Search

It is unclear to what extent genetic testing improves the ability to diagnose familial hypercholesterolaemia (FH). We investigated the percentage with FH among individuals referred to Danish lipid clinics, and evaluated the impact of genetic testing for a diagnosis of FH. From September 2020 through November 2021, all patients referred for possible FH to one of the 15 Danish lipid clinics were invited for study participation and >97% (n = 1488) accepted. The Dutch Lipid Clinical Network criteria were used to diagnose clinical FH. The decision of genetic testing for FH was based on local practice. A total of 1243 individuals were referred, of whom 25.9% were diagnosed with genetic and/or clinical FH. In individuals genetically tested (n = 705), 21.7% had probable or definite clinical FH before testing, a percentage that increased to 36.9% after genetic testing. In individuals with unlikely and possible FH before genetic testing, 24.4% and 19.0%, respectively, had a causative pathogenic variant. In a Danish nationwide study, genetic testing increased a diagnosis of FH from 22% to 37% in patients referred with hypercholesterolaemia suspected of having FH. Importantly, approximately 20% with unlikely or possible FH, who without genetic testing would not have been considered having FH (and family screening would not have been undertaken), had a pathogenic FH variant. We therefore recommend a more widespread use of genetic testing for evaluation of a possible FH diagnosis and potential cascade screening. [Display omitted] • Large nationwide study including all 1243 individuals referred to Danish lipid clinics for suspected FH in a 15 month period. • A total of 26% of the referred patients had FH despite only 705/1243 were genetically tested. • Genetic testing increased the diagnoses of FH from 22% to 37% in patients referred with hypercholesterolemia suspected of FH. • Approximately 20% with unlikely or possible FH according to DLCN criteria (before genetic testing) had causative FH mutations. [ABSTRACT FROM AUTHOR]

The European Atherosclerosis Society (EAS) Lipid Clinics Network promoted a survey in order to identify and understand how and when lipoprotein(a) [Lp(a)] is tested and clinically evaluated in lipid clinics throughout Europe, and the challenges that may prevent evaluation from being carried out. This survey was divided into three areas of inquiry: background and clinical setting information of clinicians, questions for doctors who claimed not to measure Lp(a), in order to understand what were the reasons for not ordering the test, and questions for doctors who measure Lp(a), to investigate the use of this value in the management of patients. A total of 151 centres clinicians filled in the survey, out of 226 invited. The proportion of clinicians who declare to routinely measure Lp(a) in clinical practice was 75.5%. The most common reasons for not ordering the Lp(a) test were the lack of reimbursement or of treatment options, the non-availability of Lp(a) test, and the high cost of performing the laboratory test. The availability of therapies targeting this lipoprotein would result in a greater propensity of clinicians to start testing Lp(a). Among those who declared to routinely measure Lp(a), the Lp(a) measurement is mostly requested to further stratify patients' cardiovascular risk, and half of them recognized 50 mg/dL (approx. 110 nmol/L) as the threshold for increased cardiovascular risk due. These results warrant for a great deal of effort from scientific societies to address the barriers that limit the routine use of the measurement of Lp(a) concentration and to recognise the importance of Lp(a) as a risk factor. [ABSTRACT FROM AUTHOR]

Effective lipid lowering therapies are essential for the prevention of atherosclerosis and cardiovascular disease. Available treatments have evolved in both their efficacy and their frequency of administration, and currently include monoclonal antibodies, antisense oligonucleotides and siRNA approaches. However, an unmet need remains for more effective and long-lasting therapeutics. Gene editing permanently alters endogenous gene expression and has the potential to revolutionize disease treatment. Despite the existence of several gene editing approaches, the CRISPR/Cas9 system has emerged as the preferred technology because of its high efficiency and relative simplicity. This review provides a general overview of this promising technology and an update on the progress made towards the development of treatments of dyslipidemia. The recently started phase 1b gene editing clinical trial targeting PCSK9 in patients with heterozygous familial hypercholesterolemia and cardiovascular disease highlights how gene editing may become available to treat not only patients affected by rare disorders of lipid metabolism, but also patients that are difficult-to-treat or at high risk. Other targets like ANGPTL3 , LDLR , and APOC 3 are on track for further pre-clinical development. The identification of novel targets using electronic health record-linked biobanks and human sequencing studies will continue to expand the potential target pool, and clinical assessment of treated patients will provide essential efficacy and safety information on current strategies. Gene editing of genes regulating lipid metabolism holds promise as an exciting new therapeutic approach. However, since gene editing permanently alters a patient's genome, its therapeutic application in humans will require careful safety assessment and ethical considerations. [Display omitted] • Gene editing can be used to better understand the function of genes and is a potential therapeutic approach. • Improvements in the efficiency and precision of CRISPR/Cas and its delivery are advancing somatic gene editing. • A Phase 1b clinical trial using base editing to target PCSK9 is ongoing. Other dyslipidemia targets are being explored. • Careful assessments of safety and clear ethical boundaries must accompany the development of somatic gene editing. [ABSTRACT FROM AUTHOR]

Randomized clinical trials have demonstrated that increasingly intensive lowering of low-density lipoprotein cholesterol (LDL-C) reduces the rate of cardiovascular events in the primary and secondary prevention setting. Integration of serial coronary imaging within clinical trials has enabled evaluation of medical therapies on the natural history of coronary disease. These studies have extended from early investigation of coronary obstruction with angiography to more contemporary evaluation of plaque burden and composition with imaging modalities that directly visualize the artery wall. The findings of these trials have demonstrated that intensive lipid lowering promotes plaque regression and stabilization. The lessons of this body of research provide a biological rationale underscoring the ability of intensive lipid lowering to reduce cardiovascular risk and have the potential to promote greater uptake in clinical practice. [Display omitted] • Intensive lipid lowering with statin monotherapy or combination therapy is achievable in most high risk patients. • Intensive lipid lowering slows progression of obstructive disease on coronary angiography. • Intensive lipid lowering promotes plaque regression and stabilization, proportional to LDL-C lowering. • These benefits are likely to underscore the impact of intensive lipid lowering on cardiovascular risk. [ABSTRACT FROM AUTHOR]

Carotid atherosclerosis is an important cause of ischemic stroke. Lipids play a key role in the progression of atherosclerosis. To date, the spatial lipid profile of carotid atherosclerotic plaques related to histology has not been systematically investigated. Carotid atherosclerosis samples from 12 patients were obtained and classified into four classical pathological stages (preatheroma, atheroma, fibroatheroma and complicated lesion) by histological staining. Desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) was used to investigate the lipid profile of carotid atherosclerosis, and correlated it with histological information. Bioinformatics technology was used to process MSI data among different pathological stages of atherosclerosis lesions. A total of 55 lipids (26 throughout cross-section regions [TCSRs], 13 in lipid-rich regions [LRRs], and 16 in collagen-rich regions [CRRs]) were initially identified in carotid plaque from one patient. Subsequently, 32 of 55 lipids (12 in TCSRs, eight in LRRs, and 12 in CRRs) were further screened in 11 patients. Pathway enrichment analysis showed that multiple metabolic pathways, such as fat digestion and absorption, cholesterol metabolism, lipid and atherosclerosis, were enriched in TCSRs; sphingolipid signaling pathway, necroptosis pathway were enriched in LRRs; and glycerophospholipid metabolism, ether lipid metabolism pathway were mainly enriched in CRRs. This study comprehensively showed the spatial lipid metabolism footprint in human carotid atherosclerotic plaques. The lipid profiles and related metabolism pathways in three regions of plaque with disease progression were different markedly, suggesting that the different metabolic mechanisms in these regions of carotid plaque may be critical in atherosclerosis progression. [Display omitted] • Specific lipids located in lipid-rich regions and collagen-rich regions were identified. • The spatial dynamic lipid metabolism footprint of atherosclerosis was delineated. • Different metabolic pathways between lipid-rich regions and collagen-rich regions with atherosclerosis progression were found. [ABSTRACT FROM AUTHOR]

