Prognostic Usefulness of Serum Cholesterol Efflux Capacity in Patients With Coronary Artery Disease

Expanding the Molecular Disturbances of Lipoproteins in Cardiometabolic Diseases: Lessons from Lipidomics

The increasing global burden of cardiometabolic diseases highlights the urgent clinical need for better personalized prediction and intervention strategies. Early diagnosis and prevention could greatly reduce the enormous socio-economic burden posed by these states. Plasma lipids including total cholesterol, triglycerides, HDL-C, and LDL-C have been at the center stage of the prediction and prevention strategies for cardiovascular disease; however, the bulk of cardiovascular disease events cannot be explained sufficiently by these lipid parameters. The shift from traditional serum lipid measurements that are poorly descriptive of the total serum lipidomic profile to comprehensive lipid profiling is an urgent need, since a wealth of metabolic information is currently underutilized in the clinical setting. The tremendous advances in the field of lipidomics in the last two decades has facilitated the research efforts to unravel the lipid dysregulation in cardiometabolic diseases, enabling the understanding of the underlying pathophysiological mechanisms and identification of predictive biomarkers beyond traditional lipids. This review presents an overview of the application of lipidomics in the study of serum lipoproteins in cardiometabolic diseases. Integrating the emerging multiomics with lipidomics holds great potential in moving toward this goal.

Differential Effects of Genetically Determined Cholesterol Efflux Capacity on Coronary Artery Disease and Ischemic Stroke

Background

Observational studies indicated that cholesterol efflux capacity (CEC) of high-density lipoprotein (HDL) is inversely associated with cardiovascular events, independently of the HDL cholesterol concentration. The aim of the study is to examine the casual relevance of CEC for coronary artery disease (CAD) and myocardial infarction (MI), and compare it with that for ischemic stroke and its subtypes using a Mendelian randomization approach.

Methods

We performed a 2-sample Mendelian randomization to estimate the casual relationship of CEC with the risk of CAD, MI, and ischemic stroke. A CEC-related genetic variant (rs141622900) and other five genetic variants were used as the instrumental variables. Association of genetic variants with CAD were estimated in a GWAS involving 60,801 CAD cases and 123,504 controls. They were then compared with the associations of these variants with ischemic stroke and its subtypes (large vessel, small vessel, and cardioembolic) involving 40,585 ischemic stroke cases and 406,111 controls.

Results

Using the SNP of rs141622900 as the instrument, a 1-SD increase in CEC was associated with 45% lower risk for CAD (odds ratio [OR] 0.55, 95% confidence interval [CI] 0.44–0.69, p < 0.001) and 33% lower risk for MI (odds ratio [OR] 0.67, 95% CI 0.52–0.87, p = 0.002). By contrast, the causal effect of CEC was much weaker for ischemic stroke (odds ratio [OR] 0.79, 95% CI 0.64–0.97, p = 0.02; p for heterogeneity = 0.03) and, in particular, for cardioembolic stroke (p for heterogeneity = 0.006) when compared with that for CAD. Results using five genetic variants as the instrument also indicated consistently weaker effects on ischemic stroke than on CAD.

Conclusion

Genetic predicted higher CEC may be associated with decreased risk of CAD. However, the casual association of CEC with ischemic stroke and specific subtypes would need to be validated in further Mendelian randomization studies.

High-density lipoprotein cholesterol efflux capacity and incidence of coronary artery disease and cardiovascular mortality: a systematic review and meta-analysis

Background

The preventive effect of cholesterol efflux capacity (CEC) on the progression of atherosclerotic lesions has been confirmed in animal models, but findings in the population are inconsistent. Therefore, this meta-analysis aimed to systematically investigate the relationship of CEC with coronary artery disease (CAD) and cardiovascular mortality in a general population.

Methods

Four electronic databases (PubMed, Embase database, Cochrane Library, Web of Science) were searched from inception to February 1st, 2022 for relevant studies, without any language restriction. For continuous variables, the mean and standard deviation (SD), maximum adjusted odds ratios (ORs), relative risks (RRs), or hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted. The random-effects model was adopted to calculate the pooled results, and dose-response analyses were conducted. All pooled results were expressed by standardized mean difference (SMD) and ORs.

Results

Finally, 18 observational studies were included. Compared with the non-CAD group, the CAD group (SMD -0.48, 95% CI − 0.66 to − 0.30; I² 88.9%) had significantly lower CEC. In the high-CEC population, the risks of CAD (OR 0.52, 95% CI 0.37 to 0.71; I² 81%) significantly decreased, and a linear negative dose-response was detected. However, an association between CEC and the risk of cardiovascular mortality was not found (OR 0.44, 95% CI 0.18 to 1.06; I² 83.2%).

