Effects of EPA on coronary artery disease in hypercholesterolemic patients with multiple risk factors: Sub-analysis of primary prevention cases from the Japan EPA Lipid Intervention Study (JELIS)

The EPA oxylipin, 12-HEPE, directly regulates human platelet activity

Arterial thrombosis, driven by platelet hyperactivity, is the underlying pathophysiology of most major cardiovascular events. Dietary fish oil supplementation containing ω-3 polyunsaturated fatty acids (PUFAs) elicits cardiovascular protection in at-risk patients. Studies have attributed the cardiovascular benefits of ω-3 PUFAs to eicosapentaenoic acid (EPA), the primary ω-3 PUFA present in fish oil supplements. However, the role of EPA in platelet activation remains unclear. This study aimed to evaluate whether the cardiovascular protection observed in individuals taking dietary supplements containing EPA is achieved by altering platelet function. Additionally, we investigated whether these effects are mediated through the 12-lipoxygenase (12-LOX)-derived oxidized lipid (oxylipin) metabolite of EPA, 12(S)-hydroxy-5Z,8Z,10E,14Z,17Z-eicosapentaenoic acid (12-HEPE). Human whole blood, platelet-rich plasma, and washed platelets were treated with EPA or 12-HEPE to assess their ability to regulate platelet activity. Both EPA and 12-HEPE inhibited agonist-stimulated platelet aggregation, and 12-HEPE was found to be the primary oxylipin produced by platelets in the presence of EPA. Furthermore, 12-HEPE more potently attenuated dense granule secretion, α-granule secretion, and integrin αIIbβ3 activation, in comparison to EPA. Interestingly, while EPA delayed thrombin-induced clot retraction and reduced platelet adhesion under flow, 12-HEPE did not affect these processes. Both EPA and 12-HEPE attenuated ex vivo thrombus formation; however, the same inhibitory concentrations did not alter coagulation parameters in thromboelastography. This study demonstrates that EPA and its 12-LOX metabolite, 12-HEPE, effectively inhibit platelet activation. These findings suggest the antiplatelet effects of EPA are regulated, in part, through 12-HEPE, advancing our understanding of the cardiovascular benefits of EPA.

Triglyceride/high density lipoprotein cholesterol index and future cardiovascular events in diabetic patients without known cardiovascular disease

The triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) index, calculated as TG divided by HDL-C, has been suggested as a predictor of cardiovascular disease (CVD). We investigated the association between the TG/HDL-C index and CVD events in type 2 diabetes mellitus (T2DM) patients with retinopathy and hyperlipidemia but no known CVD, enrolled in the EMPATHY study, which compared intensive and standard statin therapy (targeting LDL-C levels < 70 mg/dL and ≥ 100 to < 120 mg/dL, respectively). A total of 4665 patients were divided into high (TG/HDL-C ≥ 2.5, n = 2013) and low (TG/HDL-C < 2.5, n = 2652) TG/HDL-C index groups. During a median follow-up of 36.8 months, 260 CVD events occurred. The high TG/HDL-C index group had higher CVD risk than the low group (HR 1.89, 95% CI 1.45-2.47, p < 0.001). This association remained consistent across subgroups. A trend toward interaction between TG/HDL-C index and statin treatment allocation for CVD risk was observed (p for interaction = 0.062). Intensive statin treatment reduced CVD risk in the high TG/HDL-C group but not in the low group. In conclusion, a TG/HDL-C index ≥ 2.5 was associated with higher CVD risk in T2DM patients with retinopathy and hyperlipidemia without a history of CVD. The TG/HDL-C index may identify patients who benefit from intensive statin treatment.

Clinical Significance of Serum Omega-3 Fatty Acids on Endothelial Function in Patients with Coronary Artery Disease Under Statin Therapy

Vascular endothelial function plays an important role in the pathogenesis of atherosclerosis. The reduction in low-density lipoprotein cholesterol (LDL-C) is a key therapy for preventing coronary artery disease (CAD), but the role of omega-3 fatty acids as residual risk factors of CAD remains controversial. We studied the correlation between serum omega-3 fatty acid levels and endothelial function in patients with CAD receiving statin therapy and examined the effect of eicosapentaenoic acid (EPA) therapy on endothelial function.

METHODS

A total of 150 consecutive patients with CAD receiving statin therapy (LDL-C levels < 100 mg/dL) were enrolled. Serum omega-3 fatty acid levels were measured, and endothelial function was assessed by flow-mediated dilation (FMD) of the brachial artery. Subsequently, 65 patients with impaired FMD (<6%) and low EPA/arachidonic acid (AA) (<0.3) were administered EPA, and FMD was reassessed after 3 months.

RESULTS

A multivariate linear regression analysis demonstrated that serum docosahexaenoic acid (DHA) and EPA plus DHA levels were independent determinants of %FMD (β = 0.214 and 0.163, p < 0.05, respectively). The EPA therapy significantly improved %FMD (from 3.7 ± 1.0% to 4.1 ± 1.0%, p < 0.05) in patients with low EPA/AA, and especially in patients with low EPA/AA and high triglyceride levels (from 3.4 ± 1.0% to 4.0 ± 1.1%, p < 0.01).

CONCLUSIONS

Serum omega-3 fatty acid levels were associated with endothelial dysfunction in patients with CAD receiving statin therapy. EPA therapy improves endothelial function in patients with low EPA/AA, especially those with low EPA/AA and high triglycerides.

Impact of Controlling Serum Low-Density Lipoprotein Cholesterol and Triglycerides on Long-Term Clinical Outcomes in Diabetic Patients Who Have Undergone Percutaneous Coronary Intervention

Background

We investigated whether patients with diabetes who had good control of both low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) would be associated with better long-term clinical outcomes after percutaneous coronary intervention (PCI).

Methods and Results

Using our PCI registry (Fu-Registry), the 1,006 cases with diabetes were divided into 4 groups: Group 1, LDL-C ≥100 mg/dL and TG ≥175 mg/dL; Group 2, LDL-C <100 mg/dL and TG ≥175 mg/dL; Group 3, LDL-C ≥100 mg/dL and TG <175 mg/dL; and Group 4, LDL-C <100 mg/dL and TG <175 mg/dL. The primary endpoint during the follow-up period (median follow up of 1,984 days) was defined as major adverse cardiac events (MACEs). Additionally, all coronary events were defined as a secondary endpoint. The incidence rates of MACEs were as follows: Group 1, 38%; Group 2, 26%; Group 3, 31%; and Group 4, 27% (P=0.074), and the rates tended to be higher in Group 1. All coronary events were as follows: Group 1, 66%; Group 2, 56%; Group 3, 58%; and Group 4, 51% (P=0.032).

Conclusions

In patients with diabetes who underwent PCI, the LDL-C and TG levels in Group 4 met secondary prevention targets for coronary artery disease and these patients showed better long-term clinical outcomes compared with those in other groups.

Phenotyping lipid profiles in type 2 diabetes: Risk association and outcomes from the Cardiovascular Health Study

Aims

To determine whether discrete lipid profiles (refer to as lipid phenotyping) can be used to stratify cardiovascular risk in individuals with type 2 diabetes.

Methods and results

Cardiovascular Health Study participants with diabetes and fasting lipid profiles at baseline (n = 866) were categorized separately by level of LDL cholesterol and HDL-C/Triglyceride (Tg) profiles (low Tg/high HDL-C; high Tg/low HDL-C; high Tg only or low HDL-C only). We performed Cox multivariate regression analysis to assess the risk of CVD mortality, incident myocardial infarction (MI), heart failure (HF), stroke, and composite MACE (MI, HF, stroke, and CVD mortality) associated with each lipid category. We also calculated risk estimates for MACE using lipid measures as continuous variables. In the fully adjusted model, the high triglyceride plus low HDL-C cholesterol phenotype demonstrated risk that was at least as high as the highest LDL-C sub-group phenotype for CVD mortality (Hazard ratio {HR} 1.58 vs 1.48), MI (HR 1.53 vs 1.58), HF (HR 1.47 vs 1.20), stroke (HR 2.02 vs 1.43), and MACE (HR 1.58 vs 1.38). When modeled continuously, the HR per SD for MACE was 1.12 (p = 0.03) for LDL-C and 1.19-1.20 (p < 0.001) for triglycerides or remnant cholesterol.

