Comparative Analysis of Atherogenic Lipoproteins L5 and Lp(a) in Atherosclerotic Cardiovascular Disease.

PURPOSE OF REVIEW: Low-density lipoprotein (LDL) poses a risk for atherosclerotic cardiovascular disease (ASCVD). As LDL comprises various subtypes differing in charge, density, and size, understanding their specific impact on ASCVD is crucial. Two highly atherogenic LDL subtypes-electronegative LDL (L5) and Lp(a)-induce vascular cell apoptosis and atherosclerotic changes independent of plasma cholesterol levels, and their mechanisms warrant further investigation. Here, we have compared the roles of L5 and Lp(a) in the development of ASCVD. RECENT FINDINGS: Lp(a) tends to accumulate in artery walls, promoting plaque formation and potentially triggering atherosclerosis progression through prothrombotic or antifibrinolytic effects. High Lp(a) levels correlate with calcific aortic stenosis and atherothrombosis risk. L5 can induce endothelial cell apoptosis and increase vascular permeability, inflammation, and atherogenesis, playing a key role in initiating atherosclerosis. Elevated L5 levels in certain high-risk populations may serve as a distinctive predictor of ASCVD. L5 and Lp(a) are both atherogenic lipoproteins contributing to ASCVD through distinct mechanisms. Lp(a) has garnered attention, but equal consideration should be given to L5.

Serum opacity factor normalizes erythrocyte morphology in Scarb1-/- mice in an HDL-free cholesterol-dependent way.

Compared with WT mice, HDL receptor-deficient (Scarb1-/-) mice have higher plasma levels of free cholesterol (FC)-rich HDL and exhibit multiple pathologies associated with a high mol% FC in ovaries, platelets, and erythrocytes, which are reversed by lowering HDL. Bacterial serum opacity factor (SOF) catalyzes the opacification of plasma by targeting and quantitatively converting HDL to neo HDL (HDL remnant), a cholesterol ester-rich microemulsion, and lipid-free APOA1. SOF delivery with an adeno-associated virus (AAVSOF) constitutively lowers plasma HDL-FC and reverses female infertility in Scarb1-/- mice in an HDL-dependent way. We tested whether AAVSOF delivery to Scarb1-/- mice will normalize erythrocyte morphology in an HDL-FC-dependent way. We determined erythrocyte morphology and FC content (mol%) in three groups-WT, untreated Scarb1-/- (control), and Scarb1-/- mice receiving AAVSOF-and correlated these with their respective HDL-mol% FC. Plasma-, HDL-, and tissue-lipid compositions were also determined. Plasma- and HDL-mol% FC positively correlated across all groups. Among Scarb1-/- mice, AAVSOF treatment normalized reticulocyte number, erythrocyte morphology, and erythrocyte-mol% FC. Erythrocyte-mol% FC positively correlated with HDL-mol% FC and with both the number of reticulocytes and abnormal erythrocytes. AAVSOF treatment also reduced FC of extravascular tissues to a lesser extent. HDL-FC spontaneously transfers from plasma HDL to cell membranes. AAVSOF treatment lowers erythrocyte-FC and normalizes erythrocyte morphology and lipid composition by reducing HDL-mol% FC.

The pathophysiology of excess plasma-free cholesterol.

PURPOSE OF REVIEW: Several large studies have shown increased mortality due to all-causes and to atherosclerotic cardiovascular disease. In most clinical settings, plasma HDL-cholesterol is determined as a sum of free cholesterol and cholesteryl ester, two molecules with vastly different metabolic itineraries. We examine the evidence supporting the concept that the pathological effects of elevations of plasma HDL-cholesterol are due to high levels of the free cholesterol component of HDL-C. RECENT FINDINGS: In a small population of humans, a high plasma HDL-cholesterol is associated with increased mortality. Similar observations in the HDL-receptor deficient mouse (Scarb1 -/- ), a preclinical model of elevated HDL-C, suggests that the pathological component of HDL in these patients is an elevated plasma HDL-FC. SUMMARY: Collective consideration of the human and mouse data suggests that clinical trials, especially in the setting of high plasma HDL, should measure free cholesterol and cholesteryl esters and not just total cholesterol.

