Plasma Omega-3 Fatty Acids and the Risk of Cardiovascular Events in Patients After an Acute Coronary Syndrome in MERLIN-TIMI 36

Circulating Omega-3 Polyunsaturated Fatty Acids Levels in Coronary Heart Disease: Pooled Analysis of 36 Observational Studies

Long-chain n-3 polyunsaturated fatty acid (PUFA) supplementation has shown potential benefits in the prevention of coronary heart disease (CHD); however, the impact of omega-3 fatty acid levels on CHD risk remains a subject of debate. Here, we aimed to investigate the association between n-3 PUFA levels and the risk of CHD, with particular reference to the subtypes of n-3 PUFA.

METHODS

Prospective studies and retrospective case-control studies analyzing n-3 PUFA levels in CHD, published up to 30 July 2022, were selected. A random effects meta-analysis was used for pooled assessment, with relative risks (RRs) expressed as 95% confidence intervals (CIs) and standardized mean differences expressed as weight mean differences (WMDs). Subgroup and meta-regression analyses were conducted to assess the impact of n-3 PUFA exposure interval on the CHD subtype variables of the study.

RESULTS

We included 20 prospective studies (cohort and nested case-control) and 16 retrospective case-control studies, in which n-3 PUFAs were measured. Higher levels of n-3 PUFAs (ALA, EPA, DPA, DHA, EPA + DHA, total n-3 PUFAs) were associated with a reduced risk of CHD, with RRs (95% CI) of 0.89 (0.81, 0.98), 0.83 (0.72, 0.96); 0.80 (0.67,0.95), 0.75 (0.64, 0.87), 0.83 (0.73, 0.95), and 0.80 (0.70, 0.93), respectively, p < 0.05. CHD patients had significantly lower n-3 PUFA levels compared to healthy controls (p < 0.05). In the subgroup analysis, a significant inverse trend was found for both fatal CHD and non-fatal CHD with n-3 PUFA (EPA + DHA) levels. Also, the link between n-3 PUFA levels in erythrocytes with total CHD was generally stronger than other lipid pools.

CONCLUSIONS

n-3 PUFAs are significantly related to CHD risk, and these findings support the beneficial effects of n-3 PUFAs on CHD.

Regular use of fish oil supplements and course of cardiovascular diseases: prospective cohort study

Objective

To examine the effects of fish oil supplements on the clinical course of cardiovascular disease, from a healthy state to atrial fibrillation, major adverse cardiovascular events, and subsequently death.

Design

Prospective cohort study.

Setting

UK Biobank study, 1 January 2006 to 31 December 2010, with follow-up to 31 March 2021 (median follow-up 11.9 years).

Participants

415 737 participants, aged 40-69 years, enrolled in the UK Biobank study.

Main outcome measures

Incident cases of atrial fibrillation, major adverse cardiovascular events, and death, identified by linkage to hospital inpatient records and death registries. Role of fish oil supplements in different progressive stages of cardiovascular diseases, from healthy status (primary stage), to atrial fibrillation (secondary stage), major adverse cardiovascular events (tertiary stage), and death (end stage).

Results

Among 415 737 participants free of cardiovascular diseases, 18 367 patients with incident atrial fibrillation, 22 636 with major adverse cardiovascular events, and 22 140 deaths during follow-up were identified. Regular use of fish oil supplements had different roles in the transitions from healthy status to atrial fibrillation, to major adverse cardiovascular events, and then to death. For people without cardiovascular disease, hazard ratios were 1.13 (95% confidence interval 1.10 to 1.17) for the transition from healthy status to atrial fibrillation and 1.05 (1.00 to 1.11) from healthy status to stroke. For participants with a diagnosis of a known cardiovascular disease, regular use of fish oil supplements was beneficial for transitions from atrial fibrillation to major adverse cardiovascular events (hazard ratio 0.92, 0.87 to 0.98), atrial fibrillation to myocardial infarction (0.85, 0.76 to 0.96), and heart failure to death (0.91, 0.84 to 0.99).