Conclusions

Participants with the high triglyceride/low HDL-C phenotype had equivalent or higher CVD risk than those with the high LDL-C phenotype. Further studies are necessary to determine whether lipid phenotyping accounts for the substantial CVD risk not explained by LDL cholesterol among individuals with type 2 diabetes.

Fish oil supplementation modifies the associations between genetically predicted and observed concentrations of blood lipids: a cross-sectional gene-diet interaction study in UK Biobank

BACKGROUND

Dyslipidemia is a well-known risk factor for cardiovascular disease, the leading cause of mortality worldwide. Although habitual intake of fish oil is associated with cardioprotective effects through triglyceride reduction, the interactions of fish oil with the genetic predisposition to dysregulated lipids remain elusive.

OBJECTIVES

We examined whether fish oil supplementation modifies the association between genetically predicted and observed concentrations of total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides.

METHODS

A total of 441,985 participants with complete genetic and phenotypic data from the UK Biobank were included. Polygenic scores (PGS) of the 4 lipids were calculated in participants of diverse ancestries. For each lipid, multivariable linear regression models were used to assess if fish oil supplementation modified the association between PGS and the observed circulating concentration, with adjustment for relevant covariates.

RESULTS

Fish oil supplementation attenuates the associations between genetically predicted and observed circulating concentrations of total cholesterol, LDL cholesterol, and triglycerides while accentuating the corresponding association for HDL cholesterol among 424,090 participants of European ancestry. Consistent significant findings were obtained using PGS calculated based on multiple genome-wide association studies or alternative PGS methods. For triglycerides, each standard deviation (SD) increment in PGS is associated with 0.254 [95% confidence interval (CI): 0.248, 0.259] SD increase in the observed concentration among European-ancestry participants who reported fish oil usage. In contrast, a stronger association was observed in nonusers (0.267; 95% CI: 0.263, 0.270). Consistently, we showed that fish oil significantly attenuates the association between genetically predicted and observed concentrations of triglycerides in African-ancestry participants.

CONCLUSIONS

Fish oil supplementation attenuates the association between genetically predicted and observed circulating concentrations of total cholesterol, LDL cholesterol, and triglycerides while accentuating the corresponding association for HDL cholesterol in individuals of European ancestry. Further research is needed to understand the clinical implications of these findings.

Pemafibrate and other triglyceride-lowering therapies to reduce risk of cardiovascular and metabolic disease

PURPOSE OF REVIEW

Although high triglycerides are consistently associated with elevated risk of cardiovascular disease (CVD), therapies that reduce triglyceride levels have inconsistently translated into reduced CVD risk.

RECENT FINDINGS

To date, three clinical trials have tested triglyceride-lowering therapies in patients with hypertriglyceridemia (HTG) and elevated risk of incident/recurrent CVD. In REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial), assignment to IPE, a highly purified eicosapentanoic acid (EPA), resulted in a 25% reduction in nonfatal myocardial infarction), nonfatal stroke, cardiovascular death, coronary revascularization and hospitalization for unstable angina. By contrast, the combination of EPA and docosahexanoic acid (DHA) carboxylic fatty acids used in the STRENGTH trial (Statin Residual Risk With Epanova in High Cardiovascular Risk Patients With Hypertriglyceridemia) failed to reduce CVD risk. Most recently, PROMINENT (Pemafibrate to Reduce Cardiovascular Outcomes by Reducing Triglycerides in Patients with Diabetes) also failed to demonstrate reduction in CVD events despite use of a potent triglyceride-lowering, fibric-acid derivative. However, improvement in HTG-associated metabolic complications (e.g. nonalcoholic fatty liver disease) was observed with pemafibrate as well as with another potent triglyceride-lowering therapy (i.e. pegozafermin). Moreover, trials are underway evaluating whether the most fatal metabolic complication of HTG, pancreatitis, may be reduced with highly potent triglyceride-lowering therapies (e.g. apolipoprotein C3 inhibitors).

SUMMARY

Taken together, HTG is associated with increased risk of CVD and attendant adverse metabolic sequalae. To this end, a potentially promising and evidence-based landscape is emerging for treating a clinical phenotype that in the past has been insufficiently addressed.

Omega-3 fatty acids for cardiovascular event lowering

Low-density lipoprotein cholesterol (LDL-C) is the main target for therapeutics aimed at reducing the risk of atherosclerotic cardiovascular disease (ASCVD) and downstream cardiovascular (CV) events. However, multiple studies have demonstrated that high-risk patient populations harbour residual risk despite effective LDL-C lowering. While data support the causal relationship between triglycerides and ASCVD risk, triglyceride-lowering therapies such as omega-3 fatty acids have shown mixed results in CV outcomes trials. Notably, icosapent ethyl, a purified formulation of eicosapentaenoic acid (EPA), has garnered compelling evidence in lowering residual CV risk in patients with hypertriglyceridaemia and treated with statins. In this review, we summarize studies that have investigated omega-3-fatty acids for CV event lowering and discuss the clinical implementation of these agents based on trial data and guidelines.

New targets and mechanisms of action for lipid-lowering and anti-inflammatory therapies in atherosclerosis: where does the field stand?

INTRODUCTION

Atherosclerotic cardiovascular disease remains a leading cause of morbidity and mortality worldwide, despite widespread use of statins. There is a need to develop additional therapeutic strategies that will complement statins to achieve more effective reductions in cardiovascular risk.

AREAS COVERED

This review provides a comprehensive summary of current areas of therapeutic development targeting both lipid and inflammatory factors implicated in the pathogenesis of atherosclerosis. In addition to develop of novel approaches that will produce more effective lowering of low-density lipoprotein cholesterol, clinical trials are currently evaluating the potential to target other atherogenic lipid parameters such as triglyceride-rich lipoproteins and Lp(a), in addition to promoting the biological properties of high-density lipoproteins. Targeting inflammation within the vascular wall has emerged as a new frontier in cardiovascular prevention, with early evidence that use of anti-inflammatory agents have the potential to reduce cardiovascular risk.

EXPERT OPINION

Clinical practice has an increasing array of therapeutic tools to achieve more effective lowering of low-density lipoprotein cholesterol for high-risk patients. In addition, clinical trials have the potential to deliver a range of additional agents to the clinic, that target alternative lipid and inflammatory mediators. This will permit the potential to personalize cardiovascular prevention.

Do patients benefit from omega-3 fatty acids?

Omega-3 fatty acids (O3FAs) possess beneficial properties for cardiovascular (CV) health and elevated O3FA levels are associated with lower incident risk for CV disease (CVD.) Yet, treatment of at-risk patients with various O3FA formulations has produced disparate results in large, well-controlled and well-conducted clinical trials. Prescription formulations and fish oil supplements containing low-dose mixtures of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have routinely failed to prevent CV events in primary and secondary prevention settings when added to contemporary care, as shown most recently in the STRENGTH and OMEMI trials. However, as observed in JELIS, REDUCE-IT, and RESPECT-EPA, EPA-only formulations significantly reduce CVD events in high-risk patients. The CV mechanism of action of EPA, while certainly multifaceted, does not depend solely on reductions of circulating lipids, including triglycerides (TG) and LDL, and event reduction appears related to achieved EPA levels suggesting that the particular chemical and biological properties of EPA, as compared to DHA and other O3FAs, may contribute to its distinct clinical efficacy. In vitro and in vivo studies have shown different effects of EPA compared with DHA alone or EPA/DHA combination treatments, on atherosclerotic plaque morphology, LDL and membrane oxidation, cholesterol distribution, membrane lipid dynamics, glucose homeostasis, endothelial function, and downstream lipid metabolite function. These findings indicate that prescription-grade, EPA-only formulations provide greater benefit than other O3FAs formulations tested. This review summarizes the clinical findings associated with various O3FA formulations, their efficacy in treating CV disease, and their underlying mechanisms of action.