Conclusions

This meta-analysis suggests that decreased CEC is strongly associated with the risk of CAD, independent of HDL-C level. However, a decreased CEC seems not to be related to cardiovascular mortality. Meanwhile, CEC is linearly negatively correlated with the risk of CAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01657-3.

CSL112 (Apolipoprotein A-I [Human]) Strongly Enhances Plasma Apoa-I and Cholesterol Efflux Capacity in Post-Acute Myocardial Infarction Patients: A PK/PD Substudy of the AEGIS-I Trial

Introduction:

Cholesterol efflux capacity (CEC) is impaired following acute myocardial infarction (AMI). CSL112 is an intravenous preparation of human plasma-derived apoA-I formulated with phosphatidylcholine (PC). CSL112 is intended to improve CEC and thereby prevent early recurrent cardiovascular events following AMI. AEGIS-I (ApoA-I Event Reducing in Ischemic Syndromes I) was a multicenter, randomized, double-blind, placebo-controlled, dose-ranging phase 2b study, designed to evaluate the hepatic and renal safety of CSL112. Here, we report an analysis of a pharmacokinetic (PK) and pharmacodynamic (PD) substudy of AEGIS-I.

Methods:

AMI patients were stratified by renal function and randomized 3:3:2 to 4, weekly, 2-hour infusions of low- and high-dose (2 g and 6 g) CSL112, or placebo. PK/PD assessments included plasma concentrations of apoA-I and PC, and measures of total and ABCA1-dependent CEC, as well as lipids/lipoproteins including high density lipoprotein cholesterol (HDL-C), non-HDL-C, low density lipoprotein cholesterol (LDL-C), ApoB, and triglycerides. Inflammatory and cardio-metabolic biomarkers were also evaluated.

Results:

The substudy included 63 subjects from AEGIS-I. CSL112 infusions resulted in rapid, dose-dependent increases in baseline corrected apoA-I and PC, which peaked at the end of the infusion (Tmax ≈ 2 hours). Similarly, there was a dose-dependent elevation in both total CEC and ABCA1-mediated CEC. Mild renal impairment did not affect the PK or PD of CSL112. CSL112 administration was also associated with an increase in plasma levels of HDL-C but not non-HDL-C, LDL-C, apoB, or triglycerides. No dose-effects on inflammatory or cardio-metabolic biomarkers were observed.

Conclusion:

Among patients with AMI, impaired CEC was rapidly elevated by CSL112 infusions in a dose-dependent fashion, along with an increase in apoA-I plasma concentrations. Findings from the current sub-study of the AEGIS-I support a potential atheroprotective benefit of CSL112 for AMI patients.

Cholesterol Efflux Capacity and Its Association With Adverse Cardiovascular Events: A Systematic Review and Meta-Analysis

Background: Serum high-density lipoprotein cholesterol (HDL-C) levels are inversely associated with cardiovascular disease events. Yet, emerging evidence suggests that it is the functional properties of HDL, in particular, reverse cholesterol transport, which is a key protective mechanism mediating cholesterol removal from macrophage cells and reducing plaque lipid content. Cholesterol efflux capacity (CEC) measures the capacity of HDL to perform this function. A systematic review and meta-analysis were conducted to explore the association of CEC and adverse cardiovascular events.

Methods: A comprehensive literature review of Embase, PubMed, and Web of Science Core Collection from inception to September 2019 was performed for all studies that examined the association between CEC and cardiovascular outcomes. The primary outcome was adverse cardiovascular events, which were inclusive of atherosclerotic cardiovascular disease (ASCVD) or mortality.

Results: A total of 20 trials were included. Compared with low CEC levels, high CEC levels were associated with a 37% lower risk of adverse cardiovascular events (crude RR = 0.63; 95% CI, 0.52–0.76; P < 0.00001). Every SD increase of CEC was associated with a 20% lower risk of adverse cardiovascular events (HR = 0.80; 95% CI, 0.66–0.97; P = 0.02). The association remained significant after adjusting for cardiovascular risk factors, medications, and HDL-C levels (HR = 0.76; 95% CI, 0.63–0.91; P = 0.004). A significant CEC-endpoint relationship was observed (P = 0.024) such that for every 0.1 unit increase in CEC, there was a 5% reduced risk for adverse cardiovascular events (RR = 0.95; 95% CI, 0.91–0.99).

Conclusions: Higher CEC is associated with lower adverse cardiovascular outcomes. These findings warrant further research on whether CEC is merely a biomarker or a mechanism that could be targeted as a pharmacologic intervention for improving clinical outcomes.