Bempedoic acid lowers high-sensitivity C-reactive protein and low-density lipoprotein cholesterol: Analysis of pooled data from four phase 3 clinical trials.

BACKGROUND AND AIMS: High-sensitivity C-reactive protein (hsCRP), a marker for atherosclerotic cardiovascular disease risk, is reduced by bempedoic acid. We assessed the relationship between changes in low-density lipoprotein cholesterol (LDL-C) and hsCRP in relation to baseline statin use. METHODS: Pooled data from four phase 3 trials (patients on maximally tolerated statins [Pool 1] and patients receiving no or low-dose statins [Pool 2]) were used to determine the proportion of patients with baseline hsCRP ≥2 mg/L who achieved hsCRP <2 mg/L at week 12. The percentage of patients who achieved hsCRP <2 mg/L and guideline-recommended LDL-C (Pool 1, <70 mg/dL; Pool 2, <100 mg/dL) was determined for patients on statins in Pool 1 and those not on statins in Pool 2, as was the correlation between percent changes in hsCRP and LDL-C. RESULTS: Overall, 38.7% in Pool 1 and 40.7% in Pool 2 with baseline hsCRP ≥2 mg/L achieved hsCRP <2 mg/L with bempedoic acid, with little effect from background statin. Among patients taking a statin in Pool 1 or not taking a statin in Pool 2, 68.6% and 62.4% achieved hsCRP <2 mg/L. Both hsCRP <2 mg/L and United States guideline-recommended LDL-C were achieved more often with bempedoic acid vs. placebo (20.8% vs. 4.3%, respectively, in Pool 1 and 32.0% vs. 5.3%, in Pool 2). Changes in hsCRP and LDL-C were only weakly correlated (Pool 1, r = 0.112; Pool 2, r = 0.173). CONCLUSIONS: Bempedoic acid significantly reduced hsCRP irrespective of background statin therapy; the effect was largely independent of LDL-C lowering.

Serum opacity factor rescues fertility among female Scarb1-/- mice by reducing HDL-free cholesterol bioavailability.

Human female infertility, 20% of which is idiopathic, is a public health problem for which better diagnostics and therapeutics are needed. A novel cause of infertility emerged from studies of female mice deficient in the HDL receptor gene (Scarb1). These mice are infertile and have high plasma HDL cholesterol (C) concentrations, due to elevated HDL-free cholesterol (FC), which transfers from HDL to all tissues. Previous studies have indicated that oral delivery of probucol, an HDL-lowering drug, to female Scarb1-/- mice reduces plasma HDL-C concentrations and rescues fertility. Additionally, serum opacity factor (SOF), a bacterial virulence factor, disrupts HDL structure, and bolus SOF injection into mice reduces plasma HDL-C concentrations. Here, we discovered that delivering SOF to female Scarb1-/- mice with an adeno-associated virus (AAVSOF) induces constitutive SOF expression, reduces HDL-FC concentrations, and rescues fertility while normalizing ovary morphology. Although AAVSOF did not alter ovary-FC content, the ovary-mol% FC correlated with plasma HDL-mol% FC in a fertility-dependent way. Therefore, reversing the abnormal plasma microenvironment of high plasma HDL-mol% FC in female Scarb1-/- mice rescues fertility. These data provide the rationale to search for similar mechanistic links between HDL-mol% FC and infertility and the rescue of fertility in women by reducing plasma HDL-mol% FC.

Atherosclerosis risk classification with computed tomography angiography: A radiologic-pathologic validation study.