Effects of omega-3, omega-6, and total dietary polyunsaturated fatty acid supplementation in patients with atherosclerotic cardiovascular disease: a systematic review and meta-analysis

Background: Uncertainty exists about the link between omega-3 fatty acid, omega-6 fatty acid, and total polyunsaturated fatty acid (PUFA) intake and mortality in atherosclerotic cardiovascular disease (ASCVD) patients, and no meta-analyses summarize the relationship between these various types of PUFAs and ASCVD. Methods: Web of Science, PubMed, EBSCO and Cochrane Library up to November 30, 2022 were searched for prospective randomized controlled studies investigating the relationships among omega-3, omega-6, and PUFA intake and mortality and cardiovascular events in ASCVD patients. This study has been registered at PROSPERO (No. CRD42023407566). Results: This meta-analysis included 21 publications from 17 studies involving 40 861 participants published between 1965 and 2022. In ASCVD patients, omega-3 may lower all-cause mortality (RR: 0.90, 95% CI [0.83, 0.98], I2 = 8%), CVD mortality (RR: 0.82, 95% CI [0.73, 0.91], I2 = 34%) and CVD events (RR: 0.90, 95% CI [0.86, 0.93], I2 = 79%). Subgroup analyses showed that EPA or EPA ethyl ester supplementation reduced CVD events, while the mixture of EPA and DHA had no significant impact. Long-chain omega-3 consumption of 1.0-4.0 g per d reduced death risk by 3.5% for each 1 g per d increase. Omega-6 and PUFA had no significant effect on mortality or CVD events, with low-quality evidence and significant heterogeneity. Conclusions: omega-3 intake is associated with a reduced risk of all-cause mortality, CVD mortality, and CVD events in ASCVD patients, while omega-6 or total PUFA intake showed no significant association. Increasing the omega-3 intake by 1 g per d resulted in a 3.5% decrease in the risk of death. These findings support the recommendation of supplements with omega-3 fatty acids for the secondary prevention of ASCVD.

The Role of Triglyceride-rich Lipoproteins and Their Remnants in Atherosclerotic Cardiovascular Disease

Atherosclerotic cardiovascular disease (ASCVD) is the world's leading cause of death. ASCVD has multiple mediators that therapeutic interventions target, such as dyslipidaemia, hypertension, diabetes and heightened systemic inflammatory tone, among others. LDL cholesterol is one of the most well-studied and established mediators targeted for primary and secondary prevention of ASCVD. However, despite the strength of evidence supporting LDL cholesterol reduction by multiple management strategies, ASCVD events can still recur, even in patients whose LDL cholesterol has been very aggressively reduced. Hypertriglyceridaemia and elevated levels of triglyceride-rich lipoproteins (TRLs) may be key contributors to ASCVD residual risk. Several observational and genetic epidemiological studies have highlighted the causal role of triglycerides within the TRLs and/or their remnant cholesterol in the development and progression of ASCVD. TRLs consist of intestinally derived chylomicrons and hepatically synthesised very LDL. Lifestyle modification has been considered the first line intervention for managing hypertriglyceridaemia. Multiple novel targeted therapies are in development, and have shown efficacy in the preclinical and clinical phases of study in managing hypertriglyceridaemia and elevated TRLs. This comprehensive review provides an overview of the biology, pathogenicity, epidemiology, and genetics of triglycerides and TRLs, and how they impact the risk for ASCVD. In addition, we provide a summary of currently available and novel emerging triglyceride-lowering therapies in development.

Fish oil supplementation modifies the genetic potential for blood lipids

Background

Dyslipidemia is a well-known risk factor for cardiovascular disease, which has been the leading cause of mortality worldwide. Although habitual intake of fish oil has been implicated in offering cardioprotective effects through triglyceride reduction, the interactions of fish oil with the genetic predisposition to dysregulated lipids remain elusive.

Objectives

We examined whether fish oil supplementation can modify the genetic potential for the circulating levels of four lipids, including total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides.

Methods

A total of 441,985 participants with complete genetic and phenotypic data from the UK Biobank were included in our study. Polygenic scores (PGS) were calculated in participants of diverse ancestries. Multivariable linear regression models were used to assess associations with adjustment for relevant risk factors.

Results

Fish oil supplementation mitigated genetic susceptibility to elevated levels of total cholesterol, LDL-C, and triglycerides, while amplifying genetic potential for increased HDL-C among 424,090 participants of European ancestry P interaction < 0.05 . Consistent significant findings were obtained using PGS calculated based on multiple genome-wide association studies or alternative PGS methods. We also showed that fish oil significantly attenuated genetic predisposition to high triglycerides in African-ancestry participants.

Conclusions

Fish oil supplementation attenuated the genetic susceptibility to elevated blood levels of total cholesterol, LDL-C, and triglycerides, while accentuating genetic potential for higher HDL-C. These results suggest that fish oil may have a beneficial impact on modifying genome-wide genetic effects on elevated lipid levels in the general population.

Risk factors, lab parameters, angiographic characteristics and outcomes of coronary artery disease in young South Asian patients: a systematic review

This systematic review provides a qualitative summary of the risk factors, angiographic characteristics, treatment, and complications of young South Asians with coronary artery disease (CAD). PubMed, Embase, and Google Scholar were searched to identify research articles published between 1 January 2010 and 13 November 2022. Studies in patients aged 18 to 45 years that were conducted in South Asian countries, were published in the English language, and included information on patients' clinical profiles and at least two risk factors for young CAD were included in the review. Smoking, dyslipidemia, high body mass index, increased high-sensitivity C-reactive protein, and hyperhomocysteinemia were observed in high proportions in young patients with CAD. Single-vessel disease was more common than multi-vessel disease in young CAD. The complications of CAD such as arrhythmias, cardiogenic shock, and heart failure were also commonly observed in young patients. Large-scale health promotion activities that curb modifiable risk factors such as smoking, obesity, and a sedentary lifestyle should be conducted in South Asian countries.

Association Between Omega-3 Fatty Acid Intake and Dyslipidemia: A Continuous Dose-Response Meta-Analysis of Randomized Controlled Trials

Background Previous results provide supportive but not conclusive evidence for the use of omega-3 fatty acids to reduce blood lipids and prevent events of atherosclerotic cardiovascular disease, but the strength and shape of dose-response relationships remain elusive. Methods and Results This study included 90 randomized controlled trials, reported an overall sample size of 72 598 participants, and examined the association between omega-3 fatty acid (docosahexaenoic acid, eicosapentaenoic acid, or both) intake and blood lipid changes. Random-effects 1-stage cubic spline regression models were used to study the mean dose-response association between daily omega-3 fatty acid intake and changes in blood lipids. Nonlinear associations were found in general and in most subgroups, depicted as J-shaped dose-response curves for low-/high-density lipoprotein cholesterol. However, we found evidence of an approximately linear dose-response relationship for triglyceride and non-high-density lipoprotein cholesterol among the general population and more evidently in populations with hyperlipidemia and overweight/obesity who were given medium to high doses (>2 g/d). Conclusions This dose-response meta-analysis demonstrates that combined intake of omega-3 fatty acids near linearly lowers triglyceride and non-high-density lipoprotein cholesterol. Triglyceride-lowering effects might provide supportive evidence for omega-3 fatty acid intake to prevent cardiovascular events.

Lipid-Lowering Nutraceuticals for an Integrative Approach to Dyslipidemia

Dyslipidemia is a treatable risk factor for atherosclerotic cardiovascular disease that can be addressed through lifestyle changes and/or lipid-lowering therapies. Adherence to statins can be a clinical challenge in some patients due to statin-associated muscle symptoms and other side effects. There is a growing interest in integrative cardiology and nutraceuticals in the management of dyslipidemia, as some patients desire or are actively seeking a more natural approach. These agents have been used in patients with and without established atherosclerotic cardiovascular disease. We provide an updated review of the evidence on many new and emerging nutraceuticals. We describe the mechanism of action, lipid-lowering effects, and side effects of many nutraceuticals, including red yeast rice, bergamot and others.