PROSPERO Registration Number: CRD42020146681; https://www.crd.york.ac.uk/prospero/.

HDL and reverse cholesterol transport in humans and animals: Lessons from pre-clinical models and clinical studies

The ability to accept cholesterol from cells and to promote reverse cholesterol transport (RCT) represents the best characterized antiatherogenic function of HDL. Studies carried out in animal models have unraveled the multiple mechanisms by which these lipoproteins drive cholesterol efflux from macrophages and cholesterol uptake to the liver. Moreover, the influence of HDL composition and the role of lipid transporters have been clarified by using suitable transgenic models or through experimental design employing pharmacological or nutritional interventions. Cholesterol efflux capacity (CEC), an in vitro assay developed to offer a measure of the first step of RCT, has been shown to associate with cardiovascular risk in several human cohorts, supporting the atheroprotective role of RCT in humans as well. However, negative data in other cohorts have raised concerns on the validity of this biomarker. In this review we will present the most relevant data documenting the role of HDL in RCT, as assessed in classical or innovative methodological approaches.

Lysis reagents, cell numbers, and calculation method influence high-throughput measurement of HDL-mediated cholesterol efflux capacity

HDL-mediated cholesterol efflux capacity (CEC) may protect against cardiovascular disease. However, CEC assays are not standardized, hampering their application in large cohorts and comparison between studies. To improve standardization, we systematically investigated technical differences between existing protocols that influence assay performance that have not been previously addressed. CEC was measured in 96-well plates using J774A.1 macrophages labeled with BODIPY-cholesterol and incubated for 4 h with 2% apolipoprotein B-depleted human serum. The time zero method, which calculates CEC using control wells, and the per-well method, which calculates CEC based on the actual content of BODIPY-cholesterol in each well, were compared in 506 samples. We showed that the per-well method had a considerably lower sample rejection rate (4.74% vs. 13.44%) and intra-assay (4.48% vs. 5.28%) and interassay coefficients of variation (two controls: 7.85%, 9.86% vs. 13.58%, 15.29%) compared with the time zero method. Correction for plate-to-plate differences using four controls on each plate also improved assay performance of both methods. In addition, we observed that the lysis reagent used had a significant effect. Compared with cholic acid, lysis with sodium hydroxide results in higher (P = 0.0082) and Triton X-100 in lower (P = 0.0028) CEC values. Furthermore, large cell seeding errors (30% variation) greatly biased CEC for both referencing methods (P < 0.0001) as measured by a resazurin assay. In conclusion, lysis reagents, cell numbers, and assay setup greatly impact the quality and reliability of CEC quantification and should be considered when this method is newly established in a laboratory.

High-sensitivity CRP may be a marker of HDL dysfunction and remodeling in patients with acute coronary syndrome

In patients with coronary artery disease (CAD), further increasing the level of high-density lipoprotein (HDL) cholesterol (HDL-C) as an add-on to statins cannot reduce cardiovascular risk. And it has been reported that HDL functional metric—cholesterol efflux capacity (CEC) may be a better predictor of CAD risk than HDL-C. CEC measurement is time-consuming and not applicable in clinical settings. Thus, it is meaningful to explore an easily acquired index for evaluating CEC. Thirty-six CAD patients and sixty-one non-CAD controls were enrolled in this cross-sectional study. All CAD patients had acute coronary syndrome (ACS). CEC was measured using a [³H] cholesterol loading Raw 264.7 cell model with apolipoprotein B-depleted plasma (a surrogate for HDL). Proton nuclear magnetic resonance (NMR) spectroscopy was used to assess HDL components and subclass distribution. CEC was significantly impaired in CAD patients (11.9 ± 2.3%) compared to controls (13.0 ± 2.2%, p = 0.022). In control group, CEC was positively correlated with enzymatically measured HDL-C levels (r = 0.358, p = 0.006) or with NMR-determined HDL-C levels (NMR-HDL-C, r = 0.416, p = 0.001). However, in CAD group, there was no significant correlation between CEC and HDL-C (r = 0.216, p = 0.206) or NMR-HDL-C (r = 0.065, p = 0.708). Instead, we found that the level of high-sensitivity C-reactive protein (hsCRP) was inversely associated with CEC (r = − 0.351, p = 0.036). Multiple regression analysis showed that the hsCRP level was associated with CEC after adjusting other cardiovascular risk factors and HDL-C, although the association would not reach significance if adjusting for multiple testing. NMR spectroscopy showed that HDL particles shifted to larger ones in patients with high hsCRP levels, and this phenomenon was accompanied by decreased CEC. In patients with CAD, the level of HDL-C cannot reflect HDL function. The impaired correlation between HDL-C and CEC is possibly due to an inflammation-induced HDL subclass remodeling. These hypothesis-generating data suggest that hsCRP levels, a marker of acute inflammation, may associate with HDL dysfunction in ACS subjects. Due to the design limited to be correlative in nature, not permitting causal inference and a larger, strictly designed study is still needed.

