Changes in aspects such as the collagenous fiber density and foam cell size of atherosclerotic lesions composed of foam cells, smooth muscle cells and fibrous components in rabbits caused by all-cis-5, 8, 11, 14, 17-icosapentaenoic acid

Effects of omega-3 fatty acid on major cardiovascular outcomes: A systematic review and meta-analysis

BACKGROUND

The effects of omega-3 fatty acid on cardiovascular health obtained inconsistent results. A systematic review and meta-analysis were therefore conducted to assess the effects of omega-3 fatty acid supplementation for primary and secondary prevention strategies of major cardiovascular outcomes.

METHODS

The databases of PubMed, Embase, and the Cochrane library were systematically searched from their inception until September 2020. Relative risks (RRs) with 95% confidence intervals were used to assess effect estimates by using the random-effects model.

RESULTS

Twenty-eight randomized controlled trials involving 136,965 individuals were selected for the final meta-analysis. Omega-3 fatty acid was noted to be associated with a lower risk of major cardiovascular events (RR, 0.94; 95% CI, 0.89-1.00; P = .049) and cardiac death (RR, 0.92; 95% CI, 0.85-0.99; P = .022). However, no significant differences was noted between omega-3 fatty acid and the control for the risks of all-cause mortality (RR, 0.97; 95% CI, 0.92-1.03; P = .301), myocardial infarction (RR, 0.90; 95% CI, 0.80-1.01; P = .077), and stroke (RR, 1.02; 95% CI, 0.94-1.11; P = .694).

CONCLUSIONS

Major cardiovascular events and cardiac death risks could be avoided with the use of omega-3 fatty acid. However, it has no significant effects on the risk of all-cause mortality, myocardial infarction, and stroke.

Effects of intake of fish or fish oils on the development of diabetes

The association between fish and fish oils intake and diabetes remains largely unknown. Here we systematically reviewed published articles (clinical trials, prospective cohort studies, systematic reviews and meta-analyses) about the effects of intake of fish or fish oils on the development of diabetes. An intake of fish oils seems not to affect insulin sensitivity, insulin secretion, beta-cell function or glucose tolerance. There is a considerable statistical heterogeneity in the overall summary estimates of the association between fish or fish oils consumption and the development of type 2 diabetes, which is partly explained by geographical differences. Marine n-3 polyunsaturated fatty acids have beneficial effects on the prevention of type 2 diabetes in Asian populations.

Relationship between coronary flow reserve evaluated by phase-contrast cine cardiovascular magnetic resonance and serum eicosapentaenoic acid

BACKGROUND

Long-term intake of long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs), especially eicosapentaenoic acid (EPA) is associated with a low risk for cardiovascular disease. Phase-contrast cine cardiovascular magnetic resonance (PC cine CMR) can assess coronary flow reserve (CFR). The present study investigates the relationship between CFR evaluated by PC cine CMR and the serum EPA.

METHODS

We studied 127 patients (male, 116 (91%); mean age, 72.2 ± 7.4 years) with known or suspected coronary artery disease (CAD). X-ray coronary angiography revealed no significant coronary arterial stenoses (defined as luminal diameter reduction ≥ 50% on quantitative coronary angiogram (QCA) analysis) in all study participants. Breath-hold PC cine CMR images of the coronary sinus (CS) were acquired to assess blood flow of the CS both at rest and during adenosine triphosphate (ATP) infusion. We calculated CFR as CS blood flow during ATP infusion divided by that at rest. Patients were allocated to groups according to whether they had high (n = 64, EPA ≥ 75.8 μg/mL) or low (n = 63, EPA < 75.8 μg/mL) median serum EPA.

RESULTS

CFR was significantly lower in the low, than in the high EPA group (2.54 ± 1.00 vs. 2.91 ± 0.98, p = 0.038). Serum EPA positively correlated with CFR (R = 0.35, p < 0.001). We defined preserved CFR as > 2.5, which is the previously reported lower limit of normal flow reserve without obstructive CAD. Multivariate analysis revealed that EPA is an independent predictor of CFR > 2.5 (odds ratio, 1.01; 95% confidence interval, 1.00 - 1.02, p = 0.008).

CONCLUSIONS

The serum EPA is significantly correlated with CFR in CAD patients without significant coronary artery stenosis.

