Omega-3 fatty acids in the treatment of heart failure

Omega-3 polyunsaturated fatty acids (Ω-3 PUFAs) have garnered increased attention as a therapeutic option in cardiovascular disease. Most of the research to date has focused on their lipid altering effects and clinical benefits in patients with coronary artery disease, however, there are data supporting their use in the treatment of heart failure. We review the mechanisms through which Ω-3 PUFAs exert their positive effects on the cardiovascular system and highlight the observational and treatment studies that assessed their effects in patients with heart failure.

Structured Lipids Engineering for Health: Novel Formulations Enriched in n-3 Long-Chain Polyunsaturated Fatty Acids with Potential Nutritional Benefits

Structured lipids (SLs) offer a promising avenue for designing novel formulations enriched in n-3 long-chain polyunsaturated fatty acids (LCPUFAs) with potential health benefits. Triacylglycerols (TAGs), the most common fats in the human diet, are both non-toxic and chemically stable. The metabolic efficiency and digestibility of TAGs are significantly influenced by the position of fatty acids (FAs) within the glycerol backbone, with FAs at the sn-2 position being readily absorbed. Over the past two decades, advancements in SL research have led to the development of modified TAGs, achieved either through chemical or enzymatic processes, resulting in SLs. The ideal structure of SLs involves medium-chain FAs at the sn-1,3 positions and long-chain n-3 LCPUFAs at the sn-2 position of the glycerol backbone, conferring specific physicochemical and nutritional attributes. These tailored SL formulations find wide-ranging applications in the food and nutraceutical industries, showing promise for dietary support in promoting health and mitigating various diseases. In particular, SLs can be harnessed as functional oils to augment TAG metabolism, thereby impeding the development of fatty liver, countering the onset of obesity, and preventing atherosclerosis and age-related chronic diseases. In scrutinising prevailing research trajectories, this review endeavours to provide an in-depth analysis of the multifaceted advantages and repercussions associated with the synthesis of SLs. It elucidates their burgeoning potential in enhancing health and well-being across a range of demographic cohorts. Specifically, the implications of SL utilisation are discussed in the context of healthcare environments and early childhood developmental support.

Long-chain omega-3 polyunsaturated fatty acids and the risk of heart failure

Aims:

Adequate intake of long-chain (LC) omega-3 polyunsaturated fatty acids ( n-3 PUFAs) is considered important for cardiovascular health. However, the effects of LC n-3 PUFAs on the risk of heart failure (HF) remain unclear. This systematic review and meta-analysis aimed to determine the role of LC n-3 PUFAs in the incidence of HF.

Materials and Methods:

Electronic databases were searched for studies up to 31 July 2021. Studies were included for the meta-analysis if they reported the adjusted associations between different dietary intakes or circulating concentrations of LC n-3 PUFAs and the risk of HF. A random-effect model was used to calculate the pooled estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for higher LC n-3 PUFA concentrations.

Results:

Thirteen studies were included in the meta-analysis. Eight studies comprising 316,698 individuals (11,244 incident HF cases), with a median follow-up of 10.7 years, showed that a higher dietary intake of LC n-3 PUFAs was associated with a lower risk of HF (highest versus lowest quintile: HR = 0.84, 95% CI = 0.75–0.94). Six studies, comprising 17,163 participants (2520 HF cases) with a median follow-up of 9.7 years, showed that higher circulating LC n-3 PUFA concentrations were associated with a lower risk of HF (highest versus lowest quintile: HR = 0.59, 95% CI = 0.39–0.91). Higher circulating docosahexaenoic acid concentrations were associated with a decreased risk of HF (top versus bottom quintile: HR = 0.44, 95% CI = 0.26–0.77). The associations between eicosapentaenoic acid (HR = 0.58, 95% CI = 0.26–1.25), docosahexaenoic acid (HR = 0.66, 95% CI = 0.24–1.82), and the risk of HF were not significant.

Conclusion:

High LC n-3 PUFA concentrations measured by dietary intake or circulating biomarkers are associated with a lower risk of developing HF.