[Plasma high density lipoproteins phospholipds as an indirect indicator of their cholesterol efflux capacity - new suspected atherosclerosis risk factor]

High density lipoproteins (HDL) are a unique natural structure, protecting the body from the development of atherosclerotic vascular lesions and cardiovascular diseases due to this ability to remove cholesterol from cells. Plasma HDL level estimated by their cholesterol content, is a common lipid parameter, and its decrease is considered as an established atherosclerosis risk factor. However, a number of studies have shown the absence of positive clinical effects after drug-induced increase in HDL cholesterol. There is increasing evidence that not only HDL concentration, but also HDL properties, considered in this review are important. Many studies showed the decrease of HDL cholesterol efflux capacity in patients with coronary heart diseases and its association with disease severity. Some authors consider a decrease of this HDL capacity as a new additional risk factor of atherosclerosis. The review summarizes existing information on various protein and lipid components of HDL with a primary emphasis on the HDL. Special attention is paid to correlation between the HDL cholesterol efflux capacity and HDL phospholipids and the ratio "phospholipids/free cholesterol". The accumulated information indicates importance of evaluation in the HDL fraction not only in terms of their cholesterol, but also phospholipids. In addition to the traditionally used lipid criteria, this would provide more comprehensive information about the activity of the reverse cholesterol transport process in the body and could contribute to the targeted correction of the detected disorders.

Rationale and design of ApoA-I Event Reducing in Ischemic Syndromes II (AEGIS-II): A phase 3, multicenter, double-blind, randomized, placebo-controlled, parallel-group study to investigate the efficacy and safety of CSL112 in subjects after acute myocardial infarction

Acute myocardial infarction (MI) patients remain at high risk for recurrent events. Cholesterol efflux, mediated by apolipoprotein A-I, removes excess cholesterol from atherosclerotic plaque and transports it to the liver for excretion. Impaired cholesterol efflux is associated with higher cardiovascular (CV) event rates among both patients with stable coronary artery disease and recent MI. CSL112, a novel intravenous formulation of apolipoprotein A-I (human) derived from human plasma, increases cholesterol efflux capacity. AEGIS-II is a phase 3, multicenter, double-blind, randomized, placebo-controlled, parallel-group trial investigating the efficacy and safety of CSL112 compared to placebo among high-risk acute MI participants. Eligibility criteria include age ≥ 18 years with type 1 (spontaneous) MI, evidence of multivessel stable coronary artery disease, and presence of diabetes requiring pharmacotherapy, or ≥2 of the following: age ≥ 65 years, prior MI, or peripheral artery disease. A target sample of 17,400 participants will be randomized 1:1 to receive 4 weekly infusions of CSL112 6 g or placebo, initiated prior to or on the day of discharge and within 5 days of first medical contact. The primary outcome is the time to first occurrence of the composite of CV death, MI, or stroke through 90 days. Key secondary outcomes include the total number of hospitalizations for coronary, cerebral, or peripheral ischemia through 90 days and time to first occurrence of the composite primary outcome through 180 and 365 days. AEGIS-II will be the first trial to formally test whether enhancing cholesterol efflux can reduce the rate of recurrent major adverse CV events.

HDL cholesterol efflux capacity is inversely associated with subclinical cardiovascular risk markers in young adults: The cardiovascular risk in Young Finns study

The atherogenic process begins already in childhood and progresses to symptomatic condition with age. We investigated the association of cholesterol efflux capacity (CEC) and vascular markers of subclinical atherosclerosis in healthy, young adults. CEC was determined in 2282 participants of the Young Finns study using cAMP treated ³H-cholesterol-labeled J774 cells. The CEC was correlated to baseline and 6-year follow-up data of cardiovascular risk factors and ultrasound measurements of arterial structure and function. CEC was higher in women, correlated with total cholesterol, HDL-C, and apolipoprotein A-I, but not with LDL-C or apolipoprotein B. Compared to the lowest CEC quartile, the highest CEC quartile was significantly associated with high CRP levels and inversely associated with adiponectin. At baseline, high CEC was associated with decreased flow-mediated dilation (FMD) and carotid artery distensibility, as well as an increased Young's modulus of elasticity, indicating adverse changes in arterial structure, and function. The association reversed with follow-up FMD data, indicating the interaction of preclinical parameters over time. A higher CEC was directly associated with a lower risk of subclinical atherosclerosis at follow-up. In young and healthy subjects, CEC was associated with important lipid risk parameters at baseline, as in older patients and CAD patients, but inversely with early risk markers for subclinical atherosclerosis.