Despite low LDL-C goals, the residual risk for further cardiovascular (CV) events in patients with peripheral artery disease (PAD) remains high. Lipoprotein (a) (Lp(a)) is a known risk factor for PAD incidence, but little is known regarding the outcome in patients with symptomatic PAD. Thus, this study investigates Lp(a) and CV mortality in PAD after endovascular repair. A total of 1222 patients with PAD in two cohorts according to Lp(a) assay in nmol/L (n = 964, Lip-LEAD-A) or mg/dl (n = 258, Lip-LEAD-B) were followed up for 4.3 (IQR 3.0–5.6) or 7.6 (IQR 3.2–8.1) years. Lp(a) was measured before endovascular repair for either intermittent claudication (IC) or critical limb ischemia (CLI). Outcome information was obtained from the federal death registry. In Lip-LEAD-A, 141 CV-deaths occurred (annual calculated CV-death rate 3.4%), whereas 64 CV-deaths were registered in Lip-LEAD-B (annual calculated CV-death rate 3.3%). After adjustment for traditional CV risk factors Lp(a) was neither associated with outcome in Lip-LEAD-A (highest tertile HR 1.47, 95%CI [0.96–2.24]) nor in Lip-LEAD-B (highest tertile HR 1.34 [0.70–2.58]). Subanalyses for IC (HR 1.37 [0.74–2.55]; HR 1.10 [0.44–2.80], CLI (HR 1.55 [0.86–2.80], HR 3.01 [0.99–9.10]), or concomitant coronary artery disease (CAD; HR 1.34 [0.71–2.54]; HR 1.21 [0.46–3.17]) failed to show a significant association between Lp(a) and CV-mortality. In this large-scale cohort of symptomatic PAD no association of elevated Lp(a) with CV mortality was found over a median observation period of 5 years. Thus, an even longer study including asymptomatic patients is warranted. [Display omitted] • The predictive capability of Lp(a) for cardiovascular mortality was evaluated over a long-term period in two cohorts of symptomatic peripheral artery disease (PAD). • Lp(a) was not associated with cardiovascular mortality in both cohorts. • No specific pattern of lesion site (iliacal, femoral, below the knee, multivessel) for endovascular repair was detected with elevated Lp(a) levels. • This data suggests that elevated Lp(a) does not impose an additional risk to patients with symptomatic PAD and high rates of statin treatment. [ABSTRACT FROM AUTHOR]

Angiopoietin-like 3 (ANGPTL3) regulates lipid and glucose metabolism. Loss-of-function mutations in its gene, leading to ANGPTL3 deficiency, cause in humans the familial combined hypolipidemia type 2 (FHBL2) phenotype, characterized by very low concentrations of circulating lipoproteins and reduced risk of atherosclerotic cardiovascular disease. Whether this condition is accompanied by immune dysfunctions is unknown. Regulatory T cells (Tregs) are CD4 T lymphocytes endowed with immune suppressive and atheroprotective functions and sensitive to metabolic signals. By investigating FHBL2, we explored the hypothesis that Tregs expand in response to extreme hypolipidemia, through a modulation of the Treg-intrinsic lipid metabolism. Treg frequency, phenotype, and intracellular lipid content were assessed ex vivo from FHBL2 subjects and age- and sex-matched controls, through multiparameter flow cytometry. The response of CD4 T cells from healthy controls to marked hypolipidemia was tested in vitro in low-lipid culture conditions. The ex vivo analysis revealed that FHBL2 subjects showed higher percentages of Tregs with a phenotype undistinguishable from controls and with a lower lipid content, which directly correlated with the concentrations of circulating lipoproteins. In vitro , lipid restriction induced the upregulation of genes of the mevalonate pathway, including those involved in isoprenoid biosynthesis, and concurrently increased the expression of the Treg markers FOXP3 and Helios. The latter event was found to be prenylation-dependent, and likely related to increased IL-2 production and signaling. Our study demonstrates that FHBL2 is characterized by high Treg frequencies, a feature which may concur to the reduced atherosclerotic risk in this condition. Mechanistically, hypolipidemia may directly favor Treg expansion, through the induction of the mevalonate pathway and the prenylation of key signaling proteins. [Display omitted] • In ANGPTL3 deficiency, hypolipidemia correlates with Treg expansion. • Tregs from these individuals contain less intracellular lipids. • In vitro, lipid deprivation induces the mevalonate pathway and Treg markers. • Such event is prenylation-dependent and IL-2/CD25-related. [ABSTRACT FROM AUTHOR]

Lipoprotein(a) is a well-known causal risk factor for cardiovascular morbidity and mortality. Little is known about the effect of age and sex on lipoprotein(a) levels, and it is largely unknown if the same elevation in lipoprotein(a) confers the same increase in risk in women and men. We investigated whether lipoprotein(a) levels and lipoprotein(a) associated risks of morbidity and mortality by age are similar in women and men. We included 37,545 women and 32,497 men from the Copenhagen General Population Study. Plasma lipoprotein(a) increased with age, and in women we found an additional increase around age 50 (age by sex interaction p = 8∙10−7). In women, levels were 27% higher after menopause (p = 4∙10−61) and 12% lower during hormone replacement therapy (p = 2∙10−19). Adjustment for estimated Glomerular Filtration Rate in both sexes and plasma estradiol in women resulted in attenuated sex differences in lipoprotein(a) levels. In sex and age stratified multivariable adjusted models, lipoprotein(a) >40 mg/dL(83 nmol/L) versus <10 mg/dL(18 nmol/L) was associated with increased risk of myocardial infarction, ischemic heart disease, aortic valve stenosis, and heart failure (men only), but not statistically significant with risk of ischemic stroke, cardiovascular mortality, or all-cause mortality. Lipoprotein(a) levels increased modestly around age 50 selectively in women; however, risk of morbidity and mortality for high lipoprotein(a) was similar in women and men above age 50. This implies that elevated lipoprotein(a) above age 50 is a relatively more common cardiovascular risk factor in women, pointing toward repeat measurements in women above age 50. [Display omitted] • Lipoprotein(a) levels increase with increasing age in women and men. • Lipoprotein(a) levels increase around age 50 selectively in women. • Risk of morbidity and mortality for high lipoprotein(a) levels was similar in women and men above age 50. • These results imply that elevated lipoprotein(a) above age 50 is a relatively more common cardiovascular risk factor in women than men. [ABSTRACT FROM AUTHOR]

The PROMINENT trial, a cardiovascular outcome trial of the triglyceride- and remnant cholesterol-lowering agent pemafibrate, has shown neutral results despite reduction in plasma triglycerides and remnant cholesterol. We tested the hypothesis that absolute mass changes in remnant cholesterol, LDL cholesterol, and apolipoprotein B explain the results of the PROMINENT trial. Among 108,431 individuals from the Copenhagen General Population Study (CGPS), those who met the key inclusion criteria of the PROMINENT trial were analyzed to mimic the trial design. Endpoint atherosclerotic cardiovascular disease (ASCVD) was cardiovascular death, myocardial infarction, ischemic stroke, and coronary revascularization as defined in PROMINENT. In the PROMINENT trial, treatment with pemafibrate resulted in -7 mg/dL (−0.18 mmol/L; -18 %) change in remnant cholesterol, +10 mg/dL (+0.26 mmol/L; +12 %) LDL cholesterol, and +5 mg/dL (+0.05 g/L; +5 %) apolipoprotein B. In the CGPS mimicking PROMINENT, the estimated hazard ratios for ASCVD were 0.97 (95 % confidence interval: 0.94–0.99) for a -7 mg/dL (−0.18 mmol/L) change in remnant cholesterol, 1.04 (1.01–1.07) for a +10 mg/dL (+0.26 mmol/L) change in LDL cholesterol, and 1.02 (1.01–1.03) for a +5 mg/dL (+0.05 g/L) change in apolipoprotein B. When combining absolute changes in remnant cholesterol, LDL cholesterol, and apolipoprotein B, the estimated hazard ratio for ASCVD was 1.05 (0.96–1.14) in the CGPS mimicking PROMINENT compared to 1.03 (0.91–1.15) in the PROMINENT trial. Absolute mass changes in remnant cholesterol, LDL cholesterol, and apolipoprotein B can explain results of the PROMINENT trial. The 3 mg/dL (0.08 mmol/L) higher total atherogenic cholesterol together with 5 mg/dL (0.05 g/L) higher apolipoprotein B seem to explain the trend toward more ASCVD in the pemafibrate arm. [Display omitted] • Absolute mass changes in remnant cholesterol, LDL cholesterol, and apo B can explain results of the PROMINENT trial. • To reduce ASCVD lipid lowering drugs, total atherogenic cholesterol and total number of atherogenic particles need to be reduced. • Understanding the potential for causing ASCVD, lipoproteins should be judged by their absolute mass of cholesterol content. [ABSTRACT FROM AUTHOR]