Effect of n-3 PUFA on left ventricular remodelling in chronic heart failure: a systematic review and meta-analysis

Accumulating evidence suggests that supplementation of n-3 PUFA was associated with reduction in risk of major cardiovascular events. This meta-analysis was to systematically evaluate whether daily supplementation and accumulated intake of n-3 PUFA are associated with improved left ventricular (LV) remodelling in patients with chronic heart failure (CHF). Articles were obtained from Pubmed, Clinical key and Web of Science from inception to January 1 in 2021, and a total of twelve trials involving 2162 participants were eligible for inclusion. The sources of study heterogeneity were explained by I2 statistic and subgroup analysis. Compared with placebo groups, n-3 PUFA supplementation improved LV ejection fraction (LVEF) (eleven trials, 2112 participants, weighted mean difference (WMD) = 2·52, 95 % CI 1·25, 3·80, I2 = 87·8 %) and decreased LV end systolic volume (five studies, 905 participants, WMD = -3·22, 95 % CI 3·67, -2·77, I2 = 0·0 %) using the continuous variables analysis. Notably, the high accumulated n-3 PUFA dosage groups (≥ 600 g) presented a prominent improvement in LVEF, while the low and middle accumulated dosage (≤ 300 and 300-600 g) showed no effects on LVEF. In addition, n-3 PUFA supplementation decreased the levels of pro-inflammatory mediators including TNF-α, IL-6 (IL-6) and hypersensitive c-reactive protein. Therefore, the present meta-analysis demonstrated that n-3 PUFA consumption was associated with a substantial improvement of LV function and remodelling in patients subjected to CHF. The accumulated dosage of n-3 PUFA intake is vital for its cardiac protective role.

Marine-Derived Omega-3 Polyunsaturated Fatty Acids and Heart Failure: Current Understanding for Basic to Clinical Relevance

Heart failure (HF) is a rapidly growing global public health problem. Since HF results in high mortality and re-hospitalization, new effective treatments are desired. Although it remains controversial, omega 3 polyunsaturated fatty acids (n-3 PUFAs), such as the eicosapentaenoic acid and docosahexaenoic acid, have been widely recognized to have benefits for HF. In a large-scale clinical trial regarding secondary prevention of HF by n-3 PUFA (GISSI-HF trial), the supplementation of n-3 PUFA significantly reduced cardiovascular mortality and hospitalization. Other small clinical studies proposed that n-3 PUFA potentially suppresses the ventricular remodeling and myocardial fibrosis, which thereby improves the ventricular systolic and diastolic function both in ischemic and non-ischemic HF. Basic investigations have further supported our understanding regarding the cardioprotective mechanisms of n-3 PUFA against HF. In these reports, n-3 PUFA has protected hearts through (1) anti-inflammatory effects, (2) intervention of cardiac energy metabolism, (3) modification of cardiac ion channels, (4) improvement of vascular endothelial response, and (5) modulation of autonomic nervous system activity. To clarify the pros and cons of n-3 PUFA on HF, we summarized recent evidence regarding the beneficial effects of n-3 PUFA on HF both from the clinical and basic studies.

Dietary patterns and components to prevent and treat heart failure: a comprehensive review of human studies

Growing evidence has emerged about the role of dietary patterns and components in heart failure (HF) incidence and severity. The objective here is to provide a comprehensive summary of the current evidence regarding dietary patterns/components and HF. A comprehensive search of online databases was conducted using multiple relevant keywords to identify relevant human studies. The Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets have consistently been associated with decreased HF incidence and severity. Regarding specific dietary components, fruit, vegetables, legumes and whole grains appear beneficial. Current evidence suggests that red/processed meats, eggs and refined carbohydrates are harmful, while fish, dairy products and poultry remain controversial. However, there is a notable lack of human intervention trials. The existing but limited observational and interventional evidence from human studies suggests that a plant-based dietary pattern high in antioxidants, micronutrients, nitrate and fibre but low in saturated/trans-fat and Na may decrease HF incidence/severity. Potential mechanisms include decreased oxidative stress, homocysteine and inflammation but higher antioxidant defence and NO bioavailability and gut microbiome modulation. Randomised, controlled trials are urgently required.