High density lipoprotein functionality and cardiovascular events and mortality: A systematic review and meta-analysis

BACKGROUND AND AIMS

The aim of this systematic review and meta-analysis is to synthesize studies assessing the associations between high-density lipoprotein functionality and risk of cardiovascular disease and mortality.

METHODS

We searched Medline and Embase for the identification of observational studies meeting the inclusion criteria. This meta-analysis was conducted following the PRISMA statement and was registered in PROSPERO (CRD42017065857). We pooled risk estimates with a random-effect model separately for cardiovascular disease (fatal and non-fatal) and all-cause mortality.

RESULTS

Out of 29 manuscripts, 20 articles investigated cholesterol efflux capacity (13 prospective and 7 cross-sectional), 10 antioxidant capacity (7 prospective and 3 cross-sectional) and two anti-inflammatory capacity of high-density lipoprotein (1 prospective and 1 cross-sectional). A greater cholesterol efflux capacity was associated with lower risk of cardiovascular disease in 8 studies (RR for 1SD increase: 0.86; 95% CI: 0.76-0.98) and of mortality in 5 studies (RR for 1SD increase: 0,77; 0.60-1.00). Better antioxidant capacity was non-significantly associated with lower cardiovascular disease risk in 2 studies (RR for 1SD increase 0.70; 0.32-1.53) and significantly with mortality in 3 studies (RR for 1SD increase 0.48; 0.28-0.81). High-density lipoprotein anti-inflammatory ability was associated with a lower cardiovascular disease risk in the only prospective study.

CONCLUSIONS

Greater high-density lipoprotein cholesterol efflux capacity and antioxidant/anti-inflammatory capacities were associated with lower risk of cardiovascular disease. However, the heterogeneity between studies and evidence of publication bias warrants caution and highlights the need for larger prospective studies with standardized assays and specific outcomes.

Cholesterol efflux capacity in coronary artery disease: a meta-analysis

OBJECTIVE

To quantitatively analyze the association between cholesterol efflux capacity (CEC) and the risk and prognosis of coronary artery disease (CAD).

METHODS

A systematic search of electronic databases for studies published until September 2019 was performed. Cohorts, case-control studies, and randomized controlled trials that examined the effect of CEC on the risk and prognosis of CAD were included.

RESULTS

Eighteen studies with 12 685 subjects met our inclusion criteria. Among them, 14 studies reported the CEC in non-CAD and CAD groups, and eight studies reported the association between CEC and risk of CAD. Four studies reported the prognosis of stable CAD or acute coronary syndrome (ACS). In the pooled analyses, significantly decreased CEC was found in patients with stable CAD as compared with those without CAD. Decreased CEC was also present in subgroup in patients with ACS. High CEC was significantly associated with decreased risk of CAD [odds ratio (OR) = 0.65, 95% confidence interval (CI): 0.55-0.75, P < 0.001]. High CEC predicted lower all-cause mortality (OR = 0.39, 95% CI: 0.20-0.77, P = 0.007) and cardiovascular mortality (OR = 0.34, 95% CI: 0.13-0.90, P = 0.03) in patients with CAD. However, CEC failed to predict the occurrence of stroke and myocardial infraction in patients with CAD.

CONCLUSIONS

Decreased CEC is an independent risk factor for CAD, and it predicts all-cause and cardiovascular mortality in patients with CAD.

Dysfunctional High-Density Lipoproteins Are Associated With a Greater Incidence of Acute Coronary Syndrome in a Population at High Cardiovascular Risk: A Nested Case-Control Study

BACKGROUND

Studies have failed to establish a clear link between high-density lipoprotein (HDL) cholesterol and cardiovascular disease, leading to the hypothesis that the atheroprotective role of HDL lies in its biological activity rather than in its cholesterol content. However, to date, the association between HDL functional characteristics and acute coronary syndrome has not been investigated comprehensively.

