Icosapent ethyl (eicosapentaenoic acid ethyl ester): Effects on plasma apolipoprotein C-III levels in patients from the MARINE and ANCHOR studies

Eicosapentaenoic acid (EPA) reduces pulmonary endothelial dysfunction and inflammation due to changes in protein expression during exposure to particulate matter air pollution

AIMS

Inhalation of air pollution small particle matter (PM) is a leading cause of cardiovascular (CV) disease. Exposure to PMs causes endothelial cell (EC) dysfunction as evidenced by nitric oxide (NO) synthase uncoupling, vasoconstriction and inflammation. Eicosapentaenoic acid (EPA) has been shown to mitigate PM-induced adverse cardiac changes in patients receiving omega-3 fatty acid supplementation. We set out to determine the pro-inflammatory effects of multiple PMs (urban and fine) on pulmonary EC NO bioavailability and protein expression, and whether EPA restores EC function under these conditions.

METHODS AND RESULTS

We pretreated pulmonary ECs with EPA and then exposed them to urban or fine air pollution PMs. LC/MS-based proteomic analysis to assess relative expression levels. Expression of adhesion molecules was measured by immunochemistry. The ratio of NO to peroxynitrite (ONOO-) release, an indication of eNOS coupling, was measured using porphyrinic nanosensors following calcium stimulation. Urban/fine PMs also modulated 9/12 and 13/36 proteins, respectively, linked to platelet and neutrophil degranulation pathways and caused > 50% (p < 0.001) decrease in the stimulated NO/ONOO- release ratio. EPA treatment altered expression of proteins involved in these inflammatory pathways, including a decrease in peroxiredoxin-5 and an increase in superoxide dismutase-1. EPA also increased expression of heme oxygenase-1 (HMOX1), a cytoprotective protein, by 2.1-fold (p = 0.024). EPA reduced elevations in sICAM-1 levels by 22% (p < 0.01) and improved the NO/ONOO- release ratio by > 35% (p < 0.05).

CONCLUSION

These cellular changes may contribute to anti-inflammatory, cytoprotective and lipid changes associated with EPA treatment during air pollution exposure.

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.

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.

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.

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.

A Fishy Topic: VITAL, REDUCE-IT, STRENGTH, and Beyond: Putting Omega-3 Fatty Acids into Practice in 2021

PURPOSE OF REVIEW

To examine recently published data from clinical outcome and arteriographic studies that examined the addition of omega-3 fatty acids, eicosapentaenoic acid (EPA) + docosahexanoic acid (DHA), to standard of care therapy on cardiovascular disease (CVD) risk.

RECENT FINDINGS

Several trials that tested purified EPA (JELIS, REDUCE-IT, EVAPORATE) were associated with reduced CVD risk and regression of low attenuation coronary plaque volume, whereas studies that employed the combination EPA/DHA (VITAL, OMEMI, STRENGTH) failed to derive clinical benefit. Trials testing purified EPA consistently demonstrated reduction in atheromatous volume or CVD events beyond standard of care therapies, whereas the combination of EPA/DHA did not, despite producing similar reductions in triglycerides. Experimental and in vitro data suggest that compared to DHA, EPA exhibits antioxidant, anti-inflammatory, and membrane stabilizing properties that enhance vascular function and CVD risk. Consequently, purified EPA appears to be the treatment of choice for high-risk patients with hypertriglyceridemia.

Triglycerides and cardiovascular disease

PURPOSE OF REVIEW

Triglycerides (TGs) are measured as part of routine lipid profiles but their relationship to cardiovascular disease (CVD) risk has been controversial and overshadowed by high-density lipoprotein cholesterol (HDL-C).

RECENT FINDINGS

Epidemiological studies show a clear relationship of TG-containing lipoproteins including remnant particles with CVD risk with the effect being most clearly demonstrated through the excess risk captured by non-HDL-C compared with low-density lipoprotein-cholesterol (LDL-C). Mendelian randomisation studies show a consistent relationship of gene variants linked to TG metabolism with rates of CVD. Furthermore, meta-analyses of intervention trials with statins and other nonstatin drugs also suggest that reducing TGs is associated with benefits on rates of CVD events. Historical subgroup data from fibrate trials suggest benefits in patients with high TG:HDL ratios but seem to add little to optimized statin therapy. Recent trials with omega-3 fatty acids (specifically eicosapentaenoic acid) have suggested that high-dose formulations in contrast to low dose formulations have benefits on CVD outcomes.

SUMMARY

Further studies with newer agents are required to determine the place of TG-lowering drugs in therapeutic pathways. Trials with agents such as pemafibrate and vupanorsen may finally answer these questions.

Cardiovascular effects of omega-3 fatty acids: Hope or hype?