The utility of lipid screening in pediatric settings for preventing adult atherosclerotic cardiovascular diseases partly depends on the lifelong tracking of lipid levels. This systematic review aimed to quantify the tracking of lipid levels from childhood and adolescence to adulthood. We systematically searched MEDLINE, Embase, Web of Science, and Google Scholar in March 2022. The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO; ID: CRD42020208859). We included cohort studies that measured tracking of lipids from childhood or adolescence (<18 years) to adulthood (≥18) with correlation or tracking coefficients. We estimated pooled correlation and tracking coefficients using random-effects meta-analysis. Risk of bias was assessed with a review-specific tool. Thirty-three studies of 19 cohorts (11,020 participants) were included. The degree of tracking from childhood and adolescence to adulthood differed among lipids. Tracking was observed for low-density lipoprotein cholesterol (pooled r = 0.55–0.65), total cholesterol (pooled r = 0.51–0.65), high-density lipoprotein cholesterol (pooled r = 0.46–0.57), and triglycerides (pooled r = 0.32–0.40). Only one study included tracking of non-high-density lipoprotein cholesterol (r = 0.42–0.59). Substantial heterogeneity was observed. Study risk of bias was moderate, mostly due to insufficient reporting and singular measurements at baseline and follow-up. Early-life lipid measurements are important for predicting adult levels. However, further research is needed to understand the tracking of non-high-density lipoprotein cholesterol and the stability of risk classification over time, which may further inform pediatric lipid screening and assessment strategies. [Display omitted] • Over 40 years of data from longitudinal studies inform lipid level tracking from childhood/adolescence to adulthood. • We performed meta-analysis of 33 studies (19 cohorts, 11,020 participants) meeting inclusion criteria. • Meta-analysis highlighted strongest tracking in LDL-C and total cholesterol, followed by HDL-C and triglycerides. • Our systematic review outlined a research gap in non-HDL cholesterol tracking. • Study risk of bias was moderate, mostly due to insufficient reporting. [ABSTRACT FROM AUTHOR]

Lipoprotein(a) [Lp(a)] is causally associated with aortic valve stenosis (AS) but Lp(a) testing among AS patients is not broadly incorporated into clinical practice. We evaluated trends in Lp(a) testing in an academic medical center. Educational efforts and adding Lp(a) to the lipid panel on the electronic medical record (EMR) and pre-procedure order sets were used to increase awareness of Lp(a) as a risk factor in AS. Medical records at University of California San Diego Health (UCSDH) were analyzed from 2010 to 2020 to define the yearly frequency of first time Lp(a) testing in patients with diagnosis codes for AS or undergoing transcatheter aortic valve replacement (TAVR). Lp(a) testing for any indication increased over 5-fold from 2010 to 2020. A total of 3808 patients had a diagnosis of AS and 417 patients had TAVR. Lp(a) levels >30 mg/dL were present in 37% of AS and 35% of TAVR patients. The rates of Lp(a) testing in AS and TAVR were 14.0% and 65.7%, respectively. In AS, Lp(a) testing increased over time from 8.5% in 2010, peaking at 24.2% in 2017, and declining to 13.9% in 2020 (p < 0.001 for trend). Following implementation of EMR order-sets in 2016, Lp(a) testing in TAVR cases increased to a peak of 88.5% in 2018. Elevated Lp(a) is prevalent in AS and TAVR patients. Implementation of educational efforts and practice pathways resulted in increased Lp(a) testing in patients with AS. This study represents a paradigm that may allow increased global awareness of Lp(a) as a risk factor for AS. [Display omitted] • Lp(a) is strongly related to aortic valve stenosis (AS) risk. • Elevated Lp(a) is highly prevalent among AS patients. • Lp(a) testing among AS patients has improved over time. • Education and order sets can significantly increase Lp(a) testing. [ABSTRACT FROM AUTHOR]

Familial hypercholesterolemia (FH) is the most relevant genetic cause of early cardiovascular disease (CVD). FH is suspected when low density lipoprotein cholesterol (LDL-C) levels exceed the 95th percentile of the population distribution. Different diagnostic scoring systems have been developed, as the Dutch Lipid Clinic Network (DLCN) score, used worldwide. The aim of the study is to describe the characteristics of FH patients of a large cohort of more than eight hundred genotyped subjects enrolled in an Italian Lipid Clinic, and evaluate the DLCN score performance applied retrospectively to the case study. 836 hypercholesterolemic patients with LDL-C > 4.88 mmol/L were genotyped for FH causative gene variants in the LDLR , PCSK and APOB genes. Relatives of mutated patients were also analyzed by cascade screening. Gene variant carriers were younger, presented higher LDL-C and DLCN score and lower HDL-C levels in comparison with hypercholesterolemic (HC) non-carriers and presented a five-fold higher prevalence of previous CV events. Carotid US data available in 490 subjects showed that variant carriers had an odds ratio of 3.66 (1.43–10.24) for atherosclerotic plaques in comparison with non-carriers. Scoring system were evaluated by ROC analysis in 203 subjects without missing DLCN items and with available pre-therapy LDL-C levels, and LDL-C levels (A.U.C. = 0.737) resulted to be more performing than the DLCN score (A.U.C. = 0.662), even including carotid US data (A.U.C. = 0.641) in a modified DLCN score version. the DLCN score failed to demonstrate a clear superiority in predicting FH gene variants in comparison with the measure of LDL-C levels in a retrospective case study. [Display omitted] • A cohort of 836 hypercholesterolemic subjects were genotypized in a Lipid Clinic. • Dutch Lipid Clinic Score for the diagnosis of familial hypercholesterolemia (FH) was applied retrospectively. • Dutch Lipid Clinic Network (DLCN) was not superior than low density lipoprotein cholesterol (LDL-C) levels to predict FH mutation carriers. • Mutation carriers showed increased prevalence of cardiovascular disease. • Carotid US was not helpful to increase monogenic FH prediction accuracy. [ABSTRACT FROM AUTHOR]

Guideline-recommended use of risk calculators to select for statin therapy in primary prevention has never been tested in a randomized controlled trial (RCT). We determined the extent to which guideline-based statin recommendations from the American College of Cardiology/American Heart Association (ACC/AHA), Canadian Cardiovascular Society(CCS), UK National Institute for Health and Care Excellence (NICE), and European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) is supported by available evidence from RCTs. 79,171 individuals from the Copenhagen General Population Study who were free of ASCVD and statin use at baseline were included. RCT evidence supporting guideline-recommended statin allocation and the estimated number needed to treat (NNT) to prevent one ASCVD event were assessed. During 8.2 years of follow-up, 4031 ASCVD events occurred. Of individuals eligible for statin therapy with the ACC/AHA, CCS, NICE and ESC/EAS guidelines, 86%, 88%, 88% and 84% had direct RCT evidence of statin efficacy, respectively (guideline-positive&RCT-positive). This group represented 26–37% of all 79,171 individuals, while guideline-positive&RCT-negative individuals represented 5–7%, guideline-negative&RCT-positive individuals 28–39%, and guideline-negative&RCT-negative individuals represented 30–31%. The ASCVD events per 1000 person-years were 11.4–12.7 (guideline-positive&RCT-positive), 6.3–8.0 (guideline-positive&RCT-negative), 4.2–5.2 (guideline-negative&RCT-positive), and 2.3–2.5 (guideline-negative&RCT-negative), respectively, while the corresponding NNT to prevent one event in 10 years using high-intensity statin were 19–21, 30–32, 48–60, and 105–125, respectively. The far majority of individuals eligible for guideline-recommended primary prevention with statins have direct RCT evidence supporting statin use. Allocating statins based on guideline-criteria is more efficient with lower NNT for preventing ASCVD events than allocating statin therapy based solely on RCT evidence. [Display omitted] • There is a strong correlation between estimated risk and the presence of randomized controlled trial (RCT) evidence. • ≈ 90 % of those recommended statins by guidelines have RCT evidence supporting efficacy. • Allocating statins based on guideline-criteria is superior to RCT criteria. • Our results strongly support the guideline-recommended use of risk calculators. [ABSTRACT FROM AUTHOR]