METHODS

We conducted a case-control study nested within the PREDIMED (Prevención con Dieta Mediterránea) cohort, originally a randomized trial in which participants followed a Mediterranean or low-fat diet. Incident acute coronary syndrome cases (N=167) were individually matched (1:2) to control patients by sex, age, intervention group, body mass index, and follow-up time. We investigated 2 individual manifestations (myocardial infarction, unstable angina) as secondary outcomes. We measured the following functional characteristics: HDL cholesterol concentration (in plasma); cholesterol efflux capacity; antioxidant ability, measured by the HDL oxidative-inflammatory index; phospholipase A2 activity; and sphingosine-1-phosphate, apolipoproteins A-I and A-IV, serum amyloid A, and complement 3 protein (in apolipoprotein B-depleted plasma). We used conditional logistic regression models adjusted for HDL cholesterol levels and cardiovascular risk factors to estimate odds ratios (ORs) between 1-SD increments in HDL functional characteristics and clinical outcomes.

RESULTS

Low values of cholesterol efflux capacity (OR_1SD, 0.58; 95% CI, 0.40-0.83) and low levels of sphingosine-1-phosphate (OR_1SD, 0.70; 95% CI, 0.52-0.92) and apolipoprotein A-I (OR_1SD, 0.58; 95% CI, 0.42-0.79) were associated with higher odds of acute coronary syndrome. Higher HDL oxidative inflammatory index values were marginally linked to acute coronary syndrome risk (OR_1SD, 1.27; 95% CI, 0.99-1.63). Low values of cholesterol efflux capacity (OR_1SD, 0.33; 95% CI, 0.18-0.61), sphingosine-1-phosphate (OR_1SD: 0.60; 95% CI: 0.40-0.89), and apolipoprotein A-I (OR_1SD, 0.59; 95% CI, 0.37-0.93) were particularly linked to myocardial infarction, whereas high HDL oxidative-inflammatory index values (OR_1SD, 1.53; 95% CI, 1.01-2.33) and low apolipoprotein A-I levels (OR_1SD, 0.52; 95% CI, 0.31-0.88) were associated with unstable angina.

CONCLUSIONS

Low cholesterol efflux capacity values, pro-oxidant/proinflammatory HDL particles, and low HDL levels of sphingosine-1-phosphate and apolipoprotein A-I were associated with increased odds of acute coronary syndrome and its manifestations in individuals at high cardiovascular risk.

CLINICAL TRIAL REGISTRATION

URL: https://www.controlled-trials.com/ISRCTN35739639. Unique identifier: ISRCTN35739639.

High-Density Lipoprotein Function and Dysfunction in Health and Disease

High-density lipoprotein cholesterol (HDL-c) has long been referred to as 'good cholesterol' due to its apparent inverse relationship with future CVD risk. More recent research has questioned a causal role for HDL-c in this relationship, however, as both genetic studies and numerous large-scale randomised controlled trials have found no evidence of a cardiovascular protective effect when HDL-c levels are raised. Instead, focus has switched to the functional properties of the HDL particle. Evidence suggests that both the composition and function of HDL may be significantly altered in the context of an inflammatory milieu, transforming the particle from a vasoprotective anti-atherogenic particle to a noxious pro-atherogenic equivalent. This review will summarise evidence relating HDL to CVD risk, explore recent evidence characterising changes in the composition and function of HDL that may occur in chronic inflammatory diseases, and discuss the potential for future HDL-modifying therapeutic interventions.

Moderate Renal Impairment Does Not Impact the Ability of CSL112 (Apolipoprotein A-I [Human]) to Enhance Cholesterol Efflux Capacity

CSL112 (apolipoprotein A‐I [human]) is a novel intravenous formulation of plasma‐derived apolipoprotein A‐I (apoA‐I) that enhances cholesterol efflux capacity. Renal impairment is a common comorbidity in acute myocardial infarction patients and is associated with impaired lipid metabolism. The aim of this phase 1 study was to assess the impact of moderate renal impairment on the pharmacokinetic and pharmacodynamic profile of CSL112. Sixteen subjects with moderate renal impairment and 16 age‐, sex‐, and weight‐matched subjects with normal renal function participated in the study. Within each renal function cohort, subjects were randomized 3:1 to receive a single intravenous infusion of CSL112 2 g (n = 6) or placebo (n = 2) or CSL112 6 g (n = 6) or placebo (n = 2). At baseline, subjects with moderate renal impairment versus normal renal function had higher total cholesterol efflux, ABCA1‐dependent cholesterol efflux capacity, and pre‐β1‐high‐density lipoprotein (HDL) levels. Infusing CSL112 resulted in similar, immediate, robust, dose‐dependent elevations in apoA‐I and cholesterol efflux capacity in both renal function cohorts and significantly greater elevations in pre‐β1‐HDL (P < .05) in moderate renal impairment. Lecithin‐cholesterol acyltransferase activity, demonstrated by a time‐dependent change in the ratio of unesterified to esterified cholesterol, did not differ by renal function. No meaningful changes in proatherogenic lipid levels were observed. Moderate renal impairment did not impact the ability of CSL112 to enhance cholesterol efflux capacity. CSL112 may represent a novel therapy to reduce the risk of early recurrent cardiovascular events following acute myocardial infarction in patients with or without moderate renal impairment.