Eicosapentaenoic acid vs. docosahexaenoic acid for the prevention of cardiovascular disease

PURPOSE OF REVIEW

Populations with greater fatty fish intake have lower risk of coronary heart disease. However, trials testing omega-3 fatty acids (FA) on cardiovascular outcomes have yielded inconsistent results. In this review, we summarize the major cardiovascular trials examining omega-3 FA supplementation, and compare differences with eicosapentaenoic acid (EPA) alone vs. docosahexaenoic acid (DHA) combined with EPA.

RECENT FINDINGS

The JELIS and REDUCE-IT trials both demonstrated significant reduction in cardiovascular events with high dose EPA in the form of icosapent ethyl (IPE), with a similar trend seen in the RESPECT-EPA trial. In contrast, the ASCEND, VITAL, STRENGTH, and OMEMI trials examining EPA+DPA combinations failed to demonstrate benefit. Beyond the difference in omega-3 FA formulations (IPE vs. omega-3 carboxylic acid), other differences between REDUCE-IT and STRENGTH include the achieved EPA levels, differing properties that EPA and DHA have on membrane stabilization, and the comparator oils tested in the trials.

SUMMARY

The totality of evidence suggests EPA alone, administered in a highly-purified, high-dose form, improves cardiovascular outcomes among patients with elevated triglycerides at high cardiovascular risk, but EPA and DHA together does not. Current guidelines endorse the use of IPE in statin-treated patients at high cardiovascular risk who have triglycerides >135 mg/dl.

Treatment of hypertriglyceridaemia with icosapent ethyl in patients with high/very high cardiovascular risk. Consensus document of the Sociedad Española de Cardiología [Spanish Society of Cardiology] and the Sociedad Española de Diabetes [Spanish Diabetes Society]

The Working Groups of Cardiovascular Pharmacotherapy of the Sociedad Española de Cardiología and Cardiovascular Disease of the Sociedad Española de Diabetes have prepared a consensus document on the treatment of hypertriglyceridaemia in patients with high/very-high-cardiovascular risk with icosapent ethyl, a highly purified and stable eicosapentaenoic acid ethyl ester. This document is necessary since there are differences among the three main omega-3 fatty acids and there is large-scale clinical evidence with icosapent ethyl that demonstrates that in addition to its efficacy in lowering triglyceridaemia, it reduces the risk of cardiovascular events in both patients with atherosclerotic cardiovascular disease and in those with type 2 diabetes, with a good safety profile. The number needed to treat to avoid a major cardiovascular event is analysed, comparing it with other pivotal studies of pharmacological intervention in cardiovascular prevention, and an estimate of the Spanish population likely to be treated with ethyl icosapent is carried out. These recommendations are of interest to all clinicians who manage patients with lipid metabolism disorders, cardiovascular disease and diabetes.

Current and Emerging Therapies for Atherosclerotic Cardiovascular Disease Risk Reduction in Hypertriglyceridemia

Hypertriglyceridemia (HTG) is a prevalent medical condition in patients with cardiometabolic risk factors and is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD), if left undiagnosed and undertreated. Current guidelines identify HTG as a risk-enhancing factor and, as a result, recommend clinical evaluation and lifestyle-based interventions to address potential secondary causes of elevated triglyceride (TG) levels. For individuals with mild to moderate HTG at risk of ASCVD, statin therapy alone or in combination with other lipid-lowering medications known to decrease ASCVD risk are guideline-endorsed. In addition to lifestyle modifications, patients with severe HTG at risk of acute pancreatitis may benefit from fibrates, mixed formulation omega-3 fatty acids, and niacin; however, evidence does not support their use for ASCVD risk reduction in the contemporary statin era. Novel therapeutics including those that target apoC-III and ANGPTL3 have shown to be safe, well-tolerated, and effective for lowering TG levels. Given the growing burden of cardiometabolic disease and risk factors, public health and health policy strategies are urgently needed to enhance access to effective pharmacotherapies, affordable and nutritious food options, and timely health care services.

The effects of pemafibrate and omega-3 fatty acid ethyl on apoB-48 in dyslipidemic patients treated with statin: A prospective, multicenter, open-label, randomized, parallel group trial in Japan (PROUD48 study)

Background

We compared the lowering effects of pemafibrate and omega-3 fatty acid ethyl on fasting apolipoprotein (apo) B-48 (apoB-48), a marker that reflects postprandial hypertriglyceridemia, which is one of the residual risks for atherosclerotic cardiovascular disease (ASCVD) with statin treatment.

Methods

This prospective, multicenter, open-label, randomized, parallel group trial was conducted at 4 medical institutions between April 2020 and May 2022. A total of 126 ambulatory patients with dyslipidemia receiving statin treatment for more than 4 weeks, aged 20-79 years with fasting triglyceride (TG) levels of ≥177 mg/dl were randomly assigned to 16-week pemafibrate 0.4 mg per day treatment group (PEMA, n = 63) or omega-3 fatty acid ethyl 4 g per day treatment group (OMEGA-3, n = 63). The primary endpoint was the percentage change in fasting apoB-48 from baseline to week 16.

Results

The percentage changes in fasting apoB-48 in PEMA and OMEGA-3 were -50.8% (interquartile range -62.9 to -30.3%) and -17.5% (-38.3 to 15.3%) (P < 0.001), respectively. As the secondary endpoints, the changes in fasting apoB-48 in PEMA and OMEGA-3 were -3.10 μg/ml (-5.63 to -1.87) and -0.90 μg/ml (-2.95 to 0.65) (P < 0.001), respectively. Greater decreases with significant differences in the percentage changes in TG, remnant lipoprotein cholesterol, apoC-III, fasting plasma glucose, alanine aminotransferase, gamma-glutamyl transpeptidase, and alkaline phosphatase were observed in PEMA, compared with OMEGA-3. Greater increases with significant differences in those in high-density lipoprotein (HDL) cholesterol, apoA-I, and apoA-II were observed in PEMA, compared with OMEGA-3. PEMA showed anti-atherosclerotic lipoprotein profiles in gel-permeation high-performance liquid chromatography analyses, compared with OMEGA-3. Although adverse events occurred in 9 of 63 (14.3%) patients in PEMA and 3 of 63 (4.8%) patients in OMEGA-3, no serious adverse events associated with drug were observed in either group.

Conclusions

This is the first randomized trial to compare the lowering effects of pemafibrate and omega-3 fatty acid ethyl on fasting apoB-48. We concluded that pemafibrate was superior to omega-3 fatty acid ethyl in lowering effect of fasting apoB-48. Pemafibrate is expected to reduce the residual risk for ASCVD with statin treatment.

Clinical trial registration

https://rctportal.niph.go.jp/en, identifier jRCTs071200011.

Role of Omega-3 Fatty Acids in Cardiovascular Disease: the Debate Continues

PURPOSE OF REVIEW

The omega-3 fatty acids (n3-FAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have recently undergone testing for their ability to reduce residual cardiovascular (CV) risk among statin-treated subjects. The outcome trials have yielded highly inconsistent results, perhaps attributable to variations in dosage, formulation, and composition. In particular, CV trials using icosapent ethyl (IPE), a highly purified ethyl ester of EPA, reproducibly reduced CV events and progression of atherosclerosis compared with mixed EPA/DHA treatments. This review summarizes the mechanistic evidence for differences among n3-FAs on the development and manifestations of atherothrombotic disease.