BACKGROUND AND AIMS: The application of machine learning to assess plaque risk phenotypes on cardiovascular CT angiography (CTA) is an area of active investigation. Studies using accepted histologic definitions of plaque risk as ground truth for machine learning models are uncommon. The aim was to evaluate the accuracy of a machine-learning software for determining plaque risk phenotype as compared to expert pathologists (histologic ground truth). METHODS: Sections of atherosclerotic plaques paired with CTA were prospectively collected from patients undergoing carotid endarterectomy at two centers. Specimens were annotated for lipid-rich necrotic core, calcification, matrix, and intraplaque hemorrhage at 2 mm spacing and classified as minimal disease, stable plaque, or unstable plaque according to a modified American Heart Association histological definition. Phenotype is determined in two steps: plaque morphology is delineated according to histological tissue definitions, followed by a machine learning classifier. The performance in derivation and validation cohorts for plaque risk categorization and stenosis was compared to histologic ground truth at each matched cross-section. RESULTS: A total of 496 and 408 vessel cross-sections in the derivation and validation cohorts (from 30 and 23 patients, respectively). The software demonstrated excellent agreement in the validation cohort with histological ground truth plaque risk phenotypes with weighted kappa of 0.82 [0.78-0.86] and area under the receiver operating curve for correct identification of plaque type was 0.97 [0.96, 0.98], 0.95 [0.94, 0.97], 0.99 [0.99, 1.0] for unstable plaque, stable plaque, and minimal disease, respectively. Diameter stenosis correlated poorly to histologically defined plaque type; weighted kappa 0.25 in the validation cohort. CONCLUSIONS: A machine-learning software trained on histological ground-truth tissue inputs demonstrated high accuracy for identifying plaque stability phenotypes as compared to expert pathologists.

Efficacy and safety of bempedoic acid in patients not receiving statins in phase 3 clinical trials.

BACKGROUND: Despite the high incidence of patients with statin tolerance problems, randomized evaluations of nonstatin oral treatment options for lowering of low-density lipoprotein cholesterol (LDL-C) in this population are sparse. OBJECTIVE: To assess the LDL-C lowering effect of bempedoic acid in patients not taking statins. METHODS: This was a pooled analysis of data from patients enrolled in four phase 3 bempedoic acid studies (12 to 52 weeks in duration) who were not taking concomitant statins (Phase 3 No Statin Cohort) and a phase 3 bempedoic acid plus ezetimibe fixed-dose combination study (BA+EZE FDC No Statin Cohort). The primary endpoint for all studies was the percent change from baseline to week 12 in LDL-C levels. Safety and tolerability were assessed by laboratory values and adverse events. RESULTS: In the Phase 3 No Statin Cohort, bempedoic acid (n = 394) lowered LDL-C levels at week 12 significantly more than placebo (n = 192; -26.5% [95% CI, -29.7%, -23.2%]; P<0.001). The fixed-dose combination of bempedoic acid with ezetimibe lowered LDL-C by 39.2% (95% CI, -51.7% to -26.7%; P<0.001). Muscle-related disorders occurred at a rate of 26.4 and 28.6 per 100 person-years with bempedoic acid and placebo, respectively. CONCLUSIONS: In patients with hypercholesterolemia unable to take statins, bempedoic acid lowered LDL-C levels by a mean of 26.5% vs placebo and bempedoic acid + ezetimibe fixed-dose combination lowered LDL-C by 39.2%. The treatments were generally well tolerated, suggesting that bempedoic acid may be efficacious and well tolerated in this challenging-to-treat patient population.

Bempedoic acid in patients with type 2 diabetes mellitus, prediabetes, and normoglycaemia: A post hoc analysis of efficacy and glycaemic control using pooled data from phase 3 clinical trials.