Omega-3 fatty acids have emerged as a new option for controlling the residual risk for cardiovascular disease (CVD) in the statin era after a clinical trial (REDUCE-IT) reported positive results with icosapent ethyl (IPE) in patients receiving maximally tolerated statin therapy. However, another trial which used high dose eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) combination (STRENGTH) has failed. Together, these results raise clinically important questions. Are effects of omega-3 fatty acids neutral or beneficial in patients on statin therapy, or perhaps even harmful? The current contradictory results could be attributed to different types of omega-3 fatty acids (only EPA or combination of EPA + DHA), doses (higher vs. lower dose) of omega-3 fatty acids or different comparators (corn oil or mineral oil), as well as the underlying severity of the CVD risk or use of statins. Together with these issues, we will discuss different biological and clinical effects of various types of omega-3 fatty acids and then interpret different results of past and current clinical studies and propose practical suggestions, which could be applied in patient management.

Cardiovascular Impact of Nutritional Supplementation With Omega-3 Fatty Acids: JACC Focus Seminar

Omega-3 polyunsaturated fatty acids (PUFAs) are a key component of a heart-healthy diet. For patients without clinical atherosclerotic cardiovascular disease, 2 or more servings of fatty fish per week is recommended to obtain adequate intake of omega-3 PUFAs. If this not possible, dietary supplementation with an appropriate fish oil may be reasonable. Supplementation with omega-3 PUFA capsules serves 2 distinct but overlapping roles: treatment of hypertriglyceridemia and prevention of cardiovascular events. Marine-derived omega-3 PUFAs reduce triglycerides and have pleiotropic effects including decreasing inflammation, improving plaque composition and stability, and altering cellular membranes. Clinical trial data have shown inconsistent results with omega-3 PUFAs improving cardiovascular outcomes. In this paper, the authors provide an overview of PUFAs and a summary of key clinical trial data. Recent trial data suggest the use of prescription eicosapentaenoic acid ethyl ester for atherosclerotic cardiovascular disease event reduction in selected populations.

Bioactive Compounds for the Management of Hypertriglyceridemia: Evidence From Clinical Trials and Putative Action Targets

Hypertriglyceridemia refers to the presence of elevated concentrations of triglycerides (TG) in the bloodstream (TG >200 mg/dL). This lipid alteration is known to be associated with an increased risk of atherosclerosis, contributing overall to the onset of atherosclerotic cardiovascular disease (CVD). Guidelines for the management of hypertriglyceridemia are based on both lifestyle intervention and pharmacological treatment, but poor adherence, medication-related costs and side effects can limit the success of these interventions. For this reason, the search for natural alternative approaches to reduce plasma TG levels currently represents a hot research field. This review article summarizes the most relevant clinical trials reporting the TG-reducing effect of different food-derived bioactive compounds. Furthermore, based on the evidence obtained from in vitro studies, we provide a description and classification of putative targets of action through which several bioactive compounds can exert a TG-lowering effect. Future research may lead to investigations of the efficacy of novel nutraceutical formulations consisting in a combination of bioactive compounds which contribute to the management of plasma TG levels through different action targets.

Triglycerides and ASCVD Risk Reduction: Recent Insights and Future Directions

PURPOSE OF REVIEW

This review focuses on recent evidence examining the role triglycerides (TG) and triglyceride-enriched lipoproteins (TGRL) play in atherosclerotic cardiovascular disease (ASCVD). It also provides a succinct overview of current and future TG-lowering therapies for ASCVD risk reduction.

RECENT FINDINGS

Epidemiological and Mendelian randomization studies have consistently shown that TGRL are strongly associated with ASCVD. REDUCE-IT demonstrated cardiovascular benefit with icosapent ethyl in high-risk patients with hypertriglyceridemia on statin therapy. Polymorphisms in APOC3 and ANGPTL3 are associated with ASCVD and use of RNA-interfering therapies to target these proteins has shown TG lowering in early phase trials. TG and TGRL are causally associated with ASCVD. Lifestyle modifications and statin therapy can lower TG/TGRL and are considered first-line treatment for hypertriglyceridemia. Icosapent ethyl has been shown to reduce residual ASCVD risk in high-risk patients on maximally tolerated statins. Ongoing clinical trials will better define optimal therapy for patients on statins with residual hypertriglyceridemia.

Emerging Mechanisms of Cardiovascular Protection for the Omega-3 Fatty Acid Eicosapentaenoic Acid

Patients with well-controlled LDL (low-density lipoprotein) levels still have residual cardiovascular risk associated with elevated triglycerides. Epidemiological studies have shown that elevated fasting triglyceride levels associate independently with incident cardiovascular events, and abundant recent human genetic data support the causality of TGRLs (triglyceride-rich lipoproteins) in atherothrombosis. Omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower blood triglyceride concentrations but likely exert additional atheroprotective properties at higher doses. Omega-3 fatty acids modulate T-cell differentiation and give rise to various prostaglandins and specialized proresolving lipid mediators that promote resolution of tissue injury and inflammation. The REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial) with an EPA-only formulation lowered a composite of cardiovascular events by 25% in patients with established cardiovascular disease or diabetes mellitus and other cardiovascular risk factors. This clinical benefit likely arises from multiple molecular mechanisms discussed in this review. Indeed, human plaques readily incorporate EPA, which may render them less likely to trigger clinical events. EPA and DHA differ in their effects on membrane structure, rates of lipid oxidation, inflammatory biomarkers, and endothelial function as well as tissue distributions. Trials that have evaluated DHA-containing high-dose omega-3 fatty acids have thus far not shown the benefits of EPA alone demonstrated in REDUCE-IT. This review will consider the mechanistic evidence that helps to understand the potential mechanisms of benefit of EPA.