RECENT FINDINGS

Large randomized clinical trials with n3-FAs have produced discordant outcomes despite similar patient profiles, doses, and triglyceride (TG)-lowering effects. A large, randomized trial with IPE, a prescription EPA only formulation, showed robust reduction in CV events in statin treated patients in a manner proportional to achieved blood EPA concentrations. Multiple trials using mixed EPA/DHA formulations have not shown such benefits, despite similar TG lowering. These inconsistencies have inspired investigations into mechanistic differences among n3-FAs, as EPA and DHA have distinct membrane interactions, metabolic products, effects on cholesterol efflux, antioxidant properties, and tissue distribution. EPA maintains normal membrane cholesterol distribution, enhances endothelial function, and in combination with statins improves features implicated in plaque stability and reduces lipid content of plaques. Insights into reductions in residual CV risk have emerged from clinical trials using different formulations of n3-FAs. Among high-risk patients on contemporary care, mixed n3-FA formulations showed no reduction in CV events. The distinct benefits of IPE in multiple trials may arise from pleiotropic actions that correlate with on-treatment EPA levels beyond TG-lowering. These effects include altered platelet function, inflammation, cholesterol distribution, and endothelial dysfunction. Elucidating such mechanisms of vascular protection for EPA may lead to new interventions for atherosclerosis, a disease that continues to expand worldwide.

Hypertriglyceridemia and Atherosclerotic Carotid Artery Stenosis

Both fasting and non-fasting hypertriglyceridemia have emerged as residual risk factors for atherosclerotic disease. However, it is unclear whether hypertriglyceridemia increases the risks of the progression of carotid artery stenosis. Statins are well known to prevent carotid plaque progression and improve carotid plaque instability. In addition, statin therapy is also known to reduce cerebrovascular events in patients with carotid artery stenosis and to improve clinical outcomes in patients undergoing revascularization procedures. On the other hand, there have been no randomized controlled trials showing that the combination of non-statin lipid-lowering drugs with statins has additional beneficial effects over statin monotherapy to prevent cerebrovascular events and stenosis progression in patients with carotid artery stenosis. In this article, the authors demonstrate the mechanisms of atherosclerosis formation associated with hypertriglyceridemia and the potential role of lipid-lowering drugs on carotid artery stenosis. The authors also review the articles reporting the relationships between hypertriglyceridemia and carotid artery stenosis.

Study protocol of the PROUD48 study comparing the effects of pemafibrate and omega-3 fatty acid ethyl esters on ApoB-48 in statin-treated patients with dyslipidaemia: a prospective, multicentre, open-label, randomised, parallel group trial in Japan

INTRODUCTION

This study will compare the lowering effects of pemafibrate and omega-3 fatty acid ethyl esters on fasting apolipoprotein B-48 (apoB-48), a surrogate marker reflecting postprandial hypertriglyceridaemia, which is a residual risk for atherosclerotic cardiovascular disease with statin treatment.

METHODS AND ANALYSIS

This is a prospective, multicentre, open-label, randomised, parallel group, comparative trial. Adult Japanese patients with dyslipidaemia receiving statin treatment for more than 4 weeks with a fasting triglyceride level ≥177 mg/dL will be randomly assigned in a 1:1 ratio to receive pemafibrate (0.4 mg orally per day) or omega-3 fatty acid ethyl esters (4 g orally per day) for 16 weeks. The primary endpoint is the percentage change in fasting apoB-48 from baseline to 16 weeks. The key secondary endpoints include the change in fasting apoB-48 from baseline to 16 weeks, the percentage changes in clinical variables from baseline to 16 weeks and the incidence of adverse events. A total sample size of 128 was set by considering the increased drop-out rate due to the COVID-19 pandemic, in addition to estimation based on a two-sided alpha of 0.05 and a power of 0.8 for apoB-48.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Certified Review Board of the University of the Ryukyus for Clinical Research Ethics (No. CRB7200001) and will be performed in accordance with the Declaration of Helsinki. Written informed consent will be obtained from all participants. The results of the study will be disseminated through publications and conference presentations to participants, healthcare professionals and the public.

TRIAL REGISTRATION NUMBER

jRCTs071200011.

Increased residual cardiovascular risk in U.S. veterans with moderately-elevated baseline triglycerides and well-controlled LDL-C levels on statins

Background

Recent studies have demonstrated a causal role for elevated triglycerides (TG) in incident cardiovascular (CV) events in patients with established coronary heart disease (CHD) and those with CV risk factors alone, particularly diabetes.

Objective

Using a large cohort of U.S. veterans with statin-controlled LDL-C levels (40–100 mg/dL), we explored residual CV risk among patients with elevated baseline TG levels (150–499 mg/dL) vs. those with normal TG levels (<150 mg/dL).

Methods

We identified veterans receiving a statin but not a TG-lowering agent from the VA electronic health records database, from 2010 to 2015. We compared composite CV event rates (MI, stroke, unstable angina, coronary revascularization, and CV death) between the elevated TG and normal TG groups. We stratified the study cohort according to 3 CV risk groups: (1) no diabetes and no prior CV event, (2) diabetes and no prior CV event, and (3) prior CV event. We calculated crude event rates, rate ratios, and event rate ratios adjusted for age, sex, systolic blood pressure, estimated glomerular filtration rate, and weight.

Results

The cohort included 396,189 veterans (predominantly male and white) of whom 109,195 (28%) had elevated TG levels. Those with elevated TG were younger (age 73 vs. 77 years) and had a higher body mass index (31.3 vs. 28.3 Kg/M²). The overall composite crude and adjusted rate ratios comparing the elevated and normal TG groups were 1.10 (1.09, 1.12) and 1.05 (1.03, 1.06), respectively. For CV risk groups 1, 2 and 3, the adjusted rate ratios comparing the elevated and normal TG groups were 0.99 (0.96, 1.02), 1.05 (1.02, 1.08), and 1.07 (1.04, 1.10), respectively. An association of increased rate ratios did not hold for fatal events.

Conclusion

Those with elevated TG levels and well-controlled LDL-C on statins showed a modest increase in CV events compared to those with normal TG. Elevated TG levels were associated with increased CV events in patients with established CV disease and with diabetes only, suggesting that elevated TG levels are associated with a similar degree of residual risk in high-risk primary prevention and secondary prevention settings.

Membrane fatty acid desaturase: biosynthesis, mechanism, and architecture

Fatty acid desaturase catalyzes the desaturation reactions by inserting double bonds into the fatty acyl chain, producing unsaturated fatty acids, which play a vital part in the synthesis of polyunsaturated fatty acids. Though soluble fatty acid desaturases have been described extensively in advanced organisms, there are very limited studies of membrane fatty acid desaturases due to their difficulties in producing a sufficient amount of recombinant desaturases. However, the advancement of technology has shown substantial progress towards the development of elucidating crystal structures of membrane fatty acid desaturase, thus, allowing modification of structure to be manipulated. Understanding the structure, mechanism, and biosynthesis of fatty acid desaturase lay a foundation for the potential production of various strategies associated with alteration and modifications of polyunsaturated fatty acids. This manuscript presents the current state of knowledge and understanding about the structure, mechanisms, and biosynthesis of fatty acid desaturase. In addition, the role of unsaturated fatty acid desaturases in health and diseases is also encompassed. This will be useful in understanding the molecular basis and structural protein of fatty acid desaturase that are significant for the advancement of therapeutic strategies associated with the improvement of health status. KEY POINTS: • Current state of knowledge and understanding about the biosynthesis, mechanisms, and structure of fatty acid desaturase. • The role of unsaturated fatty acid desaturase. • The molecular basis and structural protein elucidated the crystal structure of fatty acid desaturase.

Forkhead box protein O1 (FoxO1) knockdown accelerates the eicosapentaenoic acid (EPA)-mediated Selenop downregulation independently of sterol regulatory element-binding protein-1c (SREBP-1c) in H4IIEC3 hepatocytes

Selenoprotein P is upregulated in type 2 diabetes, causing insulin and exercise resistance. We have previously reported that eicosapentaenoic acid (EPA) negatively regulates Selenop expression by suppressing Srebf1 in H4IIEC3 hepatocytes. However, EPA downregulated Srebf1 long before downregulating Selenop. Here, we report additional novel mechanisms for the Selenop gene regulation by EPA. EPA upregulated Foxo1 mRNA expression, which was canceled with the ERK1/2 inhibitor, but not with the PKA inhibitor. Foxo1 knockdown by siRNA initiated early suppression of Selenop, but not Srebf1, by EPA. However, EPA did not affect the nuclear translocation of the FoxO1 protein. Neither ERK1/2 nor PKA inhibitor affected FoxO1 nuclear translocation. In summary, FoxO1 knockdown accelerates the EPA-mediated Selenop downregulation independent of SREBP-1c in hepatocytes. EPA upregulates Foxo1 mRNA via the ERK1/2 pathway without altering its protein and nuclear translocation. These findings suggest redundant and conflicting transcriptional networks in the lipid-induced redox regulation.