Myeloperoxidase mediated HDL oxidation and HDL proteome changes do not contribute to dysfunctional HDL in Chinese subjects with coronary artery disease

High density lipoprotein (HDL) cholesterol levels and cholesterol efflux capacity (CEC) are inversely correlated with coronary artery disease (CAD) risk. Myeloperoxidase (MPO) derived oxidants and HDL proteome changes are implicated in HDL dysfunction in subjects with CAD in the United States; however, the effect of MPO on HDL function and HDL proteome in ethnic Chinese population is unknown. We recruited four matched ethnic Chinese groups (20 patients each): subjects with 1) low HDL levels (HDL levels in men <40mg/dL and women <50mg/dL) and non-CAD (identified by coronary angiography or cardiac CT angiography); 2) low HDL and CAD; 3) high HDL (men >50mg/dL; women >60mg/dL) with no CAD; and 4) high HDL with CAD. Serum cytokines, serum MPO levels, serum CEC, MPO-oxidized HDL tyrosine moieties, and HDL proteome were assessed by mass spectrometry individually in the four groups.

The cytokines, MPO levels, and HDL proteome profiles were not significantly different between the four groups. As expected, CEC was depressed in the entire CAD group but more specifically in the CAD low-HDL group. HDL of CAD subjects had significantly higher 3-nitrotyrosine than non-CAD subjects, but the MPO-specific 3-chlorotyrosine was unchanged; CEC in the CAD low-HDL group did not correlate with either HDL 3-chlorotyrosine or 3-nitrotyrosine levels. Neither 3-chlorotyrosine, which is MPO-specific, nor 3-nitrotyrosine generated from MPO or other reactive nitrogen species was associated with CEC. MPO mediated oxidative stress and HDL proteome composition changes are not the primary cause HDL dysfunction in Chinese subjects with CAD. These studies highlight ethnic differences in HDL dysfunction between United States and Chinese cohorts raising possibility of unique pathways of HDL dysfunction in this cohort.

CSL112 (Apolipoprotein A-I [Human]) Enhances Cholesterol Efflux Similarly in Healthy Individuals and Stable Atherosclerotic Disease Patients

Supplemental Digital Content is available in the text.

Objective—

CSL112 (apolipoprotein A-I [apoA-I; human]) is a novel formulation of apoA-I in development for reduction of early recurrent cardiovascular events after acute myocardial infarction. Cholesterol efflux capacity (CEC) is a marker of high-density lipoprotein (HDL) function that is strongly correlated with incident cardiovascular disease. Impaired CEC has been observed in patients with coronary heart disease. Here, we determined whether infused apoA-I improves CEC when administered to patients with stable atherosclerotic disease versus healthy volunteers.

Approach and Results—

Measurements of apoA-I, HDL unesterified cholesterol, HDL esterified cholesterol, pre–β1-HDL, and CEC were determined in samples from patients with stable atherosclerotic disease before and after intravenous administration of CSL112. These measures were compared with 2 prior studies in healthy volunteers for differences in CEC at baseline and after CSL112 infusion. Patients with stable atherosclerotic disease exhibited significantly lower ATP-binding cassette transporter 1–mediated CEC at baseline (P<0.0001) despite slightly higher apoA-I levels when compared with healthy individuals (2 phase 1 studies pooled; P≤0.05), suggesting impaired HDL function. However, no differences were observed in apoA-I pharmacokinetics or in pre–β1-HDL (P=0.5) or CEC (P=0.1) after infusion of CSL112. Similar elevation in CEC was observed in patients with low or high baseline HDL function (based on tertiles of apoA-I–normalized CEC; P=0.1242). These observations were extended and confirmed using cholesterol esterification as an additional measure.

Conclusions—

CSL112 shows comparable, strong, and immediate effects on CEC despite underlying cardiovascular disease. CSL112 is, therefore, a promising novel therapy for lowering the burden of atherosclerosis and reducing the risk of recurrent cardiovascular events.

High-density lipoprotein cholesterol efflux capacity is inversely associated with cardiovascular risk: a systematic review and meta-analysis

Background

A low plasma level of high-density lipoprotein (HDL) cholesterol (HDL-C) is associated with cardiovascular risk. A key cardioprotective property of HDL is cholesterol efflux capacity (CEC), the ability of HDL to accept cholesterol from macrophages. In this study, we aimed to identify the predictive value of CEC for cardiovascular risk.