Reducing Cardiovascular Disease Risk in Women Beyond Statin Therapy: New Insights 2020

Management of residual and persistent cardiovascular disease (CVD) risk among statin-treated individuals has emerged as an important preventive strategy. The purpose of this article is to review the unique landscape of CVD in women and relevant prior prevention trials, and to discuss how the recent results of the Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT) might apply to the contemporary management of CVD risk among statin-treated women. Women have unique risk factors that may impact CVD and its prevention. Historically, women have been underrepresented in CVD trials, posing a challenge to development of clinical recommendations for women. Low-density lipoprotein cholesterol-targeting treatments have demonstrated CVD risk reduction, with comparable effects in both sexes. In contrast, triglyceride-lowering treatments (niacin, fenofibrate, and omega-3 fatty acids) have reported mixed findings for CVD risk reduction. Recent clinical trials of combination omega-3 fatty acids (docosahexaenoic acid/eicosapentaenoic acid [EPA]) have not found significant CVD risk reduction. The recently published REDUCE-IT study found that icosapent ethyl, an EPA-only omega-3 fatty acid, in combination with statins, significantly reduced CVD events in high-risk patients. The icosapent ethyl group had a significantly lower occurrence of the primary composite CVD endpoint (17.2%) than the placebo group (22.0%; hazard ratio 0.75; 95% confidence interval 0.68-0.83; p < 0.001). CVD risk reduction with icosapent ethyl treatment was comparable between women and men (p for interaction, 0.33). Data from REDUCE-IT suggest women benefit similarly to men with respect to icosapent ethyl, a novel therapy for prevention of CVD.

Dietary fats and cardiometabolic disease: mechanisms and effects on risk factors and outcomes

The effect of dietary fats on cardiometabolic diseases, including cardiovascular diseases and type 2 diabetes mellitus, has generated tremendous interest. Many earlier investigations focused on total fat and conventional fat classes (such as saturated and unsaturated fats) and their influence on a limited number of risk factors. However, dietary fats comprise heterogeneous molecules with diverse structures, and growing research in the past two decades supports correspondingly complex health effects of individual dietary fats. Moreover, health effects of dietary fats might be modified by additional factors, such as accompanying nutrients and food-processing methods, emphasizing the importance of the food sources. Accordingly, the rapidly increasing scientific findings on dietary fats and cardiometabolic diseases have generated debate among scientists, caused confusion for the general public and present challenges for translation into dietary advice and policies. This Review summarizes the evidence on the effects of different dietary fats and their food sources on cell function and on risk factors and clinical events of cardiometabolic diseases. The aim is not to provide an exhaustive review but rather to focus on the most important evidence from randomized controlled trials and prospective cohort studies and to highlight current areas of controversy and the most relevant future research directions for understanding how to improve the prevention and management of cardiometabolic diseases through optimization of dietary fat intake.

Spotlight on Icosapent Ethyl for Cardiovascular Risk Reduction: Evidence to Date

Icosapent ethyl is a highly purified formulation of eicosapentaenoic acid, a type of omega-3 fatty acid contained in fish oil. While omega-3 fatty acids have long been thought to have cardioprotective benefits, the Reduction of Cardiovascular Events with EPA-Intervention Trial (REDUCE-IT) has helped to establish icosapent ethyl as an evidence-based therapy for risk reduction of atherosclerotic cardiovascular disease (ASCVD). REDUCE-IT, however, was by no means an overnight success story. Close examination of the evidence shows that the trial was a culmination of many lessons learned from previous studies. The purpose of this manuscript is to review contemporary evidence of icosapent ethyl in ASCVD risk reduction and the clinical implication of this promising therapy.

Investigational drugs in development for hypertriglyceridemia: a coming-of-age story

Introduction: Elevated triglyceride (TG) level is a prevalent condition in the general population and in patients with cardiovascular (CV) risk even under statin therapy. Severe hypertriglyceridemia (HTG) puts patients at risk for acute pancreatitis. Several TG-lowering drugs failed in clinical trials, but subgroup analyses suggest that high-risk patients, such as those with atherogenic dyslipidemia or diabetes, benefit from TG lowering.Areas covered: We review advances for TG-lowering drugs in clinical development. These include selective PPARα modulators, omega-3 fatty acid formulations that have been approved for severe HTG, and inhibitors of apolipoprotein C-III, angiopoietin-like-3 or microsomal transfer protein. Lessons learned from the success of the phase 3 trial REDUCE-IT with high-dose icosapent ethyl are also reviewed.Expert opinion: We believe that TG-lowering therapies are coming of age as they will allow to treat patients with high CV risk and moderate HTG, including T2D subjects, as well as patients with severe HTG or even homozygous familial hypercholesterolemia, all of which being 'optimally' treated with a statin. More studies on the impact of therapy on quality of life in patients with severe HTG should be conducted with the help of patient registries.