AIM: To evaluate the effect of bempedoic acid on glycaemic and lipid variables in patients with hypercholesterolaemia. METHODS: A patient-level pooled analysis of four phase 3, randomized, double-blind, placebo-controlled trials evaluated changes in glycaemia, change from baseline in LDL-C, and adverse events. Patients (N = 3621) on maximally tolerated statins were randomized 2:1 to oral bempedoic acid 180 mg or placebo once daily for 12 to 52 weeks with the results analysed by baseline glycaemic status (diabetes, prediabetes, or normoglycaemia). RESULTS: The annual rate of new-onset diabetes for bempedoic acid versus placebo in patients with normoglycaemia at baseline (n = 618) was 0.3% versus 0.8%, and for patients with prediabetes at baseline (n = 1868) it was 4.7% versus 5.9%. In patients with diabetes or prediabetes, bempedoic acid significantly (P < .0001) reduced HbA1c by -0.12% and -0.06%, respectively, and did not worsen fasting glucose versus placebo. Bempedoic acid significantly and consistently lowered LDL-C levels versus placebo, regardless of baseline glycaemic status (placebo-corrected difference range, -17.2% to -29.6%; P < .001 for each stratum). The safety of bempedoic acid was comparable with placebo and similar across glycaemic strata. CONCLUSIONS: Bempedoic acid significantly lowered LDL-C across glycaemic strata and did not worsen glycaemic variables or increase the incidence of new-onset diabetes versus placebo over a median follow-up of 1 year.

High Free Cholesterol Bioavailability Drives the Tissue Pathologies in Scarb1-/- Mice.

Objective: Overall and atherosclerosis-associated mortality is elevated in humans with very high HDL (high-density lipoprotein) cholesterol concentrations. Mice with a deficiency of the HDL receptor, Scarb1 (scavenger receptor class B type 1), are a robust model of this phenotype and exhibit several additional pathologies. We hypothesized that the previously reported high plasma concentration of free cholesterol (FC)-rich HDL in Scarb1-/- mice produces a state of high HDL-FC bioavailability that increases whole-body FC and dysfunction in multiple tissue sites. Approach and Results: The higher mol% FC in Scarb1-/- versus WT (wild type) HDL (41.1 versus 16.0 mol%) affords greater FC bioavailability for transfer to multiple sites. Plasma clearance of autologous HDL-FC mass was faster in WT versus Scarb1-/- mice. FC influx from Scarb1-/- HDL to LDL (low-density lipoprotein) and J774 macrophages was greater ([almost equal to]4x) than that from WT HDL, whereas FC efflux capacity was similar. The higher mol% FC of ovaries, erythrocytes, heart, and macrophages of Scarb1-/- versus WT mice is associated with previously reported female infertility, impaired cell maturation, cardiac dysfunction, and atherosclerosis. The FC contents of other tissues were similar in the two genotypes, and these tissues were not associated with any overt pathology. In addition to the differences between WT versus Scarb1-/- mice, there were many sex-dependent differences in tissue-lipid composition and plasma FC clearance rates. Conclusions: Higher HDL-FC bioavailability among Scarb1-/- versus WT mice drives increased FC content of multiple cell sites and is a potential biomarker that is mechanistically linked to multiple pathologies.

High-density lipoproteins, reverse cholesterol transport and atherogenesis.

Plasma HDL-cholesterol concentrations correlate negatively with the risk of atherosclerotic cardiovascular disease (ASCVD). According to a widely cited model, HDL elicits its atheroprotective effect through its role in reverse cholesterol transport, which comprises the efflux of cholesterol from macrophages to early forms of HDL, followed by the conversion of free cholesterol (FCh) contained in HDL into cholesteryl esters, which are hepatically extracted from the plasma by HDL receptors and transferred to the bile for intestinal excretion. Given that increasing plasma HDL-cholesterol levels by genetic approaches does not reduce the risk of ASCVD, the focus of research has shifted to HDL function, especially in the context of macrophage cholesterol efflux. In support of the reverse cholesterol transport model, several large studies have revealed an inverse correlation between macrophage cholesterol efflux to plasma HDL and ASCVD. However, other studies have cast doubt on the underlying reverse cholesterol transport mechanism: in mice and humans, the FCh contained in HDL is rapidly cleared from the plasma (within minutes), independently of esterification and HDL holoparticle uptake by the liver. Moreover, the reversibility of FCh transfer between macrophages and HDL has implicated the reverse process - that is, the transfer of FCh from HDL to macrophages - in the aetiology of increased ASCVD under conditions of very high plasma HDL-FCh concentrations.