The effect of maternal hypercholesterolemia on the placenta and fetal arteries in rabbits

PURPOSE: To investigate the degree of placental permeability in dyslipidemic rabbits and the consequent vascular dysfunction in fetuses of female rabbits with high lipoprotein levels. METHODS: Fifteen adult females New Zealand White rabbits were divided into two groups. Group 1(n=5) - hypercholesterolemic diet with 0.5% cholesterol, and Group 2 (n=10) - control. On day 30, the levels of plasma lipoproteins and triglycerides were analyzed in the mothers, and the presence of collagen was analyzed in the placenta as well as in fetal coronary and aorta. Statistical analyses used the Student's t and the Mann-Whitney tests. RESULTS: Lipoprotein levels were significantly different (p=0.02 to p<0.001) in experimental and control groups. In the hypercholesterolemic group, total cholesterol levels were in average 793mg/dl; triglycerides were in average 257mg/dl; HDL-C was 48mg/dl, and LDL-C was in average 692mg/dl. The amount of collagen per micrometers square (mµ²) in samples from hypercholesterolemic animals was significantly higher than in the control group. CONCLUSIONS: The study confirmed placental permeability to lipoproteins, shown by increased amounts of collagen in fetal tissues. This alteration results in increased susceptibility to atherosclerosis in adult life, representing a risk factor for the early development of disease, which may appear even in the prenatal period.

Ratio of serum n-3 to n-6 polyunsaturated fatty acids and the incidence of major adverse cardiac events in patients undergoing percutaneous coronary intervention

BACKGROUND

The relationship between major adverse cardiac events (MACE) and serum polyunsaturated fatty acid (PUFA) parameters has not been well documented in patients who have undergone percutaneous coronary intervention (PCI). The aim of the present study was to investigate this relationship.

METHODS AND RESULTS

A total of 284 consecutive patients who underwent elective PCI were enrolled and stratified according to median serum levels of n-6 PUFAs (arachidonic acid [AA]), n-3 PUFAs (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]), and serum EPA/AA and DHA/AA ratios. The relationship between these PUFA parameters and the incidence of MACE including cardiac death, acute coronary syndrome, PCI for de novo lesions, and coronary artery bypass grafting, was analyzed. Multivariate analysis showed that among the PUFA parameters, only a high serum EPA/AA ratio was significantly associated with a low incidence of MACE in all the models tested (model A, without adjusted variables: hazard ratio [HR], 0.52; 95% confidence interval [CI]: 0.27-0.99, P = 0.048; model B, adjusted for age and diabetes: HR, 0.51; 95%CI: 0.26-0.98, P = 0.043; model C, adjusted for age, sex, diabetes, hypertension, smoking, and low-density lipoprotein cholesterol: HR, 0.49; 95%CI: 0.25-0.94, P = 0.033).

CONCLUSIONS

The incidence of MACE in patients who have undergone PCI is significantly associated with serum EPA/AA ratio.

Preventive effects of eicosapentaenoic acid on coronary artery disease in patients with peripheral artery disease

BACKGROUND

The JELIS trial examined the preventive effects of eicosapentaenoic acid (EPA) on coronary artery disease (CAD) in hypercholesterolemia. Previous investigators have reported that patients with peripheral artery disease (PAD) have a poor prognosis due to the potential risk for CAD. We conducted a subanalysis to examine whether the incidence of CAD was high in patients with PAD and whether EPA prevented the occurrence of CAD.

METHODS AND RESULTS

Of 18,645 the Japan EPA lipid intervention study (JELIS) patients, 223 had PAD (control group; complicated (n=77), newly diagnosed (n=29), EPA group; complicated (n=96), newly diagnosed (n=21)). We analyzed the incidence of major coronary events (MCE) in the 2 groups. Cox proportional hazard ratio adjusted for baseline risk factor levels was used to test differences between the 2 groups. The incidence of MCE in the control group was significantly higher in patients complicated with PAD and in those newly diagnosed with PAD than in patients without PAD (complicated: hazard ratio 1.97, P=0.039; newly diagnosed: hazard ratio 2.88, P=0.030). As for patients with PAD, the EPA group had a significantly lower MCE hazard ratio than the control group (hazard ratio 0.44, 95% confidence interval 0.19-0.97, P=0.041).