Effects of Icosapent Ethyl (Eicosapentaenoic Acid Ethyl Ester) on Atherogenic Lipid/Lipoprotein, Apolipoprotein, and Inflammatory Parameters in Patients With Elevated High-Sensitivity C-Reactive Protein (from the ANCHOR Study)

Icosapent ethyl is pure prescription eicosapentaenoic acid approved at 4 g/day as an adjunct to diet to reduce triglycerides (TG) in adults with TG ≥500 mg/dl. Elevated high-sensitivity C-reactive protein (hsCRP) is associated with increased cardiovascular risk. The 12-week ANCHOR study randomized 702 statin-treated patients at increased cardiovascular risk with TG 200 to 499 mg/dl despite low-density lipoprotein cholesterol (LDL-C) control (40 to 99 mg/dl). This post hoc analysis assessed 246 ANCHOR patients with baseline hsCRP ≥ 2.0 mg/L randomized to icosapent ethyl 4 g/day (n = 126; approved dose) or placebo (n = 120). Without increasing LDL-C, icosapent ethyl significantly reduced median TG (-20%; p < 0.0001), non-high-density lipoprotein cholesterol (-12.3%; p < 0.0001), total cholesterol (-11.1%; p < 0.0001), high-density lipoprotein cholesterol (-5.2%; p = 0.0042), very LDL-C (-21.0%; p < 0.0001), very low-density lipoprotein TG (-22.9%; p < 0.0001), remnant lipoprotein cholesterol (-23.0%; p = 0.0125), apolipoprotein B (-7.4%; p = 0.0021), apolipoprotein C-III (-16%; p < 0.0001), oxidized LDL (-13.7%; p = 0.0020), lipoprotein-associated phospholipase A₂ (-19.6%; p < 0.0001), and hsCRP (-17.9%; p = 0.0213) versus placebo, while interleukin-6 and intercellular adhesion molecule-1 were not significantly changed. Eicosapentaenoic acid increased with icosapent ethyl 4 g/day +637% in plasma and +632% in red blood cells versus placebo (both p < 0.0001). Icosapent ethyl exhibited a safety profile similar to placebo. In conclusion, in statin-treated patients with hsCRP ≥ 2.0 mg/L and TG 200 to 499 mg/dl at baseline, icosapent ethyl 4 g/day significantly and safely reduced TG and other atherogenic and inflammatory parameters without increasing LDL-C versus placebo.

Icosapent ethyl reduces atherogenic markers in high-risk statin-treated patients with stage 3 chronic kidney disease and high triglycerides

Objective: Patients with chronic kidney disease (CKD) have increased cardiovascular disease (CVD) risk, likely driven by atherogenic and inflammatory markers beyond low-density lipoprotein cholesterol (LDL-C). The objective of this hypothesis-generating post hoc subgroup analysis was to explore the effects of icosapent ethyl at 2 or 4 g/day (prescription pure ethyl ester of the omega-3 fatty acid eicosapentaenoic acid [EPA]) on atherogenic lipid, apolipoprotein, inflammatory parameters (high-sensitivity C-reactive protein [hsCRP], lipoprotein-associated phospholipase A₂ [Lp-PLA₂]), and oxidative parameters (oxidized-LDL [ox-LDL]) in statin-treated patients from ANCHOR with stage 3 CKD.Methods: The 12-week ANCHOR study evaluated icosapent ethyl in 702 statin-treated patients at increased CVD risk with triglycerides (TG) 200-499 mg/dL despite controlled LDL-C (40-99 mg/dL). This post-hoc analysis included patients from ANCHOR with stage 3 CKD (estimated glomerular filtration rate [eGFR] ≤60 mL/min/1.73 m² for ≥3 months) randomized to icosapent ethyl 4 g/day (n = 19), 2 g/day (n = 30), or placebo (n = 36).Results: At the prescription dose of 4 g/day, icosapent ethyl significantly reduced TG (-16.9%; P = 0.0074) and other potentially atherogenic lipids/lipoproteins, ox-LDL, hsCRP, and Lp-PLA₂, and increased plasma and red blood cell EPA levels (+879% and +579%, respectively; both P < 0.0001) versus placebo. Icosapent ethyl did not significantly alter eGFR or serum creatinine. Safety and tolerability were similar to placebo.Conclusions: In patients with stage 3 CKD at high CVD risk with persistent high TG despite statins, icosapent ethyl 4 g/day reduced potentially atherogenic and other cardiovascular risk factors without raising LDL-C, with safety similar to placebo. These findings suggest prospective investigation may be warranted.

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 experimental 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.Our secondary outcomes were vascular-related death, recurrent events, incidence of other type of stroke, adverse events, quality of life, and mood.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register (6 August 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 1, January 2019), MEDLINE Ovid (from 1948 to 6 August 2018), Embase Ovid (from 1980 to 6 August 2018), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; from 1982 to 6 August 2018), 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 quality 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 e.g. Glasgow Outcome Scale Extended (GOSE) dichotomised into poor or good clinical outcome, Barthel Index (higher score is better; scale from 0 to 100) or Rivermead Mobility Index (higher score is better; scale from 0 to 15).