Conclusions

Regular use of fish oil supplements might be a risk factor for atrial fibrillation and stroke among the general population but could be beneficial for progression of cardiovascular disease from atrial fibrillation to major adverse cardiovascular events, and from atrial fibrillation to death. Further studies are needed to determine the precise mechanisms for the development and prognosis of cardiovascular disease events with regular use of fish oil supplements.

Alpha-Linolenic Acid and Cardiovascular Events: A Narrative Review

Cardiovascular diseases (CVDs) represent the leading cause of global mortality with 1.7 million deaths a year. One of the alternative systems to drug therapy to minimize the risk of CVDs is represented by alpha-linolenic acid (ALA), an essential fatty acid of the omega-3 series, known for its cholesterol-lowering effect. The main purpose of this review is to analyze the effects of ALA and investigate the relevant omega-6/omega-3 ratio in order to maintain functionally beneficial effects. Concerning the lipid-lowering preventive effects, ALA may favorably affect the values of LDL-C and triglycerides in both adult and pediatric populations. Furthermore, ALA has shown protective effects against hypertension, contributing to balancing blood pressure through customary diet. According to the 2009 EFSA statement, dietary ALA may contribute to reducing the risk of CVDs, thanks to anti-hypertensive, anti-atherosclerotic and cardioprotective effects.

Dietary intake, biomarkers and supplementation of fatty acids and risk of coronary events: a systematic review and dose-response meta-analysis of randomized controlled trials and prospective observational studies

We aimed to review the association of dietary fats and risk of coronary events in adults. We searched PubMed, Embase, CENTRAL, Scopus, and Web of Sciences to April 2022 for prospective cohorts and randomized trials investigating the association of dietary intake and biomarkers of fats and fatty acid interventions and the risk of coronary events. We performed random-effects meta-analyses to estimate relative risk (RR) for the top versus bottom tertiles of exposures. One-hundered sixty-five prospective cohorts and randomized trials were included. Dietary intake and biomarkers of total fat and saturated, monounsaturated, and polyunsaturated fatty acids were not associated with the risk of coronary events. Dietary intake of trans fatty acids, palmitic acid, stearic acid, and saturated fatty acids from meat and unprocessed meat was modestly associated with a higher risk and, in contrast, intake of alpha-linolenic acid, long-chain omega-3 fatty acids, and linoleic acid was modestly associated with a lower risk. Supplementation with long-chain omega-3 fatty acids and increasing the consumption of alpha-linolenic and linoleic acids in place of saturated fats reduced the risk of coronary events. Existing evidence, in its totality, provides a modest support in favor of current recommendations suggesting replacement of saturated fats with polyunsaturated fats.

Characterization of global research trends and prospects on sudden coronary death: A literature visualization analysis

Background

Sudden coronary death is a major global public health issue that has a significant impact on both individuals and society. Nowadays, scholars are active in sudden coronary death all over the world. However, no relevant bibliometric studies have been published. Here, we aim to gain a better understanding the current state of research and to explore potential new research directions through bibliometric analysis.

Methods

Articles and reviews on sudden coronary death from 2012 to 2023 were retrieved from the Web of Science Core Collection (WoSCC). The topic search was conducted using the following keywords: ((("sudden cardiac death" OR "sudden death") AND (coronary OR "myocardial infarction")) OR "sudden coronary death"). Knowledge maps of authors, countries, institutions, journals, keywords, and citations were conducted by CiteSpace. Publication dynamics, hotspots, and frontiers were analyzed independently by authors.

Results

A total of 2914 articles were identified from January 1, 2012 to June 20, 2023. The USA (n = 972) contributed the greatest absolute productivity and UK (centrality = 0.13) built a robust global collaboration. Harvard University was the institution with the highest number of publications (n = 143). Huikuri HV and Junttila MJ were the most published authors who devoted to searching for biomarkers of sudden coronary death. American Journal of Cardiology was the journal with the most publications, and Circulation was the most cited journal. Left ventricular ejection fraction, society, inflammation, and fractional flow reserve became novel burst words that lasted until 2023. Research on etiology and pathology, role of early risk factors in risk stratification, potential predictive biomarkers and novel measurement methods for the prevention and management of sudden coronary death were identified as the research hotspots and frontiers.

