Inflammation in coronary artery disease: potential role for immunomodulatory therapy

The Optimal Dosage and Duration of ω-3 PUFA Supplementation in Heart Failure Management: Evidence from a Network Meta-Analysis

Heart failure is a progressive condition associated with a high mortality rate. Despite advancements in treatment, many patients continue to experience less-than-ideal outcomes. ω-3 (n-3) polyunsaturated fatty acids (PUFAs) have been studied as a potential supplementary therapy for heart failure, but the optimal dosage and duration of supplementation remain unclear. This network meta-analysis (NMA) aimed to assess the efficacy of various n-3 PUFA supplementation regimens in patients with heart failure, focusing on dose-dependent and time-dependent effects. We conducted a systematic search for randomized controlled trials (RCTs) on n-3 PUFA supplementation in heart failure till 13 September, 2024. The primary outcome was the change in heart function, specifically left ventricular ejection fraction. Secondary outcomes included changes in peak oxygen consumption (VO2), blood B-type natriuretic peptide concentrations, and quality of life. The safety analysis focused on dropout rates (i.e., patients leaving the study for any reason before completion) and all-cause mortality. A frequentist-based NMA was performed. This NMA, which included 14 RCTs with 9075 participants (mean age, 66.0 y; 23.3% female), found that high-dose n-3 PUFA supplementation (2000-4000 mg/d) over a duration of ≥1 y significantly improved left ventricular ejection fraction and peak VO2 compared with those of control groups. Lower doses and shorter treatment periods did not produce the same benefits. No significant differences were found in dropout rates or all-cause mortality between the n-3 PUFAs and control groups. Long-term, high-dose n-3 PUFA supplementation, particularly with a predominance of docosahexaenoic acid or eicosapentaenoic acid, enhances cardiac function in patients with heart failure without increasing risk of adverse events. Further well-designed RCTs with long treatment durations (i.e., >1 y) and stringent heart failure inclusion criteria are necessary to confirm these findings and reduce potential biases. This trial was registered at PROSPERO as CRD42024590476.

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.

The chemokine network in relation to infarct size and left ventricular remodeling following acute myocardial infarction

Increased circulating chemokines have been reported during acute myocardial infarction and might give prognostic information about future ischemic events. However, data on the chemokine network in relation to infarct size and measures of left ventricular remodeling after successful percutaneous coronary intervention (PCI) are lacking. A total of 42 patients with first-time ST-segment elevation acute myocardial infarction with a single occluded vessel were recruited, and cardiac magnetic resonance was used for serial assessment (2, 7, and 60 days) of infarct size and left ventricular remodeling. The chemokines were analyzed before and after PCI. After PCI, high levels of CCL4, CXCL16, CXCL10, and, in particular, CXCL8 within the first week after PCI correlated positively with the degree of myocardial damage, as reflected by correlations with the maximum troponin T levels and infarct size after 2 months, as assessed by cardiac magnetic resonance, and with impaired myocardial function after 2 months as assessed by cardiac magnetic resonance and neurohormonal methods. In contrast, the plasma levels of CCL3 and CXCL7 during the first week correlated negatively with myocardial dysfunction after 2 months. In conclusion, our findings suggest a role for chemokines in both adaptive and maladaptive responses after myocardial infarction and might support a role for CCL4, CXCL16, CXCL10, and, in particular, CXCL8 in postmyocardial infarction reperfusion and remodeling.

VASCULAR INFLAMMATION AND ATHEROGENESIS ARE ACTIVATED VIA RECEPTORS FOR PAMPs AND SUPPRESSED BY REGULATORY T CELLS

Despite significant advances in identifying the risk factors and elucidating atherosclerotic pathology, atherosclerosis remains the leading cause of morbidity and mortality in industrialized society. These risk factors independently or synergistically lead to chronic vascular inflammation, which is an essential requirement for the progression of atherosclerosis in patients. However, the mechanisms underlying the pathogenic link between the risk factors and atherosclerotic inflammation remain poorly defined. Significant progress has been made in two major areas, which are determination of the roles of the receptors for pathogen-associated molecular patterns (PAMPs) in initiation of vascular inflammation and atherosclerosis, and characterization of the roles of regulatory T cells in suppression of vascular inflammation and atherosclerosis. In this review, we focus on three related issues: (1) examining the recent progress in endothelial cell pathology, inflammation and their roles in atherosclerosis; (2) analyzing the roles of the receptors for pathogen-associated molecular patterns (PAMPs) in initiation of vascular inflammation and atherosclerosis; and (3) analyzing the advances in our understanding of suppression of vascular inflammation and atherosclerosis by regulatory T cells. Continuous improvement of our understanding of the risk factors involved in initiation and promotion of artherogenesis, will lead to the development of novel therapeutics for ischemic stroke and cardiovascular diseases.