CONCLUSIONS

Subanalysis of the JELIS trial demonstrated that in patients with PAD the incidence of CAD was higher than in controls, and that EPA markedly reduced the occurrence of CAD in those patients.

Suppressive effect of EPA on the incidence of coronary events in hypercholesterolemia with impaired glucose metabolism: Sub-analysis of the Japan EPA Lipid Intervention Study (JELIS)

BACKGROUND

JELIS was a large-scale clinical trial that investigated the effects of eicosapentaenoic acid (EPA) on coronary artery disease (CAD). In this paper, the data of patients registered in JELIS were analysed to compare the incidence of CAD between patients with impaired glucose metabolism (IGM) and normoglycemic (NG) patients. The effect of EPA on the incidence of CAD in patients with IGM was also assessed.

METHODS

The 18,645 hypercholesterolemic patients registered in JELIS were divided into two groups. One group consisted of patients with IGM (n=4565), which included the patients who had diabetes mellitus and patients who had a fasting plasma glucose of 110mg/dL or higher, either at the time of registration or after 6 months. The other group consisted of NG patients (n=14,080). CAD incidence of the two groups over the average 4.6-year follow-up period was compared, and the effect of EPA was assessed.

RESULTS

Compared to NG patients, IGM patients had a significantly higher CAD hazard ratio (1.71 in the non-EPA group and 1.63 in the EPA group). The treatment with EPA resulted in a 22% decrease in the CAD incidence (P=0.048) in IGM patients and an 18% decrease (P=0.062) in NG patients.

CONCLUSIONS

It was found that the CAD risk in IGM patients is higher than in NG patients, and that highly purified EPA is very effective in decreasing the incidence of CAD among Japanese IGM patients, even though the intake of fish is high.

Leukocyte cathepsin S is a potent regulator of both cell and matrix turnover in advanced atherosclerosis

OBJECTIVE

A dysbalance of proteases and their inhibitors is instrumental in remodeling of atherosclerotic plaques. One of the proteases implicated in matrix degradation is cathepsin-S (CatS). To address its role in advanced lesion composition, we generated chimeric LDLr(-/-) mice deficient in leukocyte CatS by transplantation with CatS(-/-)xLDLr(-/-) or with LDLr(-/-) bone marrow and administered a high-fat diet.

METHODS AND RESULTS

No difference in aortic root lesion size could be detected between CatS(+/+) and CatS(-/-) chimeras. However, leukocyte CatS deficiency markedly changed plaque morphology and led to a dramatic reduction in necrotic core area by 77% and an abundance of large foam cells. Plaques of CatS(-/-) chimeras contained 17% more macrophages, 62% less SMCs, and 33% less intimal collagen. The latter two could be explained by a reduced number of elastic lamina fractures. Moreover, macrophage apoptosis was reduced by 60% with CatS deficiency. In vitro, CatS was found to be involved in cholesterol metabolism and in macrophage apoptosis in a collagen and fibronectin matrix.

CONCLUSIONS

Leukocyte CatS deficiency results in considerably altered plaque morphology, with smaller necrotic cores, reduced apoptosis, and decreased SMC content and collagen deposition and may thus be critical in plaque stability.

Reduction in the recurrence of stroke by eicosapentaenoic acid for hypercholesterolemic patients: subanalysis of the JELIS trial

BACKGROUND AND PURPOSE

The JELIS trial examined the preventive effect of eicosapentaenoic acid (EPA) against coronary artery diseases. Hypercholesterolemic patients received statin only (no EPA group: n=9319) or statin with EPA (EPA group: n=9326) for around 5 years. EPA significantly suppressed the incidence of coronary events in previous analysis. Herein, we investigated the effects of EPA on the primary and secondary prevention of stroke.

METHODS

We conducted a subanalysis of JELIS with respect to stroke incidence in the primary and secondary prevention subgroups defined as those without and with a prior history of stroke using Cox proportional hazard ratios, adjusted for baseline risk factor levels.

RESULTS

As for primary prevention of stroke, this occurred in 114 (1.3%) of 8862 no EPA group and in 133 (1.5%) of 8841 EPA group. No statistically significant difference in total stroke incidence (Hazard Ratio, 1.08; 95% confidence interval, 0.95 to 1.22) was observed between the no EPA and the EPA groups. In the secondary prevention subgroup, stroke occurred in 48 (10.5%) of 457 no EPA group and in 33 (6.8%) of 485 EPA group, showing a 20% relative reduction in recurrent stroke in the EPA group (Hazard Ratio, 0.80; 95% confidence interval, 0.64 to 0.997).