Conclusion

Our knowledge and understanding of sudden coronary death have significantly improved. Ongoing efforts should focus on the various etiologies and pathologies of sudden coronary death. Furthermore, a novel sudden coronary death risk model, large-scale population studies, and the rational use of multiple indicators to individualize the assessment of sudden coronary death and other risk factors are other emerging research trends.

Increased circulating uric acid aggravates heart failure via impaired fatty acid metabolism

BACKGROUND

Increased circulating uric acid (UA) concentration may disrupt cardiac function in heart failure patients, but the specific mechanism remains unclear. Here, we postulate that hyperuremia induces sterol regulatory element binding protein 1 (SREBP1), which in turn activate hepatic fatty acid biosynthesis response, leading to cardiac dysfunction.

METHODS AND RESULTS

Increased circulating uric acid was observed in heart failure patients and inversely correlated to cardiac function. Besides, uric acid correlated to circulating lipids profile based on metabolomics in heart failure patients. Using cultured human hepatoellular carcinomas (HepG2) and Tg(myl7:egfp) zebrafish, we demonstrated that UA regulated fatty acid synthase (FASN) via SREBP1 signaling pathway, leading to FFA accumulation and impaired energy metabolism, which could be rescued via SREBP1 knockdown. In ISO treated zebrafish, UA aggravated heart failure via increased cardiovascular cavity size, decreased heart beats, pericardial edema and long-stretched heart deformation.

CONCLUSIONS

Our findings suggest that UA-SREBP1-FASN signaling exacerbates cardiac dysfunction during FFA accumulation. Identification of this mechanism may help in treatment and prevention of heart failure.

Role of omega-3 fatty acids in the prevention and treatment of cardiovascular Diseases: A consensus statement from the Experts' Committee Of National Society Of Cardiometabolic Medicine

Low-density lipoprotein cholesterol (LDL-C) has been considered as the primary target for the prevention and treatment of atherosclerotic cardiovascular disease (ASCVD). However, there are still residual cardiovascular risks in some patients even if LDL-C achieves the target level. Emerging evidence suggestes that elevated triglyceride (TG) level or triglyceride-rich lipoprotein (TRL) cholesterol (TRL-C) is one of the important components of the residual cardiovascular risks. Omega-3 fatty acids have been shown to be one of the effective drugs for reducing TG. However, its efficacy in reducing the risk of ASCVD is inconsistent in large randomized clinical trials. There is lack of consensus among Experts regarding the application of omega-3 fatty acids in cardiovascular diseases including heart failure, arrhythmia, cardiomyopathy, hypertension, and sudden death. Hence, the current consensus will comprehensively and scientifically present the detailed knowledge about the omega-3 fatty acids from a variety of aspects to provide a reference for its management of omega-3 fatty acids application in the Chinese population.

Update on Omega-3 Polyunsaturated Fatty Acids on Cardiovascular Health

Twenty percent of deaths in the United States are secondary to cardiovascular diseases (CVD). In patients with hyperlipidemia and hypertriglyceridemia, studies have shown high atherosclerotic CVD (ASCVD) event rates despite the use of statins. Given the association of high triglyceride (TG) levels with elevated cholesterol and low levels of high-density lipoprotein cholesterol, the American Heart Association (AHA)/American College of Cardiology (ACC) cholesterol guidelines recommend using elevated TGs as a "risk-enhancing factor" for ASCVD and using omega 3 fatty acids (Ω3FAs) for patients with persistently elevated severe hypertriglyceridemia. Ω3FA, or fish oils (FOs), have been shown to reduce very high TG levels, hospitalizations, and CVD mortality in randomized controlled trials (RCTs). We have published the largest meta-analysis to date demonstrating significant effects on several CVD outcomes, especially fatal myocardial infarctions (MIs) and total MIs. Despite the most intensive research on Ω3FAs on CVD, their benefits have been demonstrated to cluster across multiple systems and pathologies, including autoimmune diseases, infectious diseases, chronic kidney disease, central nervous system diseases, and, most recently, the COVID-19 pandemic. A review and summary of the controversies surrounding Ω3FAs, some of the latest evidence-based findings, and the current and most updated recommendations on Ω3FAs are presented in this paper.