Immunophenotypes in the circulation of patients with mild cognitive impairment

Alterations in the peripheral immune system are associated with dementia and the neuropathology of Alzheimer's disease, but have yet to be studied early in the disease process. To test the hypothesis that the balance of immune cell phenotypes is disrupted in the early progression of memory deterioration, patients with mild cognitive impairment (MCI) and healthy elderly controls were examined for the distribution of subpopulations of leukocytes (lymphocytes, granulocytes, and monocytes) and lymphocyte subtypes (helper/inducer and suppressor/cytotoxic T lymphocytes and B lymphocytes) in blood. MCI subjects had a significantly higher percentage of total lymphocytes and a lower percentage of granulocytes compared to elderly controls. Furthermore, the expression of cell surface amyloid precursor protein (APP) and intracellular amyloid-beta peptide (Abeta) in lymphocytes and monocytes were determined. We found lymphocyte APP expression to be significantly increased in MCI subjects compared to controls. Our data indicate that changes in immunological parameters may be detected early in MCI, and an alteration of the immune response may precede clinical AD.

Homocysteine-lowering therapy does not affect inflammatory markers of atherosclerosis in patients with stable coronary artery disease

OBJECTIVES

A high level of total homocysteine (tHcy) is a risk marker for cardiovascular disease (CVD), and is related to inflammation. We wanted to test the effect of homocysteine-lowering B-vitamin therapy, as used in the Western Norway B-vitamin Intervention Trial (WENBIT), on inflammatory markers associated with atherosclerosis.

DESIGN

Single centre, prospective double-blind clinical interventional study, randomised in a 2 x 2 factorial design.

SUBJECTS AND METHODS

Ninety patients (21 female) with suspected coronary artery disease (CAD), aged 38-80 years, were blindly randomised into one of four groups of daily oral treatment with (A) folic acid (0.8 mg)/vitamin B12 (0.4 mg)/vitamin B6 (40 mg), (B) folic acid/vitamin B12, (C) vitamin B6 alone or (D) placebo. Blood samples were collected before and after 6 months of treatment.

RESULTS

Before intervention, median levels of the analytes were: tHcy 11.0 micromol L(-1), neopterin 8.1 nmol L(-1), soluble CD40 ligand (sCD40L) 3.9 ng mL(-1), interleukin (IL)-6 1.9 pg mL(-1), C-reactive protein (CRP) 1.9 mg L(-1) and low-density lipoprotein (LDL) cholesterol 3.3 mmol L(-1). tHcy was significantly associated with neopterin (r = 0.49, P < 0.001) and with IL-6 (r = 0.29, P = 0.01), but not with CRP or sCD40L. Neither treatment with folic acid/B12 nor with B6 induced significant changes in any of these inflammatory biomarkers (P >or= 0.14). In patients receiving folic acid/B12 (groups A and B), tHcy was reduced with 33% (P < 0.001).

CONCLUSIONS

In patients with stable CAD, homocysteine-lowering therapy with B-vitamins does not affect levels of inflammatory markers associated with atherogenesis. Failure to reverse inflammatory processes, may partly explain the negative results in clinical secondary B-vitamin intervention trials.

The osteoprotegerin/RANK/RANKL system: a bone key to vascular disease

Owing to the common coincidence of osteoporosis and vascular disease, pathophysiological links between both disorders have long been sought. The osteoprotegerin (OPG)/receptor activator of NF-kappaB (RANK)/receptor activator of NF-kappaB ligand (RANKL) cytokine network, a key regulatory system in bone homeostasis, has been implicated recently in vascular calcification, changes in matrix composition and diabetic macroangiopathy, aortic aneurysm development, heart failure and, most importantly, advanced atherosclerosis, plaque destabilization and manifestation of cardiovascular diseases. The concept of an active role of RANKL and OPG in vascular pathophysiology is intriguing and is gaining increasing support from both epidemiological and basic research. OPG serum level is considered to be a stable and reliable indicator of the overall activity of the OPG/RANK/RANKL axis and may find application as a biomarker of vascular risk and prognosis. RANKL in turn may be a suitable target for novel therapies. Pharmacological strategies for specific interference with the OPG/RANK/RANKL axis are currently being developed and evaluated in osteoporosis therapy.

