obesity, diabetes, and hypertension status did not significantly affect the association (P for all interactions > 0.05). These results suggest that higher serum Lp(a) level was an independent risk factor for mildly reduced eGFR.

The Oxidized Lipoproteins In Vivo: Its Diversity and Behavior in the Human Circulation

A high concentration of low-density lipoproteins (LDLs) in circulation has been well-known as a major risk factor for cardiovascular diseases. The presence of oxidized LDLs (oxLDLs) in atherosclerotic lesions and circulation was demonstrated using anti-oxLDL monoclonal antibodies. The so-called “oxLDL hypothesis”, as a mechanism for atherosclerosis development, has been attracting attention for decades. However, the oxLDL has been considered a hypothetical particle since the oxLDL present in vivo has not been fully characterized. Several chemically modified LDLs have been proposed to mimic oxLDLs. Some of the subfractions of LDL, especially Lp(a) and electronegative LDL, have been characterized as oxLDL candidates as oxidized phospholipids that stimulate vascular cells. Oxidized high-density lipoprotein (oxHDL) and oxLDL were discovered immunologically in vivo. Recently, an oxLDL-oxHDL complex was found in human plasma, suggesting the involvement of HDLs in the oxidative modification of lipoproteins in vivo. In this review, we summarize our understanding of oxidized lipoproteins and propose a novel standpoint to understand the oxidized lipoproteins present in vivo.

Lipoprotein(a), Cardiovascular Events and Sex Differences: A Single Cardiological Unit Experience

Lipoprotein(a)-Lp(a), which retains proatherogenic and prothrombotic properties, may be modified by hormonal and metabolic factors. However, few studies have focused on differences related to sex and cardiometabolic risk factors in the relationship between Lp(a) and cardiovascular disease, especially in terms of prognosis. This study aimed at evaluating the predictive value of Lp(a) (cut-off 30 mg/dL) for hard events (HEs: mortality and non-fatal myocardial infarction) according to sex and cardiometabolic risk factors in 2110 patients (1501 males, mean age: 68 ± 9 years) undergoing coronary angiography for known or suspected coronary artery disease. There were 211 events over a median follow-up period of 33 months. Lp(a) > 30 mg/dL did not confer a worse prognosis on the overall population. However, Kaplan-Meier subgroup analysis evidenced a worse prognosis in type 2 diabetes (T2D) females with elevated Lp(a) (log-rank test: p = 0.03) vs. T2D males and no-T2D patients, but not in other high-risk cardiovascular states (e.g., smoking, hypertension, reduced left ventricular ejection fraction or obesity). After Cox multivariate adjustment, Lp(a) remained an independent determinant for HEs in the T2D female subgroup, conferring an HR of 2.9 (95% CI 1.1-7.7, p < 0.05). Lp(a) is therefore a strong independent predictor of HR in T2D women, but not in T2D men, or in noT2D patients.

Long-term prognostic value of LDL-C, HDL-C, lp(a) and TG levels on cardiovascular disease incidence, by body weight status, dietary habits and lipid-lowering treatment: the ATTICA epidemiological cohort study (2002-2012)

BACKGROUND

The link between blood lipids and cardiovascular disease (CVD) is complex. Our aim was to assess the differential effect of blood lipids on CVD risk according to age, sex, body weight, diet quality, use of lipid-lowering drugs and presence of hypercholesterolemia.

METHODS

In this secondary analysis of the ATTICA prospective cohort study, serum blood lipids, i.e., total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG) and liproprotein(a) [Lp(a)], and sociodemographic, anthropometric, lifestyle and clinical parameters were evaluated at baseline (2001/2002) in 2020 CVD-free men and women. CVD incidence was recorded at the 10-year follow-up (2011/2012).

RESULTS

All blood lipids assessed were univariately related to CVD risk; however, associations remained significant only for HDL-C and TG in multivariate models adjusted for age, sex, body mass index, smoking, Mediterranean Diet Score, physical activity, presence of hypercholesterolemia, hypertension and diabetes mellitus, use of lipid-lowering drugs, and family history of CVD [RR per 1 mg/dL (95% CI): 0.983 (0.967, 1.000) and 1.002 (1.001, 1.003), respectively]. In stratified analyses, TC and LDL-C predicted CVD risk in younger subjects, normal-weight subjects, and those not on lipid-lowering drugs, while HDL-C and TG were significant predictors in older subjects, those with low adherence to the Mediterranean diet, and hypercholesterolemic subjects; a significant effect on CVD risk was also observed for TG in males, overweight participants and lipid-lowering medication users and for Lp(a) in older subjects and females (all p ≤ 0.050).

CONCLUSIONS

The impact of blood lipids on CVD risk differs according to several biological, lifestyle and clinical parameters.

Prediction of carotid plaque by blood biochemical indices and related factors based on Fisher discriminant analysis

OBJECTIVE

This study aims to establish the predictive model of carotid plaque formation and carotid plaque location by retrospectively analyzing the clinical data of subjects with carotid plaque formation and normal people, and to provide technical support for screening patients with carotid plaque.

METHODS

There were 4300 subjects in the ultrasound department of Maanshan People's Hospital collected from December 2013 to December 2018. We used demographic and biochemical data from 3700 subjects to establish predictive models for carotid plaque and its location. The leave-one-out cross-validated classification, 600 external data validation, and area under the receiver operating characteristic curve (AUC) were used to verify the accuracy, sensitivity, specificity, and application value of the model.

RESULTS

There were significant difference of age (F = - 34.049, p < 0.01), hypertension (χ² = 191.067, p < 0.01), smoking (χ² = 4.762, p < 0.05) and alcohol (χ² = 8.306, p < 0.01), Body mass index (F = 15.322, p < 0.01), High-density lipoprotein (HDL) (F = 13.840, p < 0.01), Lipoprotein a (Lp a) (F = 52.074, p < 0.01), Blood Urea Nitrogen (F = 2.679, p < 0.01) among five groups. Prediction models were built: carotid plaque prediction model (Model CP); Prediction model of left carotid plaque only (Model CP Left); Prediction model of right carotid plaque only (Model CP Right). Prediction model of bilateral carotid plaque (Model CP Both). Model CP (Wilks' lambda = 0.597, p < 0.001, accuracy = 78.50%, sensitivity = 78.07%, specificity = 79.07%, AUC = 0.917). Model CP Left (Wilks' lambda = 0.605, p < 0.001, accuracy = 79.00%, sensitivity = 86.17%, specificity = 72.70%, AUC = 0.880). Model CP Right (Wilks' lambda = 0.555, p < 0.001, accuracy = 83.00%, sensitivity = 81.82%, specificity = 84.44%, AUC = 0.880). Model CP Both (Wilks' lambda = 0.651, p < 0.001, accuracy = 82.30%, sensitivity = 89.50%, specificity = 72.70%, AUC = 0.880).

CONCLUSION

Demographic characteristics and blood biochemical indexes were used to establish the carotid plaque and its location discriminant models based on Fisher discriminant analysis (FDA), which has high application value in community screening.

Lipoprotein(a) and the Risk for Coronary Heart Disease and Ischemic Stroke Events Among Black and White Adults With Cardiovascular Disease

Background

It is unclear whether lipoprotein(a) is associated with coronary heart disease (CHD) and ischemic stroke events in White and Black adults with atherosclerotic cardiovascular disease (ASCVD).