Diet and Sudden Death: How to Reduce the Risk

In addition to the association of dietary patterns, specific foods and nutrients with several diseases, including cardiovascular disease and mortality, there is also strong emerging evidence of an association of dietary patterns with the risk of sudden cardiac death (SCD). In this comprehensive review, data are presented and analyzed about foods and diets that mitigate the risk of ventricular arrhythmias (VAs) and SCD, but also about arrhythmogenic nutritional elements and patterns that seem to enhance or facilitate potentially malignant VAs and SCD. The antiarrhythmic or protective group comprises fish, nuts and other foods enriched in omega-3 polyunsaturated fatty acids, the Mediterranean and other healthy diets, vitamins E, A and D and certain minerals (magnesium, potassium, selenium). The arrhythmogenic-food group includes saturated fat, trans fats, ketogenic and liquid protein diets, the Southern and other unhealthy diets, energy drinks and excessive caffeine intake, as well as heavy alcohol drinking. Relevant antiarrhythmic mechanisms include modification of cell membrane structure by n-3 polyunsaturated fatty acids, their direct effect on calcium channels and cardiomyocytes and their important role in eicosanoid metabolism, enhancing myocyte electric stability, reducing vulnerability to VAs, lowering heart rate, and improving heart rate variability, each of which is a risk factor for SCD. Contrarily, saturated fat causes calcium handling abnormalities and calcium overload in cardiomyocytes, while a high-fat diet causes mitochondrial dysfunction that dysregulates a variety of ion channels promoting VAs and SCD. Free fatty acids have been considered proarrhythmic and implicated in facilitating SCD; thus, diets increasing free fatty acids, e.g., ketogenic diets, should be discouraged and replaced with diets enriched with polyunsaturated fatty acids, which can also reduce free fatty acids. All available relevant data on this important topic are herein reviewed, large studies and meta-analyses and pertinent advisories are tabulated, while protective (antiarrhythmic) and arrhythmogenic specific diet constituents are pictorially illustrated.

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.

Omega-3 fatty acids in bipolar patients with a low omega-3 index and reduced heart rate variability: the "BIPO-3" trial

Background

Research suggests that a low omega-3 index may contribute to the low heart rate variability and the increased risk of cardiovascular morbidity and mortality in bipolar disorders. However, so far, no intervention trial with EPA and DHA has been conducted in bipolar patients attempting to increase their heart rate variability.

Methods

119 patients with bipolar disorder according to DSM-IV were screened, with 55 euthymic bipolar patients—owing to inclusion criteria (e.g. low omega-3 index (< 6%), SDNN < 60 ms.)—being enrolled in a randomized, double-blind, 12-week parallel study design with omega-3 fatty acids (4 capsules of 530 mg EPA, 150 mg DHA) or corn oil as a placebo, in addition to usual treatment. Heart rate variability as well as the omega-3 index were measured at baseline and at the endpoint of the study.

Results

A total of 42 patients (omega-3: n = 23, corn oil: n = 19) successfully completed the study after 12 weeks. There was a significant increase in the omega-3 index (value at endpoint minus value at baseline) in the omega-3 group compared to the corn oil group (p < 0.0001). However, there was no significant difference in the change of the SDNN (value at endpoint minus value at baseline) between the treatment groups (p = 0.22). In addition, no correlation between changes in SDNN and change in the omega-3 index could be detected in the omega-3 group (correlation coefficient = 0.02, p = 0.94) or the corn oil group (correlation coefficient =  − 0.11, p = 0.91). Similarly, no significant differences between corn oil and omega-3 group regarding the change of LF (p = 0.19), HF (p = 0.34) and LF/HF ratio (p = 0.84) could be demonstrated.