MAIN RESULTS

We included 29 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 GOSE (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.36 to 1.68; 40 participants; very low quality evidence). Mood (assessed with 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; 102 participants; low-quality 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, and RR 0.33, 95% CI 0.01 to 7.72; 142 participants; low-quality evidence); recurrent events (RR 0.41, 95% CI 0.02 to 8.84; 18 participants; very low quality 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, and RR 0.63, 95% CI 0.25 to 1.58; 58 participants; very low quality evidence); and quality of life (physical component mean difference (MD) -2.31, 95% CI -4.81 to 0.19, and mental component MD -2.16, 95% CI -5.91 to 1.59; one study; 102 participants; low-quality evidence).Adverse events were reported by two studies (57 participants; very low quality evidence), one trial reporting extracranial haemorrhage (RR 0.25, 95% CI 0.04 to 1.73) and the other one reporting bleeding complications (RR 0.32, 95% CI 0.01 to 7.35).Longer follow-up (more than three months)One small trial assessed functional outcome with both Barthel Index (MD 7.09, 95% CI -5.16 to 19.34) for activities of daily living, and Rivermead Mobility Index (MD 1.30, 95% CI -1.31 to 3.91) for mobility (52 participants; very low quality evidence). We carried out meta-analysis for vascular-related death (RR 1.02, 95% CI 0.78 to 1.35; five studies; 2237 participants; low-quality evidence) and fatal recurrent events (RR 0.69, 95% CI 0.31 to 1.55; three studies; 1819 participants; low-quality evidence).We found no evidence of an effect of the intervention for mood (MD 1.00, 95% CI -2.07 to 4.07; one study; 14 participants; low-quality 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; 1455 participants; low-quality 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-quality evidence. More well-designed RCTs are needed, specifically in acute stroke, to determine the efficacy and safety of the intervention.Studies assessing functionality 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.

Emerging Evidence that ApoC-III Inhibitors Provide Novel Options to Reduce the Residual CVD

Purpose of Review

Apolipoprotein C-III (apoC-III) is known to inhibit lipoprotein lipase (LPL) and function as an important regulator of triglyceride metabolism. In addition, apoC-III has also more recently been identified as an important risk factor for cardiovascular disease. This review summarizes the mechanisms by which apoC-III induces hypertriglyceridemia and promotes atherogenesis, as well as the findings from recent clinical trials using novel strategies for lowering apoC-III.

Recent Findings

Genetic studies have identified subjects with heterozygote loss-of-function (LOF) mutations in APOC3, the gene coding for apoC-III. Clinical characterization of these individuals shows that the LOF variants associate with a low-risk lipoprotein profile, in particular reduced plasma triglycerides. Recent results also show that complete deficiency of apoC-III is not a lethal mutation and is associated with very rapid lipolysis of plasma triglyceride-rich lipoproteins (TRL). Ongoing trials based on emerging gene-silencing technologies show that intervention markedly lowers apoC-III levels and, consequently, plasma triglyceride. Unexpectedly, the evidence points to apoC-III not only inhibiting LPL activity but also suppressing removal of TRLs by LPL-independent pathways.

Summary

Available data clearly show that apoC-III is an important cardiovascular risk factor and that lifelong deficiency of apoC-III is cardioprotective. Novel therapies have been developed, and results from recent clinical trials indicate that effective reduction of plasma triglycerides by inhibition of apoC-III might be a promising strategy in management of severe hypertriglyceridemia and, more generally, a novel approach to CHD prevention in those with elevated plasma triglyceride.

Icosapent Ethyl Effects on Fatty Acid Profiles in Statin-Treated Patients With High Triglycerides: The Randomized, Placebo-controlled ANCHOR Study

Introduction

Fatty acid content in plasma and red blood cells (RBCs) may provide insight into potential physiologic benefits of omega-3 fatty acids. Icosapent ethyl is a pure prescription form of eicosapentaenoic acid (EPA) ethyl ester approved by the US Food and Drug Administration at a dose of 4 g/day as an adjunct to diet to reduce triglyceride levels in adults with severe (≥ 500 mg/dl) hypertriglyceridemia.

Methods

This was a prespecified exploratory subset analysis of the ANCHOR study, which randomized 702 statin-treated patients at increased cardiovascular risk with triglycerides 200–499 mg/dl and controlled low-density lipoprotein cholesterol (40–99 mg/dl). This analysis examined effects of icosapent ethyl 4 g/day versus placebo on fatty acid levels in plasma and RBCs using a gas chromatograph assay method with flame ionization detector.

Results

In plasma, treatment with icosapent ethyl 4 g/day resulted in significant increases versus placebo in the mean concentrations of EPA (+ 635%; P < 0.0001) and its metabolite, docosapentaenoic acid n-3 (+ 143%; P < 0.0001) with no significant change in docosahexaenoic acid. Treatment with icosapent ethyl 4 g/day versus placebo also resulted in significant decreases in the omega-6 fatty acids linoleic acid (− 25%) and arachidonic acid (AA; − 31%), as well as the AA/EPA ratio (− 91%). Icosapent ethyl 4 g/day also decreased the omega-9 fatty acid oleic acid (− 29%) and the saturated fatty acids palmitic acid (− 23%) and stearic acid (− 16%) (all P < 0.0001). Results were similar for RBCs.