Methods and Results

We conducted a case‐cohort analysis, including Black and White REGARDS (Reasons for Geographic and Racial Differences in Stroke) study participants ≥45 years of age with prevalent ASCVD (ie, CHD or stroke) at baseline between 2003 and 2007. Baseline lipoprotein(a) molar concentration was measured in participants with ASCVD who experienced a CHD event by December 2017 (n=1166) or an ischemic stroke by September 2019 (n=492) and in a random subcohort of participants with prevalent ASCVD (n=1948). The hazard ratio (HR) for CHD events per 1 SD (1.5 units) higher log‐transformed lipoprotein(a) was 1.26 (95% CI, 1.02–1.56) among Black participants and 1.16 (95% CI, 1.02–1.31) among White participants (P value comparing HRs, 0.485). The HR for CHD events per 1 SD higher log‐lipoprotein(a) within subgroups with hs‐CRP (high‐sensitivity C‐reactive protein) ≥2 and <2 mg/L was 1.31 (95% CI, 0.99–1.73) and 1.23 (95% CI, 0.85–1.80), respectively (P value comparing HRs, 0.836), among Black participants, and 1.07 (95% CI, 0.91–1.27) and 1.36 (95% CI, 1.10–1.70), respectively (P value comparing HRs, 0.088), among White participants. There was no evidence that the association between lipoprotein(a) and CHD events differed by statin use. There was no evidence of an association between lipoprotein(a) and ischemic stroke events among Black or White participants.

Conclusions

Higher lipoprotein(a) levels were associated with an increased risk for CHD events in Black and White adults with ASCVD.

Elevated lipoprotein (a) levels and risk of peripheral artery disease outcomes: A systematic review

BACKGROUND

Despite strong association of elevated lipoprotein (a) (Lp(a)) levels with incident coronary and cerebrovascular disease, data for incident peripheral artery disease (PAD) are less robust. The main objective of the present systematic review was to analyze the association between elevated Lp(a) levels and PAD outcomes.

METHODS

This systematic review was performed according to PRISMA guidelines. A literature search was performed to detect randomized clinical trials or observational studies with a cohort design that evaluated the association between Lp(a) levels and PAD outcomes.

RESULTS

Fifteen studies including 493,650 subjects were identified and considered eligible for this systematic review. This systematic review showed that the vast majority of the studies reported a significant association between elevated Lp(a) levels and the risk of PAD outcomes. The elevated Lp(a) levels were associated with a higher risk of incident claudication (RR: 1.20), PAD progression (HR: 1.41), restenosis (HR: 6.10), death and hospitalization related to PAD (HR: 1.37), limb amputation (HR: 22.75), and lower limb revascularization (HR: 1.29 and 2.90). In addition, the presence of elevated Lp(a) values were associated with a higher risk of combined PAD outcomes, with HRs in a range between 1.14 and 2.80, despite adjusting for traditional risk factors. Heterogeneity of results can be explained by different patient populations studied and varying Lp(a) cut-off points of Lp(a) analyzed.

CONCLUSION

This systematic review suggests that evidence is available to support an independent positive association between Lp(a) levels and the risk of future PAD outcomes. PROSPERO Registration No.: 289253.

The correlation between lipoprotein(a) elevations and the risk of recurrent cardiovascular events in CAD patients with different LDL-C levels

Background

Lipoprotein(a) [Lp(a)] elevation is an important risk factor for coronary artery disease (CAD). However, the correlation between Lp(a) elevations and the risk of recurrent cardiovascular events in patients with established cardiovascular disease is controversial. Some studies have shown that Low-density lipoprotein cholesterol (LDL-C) levels may influence the association between Lp(a) and cardiovascular risk. Our study aims to explore the correlation between Lp(a) elevations and cardiovascular risk in patients with different LDL-C levels.

Methods

We included 516 patients who received coronary stents due to acute coronary syndrome (ACS) and followed them for three years. They were divided into low-Lp(a) group and high-Lp(a) group according to Lp(a) levels, and the incidence of major adverse cardiovascular events (MACE) and acute coronary events (ACE) was compared between the two groups. Then the patients were divided into three subgroups (S1:LDL-C ≥ 1.8 mmol/L; S2:1.4 ≤ LDL-C < 1.8 mmol/L; S3:LDL-C < 1.4 mmol/L). The correlation between Lp(a) elevations and cardiovascular risk in different subgroups was analysed by Cox proportional hazards models.

Results

The incidence of MACE and ACE in the high-Lp(a) group was significantly higher than those in the low-Lp(a) group (P < 0.05). Lp(a) elevations had independent prognostic value from the statistical point of view (MACE: HR = 1.63, 95%CI = 1.12–2.38, P = 0.012; ACE: HR = 1.70, 95%CI = 1.03–2.81, P = 0.037). Subgroup analysis showed that Lp(a) elevations increased cardiovascular risk when LDL-C ≥ 1.4 mmol/L. However, this correlation no longer existed when LDL-C levels were very low (< 1.4 mmol/L) (MACE: HR = 0.49, 95%CI = 0.17–1.42, P = 0.186; ACE: HR = 0.68, 95%CI = 0.18–2.61, P = 0.570).

Conclusions

Lp(a) elevations are associated with recurrent cardiovascular events when LDL-C levels are high, but this association may change when LDL-C levels are extremely low. CAD patients with combination of LDL-C ≥ 1.4 mmol/L and Lp(a) elevations shall be considered as high-risk groups and require further medication for the reduction of their LDL-C levels.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02618-5.

Combination of High-Density Lipoprotein Cholesterol and Lipoprotein(a) as a Predictor of Collateral Circulation in Patients With Severe Unilateral Internal Carotid Artery Stenosis or Occlusion

BACKGROUND AND PURPOSE

Collateral circulation is considered an important factor affecting the risk of stroke, but the factors that affect collateral circulation remain unclear. This study was performed to identify the factors associated with collateral circulation, especially blood lipids.

METHODS

The study involved patients who had undergone digital subtraction angiography and were confirmed as having severe unilateral stenosis or occlusion of the internal carotid artery (ICA). We classified the collateral circulation status of each patient as good (Grade 3 or 4) or poor (Grade 0, 1, or 2) according to the grading system of the American Society of Interventional and Therapeutic Neuroradiology/American Society of Interventional Radiology. We collected data on patients' characteristics and identified the factors that affect collateral circulation.

RESULTS

This study included 212 patients. The multivariate logistic regression analysis showed that the high-density lipoprotein cholesterol (HDL-C) concentration and a complete anterior half of the circle of Willis were independent protective factors for good collateral circulation, whereas elevated lipoprotein(a) [Lp(a)] and serum creatinine concentrations were independent risk factors for good collateral circulation. The area under the receiver operating characteristics curve (AUC) was 0.68 (95% confidence interval [CI], 0.61-0.76) for HDL-C and 0.69 (95% CI, 0.62-0.76) for Lp(a). A binary logistic regression model analysis of the joint factor of HDL-C and Lp(a) yielded an AUC of 0.77 (95% CI, 0.71-0.84).

CONCLUSIONS

In patients with severe unilateral ICA stenosis or occlusion, the combination of HDL-C and Lp(a) is a useful predictor of collateral circulation.

Lipoprotein(a) as predictor of coronary artery disease and myocardial infarction in a multi-ethnic Asian population

BACKGROUND AND AIMS

The role of Lp(a) in multi-ethnic Asian populations with coronary artery disease (CAD) has not been well established. The aims of this study were (i) to investigate whether Lp(a) is a predictor of CAD, and (ii) amongst patients with CAD, to ascertain whether Lp(a) is a predictor of acute myocardial infarction (AMI) and severity of CAD.

METHODS

We compared three cardiovascular phenotypes from patients recruited at coronary angiography. CAD was defined as ≥50% coronary artery stenosis and subdivided into a group with AMI history (CAD+AMI+) and a group without (CAD+AMI-). Minimal CAD group (CAD-) was defined as normal or <30% coronary artery stenosis and no AMI. The severity of CAD was defined using the modified Gensini score.

RESULTS

We studied 2025 patients comprising 94.5% men and 61.4% of Chinese ethnicity. The median Lp(a) level was highest in CAD+AMI+, followed by CAD+AMI- and CAD- (26.2, 20.1, and 15.8 nmol/L respectively). Similarly, the frequency of patients with Lp(a) ≥120 nmol/L were in the same order (11.8%, 9.1% and 2.4%). Lp(a) levels were highest among Asian Indians, followed by Malays and Chinese patients (p < 0.001). Lp(a) levels and Lp(a) ≥120 nmol/L were significant predictors of CAD (Odds ratio (OR) = 1.12 per 10 nmol/L increment, p < 0.001, and OR = 5.41 p = 0.004 respectively). Among patients with CAD, higher Lp(a) levels were associated with increased AMI risk (OR = 1.02 per 10 nmol/L increment, p = 0.024). Lp(a) ≥120 nmol/L was positively associated with CAD severity (p = 0.020).