Seafood Long-Chain n-3 Polyunsaturated Fatty Acids and Cardiovascular Disease: A Science Advisory From the American Heart Association

Since the 2002 American Heart Association scientific statement "Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease," evidence from observational and experimental studies and from randomized controlled trials continues to emerge to further substantiate the beneficial effects of seafood long-chain n-3 polyunsaturated fatty acids and cardiovascular disease. A recent American Heart Association science advisory addressed the specific effect of n-3 polyunsaturated fatty acid supplementation on clinical cardiovascular events. This American Heart Association science advisory extends that review and offers further support to include n-3 polyunsaturated fatty acids from seafood consumption. Several potential mechanisms have been investigated, including antiarrhythmic, anti-inflammatory, hematologic, and endothelial, although for most, longer-term dietary trials of seafood are warranted to substantiate the benefit of seafood as a replacement for other important sources of macronutrients. The present science advisory reviews this evidence and makes a suggestion in the context of the 2015-2020 Dietary Guidelines for Americans and in consideration of other constituents of seafood and the impact on sustainability. We conclude that 1 to 2 seafood meals per week be included to reduce the risk of congestive heart failure, coronary heart disease, ischemic stroke, and sudden cardiac death, especially when seafood replaces the intake of less healthy foods.

A Review of Plant-based Diets to Prevent and Treat Heart Failure

Evidence supporting the role of nutrition in heart failure (HF) incidence and severity is growing. A comprehensive search of online databases was conducted using relevant keywords to identify human studies including diet and HF. Several plant-based diets have consistently been associated with decreased HF incidence and severity, notably the Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets. Several other plant-based dietary patterns, including low-fat diets and the rice diet, also show promise. Higher dietary quality, as assessed using different scores, seems to provide protective qualities. Fruit, vegetables, legumes and wholegrains appear to be beneficial, whereas red/processed meats, eggs and refined carbohydrates appear harmful. Some evidence suggests detrimental effects of dairy products and poultry, but more research is needed. There is observational and interventional evidence that a plant-based diet high in antioxidants, micronutrients, nitrate and fibre but low in saturated/trans fats may decrease the incidence and severity of HF. Potential mechanisms for this include decreased oxidative stress, homocysteine and inflammation levels, as well as higher antioxidant defence and nitric oxide bioavailability with gut microbiome modulation. Well-designed randomised, controlled nutrition intervention trials specific to HF are urgently required.

Food groups and risk of coronary heart disease, stroke and heart failure: A systematic review and dose-response meta-analysis of prospective studies

BACKGROUND

Despite growing evidence for food-based dietary patterns' potential to reduce cardiovascular disease risk, knowledge about the amounts of food associated with the greatest change in risk of specific cardiovascular outcomes and about the quality of meta-evidence is limited. Therefore, the aim of this meta-analysis was to synthesize the knowledge about the relation between intake of 12 major food groups (whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages [SSB]) and the risk of coronary heart disease (CHD), stroke and heart failure (HF).

METHODS

We conducted a systematic search in PubMed and Embase up to March 2017 for prospective studies. Summary risk ratios (RRs) and 95% confidence intervals (95% CI) were estimated using a random effects model for highest versus lowest intake categories, as well as for linear and non-linear relationships.

RESULTS

Overall, 123 reports were included in the meta-analyses. An inverse association was present for whole grains (RRCHD: 0.95 (95% CI: 0.92-0.98), RRHF: 0.96 (0.95-0.97)), vegetables and fruits (RRCHD: 0.97 (0.96-0.99), and 0.94 (0.90-0.97); RRstroke: 0.92 (0.86-0.98), and 0.90 (0.84-0.97)), nuts (RRCHD: 0.67 (0.43-1.05)), and fish consumption (RRCHD: 0.88 (0.79-0.99), RRstroke: 0.86 (0.75-0.99), and RRHF: 0.80 (0.67-0.95)), while a positive association was present for egg (RRHF: 1.16 (1.03-1.31)), red meat (RRCHD: 1.15 (1.08-1.23), RRstroke: 1.12 (1.06-1.17), RRHF: 1.08 (1.02-1.14)), processed meat (RRCHD: 1.27 (1.09-1.49), RRstroke: 1.17 (1.02-1.34), RRHF: 1.12 (1.05-1.19)), and SSB consumption (RRCHD: 1.17 (1.11-1.23), RRstroke: 1.07 (1.02-1.12), RRHF: 1.08 (1.05-1.12)) in the linear dose-response meta-analysis. There were clear indications for non-linear dose-response relationships between whole grains, fruits, nuts, dairy, and red meat and CHD.

CONCLUSION

An optimal intake of whole grains, vegetables, fruits, nuts, legumes, dairy, fish, red and processed meat, eggs and SSB showed an important lower risk of CHD, stroke, and HF.