Conclusions

In our randomized, controlled intervention trial in euthymic bipolar patients with a low omega-3 index and reduced heart rate variability no significant effect of omega-3 fatty acids on SDNN or frequency-domain measures HF, LF and LF/HF ratio could be detected. Possible reasons include, among others, the effect of psychotropic medication present in our trial and/or the genetics of bipolar disorder itself. Further research is needed to test these hypotheses.

Trial registration ClinicalTrials.gov, NCT00891826. Registered 01 May 2009–Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT00891826

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.

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.

Dietary and Circulating Long-Chain Omega-3 Polyunsaturated Fatty Acids and Mortality Risk After Myocardial Infarction: A Long-Term Follow-Up of the Alpha Omega Cohort

Background Habitual intake of long-chain omega-3 fatty acids, especially eicosapentaenoic and docosahexaenoic acid (EPA+DHA) from fish, has been associated with a lower risk of fatal coronary heart disease (CHD) in population-based studies. Whether that is also the case for patients with CHD is not yet clear. We studied the associations of dietary and circulating EPA+DHA and alpha-linolenic acid, a plant-derived omega-3 fatty acids, with long-term mortality risk after myocardial infarction. Methods and Results We analyzed data from 4067 Dutch patients with prior myocardial infarction aged 60 to 80 years (79% men, 86% on statins) enrolled in the Alpha Omega Cohort from 2002 to 2006 (baseline) and followed through 2018. Baseline intake of fish and omega-3 fatty acids were assessed through a validated 203-item food frequency questionnaire and circulating omega-3 fatty acids were assessed in plasma cholesteryl esters. Hazard ratios (HRs) with 95% CIs were obtained from Cox regression analyses. During a median follow-up period of 12 years, 1877 deaths occurred, of which 515 were from CHD and 834 from cardiovascular diseases. Dietary intake of EPA+DHA was significantly inversely associated with only CHD mortality (HR, 0.69 [0.52-0.90] for >200 versus ≤50 mg/d; HR, 0.92 [0.86-0.98] per 100 mg/d). Similar results were obtained for fish consumption (HR_CHD, 0.74 [0.53-1.03] for >40 versus ≤5 g/d; P_trend: 0.031). Circulating EPA+DHA was inversely associated with CHD mortality (HR, 0.71 [0.53-0.94] for >2.52% versus ≤1.29%; 0.85 [0.77-0.95] per 1-SD) and also with cardiovascular diseases and all-cause mortality. Dietary and circulating alpha-linolenic acid were not significantly associated with mortality end points. Conclusions In a cohort of Dutch patients with prior myocardial infarction, higher dietary and circulating EPA+DHA and fish intake were consistently associated with a lower CHD mortality risk. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03192410.

Dietary intake and biomarkers of alpha linolenic acid and risk of all cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of cohort studies

OBJECTIVE

To examine the associations between dietary intake and tissue biomarkers of alpha linolenic acid (ALA) and risk of mortality from all causes, cardiovascular disease (CVD), and cancer.

DESIGN

Systematic review and meta-analysis of prospective cohort studies.

DATA SOURCES

PubMed, Scopus, ISI Web of Science, and Google Scholar to 30 April 2021.

STUDY SELECTION

Prospective cohort studies that reported the risk estimates for death from all causes, CVD, and cancer.

DATA SYNTHESIS

Summary relative risks and 95% confidence intervals were calculated for the highest versus lowest categories of ALA intake using random effects and fixed effects models. Linear and non-linear dose-response analyses were conducted to assess the dose-response associations between ALA intake and mortality.