CONCLUSIONS

Plasma Lp(a) concentration is a positive predictor of CAD and AMI in a mostly male South East Asian population.

Can biomarkers be used to improve diagnosis and prediction of metabolic syndrome in childhood cancer survivors? A systematic review

Childhood cancer survivors (CCS) are at increased risk to develop metabolic syndrome (MetS), diabetes, and cardiovascular disease. Common criteria underestimate adiposity and possibly underdiagnose MetS, particularly after abdominal radiotherapy. A systematic literature review and meta-analysis on the diagnostic and predictive value of nine newer MetS related biomarkers (adiponectin, leptin, uric acid, hsCRP, TNF-alpha, IL-1, IL-6, apolipoprotein B (apoB), and lipoprotein(a) [lp(a)]) in survivors and adult non-cancer survivors was performed by searching PubMed and Embase. Evidence was summarized with GRADE after risk of bias evaluation (QUADAS-2/QUIPS). Eligible studies on promising biomarkers were pooled. We identified 175 general population and five CCS studies. In the general population, valuable predictive biomarkers are uric acid, adiponectin, hsCRP and apoB (high level of evidence), and leptin (moderate level of evidence). Valuable diagnostic biomarkers are hsCRP, adiponectin, uric acid, and leptin (low, low, moderate, and high level of evidence, respectively). Meta-analysis showed OR for hyperuricemia of 2.94 (age-/sex-adjusted), OR per unit uric acid increase of 1.086 (unadjusted), and AUC for hsCRP of 0.71 (unadjusted). Uric acid, adiponectin, hsCRP, leptin, and apoB can be alternative biomarkers in the screening setting for MetS in survivors, to enhance early identification of those at high risk of subsequent complications.

Lipoprotein (a) and Cardiovascular Disease: A Missing Link for Premature Atherosclerotic Heart Disease and/or Residual Risk

ABSTRACT

Lipoprotein(a) or lipoprotein "little a" is an under-recognized causal risk factor for cardiovascular (CV) disease (CVD), including coronary atherosclerosis, aortic valvular stenosis, ischemic stroke, heart failure and peripheral arterial disease. Elevated plasma Lp(a) (≥50 mg/dL or ≥100 nmol/L) is commonly encountered in almost 1 in 5 individuals and confers a higher CV risk compared to those with normal Lp(a) levels, although such normal levels have not been generally agreed upon. Elevated Lp(a) is considered a cause of premature and accelerated atherosclerotic CVD. Thus, in patients with a positive family or personal history of premature coronary artery disease (CAD), Lp(a) should be measured. However, elevated Lp(a) may confer increased risk for incident CAD even in the absence of a family history of CAD, and even in those who have guideline-lowered LDL-cholesterol (<70 mg/dl) and continue to have a persisting CV residual risk. Thus, measurement of Lp(a) will have a significant clinical impact on the assessment of atherosclerotic CVD risk, and will assume a more important role in managing patients with CVD with the advent and clinical application of specific Lp(a)-lowering therapies. Conventional therapeutic approaches like lifestyle modification and statin therapy remain ineffective at lowering Lp(a). Newer treatment modalities, such as gene silencing via RNA interference with use of antisense oligonucleotide(s) or small interfering RNA molecules targeting Lp(a) seem very promising. These issues are herein reviewed, accumulated data are scrutinized, meta-analyses and current guidelines are tabulated and Lp(a)-related CVDs and newer therapeutic modalities are pictorially illustrated.

Lipoprotein (a): When to Measure and How to Treat?

PURPOSE OF REVIEW

The purpose of this article is to review current evidence for lipoprotein (a) (Lp(a)) as a risk factor for multiple cardiovascular (CV) disease phenotypes, provide a rationale for Lp(a) lowering to reduce CV risk, identify therapies that lower Lp(a) levels that are available clinically and under investigation, and discuss future directions.

RECENT FINDINGS

Mendelian randomization and epidemiological studies have shown that elevated Lp(a) is an independent and causal risk factor for atherosclerosis and major CV events. Lp(a) is also associated with non-atherosclerotic endpoints such as venous thromboembolism and calcific aortic valve disease. It contributes to residual CV risk in patients receiving standard-of-care LDL-lowering therapy. Plasma Lp(a) levels present a skewed distribution towards higher values and vary widely between individuals and according to ethnic background due to genetic variants in the LPA gene, but remain relatively constant throughout a person's life. Thus, elevated Lp(a) (≥50 mg/dL) is a prevalent condition affecting >20% of the population but is still underdiagnosed. Treatment guidelines have begun to advocate measurement of Lp(a) to identify patients with very high levels that have a family history of premature CVD or elevated Lp(a). Lipoprotein apheresis (LA) efficiently lowers Lp(a) and was recently associated with a reduction of incident CV events. Statins have neutral or detrimental effects on Lp(a), while PCSK9 inhibitors significantly reduce its level by up to 30%. Specific lowering of Lp(a) with antisense oligonucleotides (ASO) shows good safety and strong efficacy with up to 90% reductions. The ongoing CV outcomes study Lp(a)HORIZON will provide a first answer as to whether selective Lp(a) lowering with ASO reduces the risk of major CV events. Given the recently established association between Lp(a) level and CV risk, guidelines now recommend Lp(a) measurement in specific clinical conditions. Accordingly, Lp(a) is a current target for drug development to reduce CV risk in patients with elevated levels, and lowering Lp(a) with ASO represents a promising avenue.

Structure and Dynamics of Oxidized Lipoproteins In Vivo: Roles of High-Density Lipoprotein

Oxidative modification of lipoproteins is implicated in the occurrence and development of atherosclerotic lesions. Earlier studies have elucidated on the mechanisms of foam cell formation and lipid accumulation in these lesions, which is mediated by scavenger receptor-mediated endocytosis of oxidized low-density lipoprotein (oxLDL). Mounting clinical evidence has supported the involvement of oxLDL in cardiovascular diseases. High-density lipoprotein (HDL) is known as anti-atherogenic; however, recent studies have shown circulating oxidized HDL (oxHDL) is related to cardiovascular diseases. A modified structure of oxLDL, which was increased in the plasma of patients with acute myocardial infarction, was characterized. It had two unique features: (1) a fraction of oxLDL accompanied oxHDL, and (2) apoA1 was heavily modified, while modification of apoB, and the accumulation of oxidized phosphatidylcholine (oxPC) and lysophosphatidylcholine (lysoPC) was less pronounced. When LDL and HDL were present at the same time, oxidized lipoproteins actively interacted with each other, and oxPC and lysoPC were transferred to another lipoprotein particle and enzymatically metabolized rapidly. This brief review provides a novel view on the dynamics of oxLDL and oxHDL in circulation.

Changes in lipoprotein particle subclasses, standard lipids, and apolipoproteins after supplementation with n-3 or n-6 PUFAs in abdominal obesity: A randomized double-blind crossover study

BACKGROUND & AIMS

Marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower circulating levels of triacylglycerols (TAGs), and the plant-derived omega-6 (n-6) PUFA linoleic acid (LA) may reduce cholesterol levels. Clinical studies on effects of these dietary or supplemental PUFAs on other blood fat fractions are few and have shown conflicting results. This study aimed to determine effects of high-dose supplemental n-3 (EPA + DHA) and n-6 (LA) PUFAs from high-quality oils on circulating lipoprotein subfractions and standard lipids (primary outcomes), as well as apolipoproteins, fatty acids, and glycemic control (secondary outcomes), in females and males with abdominal obesity.