Comparing a novel machine learning method to the Friedewald formula and Martin-Hopkins equation for low-density lipoprotein estimation.

BACKGROUND: Low-density lipoprotein cholesterol (LDL-C) is a target for cardiovascular prevention. Contemporary equations for LDL-C estimation have limited accuracy in certain scenarios (high triglycerides [TG], very low LDL-C). OBJECTIVES: We derived a novel method for LDL-C estimation from the standard lipid profile using a machine learning (ML) approach utilizing random forests (the Weill Cornell model). We compared its correlation to direct LDL-C with the Friedewald and Martin-Hopkins equations for LDL-C estimation. METHODS: The study cohort comprised a convenience sample of standard lipid profile measurements (with the directly measured components of total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], and TG) as well as chemical-based direct LDL-C performed on the same day at the New York-Presbyterian Hospital/Weill Cornell Medicine (NYP-WCM). Subsequently, an ML algorithm was used to construct a model for LDL-C estimation. Results are reported on the held-out test set, with correlation coefficients and absolute residuals used to assess model performance. RESULTS: Between 2005 and 2019, there were 17,500 lipid profiles performed on 10,936 unique individuals (4,456 females; 40.8%) aged 1 to 103. Correlation coefficients between estimated and measured LDL-C values were 0.982 for the Weill Cornell model, compared to 0.950 for Friedewald and 0.962 for the Martin-Hopkins method. The Weill Cornell model was consistently better across subgroups stratified by LDL-C and TG values, including TG >500 and LDL-C <70. CONCLUSIONS: An ML model was found to have a better correlation with direct LDL-C than either the Friedewald formula or Martin-Hopkins equation, including in the setting of elevated TG and very low LDL-C.

Bempedoic acid safety analysis: Pooled data from four phase 3 clinical trials.

BACKGROUND: An ongoing need exists for safe and effective lipid-lowering therapies (LLTs) for patients unable to achieve desired lipid levels with current treatment options. OBJECTIVE: The objective of this study was to describe the safety profile of bempedoic acid, an oral, first-in-class, adenosine triphosphate (ATP)-citrate lyase inhibitor that significantly reduces low-density lipoprotein cholesterol (LDL-C) levels by 17.4%-28.5% vs placebo. METHODS: This was a pooled analysis of four phase 3, randomized (2:1), double-blind, placebo-controlled studies in patients with hypercholesterolemia who required additional LDL-C lowering, despite stable maximally-tolerated LLT. Patients received 180 mg of bempedoic acid (n = 2424) or placebo (n = 1197) once daily for 12 to 52 weeks. Assessments included treatment-emergent adverse events (TEAEs) and clinical laboratory tests. RESULTS: Of 3621 patients (the median drug exposure: 363 days), exposure-adjusted TEAE rates were 87.1/100 and 82.9/100 person-years (PY) for bempedoic acid and placebo, respectively. No single TEAE influenced the difference in rates. TEAEs leading to discontinuation occurred at rates of 13.4/100 and 8.9/100 PY for bempedoic acid vs placebo, with the most common cause being myalgia, which occurred less frequently with bempedoic acid vs placebo (1.5/100 vs 2.0/100 PY). Rates of myalgia and muscle weakness were comparable vs placebo. Bempedoic acid was associated with mild increases in blood urea nitrogen, creatinine, and uric acid and decreases in hemoglobin. These laboratory abnormalities were apparent by week 4, stable over time, and reversible after treatment cessation. Gout incidence was 1.6/100 vs 0.5/100 PY in the bempedoic acid vs placebo groups. New-onset diabetes/hyperglycemia occurred less frequently with bempedoic acid vs placebo (4.7/100 vs 6.4/100 PY). The safety profile was consistent across subgroups. CONCLUSIONS: Bempedoic acid is generally safe and well tolerated among patients with hypercholesterolemia who require additional LLT.

Highly conserved amino acid residues in apolipoprotein A1 discordantly induce high density lipoprotein assembly in vitro and in vivo.