RESULTS

41 articles from prospective cohort studies were included in this systematic review and meta-analysis, totalling 1 197 564 participants. During follow-up ranging from two to 32 years, 198 113 deaths from all causes, 62 773 from CVD, and 65 954 from cancer were recorded. High intake of ALA compared with low intake was significantly associated with a lower risk of deaths from all causes (pooled relative risk 0.90, 95% confidence interval 0.83 to 0.97, I2=77.8%, 15 studies), CVD (0.92, 0.86 to 0.99, I2=48.2%, n=16), and coronary heart disease (CHD) (0.89, 0.81 to 0.97, I2=5.6%, n=9), and a slightly higher risk of cancer mortality (1.06, 1.02 to 1.11, I2=3.8%, n=10). In the dose-response analysis, a 1 g/day increase in ALA intake (equivalent to one tablespoon of canola oil or 0.5 ounces of walnut) was associated with a 5% lower risk of all cause (0.95, 0.91 to 0.99, I2=76.2%, n=12) and CVD mortality (0.95, 0.91 to 0.98, I2=30.7%, n=14). The pooled relative risks for the highest compared with lowest tissue levels of ALA indicated a significant inverse association with all cause mortality (0.95, 0.90 to 0.99, I2=8.2%, n=26). Also, based on the dose-response analysis, each 1 standard deviation increment in blood concentrations of ALA was associated with a lower risk of CHD mortality (0.92, 0.86 to 0.98, I2=37.1%, n=14).

CONCLUSIONS

The findings show that dietary ALA intake is associated with a reduced risk of mortality from all causes, CVD, and CHD, and a slightly higher risk of cancer mortality, whereas higher blood levels of ALA are associated with a reduced risk of all cause and CHD mortality only.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021229487.

Plasma Omega-3 Fatty Acids and the Risk of Cardiovascular Events in Patients After an Acute Coronary Syndrome in MERLIN-TIMI 36

Background Plasma omega-3 polyunsaturated fatty acids (ω3-PUFAs) have been shown to be inversely correlated with the risk of cardiovascular death in primary prevention. The risk relationship in the setting of an acute coronary syndrome is less well established. Methods and Results Baseline plasma ω3-PUFA composition (α-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) was assessed through gas chromatography with flame ionization detection in a case-cohort study involving 203 patients with cardiovascular death, 325 with myocardial infarction, 271 with ventricular tachycardia, and 161 with atrial fibrillation, and a random sample of 1612 event-free subjects as controls from MERLIN-TIMI 36 (Metabolic Efficiency With Ranolazine for Less Ischemia in Non-ST-Elevation-Acute Coronary Syndrome-Thrombolysis in Myocardial Infarction 36), a trial of patients hospitalized with non-ST-segment-elevation -acute coronary syndrome. After inverse-probability-weighted multivariable adjustment including all traditional risk factors, a higher relative proportion of long-chain ω3-PUFAs (eicosapentaenoic acid, docosapentaenoic acid, docosahexaenoic acid) were associated with 18% lower odds of cardiovascular death (adjusted [adj] odds ratio [OR] per 1 SD, 0.82; 95% CI, 0.68-0.98) that was primarily driven by 27% lower odds of sudden cardiac death (adj OR per 1 SD, 0.73; 95% CI, 0.55-0.97). Long-chain ω3-PUFA levels in the top quartile were associated with 51% lower odds of cardiovascular death (adj OR 0.49; 95% CI, 0.27-0.86) and 63% lower odds of sudden cardiac death (adj OR, 0.37; 95% CI, 0.16-0.56). An attenuated relationship was seen for α-linolenic acid and subsequent odds of cardiovascular (adj OR, 0.92; 95% CI, 0.74-1.14) and sudden cardiac death (adj OR, 0.91; 95% CI, 0.67-1.25). No significant relationship was observed between any ω3-PUFAs and the odds of cardiovascular death unrelated to sudden cardiac death, myocardial infarction, atrial fibrillation, or early post-acute coronary syndrome ventricular tachycardia. Conclusions In patients after non-ST-segment-elevation-acute coronary syndrome, plasma long-chain ω3-PUFAs are inversely associated with lower odds of sudden cardiac death, independent of traditional risk factors and lipids. Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT00099788.