METHODS

This was a randomized double-blind crossover study with two 7-wk intervention periods separated by a 9-wk washout phase. Females (n = 16) were supplemented with 3 g/d of EPA + DHA (TAG fish oil) or 15 g/d of LA (safflower oil), while males (n = 23) received a dose of 4 g/d of EPA + DHA or 20 g/d of LA. In fasting blood samples, we investigated lipoprotein particle subclasses by nuclear magnetic resonance spectroscopy, as well as standard lipids, apolipoproteins, fatty acid profiles, and glucose and insulin. Data were analyzed by linear mixed-effects modeling with 'subjects' as the random factor.

RESULTS

The difference between interventions in relative change scores was among the lipoprotein subfractions significant for total very-low-density lipoproteins (VLDLs) (n-3 vs. n-6: -38%∗ vs. +16%, p < 0.001; ∗: significant within-treatment change score), large VLDLs (-58%∗ vs. -0.91%, p < 0.001), small VLDLs (-57%∗ vs. +41%∗, p < 0.001), total low-density lipoproteins (LDLs) (+5.8%∗ vs. -4.3%∗, p = 0.002), large LDLs (+23%∗ vs. -2.1%, p = 0.004), total high-density lipoproteins (HDLs) (-6.0%∗ vs. +3.7%, p < 0.001), large HDLs (+11%∗ vs. -5.3%, p = 0.001), medium HDLs (-24%∗ vs. +6.2%, p = 0.030), and small HDLs (-9.9%∗ vs. +9.6%∗, p = 0.002), and among standard lipids for TAGs (-16%∗ vs. -2.6%, p = 0.014), non-esterified fatty acids (-19%∗ vs. +5.5%, p = 0.033), and total cholesterol (-0.28% vs. -4.4%∗, p = 0.042). A differential response in relative change scores was also found for apolipoprotein (apo)B (+0.40% vs. -6.0%∗, p = 0.008), apoA-II (-6.0%∗ vs. +1.5%, p = 0.001), apoC-II (-11%∗ vs. -1.7%, p = 0.025), and apoE (+3.3% vs. -3.8%, p = 0.028).

CONCLUSIONS

High-dose supplementation of high-quality oils with n-3 (EPA + DHA) or n-6 (LA) PUFAs was followed by reductions in primarily TAG- or cholesterol-related markers, respectively. The responses after both interventions point to changes in the lipoprotein-lipid-apolipoprotein profile that have been associated with reduced cardiometabolic risk, also among people with TAG or LDL-C levels within the normal range.

REGISTRATION

Registered under ClinicalTrials.gov Identifier: NCT02647333.

CLINICAL TRIAL REGISTRATION

Registered at https://clinicaltrials.gov/ct2/show/NCT02647333.

Lipoprotein(a): a genetic marker for cardiovascular disease and target for emerging therapies

Lipoprotein(a) [Lp(a)] is an established cardiovascular risk factor, and growing evidence indicates its causal association with atherosclerotic disease because of the proatherogenic low-density lipoprotein (LDL)-like properties and the prothrombotic plasminogen-like activity of apolipoprotein(a) [apo(a)]. As genetics significantly influences its plasma concentration, Lp(a) is considered an inherited risk factor of atherosclerotic cardiovascular disease (ASCVD), especially in young individuals. Moreover, it has been suggested that elevated Lp(a) may significantly contribute to residual cardiovascular risk in patients with coronary artery disease and optimal LDL-C levels. Nonetheless, the fascinating hypothesis that lowering Lp(a) could reduce the risk of cardiovascular events - in primary or secondary prevention - still needs to be demonstrated by randomized clinical trials. To date, no specific Lp(a)-lowering agent has been approved for reducing the lipoprotein levels, and current lipid-lowering drugs have limited effects. In the future, emerging therapies targeting Lp(a) may offer the possibility to further investigate the relation between Lp(a) levels and cardiovascular outcomes in randomized controlled trials, ultimately leading to a new era in cardiovascular prevention. In this review, we aim to provide an updated overview of current evidence on Lp(a) as well as currently investigated therapeutic strategies that specifically address the reduction of the lipoprotein.

Increased cardiovascular risk associated with hyperlipoproteinemia (a) and the challenges of current and future therapeutic possibilities

Population, genetic, and clinical studies demonstrated a causative and continuous, from other plasma lipoproteins independent relationship between elevated plasma lipoprotein (a) [Lp(a)] concentration and the development of cardiovascular disease (CVD), mainly those related to athe-rosclerotic CVD, and calcific aortic stenosis. Currently, a strong international consensus is still lacking regarding the single value which would be commonly used to define hyperlipoproteinemia (a). Its prevalence in the general population is estimated to be in the range of 10%–35% in accordance with the most commonly used threshold levels (>30 or >50 mg/dL). Since elevated Lp(a) can be of special importance in patients with some genetic disorders, as well as in individuals with otherwise controlled major risk factors, the identification and establishment of the proper therapeutic interventions that would lower Lp(a) levels and lead to CVD risk reduction could be very important. The majority of the classical lipid-lowering agents (statins, ezetimibe, and fibrates), as well as nutraceuticals (CoQ10 and garlic), appear to have no significant effect on its plasma levels, whereas for the drugs with the demonstrated Lp(a)-lowering effects (aspirin, niacin, and estrogens), their clinical efficacy in reducing cardiovascular (CV) events has not been unequivocally proven yet. Both Lp(a) apheresis and proprotein convertase subtilisin/kexin type 9 inhibitors can reduce the plasma Lp(a) by approximately 20%–30% on average, in parallel with much larger reduction of low-density lipoprotein cholesterol (up to 70%), what puts us in a difficulty to conclude about the true contribution of lowered Lp(a) to the reduction of CV events. The most recent advancement in the field is the introduction of the novel apolipoprotein (a) [apo(a)] antisense oligonucleotide therapy targeting apo(a), which has already proven itself as being very effective in decreasing plasma Lp(a) (by even >90%), but should be further tested in clinical trials. The aim of this review was to present some of the most important accessible scientific data, as well as dilemmas related to the currently and potentially in the near future more widely available therapeutic options for the management of hyperlipoproteinemia (a).

Lipoprotein(a) and cardiovascular death in oldest-old (≥80 years) patients with acute myocardial infarction: A prospective cohort study

BACKGROUND AND AIMS

Compared with what is known about the prognostic value of lipoprotein(a) [Lp(a)] in middle-aged patients with atherosclerotic cardiovascular disease (ASCVD), less is understood concerning the role of Lp(a) in oldest-old (≥80 years old) with ASCVD. The aim of the present study was to investigate the relationship between Lp(a) and cardiovascular death (CD) among the oldest-old with acute myocardial infarction (AMI).

METHODS

A total of 1008 patients with AMI, older than 80 years, were consecutively enrolled between January 2012 and August 2018. The clinical characteristics were collected and Lp(a) concentrations were measured by the immunoturbidimetric method at baseline. The relationship between plasma Lp(a) concentration (≤10 mg/dL, 10-30 mg/dL, >30 mg/dL) and CD was evaluated by Kaplan-Meier analysis and Cox proportional hazard models.

RESULTS

During an average of 36.26 months of follow-up, 287 CD occurred. Data showed that patients with high Lp(a) levels (>30 mg/dL) had the highest rate of CD (p < 0.05). Kaplan-Meier analysis showed that the high Lp(a) group had the lowest event-free survival rate in the oldest-old with AMI (p = 0.030). In addition, subjects with Lp(a) > 30 mg/dL had a 1.5-fold (95% confidence interval: 1.083-2.132) higher risk of CD compared with those with Lp(a) ≤10 mg/dL in fully adjusted Cox proportional hazards model.

CONCLUSIONS

The current data firstly showed that plasma Lp(a) concentration was associated with the risk of CD in oldest-old with AMI, suggesting that Lp(a) could be a useful adjunctive measurement in the evaluation of CD in this population.

