Omega-3 fatty acids supplementation and risk of atrial fibrillation: an updated meta-analysis of randomized controlled trials

Association Between Remnant Cholesterol and Risk of Incident Atrial Fibrillation: Population-Based Evidence From a Large-Scale Prospective Cohort Study

BACKGROUND

Evidence for the relationship between remnant cholesterol (RC) and incident atrial fibrillation (AF) risk remains sparse and limited.

METHODS AND RESULTS

Participants were enrolled between 2006 and 2010 and followed up to 2021. The multivariable Cox proportional hazards model was used to examine the relationship between RC quartiles and risk of incident AF. Subgroup analyses and sensitivity analyses were performed to explore the potential modification of the association and the robustness of the main findings. A total of 422 316 participants (mean age, 56 years; 54% women) were included for analyses. During a median follow-up of 11.9 years (first quartile-third quartile, 11.6-13.2 years), there were 24 774 AF events documented with an incidence of 4.92 events per 1000 person-years (95% CI, 4.86-4.98). Participants in higher RC quartiles had a lower risk of incident AF than those in the lowest quartile (first quartile): hazard ratio (HR)=0.96 (95% CI, 0.91-1.00) for second quartile; HR=0.92 (95% CI, 0.88-0.96) for third quartile; and HR=0.85 (95% CI, 0.81-0.89) for fourth quartile (P for trend <0.001). The association between RC quartiles and risk of incident AF was stronger in participants aged ≥65 years, in men, and in participants without history of diabetes when compared with control groups (P<0.001 for interaction).

CONCLUSIONS

On the basis of data from this large-scale prospective cohort study, elevated RC was associated with a lower risk of incident AF.

Liver X Receptor Agonist 4β-Hydroxycholesterol as a Prognostic Factor in Coronary Artery Disease

BACKGROUND

Regardless of progress in treatment of coronary artery disease (CAD), there is still a significant residual risk of death in patients with CAD, highlighting the need for additional risk stratification markers. Our previous study provided evidence for a novel blood pressure-regulating mechanism involving 4β-hydroxycholesterol (4βHC), an agonist for liver X receptors, as a hypotensive factor. The aim was to determine the role of 4βHC as a prognostic factor in CAD.

METHODS AND RESULTS

The ARTEMIS (Innovation to Reduce Cardiovascular Complications of Diabetes at the Intersection) cohort consists of 1946 patients with CAD. Men and women were analyzed separately in quartiles according to plasma 4βHC. Basic characteristics, medications, ECG, and echocardiography parameters as well as mortality rate were analyzed. At baseline, subjects with a beneficial cardiovascular profile, as assessed with traditional markers such as body mass index, exercise capacity, prevalence of diabetes, and use of antihypertensives, had the highest plasma 4βHC concentrations. However, in men, high plasma 4βHC was associated with all-cause death, cardiac death, and especially sudden cardiac death (SCD) in a median follow-up of 8.8 years. Univariate and comprehensively adjusted hazard ratios for SCD in the highest quartile were 3.76 (95% CI, 1.6-8.7; P=0.002) and 4.18 (95% CI, 1.5-11.4; P=0.005), respectively. In contrast, the association of cardiac death and SCD in women showed the lowest risk in the highest 4βHC quartile.

CONCLUSIONS

High plasma 4βHC concentration was associated with death and especially SCD in men, while an inverse association was detected in women. Our results suggest 4βHC as a novel sex-specific risk marker of cardiac death and especially SCD in chronic CAD.

REGISTRATION INFORMATION

clinicaltrials.gov. Identifier NCT01426685.

Safety update: omega-3-acid ethyl esters and atrial fibrillation

Overview of: Medicines and Healthcare products Regulatory Agency. Omega-3-acid ethyl ester medicines (Omacor/Teromeg 1000 mg capsules): dose-dependent increased risk of atrial fibrillation in patients with established cardiovascular diseases or cardiovascular risk factors. Drug Safety Update 2024;17(6):3.