Polymorphisms in pro- and anti-inflammatory cytokine genes and susceptibility to atherosclerosis: a pathological study of 1503 consecutive autopsy cases

Atherosclerosis is a chronic inflammatory disease in the intima of the arterial wall, where cytokines play a crucial role in the pathogenesis of this disease. However, the question of whether or not genetic variations in the cytokine genes could influence the development of atherosclerosis has been poorly investigated. We investigated the relationship of nine common single-nucleotide polymorphisms (SNPs) in tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-10, IL-4 and transforming growth factor (TGF)-beta1 with the atherosclerotic severity in 10 different arteries based on 1503 consecutive autopsies of elderly Japanese subjects registered in the Japanese SNPs for geriatric research (JG-SNP) study. The -1031C allele of TNF-alpha was a significant protective factor for atherogenesis in the carotid, femoral and intracranial arteries [odds ratio (OR): 0.72, 0.73 and 0.70, respectively]. The -511T of IL-1beta and the +29T of TGF-beta1 were significant risk factors for atherogenesis in the subclavian and intracranial arteries (OR: 1.35 and 1.48, respectively). In contrast, conventional risk factors for atherogenesis, such as hypertension and diabetes mellitus, conferred independent risks for almost all arteries. Functional SNPs in TNF-alpha, IL-1beta and TGF-beta1 genes play a role in atherogenesis, although their influences are less pronounced than those of conventional risk factors and appear to be limited to specific arteries in the Japanese elderly.

Interleukin-6 Correlates with Endothelial Dysfunction in Young Post-Myocardial Infarction Patients

BACKGROUND

The estimation of coronary risk based on consideration of classical risk factors is insufficient in young patients with myocardial infarction who have low expressions of classical risk factors. Endothelial dysfunction (ED) and markers of vascular inflammation may be more appropriate for risk estimation. The relations among ED and inflammation markers in such patients have not yet been explored.

PATIENTS AND METHODS

Twenty-one patients (on average 44 years old) in the stable phase after myocardial infarction, with low expressions of risk factors, were included in the study. The control group consisted of 25 healthy age-matched males. ED was estimated by ultrasound measurement of the endothelium-dependent dilatation of the brachial artery. The following inflammation markers were measured: hsCRP, interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha), ICAM-1, VCAM-1, selectin-P and selectin-E.

RESULTS

Patients had a significantly reduced level of endothelium-dependent vasodilatation (5.6 +/- 3.5 vs. 8.8 +/- 6.5%, p < 0.05), and an increased level of IL-6 (3.2 [1.5-8.4] vs. 1.4 [0.9-2.3] ng/ml; p < 0.01). All other inflammation markers were comparable to controls. We found a significant negative correlation between ED and the levels of IL-6 (r = -0.54, p = 0.012).

CONCLUSION

It appears that IL-6 is the most valuable circulating marker of ED, and consequently a useful marker of coronary risk.

Inflammation and atherosclerosis: novel insights into plaque formation and destabilization

BACKGROUND AND PURPOSE

The simplistic view of atherosclerosis as a disorder of pathological lipid deposition has been redefined by the more complex concept of an ongoing inflammatory response.

SUMMARY OF REVIEW

Apolipoprotein E and low-density lipoprotein (LDL)-receptor-deficient mice develop accelerated atherosclerosis allowing in-depth pathophysiological investigations. Atherosclerotic plaques in these mice contain large numbers of T cells and macrophages. Crossbreeding apolipoprotein E-deficient mice with T-cell-deficient mice and mice with impaired macrophage function (osteopetrotic op/op mice) disclosed the important impact of immune cells on atherosclerotic lesion development. In contrast to the detrimental role of T cells and macrophages, B cells appear to be atheroprotective. These basic experimental findings have partly been confirmed in studies of the human carotid artery system. Inflammation is not only instrumental in the development of human atheromatous plaques, but, importantly, plays a crucial role in the destabilization of internal carotid artery plaques, thus converting chronic atherosclerosis into an acute thrombo-embolic disorder. Humoral factors involved in internal carotid artery destabilization include cytokines, cyclooxygenase-2, matrix metalloproteinases, and tissue factor. Antibodies to oxidized LDL can reflect disease activity on one hand, but can also confer atheroprotection. Novel MRI techniques may aid in the in vivo assessment of acute plaque inflammation in humans.

CONCLUSIONS

The impact of inflammation on the development of atherosclerotic plaques and their destabilization opens new avenues for treatment. The effects of statins, acetylsalicyclic acid and angiotensin-converting enzyme inhibitors on stroke prevention may partly be attributable to their profound anti-inflammatory actions. Vaccination against modified LDL and heat shock proteins halt plaque progression in experimental atherosclerosis. Their potential for prevention of human atherosclerosis is currently under investigation.