Recent Updates in Hypertriglyceridemia Management for Cardiovascular Disease Prevention

PURPOSE OF REVIEW

Mounting evidence continues to support the causal role of triglyceride-rich lipoproteins (TRL) in the development of atherosclerotic cardiovascular disease (ASCVD). Substantial residual ASCVD risk remains among high-risk patients who have elevated triglycerides despite reduction in low-density lipoprotein cholesterol (LDL-C) with statin therapy. Ongoing research efforts have focused on evaluating triglyceride-lowering therapies among patients with hypertriglyceridemia.

RECENT FINDINGS

The REDUCE-IT trial showed that the addition of icosapent ethyl, a highly purified form of eicosapentaenoic acid (EPA), can reduce vascular events among statin-treated individuals with elevated triglycerides who have either clinical ASCVD or diabetes plus another risk factor. Although additional evidence for EPA has emerged from other trials, conflicting results have been reported by subsequent trials that tested different omega-3 fatty acid formulations. Randomized clinical trials have not demonstrated incremental ASCVD benefit of fibrates on background of statin therapy, but fibrates are used to help prevent pancreatitis in patients with severe hypertriglyceridemia. Selective inhibitors of apolipoprotein C-III (apoC3) and angiopoietin-like protein 3 (ANGPTL3), proteins that are involved in metabolism of TRLs by regulating lipoprotein lipase, have been tested in selected patient populations and showed significant reduction in triglyceride and LDL-C levels. Statin therapy continues to be the cornerstone of pharmacologic reduction of cardiovascular risk. High-dose EPA in the form of icosapent ethyl has been demonstrated to have cardiovascular benefit on top of statins in persons with elevated triglycerides at high ASCVD risk. Ongoing clinical trials are evaluating novel selective therapies such as apoC3 and ANGPTL3 inhibitors.

Marine-derived n-3 fatty acids therapy for stroke

BACKGROUND

Currently, with stroke burden increasing, there is a need to explore therapeutic options that ameliorate the acute insult. There is substantial evidence of a neuroprotective effect of marine-derived n-3 polyunsaturated fatty acids (PUFAs) in animal models of stroke, leading to a better functional outcome.

OBJECTIVES

To assess the effects of administration of marine-derived n-3 PUFAs on functional outcomes and dependence in people with stroke.

SEARCH METHODS

We searched the Cochrane Stroke Trials Register (last searched 31 May 2021), the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 5), MEDLINE Ovid (from 1948 to 31 May 2021), Embase Ovid (from 1980 to 31 May 2021), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; from 1982 to 31 May 2021), Science Citation Index Expanded ‒ Web of Science (SCI-EXPANDED), Conference Proceedings Citation Index-Science - Web of Science (CPCI-S), and BIOSIS Citation Index. We also searched ongoing trial registers, reference lists, relevant systematic reviews, and used the Science Citation Index Reference Search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing marine-derived n-3 PUFAs to placebo or open control (no placebo) in people with a history of stroke or transient ischaemic attack (TIA), or both.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected trials for inclusion, extracted data, assessed risk of bias, and used the GRADE approach to assess the certainty of the body of evidence. We contacted study authors for clarification and additional information on stroke/TIA participants. We conducted random-effects meta-analysis or narrative synthesis, as appropriate. The primary outcome was efficacy (functional outcome) assessed using a validated scale, for example, the Glasgow Outcome Scale Extended (GOSE) dichotomised into poor or good clinical outcome, the Barthel Index (higher score is better; scale from 0 to 100), or the Rivermead Mobility Index (higher score is better; scale from 0 to 15). Our secondary outcomes were vascular-related death, recurrent events, incidence of other type of stroke, adverse events, quality of life, and mood.

MAIN RESULTS

We included 30 RCTs; nine of them provided outcome data (3339 participants). Only one study included participants in the acute phase of stroke (haemorrhagic). Doses of marine-derived n-3 PUFAs ranged from 400 mg/day to 3300 mg/day. Risk of bias was generally low or unclear in most trials, with a higher risk of bias in smaller studies. We assessed results separately for short (up to three months) and longer (more than three months) follow-up studies. Short follow-up (up to three months) Functional outcome was reported in only one pilot study as poor clinical outcome assessed with the GOSE (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.36 to 1.68, P = 0.52; 40 participants; very low-certainty evidence). Mood (assessed with the GHQ-30, lower score better) was reported by only one study and favoured control (mean difference (MD) 1.41, 95% CI 0.07 to 2.75, P = 0.04; 102 participants; low-certainty evidence). We found no evidence of an effect of the intervention for the remainder of the secondary outcomes: vascular-related death (two studies, not pooled due to differences in population, RR 0.33, 95% CI 0.01 to 8.00, P = 0.50, and RR 0.33, 95% CI 0.01 to 7.72, P = 0.49; 142 participants; low-certainty evidence); recurrent events (RR 0.41, 95% CI 0.02 to 8.84, P = 0.57; 18 participants; very low-certainty evidence); incidence of other type of stroke (two studies, not pooled due to different type of index stroke, RR 6.11, 95% CI 0.33 to 111.71, P = 0.22, and RR 0.63, 95% CI 0.25 to 1.58, P = 0.32; 58 participants; very low-certainty evidence); and quality of life (physical component, MD -2.31, 95% CI -4.81 to 0.19, P = 0.07, and mental component, MD -2.16, 95% CI -5.91 to 1.59, P = 0.26; 1 study; 102 participants; low-certainty evidence). Adverse events were reported by two studies (57 participants; very low-certainty evidence), one trial reporting extracranial haemorrhage (RR 0.25, 95% CI 0.04 to 1.73, P = 0.16) and the other one reporting bleeding complications (RR 0.32, 95% CI 0.01 to 7.35, P = 0.47). Longer follow-up (more than three months) One small trial assessed functional outcome with both the Barthel Index for activities of daily living (MD 7.09, 95% CI -5.16 to 19.34, P = 0.26), and the Rivermead Mobility Index for mobility (MD 1.30, 95% CI -1.31 to 3.91, P = 0.33) (52 participants; very low-certainty evidence). We carried out meta-analysis for vascular-related death (RR 1.02, 95% CI 0.78 to 1.35, P = 0.86; 5 studies; 2237 participants; low-certainty evidence) and fatal recurrent events (RR 0.69, 95% CI 0.31 to 1.55, P = 0.37; 3 studies; 1819 participants; low-certainty evidence). We found no evidence of an effect of the intervention for mood (MD 1.00, 95% CI -2.07 to 4.07, P = 0.61; 1 study; 14 participants; low-certainty evidence). Incidence of other type of stroke and quality of life were not reported. Adverse events (all combined) were reported by only one study (RR 0.94, 95% CI 0.56 to 1.58, P = 0.82; 1455 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

We are very uncertain of the effect of marine-derived n-3 PUFAs therapy on functional outcomes and dependence after stroke as there is insufficient high-certainty evidence. More well-designed RCTs are needed, specifically in acute stroke, to determine the efficacy and safety of the intervention. Studies assessing functional outcome might consider starting the intervention as early as possible after the event, as well as using standardised, clinically relevant measures for functional outcomes, such as the modified Rankin Scale. Optimal doses remain to be determined; delivery forms (type of lipid carriers) and mode of administration (ingestion or injection) also need further consideration.

Omega-3-fatty acids: Do they prevent cardiovascular disease?