Oxidative stress and inflammation as central mediators of atrial fibrillation in obesity and diabetes

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in humans. Several risk factors promote AF, among which diabetes mellitus has emerged as one of the most important. The growing recognition that obesity, diabetes and AF are closely intertwined disorders has spurred major interest in uncovering their mechanistic links. In this article we provide an update on the growing evidence linking oxidative stress and inflammation to adverse atrial structural and electrical remodeling that leads to the onset and maintenance of AF in the diabetic heart. We then discuss several therapeutic strategies to improve atrial excitability by targeting pathways that control oxidative stress and inflammation.

Dietary Fat and Risk of Cardiovascular Disease: Recent Controversies and Advances

Health effects of dietary fats have been extensively studied for decades. However, controversies exist on the effects of various types of fatty acids, especially saturated fatty acid (SFA), on cardiovascular disease (CVD). Current evidence supports that different types of dietary fatty acids have divergent effects on CVD risk, and the effects also depend strongly on the comparison or replacement macronutrient. A significant reduction in CVD risk can be achieved if SFAs are replaced by unsaturated fats, especially polyunsaturated fatty acids. Intake of industrially produced trans fat is consistently associated with higher CVD risk. Both n-6 and n-3 polyunsaturated fatty acids are associated with lower CVD risk, although the effects of fish oil supplementation remains inconsistent. The 2015-2020 Dietary Guidelines for Americans place greater emphasis on types of dietary fat than total amount of dietary fat and recommend replacing SFAs with unsaturated fats, especially polyunsaturated fatty acids for CVD prevention.

N-3 fatty acids for prevention of cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of death in the USA. A diet enriched with n-3 fatty acids (FA) has been reported to play an important role in preventing the development of CVD. Prior studies have demonstrated beneficial effects of n-3 FA on hypertriglyceridemia, blood pressure, inflammation, endothelial function, and platelet function. However, data on the relation of n-3 FA consumption with CVD risk remain inconsistent. This paper reviews current evidence on the effects of n-3 FA on CVD, CVD risk factors, and potential biologic mechanisms. Last, we discuss major limitations of currently available data and future directions in the field.

N-3 polyunsaturated fatty acids decrease levels of doxorubicin-induced reactive oxygen species in cardiomyocytes -- involvement of uncoupling protein UCP2

BACKGROUND

Use of the chemotherapeutic drug doxorubicin (DOX) is associated with serious cardiotoxicity, as it increases levels of reactive oxygen species (ROS). N-3 polyunsaturated fatty acid dietary supplements can be of benefit to patients undergoing cancer therapy. The aims of this study were to determine whether DOX-induced cardiotoxicity is related to mitochondrial uncoupling proteins and whether eicosapentaenoic acid (EPA, C20:5 n-3) or docosahexaenoic acid (DHA, C22:6 n-3) affects DOX-induced cardiomyocyte toxicity.

RESULTS

Treatment of H9C2 cells with DOX resulted in decreased cell viability and UCP2 expression. Treatment with 100 μM EPA or 50 μM DHA for 24 h resulted in a maximal mitochondria concentration of these fatty acids and increased UCP2 expression. Pretreatment with 100 μM EPA or 50 μM DHA prevented the DOX-induced decrease in UCP2 mRNA and protein levels, but these effects were not seen with EPA or DHA and DOX cotreatment. In addition, the DOX-induced increase in ROS production and subsequent mitochondrial membrane potential change (∆ψ) were significantly attenuated by pretreatment with EPA or DHA.

CONCLUSION

EPA or DHA pre-treatment inhibits the DOX-induced decrease in UCP2 expression, increase in ROS production, and subsequent mitochondrial membrane potential change that contribute to the cardiotoxicity of DOX.