Current Evidence and Future Directions of Omega-3 Supplementation and Cardiovascular Disease Risk

Omega-3 supplementation has a controversial role in the secondary prevention of cardiovascular diseases. Despite large clinical trials published over the years, the evidence of omega-3 in preventing cardiovascular diseases, especially coronary heart disease, is still inconclusive. However, recent clinical trials using higher dose of omega-3 or highly purified esters of omega-3 shows promising result, with reduction in cardiovascular death and incidence of cardiovascular disease. This review aims to summarize the possible mechanism of omega-3 in preventing cardiovascular disease and future directions of research regarding the benefit of omega-3 in cardiovascular disease.

Drug-induced atrial fibrillation. A narrative review of a forgotten adverse effect

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased morbidity and mortality. There is clinical evidence that an increasing number of cardiovascular and non-cardiovascular drugs, mainly anticancer drugs, can induce AF either in patients with or without pre-existing cardiac disorders, but drug-induced AF (DIAF) has not received the attention that it might deserve. In many cases DIAF is asymptomatic and paroxysmal and patients recover sinus rhythm spontaneously, but sometimes, DIAF persists, and it is necessary to perform a cardioversion. Furthermore, DIAF is not mentioned in clinical guidelines on the treatment of AF. The risk of DIAF increases in elderly and in patients treated with polypharmacy and with risk factors and comorbidities that commonly coexist with AF. This is the case of cancer patients. Under these circumstances ascribing causality of DIAF to a given drug often represents a clinical challenge. We review the incidence, the pathophysiological mechanisms, risk factors, clinical relevance, and treatment of DIAF. Because of the limited information presently available, further research is needed to obtain a deeper insight into DIAF. Meanwhile, it is important that clinicians are aware of the problem that DIAF represents, recognize which drugs may cause DIAF, and consider the possibility that a drug may be responsible for a new-onset AF episode.

Omega-3 fatty acid supplements and risk of atrial fibrillation and 'micro-atrial fibrillation': A secondary analysis from the OMEMI trial

BACKGROUND & AIMS

Recent randomized clinical trials have raised concerns regarding potential off target adverse effects from supplementation of n-3 polyunsaturated fatty acids (PUFA) on atrial fibrillation (AF) risk. We aimed to assess risk and potential mediators of AF and 'micro-AF' from n-3 PUFA in post-myocardial infarction (MI) patients.

METHODS

In the OMEMI trial, 70-82 y. o. patients with a recent MI were randomized to 1.8 g/day of eicosapentaenoic-/docosahexaenoic acid (EPA/DHA) or placebo (corn oil) for two years. New-onset AF and 'micro-AF' was recorded by clinical detection and by screening with Zenicor thumb-ECG (adjudicated by blinded investigators). Serum EPA and DHA were measured at baseline and study end.

RESULTS

At baseline, 759 of 1014 (75%) patients had no AF history. These patients were aged 75 ± 4 years and 71% were male. During follow-up, 43 patients developed new-onset AF (39 clinically-detected and 4 by thumb-ECG screening). In addition, 27 patients had episodes of micro-AF, yielding a total of 70 patients with new-onset AF or 'micro-AF'. In the n-3 PUFA group 46 (11.9%) had AF/'micro-AF' (28 AF, 18 'micro-AF') and in the placebo group 24 (6.5%) had AF/micro-AF (15 AF, 9 micro-AF); HR 1.90 (95%CI 1.16-3.11), P = 0.011. Changes in serum EPA (but not DHA) mediated the effect from n-3 PUFA on AF risk, explaining 65% of the association.

CONCLUSION

Supplementation of n-3 PUFA post MI increases the risk of 'micro-AF' and AF, and increases in EPA seems to be an important mediator of the treatment effect from n-3 PUFA on the risk of AF.

STUDY REGISTRATION

OMEMI Study; ClinicalTrails.gov identifier: NCT0184194.