Conclusions

Icosapent ethyl 4 g/day significantly increased EPA and produced other potentially beneficial shifts in fatty acids in plasma and RBCs versus placebo.

Trial Registration

ClinicalTrials.gov Identifier, NCT01047501

Funding

Amarin Pharma Inc.

Plain Language Summary

Plain language summary available for this article.

Effect of omega-3 supplements on plasma apolipoprotein C-III concentrations: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Apolipoprotein C-III (apo C-III) is a key regulator of triglycerides metabolism. The aim of this meta-analysis was to assess the effect of fish omega-3 polyunsaturated fatty acids (PUFAs) on apo C-III levels.

METHODS

Randomized placebo-controlled trials investigating the impact of omega-3 on apo C-III levels were searched in PubMed-Medline, SCOPUS, Web of Science and Google Scholar. A random-effects model and generic inverse variance method were used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. A weighted random-effects meta-regression was performed to evaluate the impact of potential confounders on glycemic parameters.

RESULTS

This meta-analysis comprising 2062 subjects showed a significant reduction of apo C-III concentrations following treatment with omega-3 (WMD: -22.18 mg/L, 95% confidence interval: -31.61, -12.75, p < .001; I²: 88.24%). Subgroup analysis showed a significant reduction of plasma apo C-III concentrations by eicosapentaenoic acid (EPA) ethyl esters but not omega-3 carboxylic acids or omega-3 ethyl esters. There was a greater apo C-III reduction with only EPA as compared with supplements containing EPA and docosahexaenoic acid (DHA) or only DHA. A positive association between the apo C-III-lowering effect of omega-3 with baseline apo C-III concentrations and treatment duration was found.

CONCLUSIONS

This meta-analysis has shown that omega-3 PUFAs might significantly decrease apo C-III. Key messages Omega-3 PUFA supplements significantly reduce apo C-III plasma levels, particularly in hypertriglyceridemic patients when applied in appropriate dose (more than 2 g/day) Triglyceride (TG)-lowering effect is achieved via peroxisome proliferator-activated receptors α Further studies should address the effect of omega-3 PUFAs alone or with other lipid-lowering drugs in order to provide a final answer whether apo C-III could be an important target for prevention of cardiovascular disease New apo C-III antisense oligonucleotide drug (Volanesorsen) showed to be promising in decreasing elevated TGs by reducing levels of apo C-III mRNA.

Lipid Effects of Icosapent Ethyl in Women with Diabetes Mellitus and Persistent High Triglycerides on Statin Treatment: ANCHOR Trial Subanalysis

Background: High triglycerides (TG) and diabetes mellitus type 2 (DM2) are stronger predictors of cardiovascular disease (CVD) in women than in men, but few randomized, controlled clinical trials have investigated lipid-lowering interventions in women and none have reported results specifically in women with high TG and DM2. Icosapent ethyl (Vascepa) is pure prescription eicosapentaenoic acid (EPA) ethyl ester approved at 4 g/day as an adjunct to diet to reduce TG ≥500 mg/dL.

Methods: The 12-week ANCHOR trial randomized 702 statin-treated patients (73% with DM; 39% women) at increased CVD risk with TG 200–499 mg/dL despite controlled low-density lipoprotein cholesterol (LDL-C; 40–99 mg/dL) to receive icosapent ethyl 2 g/day, 4 g/day, or placebo. This post hoc analysis included 146 women with DM2 (97% white, mean age 62 years) randomized to icosapent ethyl 4 g/day (n = 74) or placebo (n = 72).

Results: Icosapent ethyl significantly reduced TG (−21.5%; p < 0.0001) without increasing LDL-C and lowered other potentially atherogenic lipid/lipoprotein, apolipoprotein, and inflammatory parameters versus placebo. Icosapent ethyl increased EPA levels in plasma (+639%; p < 0.0001; n = 49) and red blood cells (+599%; p < 0.0001; n = 47) versus placebo. Safety and tolerability of icosapent ethyl were generally similar to placebo.

Conclusion: In women with DM2 at high CVD risk with persistently high TG on statins, icosapent ethyl 4 g/day reduced potentially atherogenic parameters with safety and tolerability comparable to placebo. Potential CVD benefits of icosapent ethyl are being tested in ∼8000 men and women at high CVD risk with high TG on statins in the ongoing Reduction of Cardiovascular Events with Icosapent Ethyl - Intervention Trial (REDUCE-IT) cardiovascular (CV) outcome trial.