Lipoprotein (a) as a residual risk factor for atherosclerotic renal artery stenosis in hypertensive patients: a hospital-based cross-sectional study

Background

Low-density lipoprotein cholesterol (LDL-c) has been proven to be a risk factor for atherosclerotic cardiovascular disease (CVD), while lipoprotein (a) (Lp(a)) is a residual risk factor for CVD, even though LDL-c is well controlled by statin use. Importantly, the role of Lp(a) in atherosclerotic renal artery stenosis (ARAS) is still unknown.

Methods

For this hospital-based cross-sectional study, patients who simultaneously underwent coronary and renal angiography were examined. ARAS was defined as a 50% reduction in the cross-sectional (two-dimensional plane) area of the renal artery. Data were collected and compared between ARAS and non-ARAS groups, including clinical history and metabolite profiles. Univariate analysis, three tertile LDL-c-based stratified analysis, and multivariate-adjusted logistic analysis were conducted, revealing a correlation between Lp(a) and ARAS.

Results

A total of 170 hypertensive patients were included in this study, 85 with ARAS and 85 with non-RAS. Baseline information indicated comparability between the two groups. In the univariate and multivariate analysis, common risk factors for atherosclerosis were not significantly different. Stratified analysis of LDL-c revealed a significant increase in the incidence of ARAS in patients who had high Lp(a) concentrations at low LDL-c levels (odds ratio (OR): 4.77, 95% confidence interval (CI): 1.04–21.79, P = 0.044). Further logistic analysis with adjusted covariates also confirmed the result, indicating that high Lp(a) levels were independently associated with ARAS (adjusted OR (aOR): 6.14, 95%CI: 1.03–36.47, P = 0.046). This relationship increased with increasing Lp(a) concentration based on a curve fitting graph. These results were not present in the low and intermediate LDL-c-level groups.

Conclusion

In hypertensive patients who present low LDL-c, high Lp(a) was significantly associated with atherosclerotic renal artery stenosis and thus is a residual risk factor.

Antisense lipoprotein[a] therapy: State-of-the-art and future perspectives

Several lines of evidence now attest that lipoprotein[a] (Lp[a]) is a significant risk factor for many cardiovascular disorders. This enigmatic lipoprotein, composed of a single copy of apolipoprotein B (apoB) and apolipoprotein[a] (apo [a]), expresses peculiar metabolism, virtually independent from lifestyle interventions. Several therapeutic options have hence been proposed for lowering elevated Lp[a] values, with or without concomitant effect on low density lipoprotein (LDL) particles, mostly encompassing statins, ezetimibe, nicotinic acid, lipoprotein apheresis, and anti-PCSK9 monoclonal antibodies. Since all these medical treatments have some technical and clinical drawbacks, a novel strategy is currently being proposed, based on the use of antisense apo[a] and/or apoB inhibitors. Although the role of these agents in hypercholesterolemic patients is now nearby entering clinical practice, the collection of information on Lp[a] is still underway. Preliminary evidence would suggest that apo[a] antisense therapy seems more appropriate in patients with isolated Lp[a] elevations, while apoB antisense therapy is perhaps more advisable in patients with isolated LDL elevations. In patients with concomitant elevations of Lp[a] and LDL, either combining the two apo[a] and apoB antisense therapies (a strategy which has never been tested), or the combination of well-known and relatively inexpensive drugs such as statins with antisense apo[a] inhibitors can be theoretically suggested. The results of an upcoming phase 3 study with antisense apo[a] inhibitors will hopefully provide definitive clues as to whether this approach may become the standard of care in patients with increased Lp[a] concentrations.

Impaired Spontaneous/Endogenous Fibrinolytic Status as New Cardiovascular Risk Factor?: JACC Review Topic of the Week

Endogenous fibrinolysis is a powerful natural defense mechanism against lasting arterial thrombotic occlusion. Recent prospective studies have shown that impaired endogenous fibrinolysis (or hypofibrinolysis) can be detected in a significant number of patients with acute coronary syndrome (ACS) using global assays and is a strong marker of future cardiovascular risk. This novel risk biomarker is independent of traditional cardiovascular risk factors and unaffected by antiplatelet therapy. Most prospective prognostic data have been obtained using a global assay using native whole blood at high shear or plasma turbidimetric assays, which are described herein. Tests of endogenous fibrinolysis could be used to identify patients with ACS who, despite antiplatelet therapy, remain at high cardiovascular risk. This review discusses the impact of currently available medications and those in development that favorably modulate fibrinolytic status and may offer a potential new avenue to improve outcomes in ACS.

Replacing Saturated Fats with Unsaturated Fats from Walnuts or Vegetable Oils Lowers Atherogenic Lipoprotein Classes Without Increasing Lipoprotein(a)

BACKGROUND

Walnuts have established lipid-/lipoprotein-lowering properties; however, their effect on lipoprotein subclasses has not been investigated. Furthermore, the mechanisms by which walnuts improve lipid/lipoprotein concentrations are incompletely understood.

OBJECTIVES

We aimed to examine, as exploratory outcomes of this trial, the effect of replacing SFAs with unsaturated fats from walnuts or vegetable oils on lipoprotein subclasses, cholesterol efflux, and proprotein convertase subtilisin/kexin type 9 (PCSK9).

METHODS

A randomized, crossover, controlled-feeding study was conducted in individuals at risk of cardiovascular disease (CVD) (n = 34; 62% men; mean ± SD age 44 ± 10 y; BMI: 30.1 ± 4.9 kg/m2). After a 2-wk run-in diet (12% SFAs, 7% PUFAs, 12% MUFAs), subjects consumed the following diets, in randomized order, for 6 wk: 1) walnut diet (WD) [57-99 g/d walnuts, 7% SFAs, 16% PUFAs [2.7% α-linolenic acid (ALA)], 9% MUFAs]; 2) walnut fatty acid-matched diet [7% SFAs, 16% PUFAs (2.6% ALA), 9% MUFAs]; and 3) oleic acid replaces ALA diet (ORAD) [7% SFAs, 14% PUFAs (0.4% ALA); 12% MUFAs] (all percentages listed are of total kilocalories ). Serum collected after the run-in (baseline) and each diet period was analyzed for lipoprotein classes and subclasses (vertical auto profile), cholesterol efflux, and PCSK9. Linear mixed models were used for data analysis.

RESULTS

Compared with the ORAD, total cholesterol (mean ± SEM -8.9± 2.3 mg/dL; -5.1%; P < 0.001), non-HDL cholesterol (-7.4 ± 2.0 mg/dL; -5.4%; P = 0.001), and LDL cholesterol (-6.9 ± 1.9 mg/dL; -6.5%; P = 0.001) were lower after the WD; no other pairwise differences existed. There were no between-diet differences for HDL-cholesterol or LDL-cholesterol subclasses. Lipoprotein(a) [Lp(a)], cholesterol efflux, and PCSK9 were unchanged after the diets.

CONCLUSIONS

In individuals at risk of CVD, replacement of SFAs with unsaturated fats from walnuts or vegetable oils improved lipid/lipoprotein classes, including LDL-cholesterol, non-HDL cholesterol, and total cholesterol, without an increase in Lp(a). These improvements were not explained by changes in cholesterol efflux capacity or PCSK9. This trial was registered at clinicaltrials.gov as NCT01235832.

Prognostic Value of Lipoprotein(a) Levels in Patients Undergoing Coronary Angiography for Premature Acute Coronary Syndromes

Little is known about the association between lipoprotein(a) [Lp(a)] levels and future ischemic cardiovascular events in patients with premature acute coronary syndrome (ACS). A total of 1464 consecutive patients who underwent coronary angiography for premature ACS (males <45 years and females <55 years) were enrolled in this study. Patients were divided into quartiles according to serum Lp(a) levels (Q1: ≤11.1 nmol/L; Q2: 11.1-27.7 nmol/L; Q3: 27.7-79.3 nmol/L; and Q4: >79.3 nmol/L). Major adverse cardiovascular events (MACEs) increased with Lp(a) quartiles after 2-year follow-up (among quartiles, respectively; P = .001). Kaplan-Meier curves revealed significant differences in event-free survival rates among Lp(a) quartile groups ( P = .001). Multivariate Cox proportional hazards regression analysis indicated that serum Lp(a) level was an independent predictor of MACE either as a continuous variable (hazard ratio [HR]: 1.002, 95% confidence interval [CI]: 1.001-1.004; P = .009) or as a categorical variable (HR: 1.443, 95% CI: 1.074-1.937; P = .015). Furthermore, Lp(a) levels (as a variable) significantly improved the prognostic value for MACE. These findings suggest that Lp(a) measurement has value for cardiovascular risk stratification in patients with premature ACS.