The low density lipoprotein cholesterol to Apolipoprotein B (LDL-C/ApoB) ratio is a validated proxy for low density lipoprotein (LDL) particle size that can be easily calculated from a standard lipid/apolipoprotein profile. Whether it is predictive of cardiovascular events in patients with established atherosclerosis is not known and is addressed in the present investigation. We determined the LDL-C/ApoB ratio in a cohort of 1687 subjects with established atherosclerosis. Prospectively, major cardiovascular events (MACE) including cardiovascular death, non-fatal myocardial infarction and non-fatal stroke were recorded over a period of 9.9 ± 4.6 years. The study covers >16,000 patient-years. At baseline, the LDL-C/ApoB ratio was 1.36 ± 0.28 in our cohort. During follow up, a total of 558 first MACE were recorded. The LDL-C/ApoB ratio predicted MACE in univariate Cox proportional hazard analysis (HR 0.90 [0.82–0.98]; p = 0.014); this finding was confirmed after adjustment for age, gender, intensity of statin treatment, hypertension, history of smoking, type 2 diabetes, body mass index and ApoB (HR 0.87 [0.78–0.97]; p = 0.013). The LDL-C/ApoB ratio is independently predictive of MACE in subjects with established atherosclerosis. [Display omitted] • LDL-C and ApoB are recommended targets for therapy in the latest ESC/EAS guidelines on dyslipidemia. • The atherogenicity of LDL-C particles depends on their size, but measuring LDL particle size in clinical routine is not feasible. • The LDL-C/ApoB ratio is an easily obtainable proxy of LDL size in clinical practice. • We show that in patients with established cardiovascular disease this ratio independently predicts MACE. • With new lipid-lowering drugs, e.g. triglyceride lowering agents, the LDL-C/ApoB ratio may be a valuable risk indicator. [ABSTRACT FROM AUTHOR]

Secretory phospholipase A 2 (PLA 2) hydrolyzes LDL phospholipids generating modified LDL particles (PLA 2 -LDL) with increased atherogenic properties. Exocytosis of Weibel–Palade bodies (WPB) releases angiopoietin 2 (Ang2) and externalizes P-selectin, which both play important roles in vascular inflammation. Here, we investigated the effects of PLA 2 -LDL on exocytosis of WPBs. Human coronary artery endothelial cells (HCAECs) were stimulated with PLA 2 - LDL, and its uptake and effect on Ang2 release, leukocyte adhesion, and intracellular calcium levels were measured. The effects of PLA 2 -LDL on Ang2 release and WPB exocytosis were measured in and ex vivo in mice. Exposure of HCAECs to PLA 2 -LDL triggered Ang2 secretion and promoted leukocyte-HCAEC interaction. Lysophosphatidylcholine was identified as a critical component of PLA 2 -LDL regulating the WPB exocytosis, which was mediated by cell-surface proteoglycans, phospholipase C, intracellular calcium, and cytoskeletal remodeling. PLA 2 -LDL also induced murine endothelial WPB exocytosis in blood vessels in and ex vivo, as evidenced by secretion of Ang2 in vivo, P-selectin translocation to plasma membrane in intact endothelial cells in thoracic artery and tracheal vessels, and reduced Ang2 staining in tracheal endothelial cells. Finally, in contrast to normal human coronary arteries, in which Ang2 was present only in the endothelial layer, at sites of advanced atherosclerotic lesions, Ang2 was detected also in the intima, media, and adventitia. Our studies reveal PLA 2 -LDL as a potent agonist of endothelial WPB exocytosis, resulting in increased secretion of Ang2 and translocation of P-selectin. The results provide mechanistic insight into PLA 2 -LDL-dependent promotion of vascular inflammation and atherosclerosis. • Phospholipase A 2 -modified LDL induces secretion of angiopoietin 2 and translocation of P-selectin from endothelial cells. • Lysophosphatidylcholine is responsible for the effect of phospholipase A 2 -modified LDL on endothelial cells. • Phospholipase A 2 -modified LDL mediates its effects via cell surface proteoglycans. [ABSTRACT FROM AUTHOR]

Familial dysbetalipoproteinemia (FD), characterized by remnant lipoprotein accumulation and premature cardiovascular disease, occurs in homozygous carriers of the APOE ε2 allele, but genetic predisposition alone does not suffice for the clinical phenotype. Cross-sectional studies suggest that a second metabolic hit – notably adiposity or insulin resistance – is required, but the association between these risk factors and development of FD has not been studied prospectively. For this study, we evaluated 18,987 subjects from two large prospective Dutch population-based cohorts (PREVEND and Rotterdam Study) of whom 118 were homozygous APOE ε2 carriers. Of these, 69 subjects were available for prospective analyses. Dyslipidemia – likely to be FD – was defined as fasting triglyceride (TG) levels >3 mmol/L in untreated subjects or use of lipid lowering medication. The effect of weight, body mass index (BMI), waist circumference, type 2 diabetes mellitus and non-TG metabolic syndrome on development of dyslipidemia was investigated. Eleven of the 69 ε2ε2 subjects (16%) developed dyslipidemia – likely FD – during follow-up. Age-, sex- and cohort-adjusted risk factors for the development of FD were BMI (OR 1.19; 95%CI 1.04–1.39), waist circumference (OR 1.26 95%CI 1.01–1.61) and presence of non-TG metabolic syndrome (OR 4.39; 95%CI 1.04–18.4) at baseline. Change in adiposity during follow-up was not associated with development of dyslipidemia. Adiposity increases the risk of developing an FD-like lipid phenotype in homozygous APOE ε2 subjects. These results stress the importance of healthy body weight in subjects at risk of developing FD. [Display omitted] • Baseline adiposity increases the risk of developing dyslipidemia – likely familial dysbetalipoproteinemia (FD) – in ε2ε2 subjects from the general population. • Change in adiposity during follow-up was not associated with the development of dyslipidemia – likely FD. • This suggests that in ε2ε2 subjects the 'switch' to FD-like lipid phenotype is a gradual process that starts early in life. [ABSTRACT FROM AUTHOR]

Clinical trials have demonstrated reductions in major adverse cardiovascular events with purified high-dose eicosapentaenoic acid (EPA), independent of effects on lipids. We aimed to investigate whether omega-3 fatty acids reduce vascular inflammation, a critical mediator of atherosclerosis, and hypothesised that EPA is superior to docosahexaenoic acid (DHA). In a double-blind randomised controlled trial and cell-culture study, 40 healthy volunteers were supplemented with 4 g daily of either EPA, DHA, fish oil (2:1 EPA:DHA), or placebo for 30 days. Serum was incubated with TNF-stimulated human umbilical vein endothelial cells (HUVECs), and markers of acute vascular inflammation (AVI) were measured. The effects of EPA, DHA (600 mg/kg/day), olive oil, or no treatment were also measured in preclinical models of [1] AVI using a periarterial collar (C57Bl/6J; n = 40 mice) and [2] atherosclerosis where ApoE −/− mice (n = 40) were fed a 16-week atherogenic diet. EPA supplementation reduced expression of C–C motif chemokine ligand 2 (CCL2) by 25% compared to placebo (p = 0.03). In the AVI model, EPA reduced vascular expression of VCAM1 by 43% (p = 0.02) and CCL2 by 41% (p = 0.03). Significant inverse correlations were observed between EPA levels and vascular expression of VCAM1 (r = −0.56, p = 0.001) and CCL2 (r = −0.56, p = 0.001). In ApoE −/- mice, EPA reduced aortic expression of Il1b by 44% (p = 0.04) and Tnf by 49% (p = 0.04), with similar inverse correlations between EPA levels and both Il1b (r = −0.63, p = 0.009) and Tnf (r = −0.50, p = 0.04). Supplementation with EPA, more so than DHA, ameliorates acute and chronic vascular inflammation, providing a rationale for the cardiovascular benefit observed with high dose omega-3 fatty acid administration. [Display omitted] • Eicosapentaenoic acid (EPA) reduced expression of markers of acute vascular inflammation after inflammatory stimuli, in in vitro and in vivo models. • EPA reduced expression of markers of chronic vascular inflammation but not plaque burden, in an atherogenic mouse model. • Blood EPA and docosahexaenoic acid (DHA) levels correlated inversely with markers of vascular inflammation, with EPA having a stronger correlation. [ABSTRACT FROM AUTHOR]