Effect of Vascepa (icosapent ethyl) on progression of coronary atherosclerosis in patients with elevated triglycerides (200-499 mg/dL) on statin therapy: Rationale and design of the EVAPORATE study

Despite reducing progression and promoting regression of coronary atherosclerosis, statin therapy does not fully address residual cardiovascular (CV) risk. High‐purity eicosapentaenoic acid (EPA) added to a statin has been shown to reduce CV events and induce regression of coronary atherosclerosis in imaging studies; however, data are from Japanese populations without high triglyceride (TG) levels and baseline EPA serum levels greater than those in North American populations. Icosapent ethyl is a high‐purity prescription EPA ethyl ester approved at 4 g/d as an adjunct to diet to reduce TG levels in adults with TG levels >499 mg/dL. The objective of the randomized, double‐blind, placebo‐controlled EVAPORATE study is to evaluate the effects of icosapent ethyl 4 g/d on atherosclerotic plaque in a North American population of statin‐treated patients with coronary atherosclerosis, TG levels of 200 to 499 mg/dL, and low‐density lipoprotein cholesterol levels of 40 to 115 mg/dL. The primary endpoint is change in low‐attenuation plaque volume measured by multidetector computed tomography angiography. Secondary endpoints include incident plaque rates; quantitative changes in different plaque types and morphology; changes in markers of inflammation, lipids, and lipoproteins; and the relationship between these changes and plaque burden and/or plaque vulnerability. Approximately 80 patients will be followed for 9 to 18 months. The clinical implications of icosapent ethyl 4 g/d treatment added to statin therapy on CV endpoints are being evaluated in the large CV outcomes study REDUCE‐IT. EVAPORATE will provide important imaging‐derived data that may add relevance to the clinically derived outcomes from REDUCE‐IT.

Eicosapentaenoic Acid as a Potential Therapeutic Approach to Reduce Cardiovascular Risk in Patients with End-Stage Renal Disease on Hemodialysis: A Review

Background

Patients with end-stage renal disease on hemodialysis have excess cardiovascular disease (CVD) burden with substantially increased CV event rates compared with the general population.

Summary

Traditional interventions that, according to standard clinical guidelines, reduce CV risk such as antihypertensive therapy, diet, exercise, and statins are not similarly effective in the hemodialysis population. This raises the question of whether additional risk factors, such as enhanced inflammation and oxidative stress, may drive the increased CVD burden in hemodialysis patients. Eicosapentaenoic acid (EPA), an omega-3 polyunsaturated fatty acid, is incorporated into the atherosclerotic plaque as well as membrane phospholipid bilayers and produces beneficial effects on inflammatory and oxidative mechanisms involved in atherosclerotic plaque formation and progression. EPA levels and the ratio of EPA to the omega-6 polyunsaturated fatty acid arachidonic acid (AA) are reduced in hemodialysis patients. Serum EPA levels have been inversely correlated with proinflammatory cytokines, and the EPA/AA ratio has been inversely associated with CV events in hemodialysis cohorts. Three recent studies involving over 800 hemodialysis patients and follow-up of 2-3 years suggest that EPA therapy may improve clinical outcomes in this patient population as evidenced by significant reductions in cardiovascular mortality, all-cause mortality, and/or CV events.

Key Messages

Further studies with high-purity EPA are warranted in patients on hemodialysis, especially given the fact that other interventions including antihypertensives, diet, exercise, and statins have not provided meaningful benefit.

Rationale and design of REDUCE-IT: Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial

Residual cardiovascular risk persists despite statins, yet outcome studies of lipid-targeted therapies beyond low-density lipoprotein cholesterol (LDL-C) have not demonstrated added benefit. Triglyceride elevation is an independent risk factor for cardiovascular events. High-dose eicosapentaenoic acid (EPA) reduces triglyceride-rich lipoproteins without raising LDL-C. Omega-3s have postulated pleiotropic cardioprotective benefits beyond triglyceride-lowering. To date, no large, multinational, randomized clinical trial has proved that lowering triglycerides on top of statin therapy improves cardiovascular outcomes. The Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT; NCT01492361) is a phase 3b randomized, double-blinded, placebo-controlled trial of icosapent ethyl, a highly purified ethyl ester of EPA, vs placebo. The main objective is to evaluate whether treatment with icosapent ethyl reduces ischemic events in statin-treated patients with high triglycerides at elevated cardiovascular risk. REDUCE-IT enrolled men or women age ≥45 years with established cardiovascular disease or age ≥50 years with diabetes mellitus and 1 additional risk factor. Randomization required fasting triglycerides ≥150 mg/dL and <500 mg/dL and LDL-C >40 mg/dL and ≤100 mg/dL with stable statin (± ezetimibe) ≥4 weeks prior to qualifying measurements. The primary endpoint is a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or unstable angina. The key secondary endpoint is the composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. Several secondary, tertiary, and exploratory endpoints will be assessed. Approximately 8000 patients have been randomized at approximately 470 centers worldwide. Follow-up will continue in this event-driven trial until approximately 1612 adjudicated primary-efficacy endpoint events have occurred.

Usefulness of Icosapent Ethyl (Eicosapentaenoic Acid Ethyl Ester) in Women to Lower Triglyceride Levels (Results from the MARINE and ANCHOR Trials)