Fish oil nano-emulsion kills macrophage: Ferroptosis triggered by catalase-catalysed superoxide eruption

Fish oil is increasingly utilised in the form of nano-emulsion as a nutrient and function fortifier. The nano-emulsions exceptionally high content of polyunsaturated fatty acids and electron donors at the oil/water interface provide an ideal site of the redox reaction. Here we report that a vigorous superoxide production in the fish oil nano-emulsion was catalysed by mammalian catalase in acellular and cellular systems. The resulting superoxide increased cytosolic reactive oxygen species (ROS) and membrane lipid peroxidation of murine macrophage, which eventually causes fatal oxidative damages. Cell death, was significantly inhibited by a catalase-specific inhibitor 3-Amino-1,2,4-triazole (3-AT), was via ferroptosis and not apoptosis. The ferroptosis was independent of free iron or glutathione peroxidase suppression. Our findings discovered a hidden health risk of the widely acclaimed fish oil emulsion, suggesting a novel cellular damage mechanism caused by dietary unsaturated fats on the alimentary tract mucosa.

Pros and Cons of Long-Chain Omega-3 Polyunsaturated Fatty Acids in Cardiovascular Health

The long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found in seafood, supplements, and concentrated pharmaceutical preparations. Prospective cohort studies demonstrate an association between higher intakes of EPA+DHA or higher levels of EPA and DHA in the body and lower risk of developing cardiovascular disease (CVD), especially coronary heart disease and myocardial infarction, and of cardiovascular mortality in the general population. The cardioprotective effect of EPA and DHA is due to the beneficial modulation of a number of risk factors for CVD. Some large trials support the use of EPA+DHA (or EPA alone) in high-risk patients, although the evidence is inconsistent. This review presents key studies of EPA and DHA in the primary and secondary prevention of CVD, briefly describes potential mechanisms of action, and discusses recently published RCTs and meta-analyses. Potential adverse aspects of long-chain omega-3 fatty acids in relation to CVD are discussed.

Omega-3 fatty acids and atrial fibrillation

Although some clinical trials have demonstrated reduced incidence of cardiovascular disease with the use of omega-3 fatty acids, others have found an increased risk of atrial fibrillation (AF). AF is the most common sustained cardiac arrhythmia worldwide. It is associated with high morbidity and mortality rates and significant public health burden. Previous studies of the effect of omega-3 fatty acids on AF occurrence have reported contradictory results. Here we reviewed the effect of omega-3 fatty acids on the risk of AF.

Eicosapentaenoic Acid for Cardiovascular Events Reduction- Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Randomized clinical trials (RCTs) investigating the impact of omega-3-fatty acid supplementation on cardiovascular events have largely shown no benefit. However, there is debate about the benign nature of the placebo in these trials. We aimed to conduct a network meta-analysis of RCTs to compare the outcomes of omega-3 fatty acid supplementation to various placebo oils.

METHODS

MEDLINE and EMBASE were searched through May, 2021 to identify RCTs investigating cardiovascular outcomes with omega-3-fatty acid formulations [eicosapentaenoic acid (EPA), decosahexanoic acid (DHA), or the combination] versus placebo or standard of care controls.

RESULTS

Our analysis included 17 RCTs that enrolled a total of 141,009 patients randomized to EPA (n=13,655), EPA+DHA (n=56,908), mineral oil placebo (n=5,338), corn oil placebo (n =8,876), olive oil placebo (n=41,009), and controls (no placebo oil; n=15,223). Rates of cardiovascular death [hazard ratio (HR) (95% confidence interval, CI) =0.80 (0.65-0.98); p =0.033], myocardial infarction [HR (95% CI) =0.73 (0.55-0.97); p=0.029] and stroke [HR (95% CI) =0.74 (0.58-0.94); p=0.014] were significantly lower in those receiving EPA compared to those receiving mineral oil, but were not different from rates in those receiving other oils or controls. Rates of coronary revascularization were significantly lower in those receiving EPA than in those receiving either EPA+DHA, mineral oil, corn oil, or olive oil placebo, but not controls. All-cause death was similar among all groups, but combined EPA+DHA was associated with reduced risk of cardiovascular death compared to controls [HR (95%CI): 0.83 (0.71-0.98)].