The Ratio of Oxidized Lipoprotein(a) to Native Lipoprotein(a) and the Endothelial Function in Patients with Type 2 Diabetes Mellitus

The ratio of oxidized lipoprotein(a) to native lipoprotein(a) (oxLp(a)/Lp(a)) may be a reasonable index for assessing endothelial dysfunction in type 2 diabetes mellitus (T2DM). The present study investigated whether the oxLp(a)/Lp(a) level is correlated with the endothelial function using the Endo-PAT^TM, a newly developed device, in patients with T2DM. A total of 63 patients with T2DM (mean age: 59 years old) were enrolled in the study. The patients’ serum Lp(a) and oxLp(a) levels were measured using an enzyme-linked immunosorbent assay. The reactive hyperemia index (RHI) level was measured using an Endo-PAT^TM 2000. A correlation analysis between the measured variables was conducted. Among the patients, the mean hemoglobin A1c was 7.8%. The median level of oxLp(a)/Lp(a) was 0.28 (interquartile range: 0.07–0.54), and the mean RHI was 1.8 (standard deviation: 0.4). In a multiple linear regression analysis, the oxLp(a)/Lp(a) level was an independent, significant, and inverse variable for the RHI level (β = −0.26, p < 0.05), along with male gender. A high oxLp(a)/Lp(a) level may reflect endothelial dysfunction, as assessed by the Endo-PAT^TM, in patients with T2DM. Further studies are warranted to confirm the observed findings.

Lipoprotein(a) and coronary artery disease in Chinese postmenopausal female patients: a large cross-sectional cohort study

BACKGROUND

It has been reported that lipoprotein(a) (Lp(a)) is associated with the risk of cardiovascular disease. The present study aimed to examine the association of Lp(a) levels with the presence and severity of coronary artery disease (CAD) in female patients.

METHODS

A total of 3712 female patients who received coronary angiography were consecutively enrolled. The levels of Lp(a) were measured and compared among patients with or without CAD, myocardial infarction and menopause. Spearman correlation analysis and logistic regression analysis were used to examine the association of Lp(a) with the presence of CAD and the severity of coronary atherosclerosis assessed by Gensini score (GS).

RESULTS

The average of Lp(a) levels was elevated as age increased in female subjects. Notably, women after menopause had higher Lp(a) levels compared with that before menopause (16.8 mg/dL (IQR 7.54-41.12 mg/dL) vs 14.7 mg/dL (IQR 6.72-30.82 mg/dL), p=0.002). Furthermore, multiple logistic regression analysis identified that Lp(a)>30 mg/dL was an independent risk factor of CAD in the postmenopausal females (OR: 1.33, 95% CI: 1.08 to 1.63, p=0.007). Finally, Lp(a) had a positive correlation with GS (r=0.11, p<0.001), and Lp(a)>30 mg/dL was an independent risk factor for high GS (OR: 1.43, 95% CI: 1.14 to 1.79, p=0.02) in the postmenopausal females.

CONCLUSION

Circulating Lp(a) levels were independently associated with the presence and severity of CAD in the postmenopausal females, suggesting that Lp(a) may be useful for prevention and risk-stratification of CAD in female individuals.

Impact of serum lipoprotein(a) on endothelium-dependent coronary vasomotor response assessed by intracoronary acetylcholine provocation

BACKGROUND

Lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic vascular disease. However, there are limited data regarding the impact of Lp(a) levels on the incidence and severity of endothelium-dependent coronary vasomotor response.

PATIENTS AND METHODS

A total of 2416 patients without significant coronary artery lesion (<50% stenosis) by coronary angiography and underwent acetylcholine (ACh) provocation test were enrolled and categorized according to their serum Lp(a) level into four quartile groups: less than 6.70, 6.70-13.30, 13.30-26.27, and more than 26.27 mg/dl. The aim of this study is to estimate the incidence and severity of endothelium-dependent positive ACh provocation test in each group; moreover, to access the incidence of major adverse cardiovascular events, the composite of total death, myocardial infarction, and de novo percutaneous coronary intervention were compared between the four groups up to 5 years.

RESULTS

The group with higher Lp(a) had a higher incidence of coronary heart disease, myocardial infarction, and peripheral arterial disease history. However, there was no difference among the four groups as regards the incidence of positive ACh provocation test, spasm severity, spasm extent, and location. However, at up to 5 years of clinical follow-up, the higher-Lp(a) group showed higher total death, de novo percutaneous coronary intervention, recurrent angina, and total major adverse cardiovascular events compared with the lower-Lp(a) groups.

CONCLUSION

In our study, there was no relationship between the elevated Lp(a) level and the vasospastic response to the intracoronary ACh provocation test; however, higher Lp(a) levels were associated with poor clinical outcomes up to 5 years.

Lipoprotein(a) reductions from PCSK9 inhibition and major adverse cardiovascular events: Pooled analysis of alirocumab phase 3 trials

BACKGROUND AND AIMS

Elevated lipoprotein(a) [Lp(a)] levels are considered a causal factor for cardiovascular disease. In phase 3 ODYSSEY trials, alirocumab reduced levels of low-density lipoprotein cholesterol (LDL-C) and Lp(a), with concomitant reductions in the risk of major adverse cardiovascular events (MACE). We assessed whether lower on-study and greater percentage reductions in Lp(a) are associated with a lower risk of MACE.

METHODS

Post-hoc analysis of data pooled from 10 phase 3 ODYSSEY trials comparing alirocumab with control (placebo or ezetimibe) in patients (n = 4983) with cardiovascular disease and/or risk factors, and hypercholesterolemia despite statin/other lipid-lowering therapies.

RESULTS

Median (Q1, Q3) baseline Lp(a) levels were 23.5 (8.0, 67.0) mg/dL. Median Lp(a) changes from baseline with alirocumab were -25.6% vs. -2.5% with placebo (absolute reductions 6.8 vs. 0.5 mg/dL) in placebo-controlled trials, and -21.4% vs. 0.0% with ezetimibe (4.5 vs. 0.0 mg/dL) in ezetimibe-controlled trials. During follow-up (6699 patient-years), 104 patients experienced MACE. A 12% relative risk reduction in MACE per 25% reduction in Lp(a) (p=0.0254) was no longer significant after adjustment for LDL-C changes: hazard ratio per 25% reduction: 0.89 (95% confidence interval, 0.79-1.01; p=0.0780). In subgroup analysis, the association between Lp(a) reduction and MACE remained significant in a fully adjusted model among participants with baseline Lp(a) ≥50 mg/dL (p-interaction vs. Lp(a) < 50 mg/dL: 0.0549).

CONCLUSIONS

In this population, Lp(a) reductions were not significantly associated with MACE independently of LDL-C reductions. Reducing the risk of MACE by targeting Lp(a) may require greater reductions in Lp(a) with more potent therapies and/or higher initial Lp(a) levels.