CONCLUSIONS

Administration of highly purified EPA appeared to reduce the risk of recurrent stroke in a Japanese population of hypercholesterolemic patients receiving low-dose statin therapy. Further research is needed to determine whether similar benefits are found in other populations with lower levels of fish intake. The trial is registered at ClinicalTrials.gov (number NCT00231738).

Effects of eicosapentaenoic acid on major coronary events in hypercholesterolaemic patients (JELIS): a randomised open-label, blinded endpoint analysis

BACKGROUND

Epidemiological and clinical evidence suggests that an increased intake of long-chain n-3 fatty acids protects against mortality from coronary artery disease. We aimed to test the hypothesis that long-term use of eicosapentaenoic acid (EPA) is effective for prevention of major coronary events in hypercholesterolaemic patients in Japan who consume a large amount of fish.

METHODS

18 645 patients with a total cholesterol of 6.5 mmol/L or greater were recruited from local physicians throughout Japan between 1996 and 1999. Patients were randomly assigned to receive either 1800 mg of EPA daily with statin (EPA group; n=9326) or statin only (controls; n=9319) with a 5-year follow-up. The primary endpoint was any major coronary event, including sudden cardiac death, fatal and non-fatal myocardial infarction, and other non-fatal events including unstable angina pectoris, angioplasty, stenting, or coronary artery bypass grafting. Analysis was by intention-to-treat. The study was registered at ClinicalTrials.gov, number NCT00231738.

FINDINGS

At mean follow-up of 4.6 years, we detected the primary endpoint in 262 (2.8%) patients in the EPA group and 324 (3.5%) in controls-a 19% relative reduction in major coronary events (p=0.011). Post-treatment LDL cholesterol concentrations decreased 25%, from 4.7 mmol/L in both groups. Serum LDL cholesterol was not a significant factor in a reduction of risk for major coronary events. Unstable angina and non-fatal coronary events were also significantly reduced in the EPA group. Sudden cardiac death and coronary death did not differ between groups. In patients with a history of coronary artery disease who were given EPA treatment, major coronary events were reduced by 19% (secondary prevention subgroup: 158 [8.7%] in the EPA group vs 197 [10.7%] in the control group; p=0.048). In patients with no history of coronary artery disease, EPA treatment reduced major coronary events by 18%, but this finding was not significant (104 [1.4%] in the EPA group vs 127 [1.7%] in the control group; p=0.132).

INTERPRETATION

EPA is a promising treatment for prevention of major coronary events, and especially non-fatal coronary events, in Japanese hypercholesterolaemic patients.

Effect of n-3 fatty acids on carotid atherosclerosis and haemostasis in patients with combined hyperlipoproteinemia: a double-blind pilot study in primary prevention

BACKGROUND

Intake of n-3 polyunsaturated fatty acids (n-3 PUFA) either from natural sources or dietary supplementation is inversely associated with atherothrombosis.

AIM

A double-blind pilot study was designed to address the impact of n-3 PUFA on atherosclerosis, haemostasis and vascular status in patients with combined hyperlipoproteinemia.

METHODS

Carotid intima-media thickness (C-IMT), texture of intima-media complex (T-IMC), lipids and platelet function were evaluated in 64 patients with combined hyperlipoproteinemia who received placebo or n-3 PUFA (6 g/day) for 2 years. C-IMT and T-IMC were assessed by B-mode ultrasound. Lipids and platelet function were determined by validated methods.

RESULTS

C-IMT increased in placebo, but not in n-3 PUFA group with respect to baseline. In contrast T-IMC decreased in n-3 PUFA, but not in placebo; in both cases, however, treatment effect did not reach statistical significance. A fall of triglycerides, concomitant to a rise of high- and low-density lipoprotein cholesterol (HDL and LDL), was observed in the active treated group. Platelet function was significantly reduced by n-3 PUFA.

CONCLUSIONS

Results show a favourable effectiveness of n-3 PUFA on IMT progression and T-IMC that deserves to be confirmed in larger studies. Despite the small sample size, the beneficial effect of n-3 PUFA on platelet function, triglycerides and HDL-C is clearly highlighted.