CONCLUSIONS

Our analyses demonstrate that although EPA supplementation lowers risk of coronary revascularization more than other oils, there may not be a benefit relative to standard of care. Further, EPA reduces the risk of cardiovascular events only in comparison to mineral oil and not when compared with other placebo oils or controls. In contrast, combined EPA+DHA was associated with reduced risk of cardiovascular death compared to controls.

Changes in eicosapentaenoic acid and docosahexaenoic acid and risk of cardiovascular events and atrial fibrillation: A secondary analysis of the OMEMI trial

BACKGROUND

The cardiovascular benefit from n-3 polyunsaturated fatty acids (PUFAs) after acute myocardial infarction (AMI) is controversial, and the importance of serum eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations for clinical events is unclear.

OBJECTIVES

To assess changes in EPA and DHA serum concentrations during n-3 PUFA supplementation and their association with incident cardiovascular events.

METHODS

In the OMEMI trial, elderly patients with a recent AMI were randomized to 1.8 g/day of EPA/DHA or control (corn oil) for 2 years. The primary outcome was a composite of AMI, coronary revascularization, stroke, heart failure hospitalization, or all-cause death (major adverse cardiovascular event [MACE]) and the secondary outcome was new-onset atrial fibrillation (AF).

RESULTS

EPA and DHA measurements were available in 881 (92% of survivors) participants at randomization and study completion. EPA and DHA increased in the active treatment arm (n = 438) by a median of 87% and 16%, respectively. Greater on-treatment increases in EPA and DHA were associated with decreasing triglycerides, increasing high-density lipoprotein cholesterol, and lower baseline EPA and DHA concentrations. Greater on-treatment increases in EPA were associated with lower risk of MACE (adjusted hazard ratio 0.86 [95% confidence interval, CI, 0.75-0.99], p = 0.034), and higher risk of AF (adjusted hazard ratio (HR) 1.36 [95% CI 1.07-1.72], p = 0.011). Although there were similar tendencies for DHA changes and outcomes, these associations were not statistically significant (HR 0.84 [0.66-1.06] for MACE and 1.39 [0.90-2.13] for AF).

CONCLUSION

Greater on-treatment increases in EPA were associated with lower risk of MACE and higher risk of new-onset AF. These data suggest that the cardiovascular effects of increasing n-3 PUFA levels through supplements are complex, involving both potential benefits and harm.

Nutrition Assessment and Dietary Interventions in Heart Failure: JACC Review Topic of the Week

Despite the high prevalence of nutrition disorders in patients with heart failure (HF), major HF guidelines lack specific nutrition recommendations. Because of the lack of standardized definitions and assessment tools to quantify nutritional status, nutrition disorders are often missed in patients with HF. Additionally, a wide range of dietary interventions and overall dietary patterns have been studied in this population. The resulting evidence of benefit is, however, conflicting, making it challenging to determine which strategies are the most beneficial. In this document, we review the available nutritional status assessment tools for patients with HF. In addition, we appraise the current evidence for dietary interventions in HF, including sodium restriction, obesity, malnutrition, dietary patterns, and specific macronutrient and micronutrient supplementation. Furthermore, we discuss the feasibility and challenges associated with the implementation of multimodal nutrition interventions and delineate potential solutions to facilitate addressing nutrition in patients with HF.