Familial hypercholesterolaemia (FH) is commonly caused by mutations in the LDLR, APOB or PCSK9 genes, with untreated mean low density lipoprotein-cholesterol (LDL-C) concentrations being elevated in APOB mutation carriers, even higher in LDLR mutation and highest in those with a PCSK9 mutation. Here we examine this in children with FH from Norway, UK, The Netherlands, Belgium, Czech Republic, Austria, Portugal and Greece. Differences in characteristics and pre- and post-treatment lipid concentrations in those with different molecular causes were compared by standard statistical tests. Data were obtained from 2866 children, of whom 2531 (88%) carried a reported LDLR/APOB/PCSK9 variant. In all countries, the most common cause of FH was an LDLR mutation (79% of children, 297 different), but the prevalence of the APOB p.(Arg3527Gln) mutation varied significantly (ranging from 0% in Greece to 39% in Czech Republic, p < 2.2 × 10−16). The prevalence of a family history of premature CHD was significantly higher in children with an LDLR vs APOB mutation (16% vs 7% p= 0.0005). Compared to the LDLR mutation group, mean (±SD) concentrations of pre-treatment LDL-C were significantly lower in those with an APOB mutation (n = 2260 vs n = 264, 4.96 (1.08)mmol/l vs 5.88 (1.41)mmol/l, p < 2.2 × 10−16) and lowest in those with a PCSK9 mutation (n = 7, 4.71 (1.22)mmol/l). The most common cause of FH in children from eight European countries was an LDLR mutation, with the prevalence of the APOB p.(Arg3527Gln) mutation varying significantly across countries. In children, LDLR- FH is associated with higher concentrations of LDL-C and family history of CHD compared to those with APOB- FH. Image 1 • LDLR mutations are the most common cause of familial hypercholesterolaemia (FH) in children from 8 European countries. • Overall, 279 different LDLR mutations were found in 2531 FH children. • The frequency of APOB p.(Arg3527Gln) varied significantly over the 8 countries. • APOB -FH was less severe than LDLR -FH for low density lipoprotein-cholesterol (LDL-C) concentration and family onset of coronary heart disease (CHD). [ABSTRACT FROM AUTHOR]

The lipid profile is consistently associated with coronary artery disease (CAD) and ischemic stroke (IS). However, the lipoprotein subfractions have not been deeply explored in stroke subtypes, especially in IS outcome. We performed two-sample Mendelian randomization (MR) analysis using 92 lipid traits measured by nuclear magnetic resonance in 115,000 subjects from the UK Biobank. Data for genetic associations with IS, its subtypes, and long-term outcome (LTO) were obtained from three cohorts of European ancestry: GIGASTROKE (73,652 cases, 1,234,808 controls), GODS (n = 1791) and GISCOME (n = 6165). Results obtained using CARDIoGRAMPlusC4D were used to identify differences with CAD. Genetically determined low concentration of medium high-density lipoprotein (HDL) particles (odds ratio (OR) = 0.92, 95% CI 0.88–0.96; p = 3.6 × 10−4) and its cholesterol content (OR = 0.92, 95% CI 0.88–0.96; p = 1.9 × 10−4) showed causal associations with an increased risk of stroke. Genetic predisposition to high apolipoprotein (apo)B to apoA-I ratio was causally associated with an increased risk of IS (OR = 1.12, 95% CI 1.06–1.18, p = 1.1 × 10−4), and a highly suggestive association was found between non-esterified cholesterol in low-density lipoprotein (LDL) and increased risk of atherothrombotic stroke (LAS) (OR = 1.35, 95% CI 1.10–1.66; p = 4.0 × 10−3). Low cholesterol in small and medium LDL was suggestively associated with poor LTO. Our results support that low medium HDL concentration was causally associated with an increased stroke risk, while high levels of non-esterified cholesterol in LDL were suggestively associated with an increased risk of LAS and with a better LTO. [Display omitted] • Causal association of low HDL-C with stroke risk is due to the medium subfraction. • Free cholesterol content is implicated in the association of high LDL with stroke risk. • The association of triglyceride-rich lipoproteins with stroke remains inconclusive. • ApoB-lipoproteins play a more important role in CAD risk than in stroke risk. • The association of low LDL-C with a poor long-term outcome needs further studies. [ABSTRACT FROM AUTHOR]

Epidemiological data and interventional studies with hormone replacement therapy suggest that women, at least until menopause, are at decreased cardiovascular risk compared to men. Still the molecular mechanisms beyond this difference are debated and the investigation in experimental models of atherosclerosis has been pivotal to prove that the activation of the estrogen receptor is atheroprotective, despite not enough to explain the differences reported in cardiovascular disease between male and female. This casts also for investigating the importance of the sex chromosome complement (genetic sex) beyond the contribution of sex hormones (gonadal sex) on atherosclerosis. Aim of this review is to present the dualism between gonadal sex and genetic sex with a focus on the data available from experimental models. The molecular mechanisms driving changes in lipid metabolism, immuno-inflammatory reactivity and vascular response in males and females that affect atherosclerosis progression will be discussed. [Display omitted] • Women are at decreased cardiovascular risk compared to men until menopause, an effect not solely explained by estrogens. • Experimental models have deepened our knowledge of atherosclerosis, but sex differences are still underestimated. • Animal models are depicting the impact of sexual hormones (gonadal sex) versus sexual chromosomes (genetic sex). • Both lipid and inflammatory traits can be differently modulated by genetic versus gonadal sex. [ABSTRACT FROM AUTHOR]

Differences between men and women in lipids and lipoproteins are observed in distribution and trajectory from infancy to adulthood in the general population. However, these differences are more pronounced in hereditary lipid disorders such as familial hypercholesterolemia (FH) when absolute cholesterol levels are higher from birth onwards. In the early life course, girls compared to boys have higher low-density lipoprotein cholesterol (LDL-C) levels and total cholesterol, while high-density lipoprotein cholesterol (HDL-C) levels are similar. In early adulthood to middle-age, women have lower LDL-C and higher HDL-C levels, as LDL-C levels increase and HDLC levels decrease in men. In the elderly, all lipids – total cholesterol, LDL-C, HDL-C and triglyceride levels decrease but are more pronounced in men. Lipid levels are also affected by specific transitions in girls/women such as the menstrual cycle, pregnancy, breastfeeding and menopause. Lipid levels fluctuate during the menstrual cycle. During pregnancy a physiological increase of LDL-C and even a larger increase in triglyceride levels are observed. Pregnancy has a double impact on LDL-C accumulation in women with FH as they have to stop statins, and the absolute increase in LDL-C is higher than in women without FH. In the menopausal transition, women develop a more adverse lipid profile. Therefore, it is important to take into account both sex and the life course when assessing a lipid profile. [Display omitted] • Women are characterized by a more atherogenic lipid profile from infancy to early adulthood and from middle age to old age. • Transition periods in women, such as menstrual cycle, pregnancy, breastfeeding and menopause, influence lipid levels. • The sex difference and the effect of the female transition periods seem to be more pronounced in women with FH. [ABSTRACT FROM AUTHOR]

During fat tolerance tests, plasma triglycerides increase while high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and intermediate-density lipoprotein (IDL) cholesterol decrease. However, it is unknown whether triglyceride content increases and cholesterol content decreases in HDL and LDL + IDL fractions following normal meals in the general population. Therefore, we tested the hypothesis that triglyceride content increases while cholesterol content decreases in HDL and LDL + IDL fractions following normal meals. In this cross-sectional study, we included 25,656 individuals aged 20–100 years, all without lipid-lowering therapy at examination and selected for metabolomic profiling from the Copenhagen General Population Study. Triglyceride and cholesterol content of 14 lipoprotein fractions weas measured using nuclear magnetic resonance (NMR) spectroscopy. Time since last meal was recorded by the examiner immediately before blood sampling. Following normal meals in age and sex-adjusted analyses and when compared with fasting levels, plasma triglycerides were higher for up to 5–6 h, and triglyceride content was higher for up to 6–7 h in HDL fractions, for up to 6–7 h in LDL + IDL fractions, and for up to 5–6 h in very-low-density lipoprotein (VLDL) fractions. Further, plasma cholesterol was lower for up to 2–3 h, and cholesterol content was lower for up to 0–1 h in HDL fractions and for up to 4–5 h in LDL + IDL fractions, while cholesterol content was higher for up to 4–5 h in VLDL fractions. Following normal meals, triglyceride content increases while cholesterol content decreases in HDL and LDL + IDL fractions. [Display omitted] • Following normal meals, triglyceride content increases in HDL and LDL + IDL fractions. • Following normal meals, cholesterol content decreases in HDL and LDL + IDL fractions. • Following normal meals, cholesterol content decreases in the smallest HDL fractions. • Following normal meals, cholesterol content increases in the largest VLDL fractions. • Results were similar in women and men, and in individuals with low and high BMI. [ABSTRACT FROM AUTHOR]