Despite cardiovascular disease (CVD) reductions with high-intensity statins, there remains residual risk among patients with metabolic disorders. Alongside low-density lipoproteins (LDL-C), elevated triglycerides (TG) are associated with incident CVD events. Omega-3 fatty acids (n3-FAs), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower TG levels, but their ability to reduce CV risk has been highly inconsistent. Trials using icosapent ethyl (IPE), a purified EPA ethyl ester, produced reductions in CVD events and atherosclerotic plaque regression compared with mixed EPA/DHA formulations despite similar TG-reductions. The separate effects of EPA and DHA on tissue distribution, oxidative stress, inflammation, membrane structure and endothelial function may contribute to these discordant outcomes. Additional mechanistic trials will provide further insights into the role of n3-FAs in reducing CVD risk beyond TG lowering.

Triglyceride and Triglyceride-Rich Lipoproteins in Atherosclerosis

Cardiovascular disease (CVD) is still the leading cause of death globally, and atherosclerosis is the main pathological basis of CVDs. Low-density lipoprotein cholesterol (LDL-C) is a strong causal factor of atherosclerosis. However, the first-line lipid-lowering drugs, statins, only reduce approximately 30% of the CVD risk. Of note, atherosclerotic CVD (ASCVD) cannot be eliminated in a great number of patients even their LDL-C levels meet the recommended clinical goals. Previously, whether the elevated plasma level of triglyceride is causally associated with ASCVD has been controversial. Recent genetic and epidemiological studies have demonstrated that triglyceride and triglyceride-rich lipoprotein (TGRL) are the main causal risk factors of the residual ASCVD. TGRLs and their metabolites can promote atherosclerosis via modulating inflammation, oxidative stress, and formation of foam cells. In this article, we will make a short review of TG and TGRL metabolism, display evidence of association between TG and ASCVD, summarize the atherogenic factors of TGRLs and their metabolites, and discuss the current findings and advances in TG-lowering therapies. This review provides information useful for the researchers in the field of CVD as well as for pharmacologists and clinicians.

Targeting triglycerides to lower residual cardiovascular risk

INTRODUCTION

Dyslipidemia therapeutics have primarily focused on lowering levels of low-density lipoprotein cholesterol. However, many patients continue to experience cardiovascular events, despite effective lowering of LDL-C. This has prompted efforts to target additional risk factors to achieve more effective prevention of cardiovascular disease. Emerging evidence suggests that triglyceride rich lipoproteins play a causal role in atherosclerosis, highlighting the potential for specific therapeutic lowering.

AREAS COVERED

(1) Evidence to support the causal role of triglyceride rich lipoproteins in atherosclerotic cardiovascular disease. (2) Use of existing lipid modifying therapies to target triglyceride rich lipoproteins. (3) Development of novel therapeutic agents that target triglyceride rich lipoproteins and their potential impact on cardiovascular risk.

EXPERT OPINION/COMMENTARY

Evidence from preclinical, observational and genetic studies highlight the role of triglyceride rich lipoproteins in the causal pathway of atherosclerotic cardiovascular disease. A number of existing agents have the potential to reduce residual cardiovascular risk associated with hypertriglyceridemia. However, emerging agents have the potential to substantially and preferentially lower triglyceride levels beyond contemporary therapeutics. How they will modulate cardiovascular risk will ultimately be determined by large clinical outcomes trials. They do provide the opportunity to substantially influence the way we target dyslipidemia in the prevention of cardiovascular disease.

Effects of eicosapentaenoic acid on serum levels of selenoprotein P and organ-specific insulin sensitivity in humans with dyslipidemia and type 2 diabetes

AIM

Selenoprotein P (SeP, encoded by SELENOP in humans) is a hepatokine that causes insulin resistance in the liver and skeletal muscle. It was found that polyunsaturated fatty acid eicosapentaenoic acid (EPA) downregulates Selenop expression by inactivating SREBP-1c. The present study aimed to examine the effect of EPA for 12 weeks on circulating SeP levels and insulin sensitivity in humans with type 2 diabetes.

METHODS

A total of 20 participants with dyslipidemia and type 2 diabetes were randomly assigned to an EPA (900 mg, twice daily) group and a control group. The primary endpoint was a change in serum SeP levels. Organ-specific insulin sensitivity in the liver (HGP and %HGP), skeletal muscle (Rd), and adipose tissue (FFA and %FFA) were assessed using a hyperinsulinemic-euglycemic clamp study with stable isotope-labeled glucose infusion.

RESULTS

Serum SeP levels were not changed in either group at the end of the study. In the EPA group, the changes in SeP levels were positively correlated with the change in serum EPA levels (r = 0.709, P = 0.022). Treatment with EPA significantly enhanced %FFA but not %HGP and Rd. The change in serum EPA levels was significantly positively correlated with the change in %HGP, and negatively correlated with changes in Rd.

CONCLUSIONS

The change in serum EPA levels was positively correlated with serum SeP levels, hepatic insulin sensitivity, and negatively with skeletal muscle insulin sensitivity in humans with type 2 diabetes. The EPA-induced enhancement of hepatic insulin sensitivity might be associated with a mechanism independent of serum SeP levels.

Addressing dyslipidemic risk beyond LDL-cholesterol

Despite the success of LDL-lowering drugs in reducing cardiovascular disease (CVD), there remains a large burden of residual disease due in part to persistent dyslipidemia characterized by elevated levels of triglyceride-rich lipoproteins (TRLs) and reduced levels of HDL. This form of dyslipidemia is increasing globally as a result of the rising prevalence of obesity and metabolic syndrome. Accumulating evidence suggests that impaired hepatic clearance of cholesterol-rich TRL remnants leads to their accumulation in arteries, promoting foam cell formation and inflammation. Low levels of HDL may associate with reduced cholesterol efflux from foam cells, aggravating atherosclerosis. While fibrates and fish oils reduce TRL, they have not been uniformly successful in reducing CVD, and there is a large unmet need for new approaches to reduce remnants and CVD. Rare genetic variants that lower triglyceride levels via activation of lipolysis and associate with reduced CVD suggest new approaches to treating dyslipidemia. Apolipoprotein C3 (APOC3) and angiopoietin-like 3 (ANGPTL3) have emerged as targets for inhibition by antibody, antisense, or RNAi approaches. Inhibition of either molecule lowers TRL but respectively raises or lowers HDL levels. Large clinical trials of such agents in patients with high CVD risk and elevated levels of TRL will be required to demonstrate efficacy of these approaches.

Omega-3 Fatty Acids and Cardiovascular Disease: A Narrative Review for Pharmacists

BACKGROUND

Atherosclerotic cardiovascular disease is a significant cause of morbidity and mortality worldwide. While use of statin therapy has improved management of lipids, an unmet need in reducing residual atherosclerotic cardiovascular disease risk and ischemic events persists. We provide an overview of the pharmacology of omega-3 fatty acids, omega-3 fatty acid cardiovascular outcomes trials, landmark clinical data and pharmacology of icosapent ethyl (a stable and highly purified ethyl ester of eicosapentaenoic acid), and the critical differences between fish oil supplements and prescription omega-3 fatty acids.

METHOD

A PubMed literature review was conducted in April 2020 to identify articles discussing omega-3 fatty acid cardiovascular outcomes trials, pharmacology of icosapent ethyl, and the evaluation of fish oil dietary supplements and prescription omega-3 fatty acids.

RESULTS

Both eicosapentaenoic acid and docosahexaenoic acid have been widely associated with positive health benefits; however, data are inconsistent regarding the benefit of combination eicosapentaenoic acid and docosahexaenoic acid in patients with cardiovascular disease. Eicosapentaenoic acid, and specifically icosapent ethyl, has demonstrated atherosclerotic cardiovascular disease risk reduction among statin-treated patients. Important clinical differences exist between dietary supplement and prescription omega-3 fatty acid products.

CONCLUSIONS

As research regarding the optimal management of dyslipidemia continues, additional therapy beyond statins is necessary to reduce atherosclerotic cardiovascular disease risk. In large cardiovascular outcomes trials, eicosapentaenoic acid has demonstrated cardiovascular benefit. Icosapent ethyl possesses a favorable efficacy and safety profile and should be considered as an adjunct to statin therapy to reduce ischemic event risk.