Omega-3 polyunsaturated fatty acids: moving towards precision use for prevention and treatment of colorectal cancer

Data from experimental studies have demonstrated that marine omega-3 polyunsaturated fatty acids (O3FAs) have anti-inflammatory and anticancer properties. In the last decade, large-scale randomised controlled trials of pharmacological delivery of O3FAs and prospective cohort studies of dietary O3FA intake have continued to investigate the relationship between O3FA intake and colorectal cancer (CRC) risk and mortality. Clinical data suggest that O3FAs have differential anti-CRC activity depending on several host factors (including pretreatment blood O3FA level, ethnicity and systemic inflammatory response) and tumour characteristics (including location in the colorectum, histological phenotype (eg, conventional adenoma or serrated polyp) and molecular features (eg, microsatellite instability, cyclooxygenase expression)). Recent data also highlight the need for further investigation of the effect of O3FAs on the gut microbiota as a possible anti-CRC mechanism, when used either alone or in combination with other anti-CRC therapies. Overall, these data point towards a precision approach to using O3FAs for optimal prevention and treatment of CRC based on mechanistic understanding of host, tumour and gut microbiota factors that predict anticancer activity of O3FAs.

Impact of α-Linolenic Acid, the Vegetable ω-3 Fatty Acid, on Cardiovascular Disease and Cognition

Given the evidence of the health benefits of plant-based diets and long-chain n-3 (ω-3) fatty acids, there is keen interest in better understanding the role of α-linolenic acid (ALA), a plant-derived n-3 fatty acid, on cardiometabolic diseases and cognition. There is increasing evidence for ALA largely based on its major food sources (i.e., walnuts and flaxseed); however, this lags behind our understanding of long-chain n-3 fatty acids. Meta-analyses of observational studies have shown that increasing dietary ALA is associated with a 10% lower risk of total cardiovascular disease and a 20% reduced risk of fatal coronary heart disease. Three randomized controlled trials (RCTs) [AlphaOmega trial, Prevención con Dieta Mediterránea (PREDIMED) trial, and Lyon Diet Heart Study] all showed benefits of diets high in ALA on cardiovascular-related outcomes, but the AlphaOmega trial, designed to specifically evaluate ALA effects, only showed a trend for benefit. RCTs have shown that dietary ALA reduced total cholesterol, LDL cholesterol, triglycerides, and blood pressure, and epidemiologic studies and some trials also have shown an anti-inflammatory effect of ALA, which collectively account for, in part, the cardiovascular benefits of ALA. A meta-analysis reported a trend toward diabetes risk reduction with both dietary and biomarker ALA. For metabolic syndrome and obesity, the evidence for ALA benefits is inconclusive. The role of ALA in cognition is in the early stages but shows promising evidence of counteracting cognitive impairment. Much has been learned about the health benefits of ALA and with additional research we will be better positioned to make strong evidence-based dietary recommendations for the reduction of many chronic diseases.

Omega-3 Polyunsaturated Fatty Acids-Vascular and Cardiac Effects on the Cellular and Molecular Level (Narrative Review)

In the prevention and treatment of cardiovascular disease, in addition to the already proven effective treatment of dyslipidemia, hypertension and diabetes mellitus, omega-3 polyunsaturated fatty acids (n-3 PUFAs) are considered as substances with additive effects on cardiovascular health. N-3 PUFAs combine their indirect effects on metabolic, inflammatory and thrombogenic parameters with direct effects on the cellular level. Eicosapentaenoic acid (EPA) seems to be more efficient than docosahexaenoic acid (DHA) in the favorable mitigation of atherothrombosis due to its specific molecular properties. The inferred mechanism is a more favorable effect on the cell membrane. In addition, the anti-fibrotic effects of n-3 PUFA were described, with potential impacts on heart failure with a preserved ejection fraction. Furthermore, n-3 PUFA can modify ion channels, with a favorable impact on arrhythmias. However, despite recent evidence in the prevention of cardiovascular disease by a relatively high dose of icosapent ethyl (EPA derivative), there is still a paucity of data describing the exact mechanisms of n-3 PUFAs, including the role of their particular metabolites. The purpose of this review is to discuss the effects of n-3 PUFAs at several levels of the cardiovascular system, including controversies.