Effect of the amount and type of dietary fat on cardiometabolic risk factors and risk of developing type 2 diabetes, cardiovascular diseases, and cancer: a systematic review

The effects of both the amount and quality of dietary fat have been studied intensively during the past decades. Previously, low-fat diets were recommended without much attention to the quality of fat, whereas there is general emphasis on the quality of fat in current guidelines. The objective of this systematic review (SR) was to assess the evidence of an effect of the amount and type of dietary fat on body weight (BW), risk factors, and risk of non-communicable diseases, that is, type 2 diabetes (T2DM), cardiovascular diseases (CVD), and cancer in healthy subjects or subjects at risk for these diseases. This work was performed in the process of updating the fourth edition of the Nordic Nutrition Recommendations from 2004. The literature search was performed in October 2010 covering articles published since January 2000. A complementary search was done in February 2012 covering literature until December 2011. Two authors independently selected articles for inclusion from a total of about 16,000 abstracts according to predefined criteria. Randomized controlled trials (RCT) and prospective cohort studies (PCS) were included as well as nested case-control studies. A few retrospective case-control studies were also included when limited or no data were available from other study types. Altogether 607 articles were quality graded and the observed effects in these papers were summarized. Convincing evidence was found that partial replacement of saturated fat (SFA) with polyunsaturated fat (PUFA) or monounsaturated fat (MUFA) lowers fasting serum/plasma total and LDL cholesterol concentrations. The evidence was probable for a decreasing effect of fish oil on concentration of serum/plasma total triglycerides as compared with MUFA. Beneficial effect of MUFA both on insulin sensitivity and fasting plasma/serum insulin concentration was considered as probable in comparisons of MUFA and carbohydrates versus SFA, whereas no effect was found on fasting glucose concentration in these comparisons. There was probable evidence for a moderate direct association between total fat intake and BW. Furthermore, there was convincing evidence that partial replacement of SFA with PUFA decreases the risk of CVD, especially in men. This finding was supported by an association with biomarkers of PUFA intake; the evidence of a beneficial effect of dietary total PUFA, n-6 PUFA, and linoleic acid (LA) on CVD mortality was limited suggestive. Evidence for a direct association between total fat intake and risk of T2DM was inconclusive, whereas there was limited-suggestive evidence from biomarker studies that LA is inversely associated with the risk of T2DM. However, there was limited-suggestive evidence in biomarker studies that odd-chain SFA found in milk fat and fish may be inversely related to T2DM, but these associations have not been supported by controlled studies. The evidence for an association between dietary n-3 PUFA and T2DM was inconclusive. Evidence for effects of fat on major types of cancer was inconclusive regarding both the amount and quality of dietary fat, except for prostate cancer where there was limited-suggestive evidence for an inverse association with intake of ALA and for ovarian cancer for which there was limited-suggestive evidence for a positive association with intake of SFA. This SR reviewed a large number of studies focusing on several different health outcomes. The time period covered by the search may not have allowed obtaining the full picture of the evidence in all areas covered by this SR. However, several SRs and meta-analyses that covered studies published before year 2000 were evaluated, which adds confidence to the results. Many of the investigated questions remain unresolved, mainly because of few studies on certain outcomes, conflicting results from studies, and lack of high quality-controlled studies. There is thus an evident need of highly controlled RCT and PCS with sufficient number of subjects and long enough duration, specifically regarding the effects of the amount and quality of dietary fat on insulin sensitivity, T2DM, low-grade inflammation, and blood pressure. New metabolic and other potential risk markers and utilization of new methodology in the area of lipid metabolism may provide new insight.

Omega-3 and omega-6 fatty acids and type 2 diabetes

Polyunsaturated fatty acids are of particular interest in the nutritional therapy for diabetes, given their potential role in several pathophysiological processes related to cardiovascular disease. Both omega-3 and omega-6 fatty acids are beneficial for improving lipid profiles in healthy individuals and among type 2 diabetic patients: Supplementation with omega-3 fatty acids lowers triglycerides and VLDL-cholesterol. However, they might also increase LDL-cholesterol. Omega-3 fatty acids are, from the latest evidence, not related to mortality and cardiovascular disease. Similarly, glucose control and hypertension, as well as risk of microvascular complications, seem unaffected by omega-3 supplementation. Most studies involved mainly patients with type 2 diabetes, and future research needs to focus on the type 1 diabetic patient. Also, the role of omega-6 fatty acids remains largely unknown.

The use of ω-3 poly-unsaturated fatty acids in heart failure: a preferential role in patients with diabetes

PURPOSE

To review the evidence for a beneficial effect of ω-3 PUFAs in heart failure (HF) and its co-morbidities, their possible preferential effect in diabetes and the potential mechanism for their benefit.