Numerous low-density lipoprotein (LDL) calculating equations for more accurate estimation have emerged. With the present study, we assessed the clinical impact of implementing novel equations in terms of risk reclassification and LDL treatment goals in myocardial infarction (MI) patients. This was a post-hoc analysis of a prospective acute MI cohort study. We enrolled 805 consecutive patients presenting with acute MI. Patients with high triglyceride levels (>400 mg/dL) were excluded. In the remaining 773 acute MI patients, LDL cholesterol levels were calculated using 12 different equations including the Friedewald equation. Each patient was categorized into a 5-scale risk strata scheme according to baseline LDL cholesterol levels. Moreover, ΔLDL cholesterol (change in LDL cholesterol levels to achieve the <55 mg/dL LDL treatment goal) was calculated for each patient. Mean levels and distribution of LDL cholesterol were significantly different compared to those derived from the Friedewald equation. Net reclassification improvement (NRI) analysis, as well as heat maps, showed that this re-categorization had no significant impact on prognostic terms (NRI ranged from −6.1% to 5.9% with p values > 0.05 for each comparison). Statistically significant differences were observed in ΔLDL cholesterol levels between each one of the novel equations and the Friedewald equation. Novel LDL cholesterol calculating equations are not associated with a clinically significant risk re-classification in MI patients. In addition, use of these novel equations may have an impact on assessing potency of hypolipidemic therapy use in secondary prevention as far as succeeding lipid treatment goals in MI patients. Image 1 • Low density lipoprotein (LDL) cholesterol calculating equations for more accurate estimation have emerged. • Novel equations are not associated with significant risk re-classification. • They may have an impact on assessing potency of statins in secondary prevention. [ABSTRACT FROM AUTHOR]

An inverse relationship between lipid levels and atrial fibrillation (AF) has been suggested, but whether the association is upheld for all age groups remains unclear. The aim of the study was to examine associations between lipid levels and AF by age groups in a nationwide study in Poland. Multivariate Poisson regression models were used to estimate prevalence ratios (PRs) for AF by lipid levels. Low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), total cholesterol (TC), non-HDL-C and LDL-C/HDL-C ratios were grouped into quartiles. Of the 13,724 participants, 5.2% (n = 708) had AF. People with AF were older with more comorbidities, but lower lipid levels (all p < 0.05). The prevalence of AF was inversely associated with LDL-C (Adjusted PR (95% Confidence Interval) highest versus lowest quartile: 0.60 (0.48, 0.75)), TC (0.61 (0.49, 0.75)) and non-HDL-C (0.63 (0.51, 0.78)). The prevalence of AF was inversely associated with HDL-C (0.58 (0.46, 0.74)), but this was not statistically significant for people aged 75 years and older. For the LDL-C/HDL-C ratio, the prevalence of AF was only inversely associated with higher levels for people aged 75 years and older (0.75 (0.61, 0.94)). There was no statistically significant difference in prevalence of AF by TG levels. The results suggest an inverse relationship between lipid levels and AF. The inverse association between higher HDL-C and AF was only significant for people aged <75 years, whereas the inverse association between higher LDL-C/HDL-C ratio and AF was only significant for people aged 75 years and older. Image 1 • Cholesterol levels inversely associate with prevalence of atrial fibrillation (AF). • Inverse association between high-density lipoprotein cholesterol (HDL-C) and AF was only apparent for people aged <75 years. • Inverse association between low-density lipoprotein cholesterol/HDL-C ratio AF was only apparent for people aged ≥75 years. [ABSTRACT FROM AUTHOR]

Dysregulated lipid metabolism has emerged as one of the major risk factors of atherosclerosis. Presently, there is a consensus that oxidized LDL (oxLDL) promotes development of atherosclerosis and downstream chronic inflammatory responses. Due to the dynamic metabolic disposition of lipoprotein, conventional approach to purify bioactive lipids for subsequent comprehensive analysis has proven to be inadequate for elucidation of the oxidized lipids species accountable for pathophysiology of atherosclerotic lesions. Herein, we aimed to utilize a novel mass microscopic imaging technology, coupled with mass spectrometry (MS) to characterize oxidized lipids in atherosclerotic lesions. We attempted to use MALDI-TOF-MS and iMScope to identify selected oxidized lipid targets and visualize their respective localizations in study models of atherosclerosis. Based on the MS analysis, detection of 7-K under positive ionization through product ion peak at m/z 383 [M + H–H 2 O] indicated the distinctive presence of targeted lipid within Cu2+-oxLDL and Cu2+-oxLDL loaded macrophage-like J774A.1 cells, along with other cholesterol oxidation products. Moreover, the application of two-dimensional iMScope has successfully visualized the localization of lipids in aortic atherosclerotic plaques of the Watanabe heritable hyperlipidemic (WHHL) rabbit. Distinctive lipid distribution profiles were observed in atherosclerotic lesions of different sizes, especially the localizations of lysoPCs in atherosclerotic plaques. Taken together, we believe that both MALDI-TOF-MS and iMScope metabolomics technology may offer a novel proposition for future pathophysiological studies of lipid metabolism in atherosclerosis. Image 1 • We assembled a panel of oxidized lipids relating to progression of atherosclerosis. • Imaging mass microscopy (iMScope) can visualize distribution of lipid peroxides within atherosclerotic plaque. • MALDI-TOF-MS is able to characterize bioactive lipids from sectioned tissue samples. • IMScope and MALDI-TOF-MS offer novel approaches for lipidomics of atherosclerosis. [ABSTRACT FROM AUTHOR]

Disorders in blood lipid metabolism and leukocyte-mediated inflammation are considered the main mechanisms of the pathogenesis of atherosclerosis. This study aims to show whether and how peripheral leukocyte counts are associated with serum lipid levels. This is a cross-sectional study of 175,079 subjects from the healthy population. Age and sex are two key factors dictating the relationship between peripheral leukocyte counts and serum lipid levels. The log-transformed level of triglycerides (LnTG) was positively associated with all leukocyte counts in males except monocyte count in younger subjects. LnTG was positively associated with total leukocyte count in females regardless of age, and it was positively associated with lymphocyte and monocyte counts and neutrophil count only in elderly and young women, respectively. Total cholesterol levels were positively associated with total leukocyte, neutrophil and lymphocyte counts only in young males and with lymphocyte counts only in elderly women. LDL-C was negatively associated with monocyte count in males regardless of age; by contrast, it was positively associated with total leukocyte and lymphocyte counts in females regardless of age range and neutrophil and LnEosinophil counts only in young women. HDL-C was negatively associated with total leukocyte, lymphocyte and monocyte counts in both young men and young women; was negatively associated with monocyte count in elderly men and women; and was negatively associated with LnEosinophil count only in older men. Peripheral leukocyte counts are extensively associated with serum lipid levels, with patterns differing by sex, age, lipid and leukocyte subset. Image 1 • Leukocytes are associated with lipids, with patterns differing by sex, age and lipid. • Triglycerides (TG) level is a dominant factor positively associated with leukocyte count in males. • High-density lipoprotein (HDL) dominantly and negatively corrects leukocyte counts in youngers of both sexes. • Low-density lipoprotein (LDL) is dominantly and positively associated with leukocyte count in young females. • TG level is dominantly and positively associated with leukocyte count in older females. [ABSTRACT FROM AUTHOR]

Lipid-rich foam cell macrophages drive atherosclerosis via several mechanisms, including inflammation, lipid uptake, lipid deposition and plaque vulnerability. The atheroma environment shapes macrophage function and phenotype; anti-inflammatory macrophages improve plaque stability while pro-inflammatory macrophages promote rupture. Current evidence suggests a variety of macrophage phenotypes occur in atherosclerotic plaques with local lipids, cytokines, oxidised phospholipids and pathogenic stimuli altering their phenotype. In this study, we addressed differential functioning of macrophage phenotypes via a systematic analysis of in vitro polarised, human monocyte-derived macrophage phenotypes, focussing on molecular events that regulate foam-cell formation. We examined transcriptomes, protein levels and functionally determined lipid handling and foam cell formation capacity in macrophages polarised with IFNγ+LPS, IL–4, IL–10, oxPAPC and CXCL4. RNA sequencing of differentially polarised macrophages revealed distinct gene expression changes, with enrichment in atherosclerosis and lipid-associated pathways. Analysis of lipid processing activity showed IL–4 and IL–10 macrophages have higher lipid uptake and foam cell formation activities, while inflammatory and oxPAPC macrophages displayed lower foam cell formation. Inflammatory macrophages showed low lipid uptake, while higher lipid uptake in oxPAPC macrophages was matched by increased lipid efflux capacity. Atherosclerosis-associated macrophage polarisation dramatically affects lipid handling capacity underpinned by major transcriptomic changes and altered protein levels in lipid-handling gene expression. This leads to phenotype-specific differences in LDL uptake, cellular cholesterol levels and cholesterol efflux, informing how the plaque environment influences atherosclerosis progression by influencing macrophage phenotypes. Image 1 • Polarised macrophages are enriched in atherosclerosis and lipid pathway genes. • Anti-inflammatory macrophages had higher lipid uptake and foam cell formation. • Inflammatory and oxPAPC macrophages displayed lower foam cell formation. • Inflammatory macrophages showed low lipid uptake. • oxPAPC macrophages showed higher lipid uptake and efflux capacity. [ABSTRACT FROM AUTHOR]