An in-depth analysis shows a hidden atherogenic lipoprotein profile in non-diabetic chronic kidney disease patients

Background: Chronic kidney disease (CKD) is an independent risk factor for atherosclerotic disease. We hypothesized that CKD promotes a proatherogenic lipid profile modifying lipoprotein composition and particle number. Methods: Cross-sectional study in 395 non-diabetic individuals (209 CKD patients and 186 controls) without statin therapy. Conventional lipid determinations were combined with advanced lipoprotein profiling by nuclear magnetic resonance, and their discrimination ability was assessed by machine learning. Results: CKD patients showed an increase of very-low-density (VLDL) particles and a reduction of LDL particle size. Cholesterol and triglyceride content of VLDLs and intermediate-density (IDL) particles increased. However, low-density (LDL) and high-density (HDL) lipoproteins gained triglycerides and lost cholesterol. Total-Cholesterol, HDL-Cholesterol, LDL-Cholesterol, non-HDL-Cholesterol and Proprotein convertase subtilisin-kexin type (PCSK9) were negatively associated with CKD stages, whereas triglycerides, lipoprotein(a), remnant cholesterol, and the PCSK9/LDL-Cholesterol ratio were positively associated. PCSK9 was positively associated with total-Cholesterol, LDL-Cholesterol, LDL-triglycerides, LDL particle number, IDL-Cholesterol, and remnant cholesterol. Machine learning analysis by random forest revealed that new parameters have a higher discrimination ability to classify patients into the CKD group, compared to traditional parameters alone: area under the ROC curve (95% CI), .789 (.711, .853) vs .687 (.611, .755). Conclusions: non-diabetic CKD patients have a hidden proatherogenic lipoprotein profile.

Low LPA gene kringle IV-2 repeat copy number association with elevated lipoprotein (a) concentration as an independent risk factor of coronary atherosclerotic heart disease in the Chinese Han population

Background

Lipoprotein (a) [Lp(a)], which is genetically determined by the LPA gene kringle IV type 2 (KIV-2) repeat copy number, has previously been reported in different populations. However, it is uncertain if the same occurs in the Chinese Han population. This study explored the correlation of Lp(a) mass or particle concentration with KIV-2 repeat copy number and application for coronary atherosclerotic heart disease (CAHD) risk assessment.

Methods

A cross-sectional study including 884 subjects was conducted. The Lp(a) level and routine risk factors of CAHD were compared. The KIV-2 copy number distribution, relationship with Lp(a), and assessment for CAHD risk were explored.

Results

The mean of Lp(a) mass or particle concentration in the CAHD group was higher than that in the non-CAHD group, while the KIV-2 copy number in the CAHD group was lower. Lp(a) had auxiliary values in gauging the type of plaque and was significantly higher in the soft-plaque group than that in the other two groups (200 mg/L [21.5 nmol/L], 166 mg/L [18.6 nmol/L], 149 mg/L [17.1 nmol/L], respectively, P < 0.05). Kappa test indicated divergence for the same individual using two Lp(a) concentrations (kappa value was 0.536 [< 0.75]). Elevated Lp(a) was an independent CAHD risk factor, whatever mass or particle concentration, and large KIV-2 copy number was a protective factor.

Conclusion

Lp(a) level and small KIV-2 copy number are risk factors for CAHD in the Chinese Han population; furthermore, elevated Lp(a) may gauge the type of coronary plaque.

Lipoprotein(a): the revenant

In the mid-1990s, the days of lipoprotein(a) [Lp(a)] were numbered and many people would not have placed a bet on this lipid particle making it to the next century. However, genetic studies brought Lp(a) back to the front-stage after a Mendelian randomization approach used for the first time provided strong support for a causal role of high Lp(a) concentrations in cardiovascular disease and later also for aortic valve stenosis. This encouraged the use of therapeutic interventions to lower Lp(a) as well numerous drug developments, although these approaches mainly targeted LDL cholesterol, while the Lp(a)-lowering effect was only a 'side-effect'. Several drug developments did show a potent Lp(a)-lowering effect but did not make it to endpoint studies, mainly for safety reasons. Currently, three therapeutic approaches are either already in place or look highly promising: (i) lipid apheresis (specific or unspecific for Lp(a)) markedly decreases Lp(a) concentrations as well as cardiovascular endpoints; (ii) PCSK9 inhibitors which, besides lowering LDL cholesterol also decrease Lp(a) by roughly 30%; and (iii) antisense therapy targeting apolipoprotein(a) which has shown to specifically lower Lp(a) concentrations by up to 90% in phase 1 and 2 trials without influencing other lipids. Until the results of phase 3 outcome studies are available for antisense therapy, we will have to exercise patience, but with optimism since never before have we had the tools we have now to prove Koch's extrapolated postulate that lowering high Lp(a) concentrations might be protective against cardiovascular disease.

Serum lipoprotein (a) predicts acute coronary syndromes in patients with severe carotid stenosis

BACKGROUND

Different cut-off values of serum lipoprotein (a) [Lp (a)] were recently identified to better stratify cardiovascular risk categories. Both pathophysiological and prognostic values of Lp (a) remain unclear.

MATERIALS AND METHODS

Here, the prognostic value of Lp (a) and its correlation with intraplaque features were assessed in patients with severe carotid artery stenosis undergoing endarterectomy (n = 180). The cut-off value of 10 mg/dL for serum Lp (a) was selected to predict 24-month follow-up acute coronary syndrome (ACS). In addition, the association between serum Lp (a) and intraplaque lipids, collagen, inflammatory and vascular cells was assessed. Serum Lp (a) levels were measured by nephelometric assay.

RESULTS

Patients with high Lp (a) had similar comorbidities, medications and laboratory parameters as compared to low Lp (a) levels. At 24-month follow-up, patients with high Lp (a) had more ACS as compared to low levels. Histological parameters within plaques were comparable in the study groups. No significant correlation between Lp (a) serum levels and intraplaque parameters was found, except for a weak positive association with smooth muscle cells in upstream plaque portions. When adjusted for gender, the presence of dyslipidaemia and chronic coronary artery disease, Lp (a) ≥10 mg/dL remained predictive for ACS.

CONCLUSIONS

Lp (a) determination could be a useful tool to predict ACS in patients with severe carotid stenosis.

Update on the laboratory investigation of dyslipidemias

The role of the clinical laboratory is evolving to provide more information to clinicians to assess cardiovascular disease (CVD) risk and target therapy more effectively. Current routine methods to measure LDL-cholesterol (LDL-C), the Friedewald calculation, ultracentrifugation, electrophoresis and homogeneous direct methods have established limitations. Studies suggest that LDL and HDL size or particle concentration are alternative methods to predict future CVD risk. At this time there is no consensus role for lipoprotein particle or subclasses in CVD risk assessment. LDL and HDL particle concentration are measured by several methods, namely gradient gel electrophoresis, ultracentrifugation-vertical auto profile, nuclear magnetic resonance and ion mobility. It has been suggested that HDL functional assays may be better predictors of CVD risk. To assess the issue of lipoprotein subclasses/particles and HDL function as potential CVD risk markers robust, simple, validated analytical methods are required. In patients with small dense LDL particles, even a perfect measure of LDL-C will not reflect LDL particle concentration. Non-HDL-C is an alternative measurement and includes VLDL and CM remnant cholesterol and LDL-C. However, apolipoprotein B measurement may more accurately reflect LDL particle numbers. Non-fasting lipid measurements have many practical advantages. Defining thresholds for treatment with new measurements of CVD risk remain a challenge. In families with genetic variants, ApoCIII and lipoprotein (a) may be additional risk factors. Recognition of familial causes of dyslipidemias and diagnosis in childhood will result in early treatment. This review discusses the limitations in current laboratory technologies to predict CVD risk and reviews the evidence for emergent approaches using newer biomarkers in clinical practice.

Asthma is associated with atherosclerotic artery changes

Asthma is a chronic airway inflammation with a potential systemic impact. Atherosclerosis is a chronic inflammatory artery disease. The aim of our study was to prove if there is a correlation between the occurrence of asthma and increased atherosclerotic vessel disorders. Vessel status was compared between mild-to-moderate, severe allergic asthma and matched controls. Measurements of artery stiffness were calculated by central pulse wave velocity, ultrasonographic strain imaging and ankle-brachial index. Atherosclerotic plaque burden was assessed by colour-coded duplex sonography. Additionally, analysis of cardiovascular and asthma blood markers was conducted. Arterial stiffness expressed as an increased central pulse wave velocity and decreased circumferential and radial strains as well as the prevalence of media sclerosis were significantly higher among asthma patients compared to controls. Atherosclerotic plaque burden was relevantly increased in asthma groups vs. controls (severe asthma: 43.1%, mild-to-moderate asthma: 25.0%, control: 14.3% of study participants). Except for the elevated IgE and fibrinogen concentrations as well as leukocyte number there were no relevant differences in the blood parameters between the groups. Allergic asthma is associated with distinct atherosclerotic artery changes compared to the respectively matched control collective. The severity of asthma correlates with more pronounced pathological vessel alternations.