OBJECTIVE: Apolipoprotein A1 (APOA1) is essential to reverse cholesterol transport, a physiologically important process that protects against atherosclerotic cardiovascular disease. APOA1 is a 28 kDa protein comprising multiple lipid-binding amphiphatic helices initialized by proline residues, which are conserved across multiple species. We tested the hypothesis that the evolutionarily conserved residues are essential to high density lipoprotein (HDL) function. APPROACH: We used biophysical and physiological assays of the function of APOA1P➔A variants, i.e., rHDL formation via dimyristoylphosphatidylcholine (DMPC) microsolubilization, activation of lecithin: cholesterol acyltransferase, cholesterol efflux from human monocyte-derived macrophages (THP-1) to each variant, and comparison of the size and composition of HDL from APOA1-/- mice receiving adeno-associated virus delivery of each human variant. RESULTS: Differences in microsolubilization were profound and showed that conserved prolines, especially those in the C-terminus of APOA1, are essential to efficient rHDL formation. In contrast, P➔A substitutions produced small changes (-25 to +25%) in rates of cholesterol efflux and no differences in the rates of LCAT activation. The HDL particles formed following ectopic expression of each variant in APOA1-/- mice were smaller and more heterogeneous than those from control animals. CONCLUSION: Studies of DMPC microsolubilization show that proline residues are essential to the optimal interaction of APOA1 with membranes, the initial step in cholesterol efflux and HDL production. In contrast, P➔A substitutions modestly reduce the cholesterol efflux capacity of APOA1, have no effect on LCAT activation, but according to the profound reduction in the size of HDL formed in vivo, P➔A substitutions alter HDL biogenesis, thereby implicating other cellular and in vivo processes as determinants of HDL metabolism and function.

Association of Bempedoic Acid Administration With Atherogenic Lipid Levels in Phase 3 Randomized Clinical Trials of Patients With Hypercholesterolemia.

Importance: Additional lipid-lowering therapy options are needed for patients who cannot achieve sufficient decreases in low-density lipoprotein cholesterol (LDL-C) levels using statins alone or for those who are statin intolerant. Objective: To conduct a pooled analysis of phase 3 randomized clinical trials of bempedoic acid vs placebo. Design, Setting, and Participants: This analysis pooled data from 4 double-blind, placebo-controlled randomized clinical trials conducted from 2016 to 2018. Patients were enrolled in North America and Europe. Eligibility criteria included hypercholesterolemia while receiving stable lipid-lowering therapy and high cardiovascular risk or hypercholesterolemia and statin intolerance. Interventions: Patients were randomized 2:1 to bempedoic acid, 180 mg (n = 2425), or placebo (n = 1198) once daily for 12 to 52 weeks. Main Outcomes and Measures: Primary efficacy end point was percentage change from baseline in LDL-C level at week 12 in the intention-to-treat population. Patients were parsed into 2 groups according to enrollment criteria: (1) patients with hypercholesterolemia and atherosclerotic cardiovascular disease (ASCVD) or with heterozygous familial hypercholesterolemia (HeFH) or with both and receiving statins and (2) patients with hypercholesterolemia who were statin intolerant receiving maximally tolerated statins. Results: In this analysis of 3623 patients, the overall mean (SD) patient age was 65.5 (9.2) years (similar in both pools). Among patients with ASCVD or HeFH or both, the mean (SD) baseline LDL-C level was 107.6 (32.7) mg/dL. At week 12, the LDL-C level percentage change from baseline was -16.0% with bempedoic acid vs 1.8% with placebo (difference, -17.8%; 95% CI, -19.5% to -16.0%; P < .001). Patients with statin intolerance had a mean (SD) baseline LDL-C level of 144.4 (38.8) mg/dL. The percentage changes in LDL-C levels at week 12 were -23.0% in the bempedoic acid group and 1.5% in the placebo group (difference, -24.5%; 95% CI, -27.8% to -21.1%; P < .001). The decrease in LDL-C levels with bempedoic acid was sustained during long-term follow-up in both pools (patients with ASCVD or HeFH or both receiving a maximally tolerated statin, difference of -12.7% at week 52; patients with statin intolerance, difference of -22.2% at week 24). Decreases in non-high-density lipoprotein cholesterol, total cholesterol, apolipoprotein B, and high-sensitivity C-reactive protein levels were greater with bempedoic acid vs placebo. Treatment-emergent adverse events associated more frequently with bempedoic acid than with placebo included increased blood uric acid level (2.1% vs 0.5%), gout (1.4% vs 0.4%), decreased glomerular filtration rate (0.7% vs <0.1%), and increased levels of hepatic enzymes (2.8% vs 1.3%). Conclusions and Relevance: Bempedoic acid added to maximally tolerated statins, including moderate- or high-intensity statins or no background statin, was associated with decreased LDL-C levels vs placebo in patients with hypercholesterolemia with an acceptable safety profile. As a nonstatin adjunct or statin alternative, bempedoic acid has potential for use in a broad spectrum of patients. Trial Registration: ClinicalTrials.gov Identifiers: NCT02666664, NCT02991118, NCT03001076, and NCT02988115.