METHODS

We summarize the clinical studies which investigated the use of ω-3 PUFAs in patients with HF with an emphasis on diabetes. We briefly summarize the evidence for an effect of ω-3 PUFAs in patients with coronary artery disease (CAD), atrial fibrillation (AF) and ventricular arrhythmias. We also discuss the proposed mechanisms of ω-3 PUFA action in cardiovascular diseases.

RESULTS

While there is emerging evidence for a beneficial effect of ω-3 PUFA supplementation in patients with HF, the evidence for other indications have been variable and conflicting. In HF patients with diabetes, ω-3 PUFAs may have a preferential therapeutic benefit. Randomized controlled trials did not show considerable beneficial effects of ω-3 PUFAs in other conditions such as CAD and AF. In a diabetic and insulin-resistant state, ω-3 PUFAs bind to the G-protein coupled receptor, GPR120, resulting in reduced cytokine production from inflammatory macrophages and improved signaling in adipocytes, leading to a reduction in insulin resistance.

CONCLUSIONS

There is promising evidence showing that use of ω-3 PUFA supplementation improves clinical outcomes of HF patients with diabetes. Further clinical trials are needed in this regard.

Fish consumption, omega-3 fatty acids and risk of heart failure: a meta-analysis

BACKGROUND & AIMS

While marine omega-3 fatty acids have been associated with a lower mortality in heart failure patients, data on omega-3 and incident heart failure are inconsistent. We systematically reviewed the evidence on the association of omega-3 fatty acids and fish intake with the incidence of heart failure in this meta-analysis.

METHODS

We identified relevant studies by searching MEDLINE and EMBASE databases up to August 31, 2011 without restrictions and by reviewing reference lists from retrieved articles.

RESULTS

A total of 176,441 subjects and 5480 incident cases of heart failure from 7 prospective studies were included in this analysis. Using random effect model, the pooled relative risk for heart failure comparing the highest to lowest category of fish intake was 0.85 (95% CI; 0.73-0.99), p = 0.04; corresponding value for marine omega-3 fatty acids was 0.86 (0.74-1.00), p = 0.05. There was no evidence for heterogeneity across studies of fish consumption (I(2) = 8%). In contrast, there was modest heterogeneity for omega-3 fatty acid analysis (I(2) = 44%). Lastly, there was no evidence for publication bias.

CONCLUSIONS

This meta-analysis is consistent with a lower risk of heart failure with intake of marine omega-3 fatty acids. These observational findings should be confirmed in a large randomized trial.

Plasma and dietary omega-3 fatty acids, fish intake, and heart failure risk in the Physicians' Health Study

BACKGROUND

Data on the relation of plasma and dietary omega-3 (n-3) fatty acids (FAs) with heart failure (HF) risk have been inconsistent.

OBJECTIVE

We evaluated the relation of n-3 FAs with HF in US male physicians.

DESIGN

We used nested case-control (n = 1572) and prospective cohort study designs (n = 19,097). Plasma phospholipid n-3 FAs were measured by using gas chromatography, and food-frequency questionnaires were used to assess dietary n-3 FAs and fish intake. Incident HF was ascertained via annual follow-up questionnaires and validated in a subsample.

RESULTS

The mean age was 58.7 y at blood collection. In a multivariable model, plasma α-linolenic acid (ALA) was associated with a lower risk of HF in a nonlinear fashion (P-quadratic trend = 0.02), and the lowest OR was observed in quintile 4 (0.66; 95% CI: 0.47, 0.94). Plasma EPA and DHA were not associated with HF, whereas plasma docosapentaenoic acid (DPA) showed a nonlinear inverse relation with HF for quintile 2 (OR: 0.55; 95% CI: 0.39, 0.79). Dietary marine n-3 FAs showed a trend toward a lower risk of HF in quintile 4 (HR: 0.81; 95% CI: 0.64, 1.02) and a nonlinear pattern across quintiles. Fish intake was associated with a lower risk of HF, with RRs of ~0.70 for all categories of fish consumption greater than one serving per month.

CONCLUSIONS

Our data are consistent with an inverse and nonlinear relation of plasma phospholipid ALA and DPA, but not EPA or DHA, with HF risk. Fish consumption greater than once per month was associated with a lower HF risk.