Methods

The relative risks (RRs) and 95% confidence intervals (CIs) were pooled to analyze the association between CEC and the incidence of cardiovascular events and all-cause mortality. The odds ratios (ORs) and 95% CIs were pooled to estimate the association of CEC and the prevalence of cardiovascular events.

Results

A total of 15 studies were included. Results showed that the highest CEC was significantly associated with a reduced risk of cardiovascular events incidents compared to the lowest CEC (RR, 0.56; 95% CI, 0.37 to 0.85; I², 89%); the pooled RR of cardiovascular risk for per unit SD increase was 0.87 (95% CI, 0.73 to 1.04; I², 67%). Dose-response curve indicated that cardiovascular risk decreased by 39% (RR, 0.61; 95% CI, 0.51 to 0.74) for per unit CEC increase. Similarly, an inverse association was observed between CEC and the prevalence of cardiovascular events (highest vs. lowest, OR, 0.30; 95% CI, 0.17 to 0.5; I² = 63%; per unit SD increase, OR, 0.94; 95% CI, 0.90 to 0.98; I² = 71%). However, based on the current data, CEC was not significantly associated with all-cause mortality.

Conclusions

Findings from this meta-analysis suggest that HDL-mediated CEC is inversely associated with cardiovascular risk, which appears to be independent of HDL concentration. The growing understanding of CEC and its role in cardiovascular risk decrease may improve the accuracy of cardiovascular risk prediction and also open important avenues to develop novel therapeutic targeting HDL metabolism.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12944-017-0604-5) contains supplementary material, which is available to authorized users.

HDL cholesterol efflux normalised to apoA-I is associated with future development of type 2 diabetes: from the CORDIOPREV trial

This prospective study evaluated whether baseline cholesterol efflux is associated with future development of type 2 diabetes (T2DM) in cardiovascular patients. We measured cholesterol efflux in all CORDIOPREV study (NCT00924937) participants free of T2DM at baseline (n = 462) and assessed its relationship with T2DM incidence during a 4.5 years of follow-up. Cholesterol efflux was quantified by incubation of cholesterol-loaded THP-1 cells with the participants' apoB-depleted plasma. Disposition index was estimated as beta-cell function indicator. During follow-up 106 individuals progressed to T2DM. The cholesterol efflux/apoA-1 ratio was inversely associated with T2DM development independently of traditional risk factors (model-1, OR: 0.647, 95%CI: 0.495-0.846), and after additional adjustment for glycaemic parameters (model-2, OR: 0.670, 95%CI: 0.511-0.878). When cumulative incidence of diabetes was analysed by quartiles of cholesterol efflux/apoA-I, incidence of T2DM was reduced by 54% in subjects who were in the higher cholesterol efflux/apoA-I quartile compared to subjects in the lowest quartile (p = 0.018 and p = 0.042 for model-1 and 2). Moreover, participants who were in the higher cholesterol efflux/apoA-I presented significantly higher disposition index (β = 0.056, SE = 0.026; p = 0.035). In conclusion, HDL-cholesterol efflux normalised to apoA-I was inversely associated with T2DM development in cardiovascular patients. This association was independent of several T2DM risk factors, and may be related to a preserved beta-cell function.

Analysis of Serum Cholesterol Efflux Capacity in a Minipig Model of Nonischemic Heart Failure

Aim: Circulating levels of high-density lipoprotein cholesterol (HDL-C) are decreased in patients with heart failure (HF). We tested whether HDL-C serum levels are associated with cardiac contractile dysfunction in a minipig HF model.

Methods: Blood samples were collected from 13 adult male minipigs: 1) before pacemaker implantation, 2) 10 days after surgery, and 3) 3 weeks after high-rate LV pacing. Serum cholesterol efflux capacity (CEC), an index of HDL functionality, was assessed through four mechanisms: ATP Binding Cassette transporter A1 (ABCA1), ATP Binding Cassette transporter G1 (ABCG1), Scavenger Receptor-Class B Type I (SR-BI) and Passive Diffusion (PD).

Results: HDL-C serum levels significantly decrease in minipigs with HF compared with baseline (p < 0.0001). Serum CEC mediated by PD and SR-BI, but not ABCA1 or ABCG1, significantly decrease in animals with HF (p < 0.05 and p < 0.005, respectively).

Discussion: HDL-C serum levels and partial serum CEC reduction may play a pathophysiological role in the cardiac function decay sustained by high-rate LV pacing, opening new avenues to understand of the pathogenesis of nonischemic myocardial remodeling.