The Alcohol-High-Density Lipoprotein Athero-Protective Axis.

Ingestion of alcohol is associated with numerous changes in human energy metabolism, especially that of plasma lipids and lipoproteins. Regular moderate alcohol consumption is associated with reduced atherosclerotic cardiovascular disease (ASCVD), an effect that has been attributed to the concurrent elevations of plasma high-density lipoprotein-cholesterol (HDL-C) concentrations. More recent evidence has accrued against the hypothesis that raising plasma HDL concentrations prevents ASCVD so that other metabolic processes associated with alcohol consumption have been considered. This review explored the roles of other metabolites induced by alcohol consumption-triglyceride-rich lipoproteins, non-esterified free fatty acids, and acetate, the terminal alcohol metabolite in athero-protection: Current evidence suggests that acetate has a key role in athero-protection but additional studies are needed.

PCSK9 and inflammation: a review of experimental and clinical evidence.

Proprotein convertase subtilisin/kexin Type 9 (PCSK9) is now identified as an important and major player in hypercholesterolaemia and atherosclerosis pathophysiology. PCSK9, through promoting lysosomal degradation of hepatic low-density lipoprotein (LDL) receptor, can decrease the clearance of plasma LDLs, leading to hypercholesterolaemia and consequent atherosclerotic plaque formation. Hypercholesterolaemia has been found to promote systemic and vascular inflammation, which can cause atherosclerotic lesion formation and progression and subsequent incidence of cardiovascular disease. Recent studies have shown the involvement of PCSK9 in the inflammatory pathway of atherosclerosis. Although trials with PCSK9 inhibitors have not shown any alteration in plasma C-reactive protein levels, there is accumulating evidence showing lessened inflammatory response in the arterial wall that could attenuate atherosclerotic plaque development beyond the established LDL-lowering effect of PCSK9 inhibition. In this review, we represent mounting evidence indicating that PCSK9 can locally increase vascular inflammation and contribute to atherosclerotic plaque progression in patients with hypercholesterolaemia.

Cholesterol: Can't Live With It, Can't Live Without It.

Given its role in many biochemical processes essential to life, cholesterol remains a topic of intense research. Of all the plasma lipids, cholesterol is distinctive because it is a precursor to steroidogenic molecules, some of which regulate metabolism, and its blood concentration in the form of low- and high-density lipoprotein cholesterol (HDL-C) are positive and negative risk factors for atherosclerotic cardiovascular disease (ASCVD). New research, however, has challenged the widely held belief that high HDL-C levels are atheroprotective and is showing that both low and high plasma HDL-C levels confer an increased risk of ASCVD. Furthermore, it is disputing the widely cited mechanism involved in reverse cholesterol transport. This review explores the evolution of cholesterol research starting with the Gofman and Framingham studies, the development of traditional and emerging lipid-lowering therapies, and the role of reverse cholesterol transport in HDL cardioprotection.