Fish intake and risk of heart failure: A meta-analysis of five prospective cohort studies

The findings on the association between fish intake and the risk of heart failure (HF) have been inconsistent. The purpose of this study was to clarify this potential association. We searched for relevant studies in the PubMed database through January 2012 and manually reviewed references. Five independent prospective cohort studies involving 5,273 cases and 144,917 participants were included. The summary relative risk estimates (SRRE) based on the highest compared with the lowest category of fish consumption were estimated by variance-based meta-analysis. In addition, we performed sensitivity and dose-response analyses to examine the association. Overall, an absence of an association between fish intake and HF was observed (SRRE=1.00; 95% CI, 0.81-1.24). However, fried fish intake positively associated with HF (SRRE=1.40; 95% CI, 1.22-1.61). In addition, dose-response analysis of fried fish suggested that each increment of six fried fish per month corresponded to a 37% increase of HF rate (RR=1.37; 95% CI, 1.20-1.56). In conclusion, our findings suggest that there is no significant association between fish intake and risk of HF, with the exception of a possible positive correlation with individuals comsuming fried fish, based on a limited number of studies. Future studies are required to confirm these findings.

Omega-3 fatty acids and cardiovascular disease: effects on risk factors, molecular pathways, and clinical events

We reviewed available evidence for cardiovascular effects of n-3 polyunsaturated fatty acid (PUFA) consumption, focusing on long chain (seafood) n-3 PUFA, including their principal dietary sources, effects on physiological risk factors, potential molecular pathways and bioactive metabolites, effects on specific clinical endpoints, and existing dietary guidelines. Major dietary sources include fatty fish and other seafood. n-3 PUFA consumption lowers plasma triglycerides, resting heart rate, and blood pressure and might also improve myocardial filling and efficiency, lower inflammation, and improve vascular function. Experimental studies demonstrate direct anti-arrhythmic effects, which have been challenging to document in humans. n-3 PUFA affect a myriad of molecular pathways, including alteration of physical and chemical properties of cellular membranes, direct interaction with and modulation of membrane channels and proteins, regulation of gene expression via nuclear receptors and transcription factors, changes in eicosanoid profiles, and conversion of n-3 PUFA to bioactive metabolites. In prospective observational studies and adequately powered randomized clinical trials, benefits of n-3 PUFA seem most consistent for coronary heart disease mortality and sudden cardiac death. Potential effects on other cardiovascular outcomes are less-well-established, including conflicting evidence from observational studies and/or randomized trials for effects on nonfatal myocardial infarction, ischemic stroke, atrial fibrillation, recurrent ventricular arrhythmias, and heart failure. Research gaps include the relative importance of different physiological and molecular mechanisms, precise dose-responses of physiological and clinical effects, whether fish oil provides all the benefits of fish consumption, and clinical effects of plant-derived n-3 PUFA. Overall, current data provide strong concordant evidence that n-3 PUFA are bioactive compounds that reduce risk of cardiac death. National and international guidelines have converged on consistent recommendations for the general population to consume at least 250 mg/day of long-chain n-3 PUFA or at least 2 servings/week of oily fish.

Chronic heart failure: current evidence, challenges to therapy, and future directions

Heart failure (HF) is a complex syndrome characterized by the inability of the heart to maintain a normal cardiac output without elevated intracardiac filling pressures, resulting in signs of pulmonary and peripheral edema and symptoms of dyspnea and fatigue. Central to the management of HF is a multifaceted pharmacological intervention to abate the harmful counter-regulatory effects of neurohormonal activation and avid salt and water retention. Whereas up to 40 years ago HF was managed with diuretics and leaf of digitalis, the cornerstones of therapy for HF patients with systolic dysfunction now include ACE inhibitors or angiotensin II type 1 receptor antagonists (angiotensin receptor blockers), β-adrenoceptor antagonists (β-blockers), and aldosterone antagonists, which have significantly improved survival. However, with the increasing number of beneficial therapies, there are challenges to implementing all of them. Specific cardiomyopathies also merit specific considerations with respect to treatment, and - unfortunately - there is no therapy for HF with preserved left ventricular ejection fraction that has been shown to improve survival. Although mortality has improved in HF, the biggest challenge to treatment lies in addressing the morbidity of this disease, which is now the most common reason for hospital admission in our aged population. As such, there are many therapies that may serve to improve the quality of life of HF patients. Future HF treatment regimens may include direct cellular therapy via hormone and cytokine signaling or cardiac regeneration through growth factors or cell therapy.