Omega 3 Fatty Acids and Health: The Little We Know after All These Years

Elagizi et al. [1] provide an update on the effects of long-chain omega 3 fatty acids on the cardiovascular system [...].

Investigating Lipid-Modulating Agents for Prevention or Treatment of COVID-19: JACC State-of-the-Art Review

Coronavirus disease-2019 (COVID-19) is associated with systemic inflammation, endothelial activation, and multiorgan manifestations. Lipid-modulating agents may be useful in treating patients with COVID-19. These agents may inhibit viral entry by lipid raft disruption or ameliorate the inflammatory response and endothelial activation. In addition, dyslipidemia with lower high-density lipoprotein cholesterol and higher triglyceride levels portend worse outcomes in patients with COVID-19. Upon a systematic search, 40 randomized controlled trials (RCTs) with lipid-modulating agents were identified, including 17 statin trials, 14 omega-3 fatty acids RCTs, 3 fibrate RCTs, 5 niacin RCTs, and 1 dalcetrapib RCT for the management or prevention of COVID-19. From these 40 RCTs, only 2 have reported preliminary results, and most others are ongoing. This paper summarizes the ongoing or completed RCTs of lipid-modulating agents in COVID-19 and the implications of these trials for patient management.

Omega-3 fatty acids for the prevention of atherosclerotic cardiovascular disease

Marine-derived omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are a type of polyunsaturated fatty acids with many purported beneficial health effects including the prevention of atherosclerotic cardiovascular disease (ASCVD) events. Omega-3 fatty acid intake may be supplemented via dietary sources, as well as prescription or non-prescription products. Omega-3 fatty acids have been shown to reduce serum triglycerides, but there remains ongoing debate regarding the effect of omega-3 fatty acids on major adverse cardiovascular events in patients with established, or at risk of, ASCVD. Recent evidence from randomized, placebo-controlled trials has demonstrated that low-dose (1 g daily or less) omega-3 fatty acids (DHA and EPA) do not reduce cardiovascular events or death in patients with or without established ASCVD. Contrarily, the REDUCE-IT trial demonstrated that a purified form of EPA ethyl esters (icosapent ethyl) at 4 g daily reduced cardiovascular events and death in patients with ASCVD (or diabetes and multiple cardiovascular risk factors) and elevated triglycerides on background statin therapy. However, 4 g daily of omega-3 carboxylic acids (DHA and EPA) did not show a cardiovascular benefit in the STRENGTH trial, which enrolled a similar population. The explanation for this observed discrepancy remains a source of contention and discourse. For now, icosapent ethyl has the most compelling evidence to support a cardiovascular benefit and should be considered in select patients who meet the REDUCE-IT criteria. Furthermore, alternative versions of omega-3 fatty acids should not be considered equivalent to icosapent ethyl. Patients taking an omega-3 fatty acid supplement should be monitored for potential adverse effects, including gastrointestinal disorders or bleeding, in addition to a possible increased risk of atrial fibrillation.

Lipid-Modulating Agents for Prevention or Treatment of COVID-19 in Randomized Trials

Coronavirus disease 2019 (COVID-19) is associated with systemic inflammation, endothelial activation, and multi-organ manifestations. Lipid modulating agents may be useful in treating patients with COVID-19. They may inhibit viral entry by lipid raft disruption or ameliorate the inflammatory response and endothelial activation. In addition, dyslipidemia with lower high-density lipoprotein cholesterol and higher triglycerides portends worse outcome in patients with COVID-19. Upon a systematic search, 40 RCTs with lipid modulating agents were identified, including 17 statin trials, 14 omega-3 fatty acids RCTs, 3 fibrates RCTs, 5 niacin RCTs, and 1 dalcetrapib RCT for management or prevention of COVID-19. This manuscript summarizes the ongoing or completed randomized controlled trials (RCTs) of lipid modulating agents in COVID-19 and the implications of these trials for patient management.