Dyslipidemias are strongly linked to the development of atherosclerotic cardiovascular disease. Most dyslipidemias find their origin in the liver. In recent years, the differentiation of induced pluripotent stem cells (iPSCs) into hepatocyte-like cells has provided a versatile platform for the functional study of various dyslipidemias, both rare genetic dyslipidemia as well as common lipid disorders associated with insulin resistance or non-alcoholic fatty liver disease. In addition, iPSC-derived hepatocytes can serve as a cell model for developing novel lipid lowering therapies and have the potential of regenerative medicine. This review provides an overview of these developments. • Hepatocyte like cells (HLCs) can provide an in vitro hepatic cell line with specific variants without gene editing tools. • HLCs provide a versatile tool for investigating lipid/lipoprotein metabolism in vitro. • HLCs provide a platform to test the biological impact of genetic variants compared to an isogenic control. • HLCs provide a platform for high throughput drug testing. [ABSTRACT FROM AUTHOR]

Although serum lipids are widely accepted as independent predictors of myocardial infarction (MI), there is insufficient evidence for associations of changes in lipid levels with MI. The present study aimed at investigating the associations between changes in lipids and incidence of MI in people without lipid-lowering therapy. 64,031 Chinese participants (mean age: 53.42 ± 11.95 years) without previous MI were enrolled in the study. The participants were divided into four categories based on quartiles of lipid changes. Multivariable Cox regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for MI. During a median follow-up of 7.03 years, 599 individuals developed MI. After adjustment for covariates, increased total cholesterol (TC), increased low-density lipoprotein cholesterol (LDL-C), increased non-high-density lipoprotein cholesterol (non-HDL-C), and decreased high-density lipoprotein cholesterol (HDL-C) were associated with elevated risk of MI, with HRs (95% CIs) in the highest quartile group compared with the lowest quartile group of 1.56 (1.21–2.01), 1.96 (1.49–2.57), 1.95 (1.52–2.50), and 0.69 (0.53–0.90), respectively. However, changes in triglyceride (TG) were not associated with MI risk (p = 0.8030). Changes in levels of TC, LDL-C, non-HDL-C, and HDL-C, but not TG, were associated with risk of MI. Early detection and control of lipid levels may be beneficial and necessary for young people and those with healthy lipid levels at baseline. Image 1 • Changes in lipids would increase the predictive value of conventional risk factors. • Changes in lipids except triglyceride are related to myocardial infarction risk. • Early detection and control of lipids is also beneficial for young people. [ABSTRACT FROM AUTHOR]

Apolipoprotein A-I (apoA-I) infusions represent a potential novel therapeutic approach for the prevention of coronary artery disease (CAD). Although circulating apoA-I concentrations inversely associate with risk of CAD, the evidence base of this representing a causal relationship is lacking. The aim was to assess the causal role of apoA-I using human genetics. We identified a variant (rs12225230) in APOA1 locus that associated with circulating apoA-I concentrations (p < 5 × 10−8) in 20,370 Finnish participants, and meta-analyzed our data with a previous GWAS of apoA-I. We obtained genetic estimates of CAD from UK Biobank and CARDIoGRAMplusC4D (totaling 122,733 CAD cases) and conducted a two-sample Mendelian randomization analysis. We compared our genetic findings to observational associations of apoA-I with risk of CAD in 918 incident CAD cases among 11,535 individuals from population-based prospective cohorts. ApoA-I was associated with a lower risk of CAD in observational analyses (HR 0.81; 95%CI: 0.75, 0.88; per 1-SD higher apoA-I), with the association showing a dose-response relationship. Rs12225230 associated with apoA-I concentrations (per-C allele beta 0.076 SD; SE: 0.013; p = 1.5 × 10−9) but not with confounders. In Mendelian randomization analyses, apoA-I was not related to risk of CAD (OR 1.13; 95%CI: 0.98,1.30 per 1-SD higher apoA-I), which was different from the observational association. Similar findings were observed using an independent ABCA1 variant in sensitivity analysis. Genetic evidence fails to support a cardioprotective role for apoA-I. This is in line with the cumulative evidence showing that HDL-related phenotypes are unlikely to have a protective role in CAD. Image 1 • Apolipoprotein A-I relates to lower observational risk of coronary artery disease. • Robust evidence of atheroprotective properties of apolipoprotein A-I is lacking. • Mendelian randomization was used to assess the causality of apolipoprotein A-I. • Apolipoprotein A-I association with coronary artery disease is likely not causal. • Apolipoprotein A-I increasing therapies unlikely reduce risk of heart disease. [ABSTRACT FROM AUTHOR]

Ischemic heart diseases are the main cause of death worldwide, therefore secondary prevention and treatment of coronary artery disease (CAD) are highly significant for public health and mortality. The objective of this study is to evaluate LDL cholesterol (LDL-C) levels as outcomes of secondary prevention of CAD in Finland up to 24 months after being diagnosed with acute coronary syndrome (ACS). This retrospective analysis of patients with ACS was conducted in two areas of Finland that have a combined population of 400,000. The data used in the study covered all outpatient visits, inpatient episodes, prescriptions and LDL-C results for ACS patients during 2011–2015. To evaluate the outcome of the prevention, three separate measurements of patients' LDL-C levels were considered: baseline, first follow-up and final follow-up. The factors associated with reaching treatment goal were identified using logistic regression analysis. 32% of ACS patients achieved the treatment goal (LDL-C <1.8 mmol/l) at the end of the 24-month follow-up period, but 21% of patients fluctuated between being on and above target. Two thirds of CAD patients with ACS and on statin therapy do not achieve LDL-C treatment target recommended by the guidelines. Since LDL-C levels fluctuate in the follow-up, a low level during the first 12 months after the acute event does not guarantee the maintenance of the results in the long term. Hence, LDL-C levels should be monitored at least on an yearly basis on follow-ups, and treatment adapted accordingly. Image 1 • 31% of patients reached the treatment goal at the end of the follow-up period. • Improvement in LDL-C levels happened mainly before the first follow-up. • 21% of patients fluctuate between being on and above target. [ABSTRACT FROM AUTHOR]

Lipoprotein(a), Lp(a), is a modified atherogenic low-density lipoprotein particle that contains apolipoprotein(a). Its levels are highly heritable and variable in the population. This consensus statement by HEART UK is based on the evidence that Lp(a) is an independent cardiovascular disease (CVD) risk factor, provides recommendations for its measurement in clinical practice and reviews current and emerging therapeutic strategies to reduce CVD risk. Ten statements summarise the most salient points for practitioners and patients with high Lp(a). HEART UK recommends that Lp(a) is measured in adults as follows: 1) those with a personal or family history of premature atherosclerotic CVD; 2) those with first-degree relatives who have Lp(a) levels >200 nmol/l; 3) patients with familial hypercholesterolemia; 4) patients with calcific aortic valve stenosis and 5) those with borderline (but <15%) 10-year risk of a cardiovascular event. The management of patients with raised Lp(a) levels should include: 1) reducing overall atherosclerotic risk; 2) controlling dyslipidemia with a desirable non-HDL-cholesterol level of <100 mg/dl (2.5 mmol/l) and 3) consideration of lipoprotein apheresis. Image 1 • The cardiovascular risk conferred by lipoprotein(a) is determined by the lipoprotein(a) serum concentration. • Serum lipoprotein(a) levels should be measured in five specific population groups. • Recommendations on the management of patients with raised lipoprotein(a) levels (>90 nmol/l) are discussed. [ABSTRACT FROM AUTHOR]