Lipoprotein(a) and Risk of Myocardial Infarction and Death in Chronic Kidney Disease: Findings From the CRIC Study (Chronic Renal Insufficiency Cohort)

OBJECTIVE

To investigate the effect of LPA gene variants and renal function on lipoprotein(a) [Lp(a)] levels in people with chronic kidney disease and determine the association between elevated Lp(a) and myocardial infarction and death in this setting.

APPROACH AND RESULTS

The CRIC Study (Chronic Renal Insufficiency Cohort) is an ongoing prospective study of 3939 participants with chronic kidney disease. In 3635 CRIC participants with genotype data, carriers of the rs10455872 or rs6930542 variants had a higher median Lp(a) level (mg/dL) compared with noncarriers (73 versus 23; P<0.001 and 56 versus 22; P<0.001, respectively). The 3744 participants (55% male and 41% non-Hispanic White) with available baseline Lp(a) levels were stratified into quartiles of baseline Lp(a) (mg/dL): <9.8, 9.8 to 26.0, 26.1 to 61.3, and >61.3. There were 315 myocardial infarctions and 822 deaths during a median follow-up of 7.5 years. The second quartile had the lowest event rate. After adjusting for potential confounders and using a Cox proportional hazards model, the highest quartile of Lp(a) was associated with increased risk of myocardial infarction (hazard ratio, 1.49; 95% confidence interval, 1.05-2.11), death (hazard ratio, 1.28; 95% confidence interval, 1.05-1.57), and the composite outcome (hazard ratio, 1.29; 95% confidence interval, 1.07-1.56) compared with the second quartile of Lp(a).

CONCLUSIONS

Among adults with chronic kidney disease, elevated Lp(a) is independently associated with myocardial infarction and death. Future studies exploring pharmacological Lp(a) reduction in this population are warranted.

Relations between lipoprotein(a) concentrations, LPA genetic variants, and the risk of mortality in patients with established coronary heart disease: a molecular and genetic association study

BACKGROUND

Lipoprotein(a) concentrations in plasma are associated with cardiovascular risk in the general population. Whether lipoprotein(a) concentrations or LPA genetic variants predict long-term mortality in patients with established coronary heart disease remains less clear.

METHODS

We obtained data from 3313 patients with established coronary heart disease in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. We tested associations of tertiles of lipoprotein(a) concentration in plasma and two LPA single-nucleotide polymorphisms ([SNPs] rs10455872 and rs3798220) with all-cause mortality and cardiovascular mortality by Cox regression analysis and with severity of disease by generalised linear modelling, with and without adjustment for age, sex, diabetes diagnosis, systolic blood pressure, BMI, smoking status, estimated glomerular filtration rate, LDL-cholesterol concentration, and use of lipid-lowering therapy. Results for plasma lipoprotein(a) concentrations were validated in five independent studies involving 10 195 patients with established coronary heart disease. Results for genetic associations were replicated through large-scale collaborative analysis in the GENIUS-CHD consortium, comprising 106 353 patients with established coronary heart disease and 19 332 deaths in 22 studies or cohorts.

FINDINGS

The median follow-up was 9·9 years. Increased severity of coronary heart disease was associated with lipoprotein(a) concentrations in plasma in the highest tertile (adjusted hazard radio [HR] 1·44, 95% CI 1·14-1·83) and the presence of either LPA SNP (1·88, 1·40-2·53). No associations were found in LURIC with all-cause mortality (highest tertile of lipoprotein(a) concentration in plasma 0·95, 0·81-1·11 and either LPA SNP 1·10, 0·92-1·31) or cardiovascular mortality (0·99, 0·81-1·2 and 1·13, 0·90-1·40, respectively) or in the validation studies.

INTERPRETATION

In patients with prevalent coronary heart disease, lipoprotein(a) concentrations and genetic variants showed no associations with mortality. We conclude that these variables are not useful risk factors to measure to predict progression to death after coronary heart disease is established.

FUNDING

Seventh Framework Programme for Research and Technical Development (AtheroRemo and RiskyCAD), INTERREG IV Oberrhein Programme, Deutsche Nierenstiftung, Else-Kroener Fresenius Foundation, Deutsche Stiftung für Herzforschung, Deutsche Forschungsgemeinschaft, Saarland University, German Federal Ministry of Education and Research, Willy Robert Pitzer Foundation, and Waldburg-Zeil Clinics Isny.

L-Carnitine/Simvastatin Reduces Lipoprotein (a) Levels Compared with Simvastatin Monotherapy: A Randomized Double-Blind Placebo-Controlled Study

Lipoprotein (a) [Lp(a)] is an independent risk factor for cardiovascular disease. There are currently limited therapeutic options to lower Lp(a) levels. L-Carnitine has been reported to reduce Lp(a) levels. The aim of this study was to compare the effect of L-carnitine/simvastatin co-administration with that of simvastatin monotherapy on Lp(a) levels in subjects with mixed hyperlipidemia and elevated Lp(a) concentration. Subjects with levels of low-density lipoprotein cholesterol (LDL-C) >160 mg/dL, triacylglycerol (TAG) >150 mg/dL and Lp(a) >20 mg/dL were included in this study. Subjects were randomly allocated to receive L-carnitine 2 g/day plus simvastatin 20 mg/day (N = 29) or placebo plus simvastatin 20 mg/day (N = 29) for a total of 12 weeks. Lp(a) was significantly reduced in the L-carnitine/simvastatin group [-19.4%, from 52 (20-171) to 42 (15-102) mg/dL; p = 0.01], but not in the placebo/simvastatin group [-6.7%, from 56 (26-108) to 52 (27-93) mg/dL, p = NS versus baseline and p = 0.016 for the comparison between groups]. Similar significant reductions in total cholesterol, LDL-C, apolipoprotein (apo) B and TAG were observed in both groups. Co-administration of L-carnitine with simvastatin was associated with a significant, albeit modest, reduction in Lp(a) compared with simvastatin monotherapy in subjects with mixed hyperlipidemia and elevated baseline Lp(a) levels.

Very low LDL-C levels may safely provide additional clinical cardiovascular benefit: the evidence to date

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death in Europe and increased low-density lipoprotein cholesterol (LDL-C) is a major contributor to CVD risk. Extensive evidence from clinical studies of statins has demonstrated a linear relationship between LDL-C levels and CVD risk. It has been proposed that lower LDL-C levels than those currently recommended may provide additional clinical benefit to patients.

AIM

This review summarises the genetic and clinical evidence on the efficacy and safety of achieving very low LDL-C levels.

METHODS

Relevant epidemiological and clinical studies were identified using PubMed and by searching abstracts published at major congresses.

RESULTS

Genetic evidence demonstrates that individuals with naturally very low LDL-C levels are healthy and have a low risk of CVD. Clinical evidence has shown that those patients who achieve very low LDL-C levels through using lipid-lowering therapies (LLTs), such as statins, have reduced CVD risk compared with patients who only just achieve recommended target LDL-C levels. These data show that the incidence of adverse events in patients achieving very low LDL-C levels using LLT is comparable to those reaching the recommended LDL-C targets.

CONCLUSIONS

Genetic and clinical evidence supports the concept that reduction in LDL-C levels below current recommended targets may provide additional clinical benefit to patients without adversely impacting patient safety. Statin add-on therapies, such as ezetimibe and the recently approved proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors alirocumab and evolocumab, allow patients to achieve very low LDL-C levels and are likely to impact on future treatment paradigms.