Associations of plasma phospholipid omega-6 and omega-3 polyunsaturated Fatty Acid levels and MRI measures of cardiovascular structure and function: the multiethnic study of atherosclerosis

Background. The association between plasma omega-6 fatty acids and cardiovascular disease (CVD) is unclear, and discrepancy remains concerning the cardiovascular benefit of the omega-3 fatty acid alpha-linolenic acid. Methods. Associations of plasma phospholipid fatty acid levels (arachidonic acid, linoleic acid, eicosapentaenoic acid, docosahexaenoic acid (DHA), and alpha-linolenic acid) with cardiac magnetic resonance imaging measures of left ventricular (LV) mass, LV volume, ejection fraction, stroke volume, and aortic distensibility were investigated in 1,274 adults. Results. Results of multivariate analysis showed no statistically significant associations of plasma omega-6 or omega-3 levels with cardiac magnetic resonance imaging measures. Stratification by gender revealed a positive association between DHA and LV mass in women (β = 1.89, P = 0.02; P interaction = 0.003) and a trend for a positive association between DHA and ejection fraction in men (β = 0.009, P = 0.05; P interaction = 0.03). Conclusion. Additional research is warranted to clarify the effects of plasma DHA on cardiac structure and function in women versus men.

Cost-effectiveness of highly purified omega-3 polyunsaturated fatty acid ethyl esters in the treatment of chronic heart failure: results of Markov modelling in a UK setting

AIMS

A recent randomized placebo-controlled clinical trial has reported reductions in mortality and hospitalizations in patients with chronic heart failure (CHF) who were prescribed highly purified omega-3 polyunsaturated fatty acid ethyl esters (n-3 PUFA). This study aimed at evaluating the cost and benefits associated with their use in the treatment of CHF in a UK setting.

METHODS AND RESULTS

Results from a recent clinical trial were used to develop a Markov model to project clinical outcomes while capturing relevant costs and patient quality of life. The model captured outcomes over a lifetime horizon from a UK National Health Service perspective, with direct costs accounted in 2009 GBP (£) and discounted at 3.5% together with clinical benefits. Results are presented in terms of life expectancy, quality-adjusted life expectancy, direct costs, and incremental cost-effectiveness ratios. In addition to standard therapy, n-3 PUFA vs. placebo increased lifetime direct costs by £993 (≈€1150), with additional quality-adjusted life expectancy of 0.079 quality-adjusted life years (QALYs), and mean lifetime costs of £12,636 (≈€14,600) per QALY gained. Probabilistic sensitivity analyses suggested a 60% likelihood of n-3 PUFA being regarded as cost-effective versus placebo at a willingness-to-pay threshold of £30,000 (≈€34,600) per QALY gained.

CONCLUSIONS

By currently accepted standards of value for money in the UK; the addition of n-3 PUFA to optimal medical therapy for patients with heart failure is likely to be cost-effective.

Effects of a convenience drink fortified with n-3 fatty acids on the n-3 index

There is strong evidence that the intake of EPA and DHA reduces the risk of adverse cardiac events. Fish and fish oil capsules are not necessarily an ideal source of EPA and DHA for every individual. The aim of the present study was to evaluate the effect of a convenience drink enriched with 500 mg EPA and DHA on the n-3 index, a biomarker of EPA and DHA status in an individual. Of the 190 subjects with atherosclerotic disease screened between February and June 2009, 50 were recruited based on an n-3 index < 5 %. Participants were randomly assigned to receive a convenience drink supplemented either with n-3 fatty acids (n 40, 200 mg EPA and 300 mg DHA) or placebo (n 10, 1.1 g linoleic acid, C18 : 2n-6, from maize oil) daily for 8 weeks. The primary end point was a change in the n-3 index. Intention-to-treat analysis was done. After 8 weeks of daily intake of 200 mg EPA+300 mg DHA, the mean n-3 index increased from 4.37 (sd 0.51) to 6.80 (sd 1.45) % (P < 0.001). Interindividual variability in response was high (CV of the Delta, cv = 0.21). The control group showed no change in the n-3 index. The results showed that daily intake of a convenience drink supplemented with n-3 fatty acids leads to a significant increase of the n-3 index with high interindividual variability in response. Dose and preparation used were safe, well tolerated and highly palatable.