Hyperlipidemia-induced atherosclerosis is the major cause of heart attack and stroke in humans. However, pathological details and molecular mechanisms underlying early atherogenesis remain incompletely characterized. This study explored the early events of atherogenesis in a hypercholesterolemic zebrafish model in vivo. We used transparent transgenic zebrafish larvae Tg(lysc:EGFP) , Tg(mpx:EGFP) , Tg(mpeg1:EGFP) , Tg(flk1:EGFP) or Tg(lysc:EGFP/flk1:mCherry) , together with fluorescently labeled control and high cholesterol diets (HCD), to dynamically investigate the early development of atherosclerosis with confocal in vivo. Endothelial cells with green fluorescence were sorted by fluorescence-activated cell sorting (FACS) to detect gene expression. Moreover, we treated hypercholesterolemic zebrafish model in vivo or human umbilical vein endothelial cells (HUVEC) in vitro with rosiglitazone, an agonist of peroxisome proliferator-activated receptor γ (PPARγ). We found that HCD-induced endothelial inflammation was an earlier pathological alteration than myeloid cells/neutrophils accumulation and lipid deposition in zebrafish vascular vessels of HCD-fed zebrafish. Endothelial inflammation was characterized by down-regulation of anti-inflammatory PPARγ and upregulation of pro-inflammatory tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β). Pharmacological treatment with rosiglitazone reversed the decrease in the expression of PPARγ and decreased expression of TNF-α and IL-1β in HCD-fed zebrafish. Moreover, rosiglitazone ameliorated myeloid cells accumulation and lipid deposition in HCD-fed zebrafish in vivo. Hyperlipidemia-induced endothelial inflammation happens earlier than myeloid cell neutrophils accumulation in vascular vessels, and neutrophils accumulation is prior to lipid deposition during the initial stage of atherosclerosis. Early alleviation of inflammation induced by HCD would have a prophylactic effect for the initial development of atherosclerosis. Image 1 • Endothelial inflammation is prior to neutrophils accumulation and lipid deposition during the early atherogenesis. • Endothelial inflammation is characterized by the down-regulation of PPARγ and the up-regulation of TNF-α and IL-1β. • PPARγ agonist rosiglitazone inhibits HCD-induced up-regulation of TNF-α and IL-1β by reversing PPARγ expression. • Rosiglitazone ameliorated myeloid cells/neutrophils accumulation and lipid deposition in HCD-fed zebrafish. [ABSTRACT FROM AUTHOR]

Cholesterol homeostasis is of central importance for life. Therefore, cells have developed a divergent set of pathways to meet their cholesterol needs. In this review, we focus on the direct transfer of cholesterol from lipoprotein particles to the cell membrane. More molecular details on the transfer of lipoprotein-derived lipids were gained by recent studies using phospholipid bilayers. While amphiphilic lipids are transferred right after contact of the lipoprotein particle with the membrane, the transfer of core lipids is restricted. Amphiphilic lipid transfer gains special importance in genetic diseases impairing lipoprotein metabolism like familial hypercholesterolemia. Taken together, these data indicate that there is a constant exchange of amphiphilic lipids between lipoprotein particles and the cell membrane. Image 1 • Free cholesterol transfer from lipoprotein particles to the plasma membrane occurs in mammals. • Amphiphilic lipid transfer occurs upon contact of lipoprotein particles to the plasma membrane. • Both transfer mechanisms are driven by a concentration gradient. • They are independent of the apolipoprotein/protein composition of the lipoprotein particle. • Close proximity of lipoprotein particles to the membrane yields immediate transfer of cholesterol. [ABSTRACT FROM AUTHOR]

Familial hypercholesterolemia (FH) is a monogenic disease characterized by high levels of low-density lipoprotein cholesterol and premature atherosclerotic cardiovascular disease. FH is caused by loss of function mutations in genes encoding LDL receptor (LDLR), and Apolipoprotein B (APOB) or gain of function (GOF) mutations in proprotein convertase subtilisin/kexin type 9 (PCSK9). In this study, we identified a novel variant in PCSK9 , p.(Arg499His), located in the C-terminal domain , in two unrelated FH patients from Spain and Italy. We studied familial segregation and determined variant activity in vitro. We determined PCSK9 expression, secretion and activity of the variant in transfected HEK293 cells; extracellular activity of the recombinant p.(Arg499His) PCSK9 variant in HEK 293 and HepG2 cells; PCSK9 affinity to the LDL receptor at neutral and acidic pH; the mechanism of action of the p.(Arg499His) PCSK9 variant by co-transfection with a soluble construct of the LDL receptor and by determining total PCSK9 intracellular accumulation when endosomal acidification is impaired and when an excess of soluble LDLr is present in the culture medium. Our results show high LDL-C concentrations and FH phenotype in p.(Arg499His) carriers. In vitro functional characterization shows that p.(Arg499His) PCSK9 variant causes a reduction in LDLr expression and LDL uptake. An intracellular activity for this variant is also shown when blocking the activity of secreted PCSK9 and by inhibiting endosomal acidification. We demonstrated that p.(Arg499His) PCSK9 variant causes a direct intracellular degradation of LDLr therefore causing FH by reducing LDLr availability. Image 1 • We identified a novel PCSK9 GOF variant, p.(Arg499His), in two unrelated FH patients from Spain and Italy. • p.(Arg499His) PCSK9 variant carriers show high LDL-C concentrations and FH phenotype. • In vitro assays revealed reduced LDL receptor expression at membrane surface with p.(Arg499His). • p.(Arg499His) is a GOF mutation that causes FH through an intracellular effect reducing LDLr availability. [ABSTRACT FROM AUTHOR]

Krüppel-like factor 14 (KLF14) is known to play a role in atherosclerosis, but the underlying mechanisms are still largely unknown. The aim of our study was to explore the effects of KLF14 on lipid metabolism and inflammatory response, providing a potential target for lowering the risk of atherosclerosis-causing disease. mRNA and protein levels of KLF14 were significantly decreased in oxidized low-density lipoprotein (oxLDL)-treated macrophages and in the atherosclerotic lesion area. Chromatin immunoprecipitation (ChIP) and luciferase reporter gene assays were used to confirm that KLF14 positively regulated miR-27a expression by binding to its promoter. We also found that KLF14 could restored appropriate cellular lipid homeostasis and inflammatory responses via negatively regulating lipoprotein lipase (LPL) expression in THP1-derived macrophages through miR-27a. In addition, gypenosides (GP), a KLF14 activator, delayed the development of atherosclerosis in apolipoprotein E deficient (apoE −/− ) mice. KLF14 plays an antiatherogenic role via the miR-27a-dependent down-regulation of LPL and subsequent inhibition of proinflammatory cytokine secretion and lipid accumulation. Image 1 • KLF14 inhibits proinflammatory cytokines and lipid accumulation in macrophages via binding to the promoter of miR-27a. • MiR-27a-mediated LPL downregulation participates in the inhibitory effect of KLF14 on inflammation and lipid accumulation. • Gypenosides, a KLF14 activator, delays the development of atherosclerosis in apoE −/− mice. [ABSTRACT FROM AUTHOR]

Atherosclerosis is usually the underlying cause of heart attacks, strokes and peripheral vascular diseases – collectively known as cardiovascular diseases. Oxidation of low density lipoprotein (LDL) and its lipid content has an important role in the formation of lipid-laden atherosclerotic plaques. Not much is known about the impact of oxidative stress on bioactive oxylipin molecules present in LDL. The aim of this study is to understand the changes in oxylipin molecules present in LDL characterized by varying degrees of LDL oxidation. LDL was isolated from the pooled plasma of healthy normolipidemic volunteers and was subjected to in vitro copper-catalyzed oxidation for varying time intervals (0 h, 6 h, 12 h, 24 h and 30 h). At each time interval, oxylipins were isolated through solid phase extraction and quantified using a targeted LC/-MS/MS approach employing stable isotope dilution method. Our results demonstrate that different forms of oxidized LDL (OxLDL) are characterized by specific oxylipin distribution and concentration. Compared to non-oxidized LDL, there is a significant increase in oxylipin generation (p ≤ 0.05) in OxLDL subjected to 12 h and 24 h of oxidation. Though linoleate derived oxylipins are the most abundant in OxLDL extracts, the concentration of particular oxylipin species differed with different degrees of oxidation. Specifically, two pro-inflammatory linoleate-derived triols, namely 9,10,13-triHOME and 9,12,13-triHOME, exhibited a concentration increase of ~25 fold in 12h-OxLDL compared to non-oxidized LDL. Moreover, Partial least squares Discriminant Analysis (PLS-DA) identified 10 oxylipins, primarily prostaglandins, which could serve as additional biomarkers for oxidative stress or cardiovascular risk assessment. Our data suggests that oxidative stress induces profound changes in the oxylipin content of LDL and the pattern of change is based on the extent of oxidation. Image 1 • Oxylipin profile of LDL changes dramatically during copper oxidation. • Oxidation of LDL generates new oxylipins, with both pro- and anti-inflammatory properties. • Oxylipin profile of LDL can determine the level of oxidation of the LDL particle. [ABSTRACT FROM AUTHOR]