There are limited data on the efficacy and safety of triglyceride (TG)-lowering agents in women. We conducted subgroup analyses of the effects of icosapent ethyl (a high-purity prescription form of the ethyl ester of the omega-3 fatty acid, eicosapentaenoic acid) on TG levels (primary efficacy variable) and other atherogenic and inflammatory parameters in a total of 215 women with a broad range of TG levels (200-2000 mg/dl) enrolled in two 12-week placebo-controlled trials: MARINE (n = 18; placebo, n = 18) and ANCHOR (n = 91; placebo, n = 88). Icosapent ethyl 4 g/day significantly reduced TG levels from baseline to week 12 versus placebo in both MARINE (-22.7%; p = 0.0327) and ANCHOR (-21.5%; p <0.0001) without increasing low-density lipoprotein cholesterol levels. Significant improvements were also observed in non-high-density lipoprotein cholesterol levels in MARINE (-15.7%; p = 0.0082) and ANCHOR (-14.2%; p <0.0001) and total cholesterol levels in MARINE (-14.9%; p = 0.0023) and ANCHOR (-12.1%; p <0.0001), along with significant increases of >500% in eicosapentaenoic acid levels in plasma and red blood cells (all p <0.001). Icosapent ethyl was well tolerated, with adverse-event profiles comparable with findings in the overall studies. In conclusion, icosapent ethyl 4 g/day significantly reduced TG levels and other atherogenic parameters in women without increasing low-density lipoprotein cholesterol levels compared with placebo; the clinical implications of these findings are being evaluated in the REDUCtion of Cardiovascular Events With Eicosapentaenoic Acid [EPA]-Intervention Trial (REDUCE-IT) cardiovascular outcomes study.

Prescription omega-3 fatty acid products containing highly purified eicosapentaenoic acid (EPA)

The omega-3 fatty acid eicosapentaenoic acid (EPA) has multiple actions potentially conferring cardiovascular benefit, including lowering serum triglyceride (TG) and non-high-density lipoprotein cholesterol (non-HDL-C) levels and potentially reducing key steps in atherogenesis. Dietary supplements are a common source of omega-3 fatty acids in the US, but virtually all contain docosahexaenoic acid (DHA) in addition to EPA, and lipid effects differ between DHA and EPA. Contrary to popular belief, no over-the-counter omega-3 products are available in the US, only prescription products and dietary supplements. Among the US prescription omega-3 products, only one contains EPA exclusively (Vascepa); another closely related prescription omega-3 product also contains highly purified EPA, but is approved only in Japan and is provided in different capsule sizes. These high-purity EPA products do not raise low-density lipoprotein cholesterol (LDL-C) levels, even in patients with TG levels >500 mg/dL, in contrast to the increase in LDL-C levels with prescription omega-3 products that also contain DHA. The Japanese prescription EPA product was shown to significantly reduce major coronary events in hypercholesterolemic patients when added to statin therapy in the Japan EPA Lipid Intervention Study (JELIS). The effects of Vascepa on cardiovascular outcomes are being investigated in statin-treated patients with high TG levels in the Reduction of Cardiovascular Events With EPA-Intervention Trial (REDUCE-IT).

Recent explanatory trials of the mode of action of drug therapies on lipoprotein metabolism

PURPOSE OF REVIEW

Dysregulated lipoprotein metabolism leads to increased plasma concentrations of atherogenic lipoproteins. We highlight the findings from recent studies of the effect of lipid-regulating therapies on apolipoprotein metabolism in humans employing endogenous labelling with stable isotopically labelled isotopomers.

RECENT FINDINGS

Fish oil supplementation and niacin treatment both reduce fasting and postprandial triglyceride levels by decreasing the hepatic secretion of VLDL-apoB-100 (apoB) and apoB-48-containing chylomicron particles in obese and/or type 2 diabetes. Niacin also lowers plasma LDL-apoB and Lp(a) levels by increasing catabolism of LDL-apoB and decreasing secretion of Lp(a), respectively. In subjects with hypercholesterolaemia, inhibition of cholesteryl ester transfer protein raises apoA-I and lowers apoB by decreasing and increasing the catabolism of HDL-apoA-I and LDL-apoB, respectively. Antisense oligonucleotides directed at apoB mRNA lowers plasma LDL-cholesterol and apoB chiefly by increasing the catabolism and decreasing the secretion of LDL-apoB in healthy subjects. That apoB ASO treatment does not lower hepatic secretion in humans is unexpected and merits further investigation.

SUMMARY

Kinetic studies provide mechanistic insight into the mode of action of lipid lowering therapies and lipoprotein disorders. Understanding the mode of action of new drugs in vivo is important to establish their effective use in clinical practice.

New oral agents for treating dyslipidemia

PURPOSE OF REVIEW

We provide an overview of orally administered lipid-lowering therapies under development.

RECENT FINDINGS

Recent data support statins for intermediate risk primary prevention, and ezetimibe for high-risk secondary prevention. Novel agents in development include bempedoic acid and gemcabene, and work continues on one remaining cholesteryl ester transfer protein inhibitor, anacetrapib, to determine whether this class can reduce cardiovascular risk. Selective peroxisome proliferator-activated receptor modulators such as K-877 are under study to determine whether they have an advantage over older fibrates. Diacylglycerol transferase inhibitors such as pradigastat appear to have potent triglyceride-lowering effects, even for patients with familial chylomicronemia syndrome. Finally, novel ω-3 preparations are available with significant triglyceride lowering, although their role in therapy remains unclear.

SUMMARY

Statins will remain the backbone of lipid-lowering therapy, although several novel oral agents are promising. The common theme across drugs in development is the demonstration of good lipid-lowering effect, although lacking cardiovascular outcomes data, which will likely be necessary before any of them, can be recommended or approved for widespread use.