Icosapent ethyl: safely reducing cardiovascular risk in adults with elevated triglycerides

INTRODUCTION

In patients at high cardiovascular risk, the rate of events remains elevated despite traditional, evidence-based lipid-lowering therapy. Residual hypertriglyceridemia is an important contributor to this risk. However, prior medications with triglyceride-lowering effects have not reduced adverse clinical outcomes in the statin era.

AREAS COVERED

The present review summarizes evidence and recommendations related to triglyceride-lowering therapy in the primary and secondary preventive settings. We provide an overview of findings from recent meta-analyses, important observational studies, and a detailed description of landmark trials, including the Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT). We further review recommendations from current guidelines.

EXPERT OPINION

Icosapent ethyl is a stable, highly purified ethyl ester of eicosapentaenoic acid that safely and effectively reduces cardiovascular events in the contemporary setting. It is prescribed at a dose of 2 grams twice daily and is indicated in patients at high cardiovascular risk who have fasting or non-fasting triglyceride levels ≥150 mg/dl despite maximally tolerated statin treatment, or in individuals with triglyceride levels ≥500 mg/dl. Conversely, omega-3 fatty acid preparations containing a combination of eicosapentaenoic acid and docosahexaenoic acid are not indicated for reduction of cardiovascular risk and should be actively deprescribed.

Mechanistic Insights from REDUCE-IT STRENGTHen the Case Against Triglyceride Lowering as a Strategy for Cardiovascular Disease Risk Reduction

Elevated triglyceride (TG) levels have been linked to residual atherosclerotic cardiovascular risk in patients with controlled low-density lipoprotein cholesterol. However, outcome trials testing TG-lowering agents have failed to demonstrate cardiovascular risk reduction in statin-treated subjects. One such example is the recent STRENGTH trial, which tested mixed omega fatty acids (n3-FAs, 4 g/d) in high-risk patients with elevated TGs. Similar to trials using fibrates and niacin, the STRENGTH trial failed despite effective TG lowering. Results from these studies have contributed to skepticism about the use of TG-lowering therapy for cardiovascular risk. However, new mechanistic insights are provided by the REDUCE-IT trial that used icosapent ethyl (IPE), a purified formulation of the n3-FA eicosapentaenoic acid. In high-risk patients, IPE reduced a composite of cardiovascular events (25%, P < .001) in a manner not predicted by TG lowering. Benefits with IPE appear linked to broad pleiotropic actions associated with on-treatment eicosapentaenoic acid levels. These studies indicate that although TGs are a potential biomarker of cardiovascular risk, there is no evidence that TG lowering itself is an effective strategy for reducing such risk.

Vascepa protects against high-fat diet-induced glucose intolerance, insulin resistance, and impaired β-cell function

Omega-3 fatty acid prescription drugs, Vascepa (≥96% eicosapentaenoic acid [EPA] ethyl ester) and Lovaza (46.5% EPA and 37.5% docosahexaenoic acid ethyl ester) are known therapeutic regimens to treat hypertriglyceridemia. However, their impact on glucose homeostasis, progression to type 2 diabetes, and pancreatic beta cell function are not well understood. In the present study, mice were treated with Vascepa or Lovaza for one week prior to six weeks of high-fat diet feeding. Vascepa but not Lovaza led to reduced insulin resistance, reduced fasting insulin and glucose, and improved glucose intolerance. Vascepa improved beta cell function, reduced liver triglycerides with enhanced expression of hepatic fatty acid oxidation genes, and altered microbiota composition. Vascepa has protective effects on diet-induced insulin resistance and glucose intolerance in mice.

Association Between Achieved ω-3 Fatty Acid Levels and Major Adverse Cardiovascular Outcomes in Patients With High Cardiovascular Risk: A Secondary Analysis of the STRENGTH Trial

Importance

In patients treated with ω-3 fatty acids, it remains uncertain whether achieved levels of eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) are associated with cardiovascular outcomes.

Objective

To determine the association between plasma levels of EPA and DHA and cardiovascular outcomes in a trial of ω-3 fatty acids compared with corn oil placebo.

Design, Setting, and Participants

A double-blind, multicenter trial enrolled patients at high cardiovascular risk with elevated triglyceride levels and low levels of high-density lipoprotein cholesterol at 675 centers (enrollment from October 30, 2014, to June 14, 2017; study termination January 8, 2020; last visit May 14, 2020).

Interventions

Participants were randomized to receive 4 g daily of ω-3 carboxylic acid (CA) or an inert comparator, corn oil.

Main Outcomes and Measures

The primary prespecified end point was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or unstable angina requiring hospitalization. The primary outcome measure was the hazard ratio, adjusted for baseline characteristics, for patients treated with the ω-3 CA compared with corn oil for the top tertile of achieved EPA and DHA plasma levels 12 months after randomization.

Results

Of the 13 078 total participants, 6539 (50%) were randomized to receive ω-3 CA and 6539 (50%) randomized to corn oil. ω-3 Fatty acid levels were available at both baseline and 12 months after randomization in 10 382 participants (5175 ω-3 CA patients [49.8%] and 5207 corn oil-treated patients [50.2%]; mean [SD] age, 62.5 [8.9] years, 3588 [34.6%] were women, 9025 [86.9%] were White, and 7285 [70.2%] had type 2 diabetes). The median plasma levels at 12 months in ω-3 CA patients were 89 μg/mL (interquartile range [IQR], 46-131 μg/mL) for EPA and 91 μg/mL (IQR, 71-114 μg/mL) for DHA with top tertile levels of 151 μg/mL (IQR, 132-181 μg/mL) and 118 μg/mL (IQR, 102-143 μg/mL), respectively. Compared with corn oil, the adjusted hazard ratios for the highest tertile of achieved plasma levels were 0.98 (95% CI, 0.83-1.16; P = .81) for EPA, and 1.02 (95% CI, 0.86-1.20; P = .85 for DHA. Sensitivity analyses based on changes in plasma and red blood cell levels of EPA and DHA and primary and secondary prevention subgroups showed similar results.

Conclusions and Relevance

Among patients treated with ω-3 CA, the highest achieved tertiles of EPA and DHA were associated with neither benefit nor harm in patients at high cardiovascular risk.

Trial Registration

ClinicalTrials.gov Identifier: NCT02104817.

The Evolving Role of Omega 3 Fatty Acids in Cardiovascular Disease: Is Icosapent Ethyl the Answer?

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of morbidity and mortality globally. Despite significant advances in pharmacotherapies and the beneficial effects of statin therapy on ASCVD outcomes and progression of atherosclerosis, residual cardiovascular (CV) risk remains. Extensive evidence has identified the contribution of atherogenic dyslipidaemia, which is particularly characterised by elevated triglycerides (TGL) as a key driver of CV risk, even if low-density lipoprotein cholesterol levels are well controlled. Epidemiologic and genetic/Mendelian randomisation studies have demonstrated that elevated TGL levels serve as an independent marker for an increased risk of ischaemic events, highlighting TGLs as a suitable therapeutic target. Clinical studies have shown that omega 3 fatty acids (OM3FA) are effective in lowering TGLs; however, to date, trials and meta-analyses of combined OM3FA products have not demonstrated any clinical CV outcome benefit in patients receiving statins. However, icosapent ethyl (IPE) - a highly purified, stable ethyl ester of eicosapentaenoic acid (EPA) - has been rigorously demonstrated in multiple studies to be a useful adjunctive therapy to address residual CV risk. EPA is an omega-3 polyunsaturated fatty acid that is incorporated into membrane phospholipid bilayers and is reported to exert multiple beneficial effects along the pathway of coronary atherosclerosis. In this brief review, we will provide an overview of the mode of action of IPE in coronary atherosclerosis, the robust clinical evidence and trial data supporting its use, and expert consensus/recommendations on its use in specific populations, as an adjunct to existing anti-atherosclerotic therapies.