Inflammatory Cytokines as Risk Factors for Mortality After Acute Cardiac Events

Immune-related biomarkers in myocardial infarction; diagnostic/prognostic value and therapeutic potential

The incidence of myocardial infarction (MI) is increasing worldwide on an annual basis. The incorporation of circulating biomarkers, along with electrocardiography, echocardiography, coronary angiograms, and other diagnostic techniques, is essential in the evaluation, prediction, and therapeutic efficacy assessment of patients afflicted with MI. Biomarker evaluation has been employed in the diagnosis of MI for over five decades. Further biomarker research can be carried out as newer biomarkers have been discovered in pathways such as inflammatory response, neurohormonal stimulation, or myocardial stress that initiate significantly earlier than myocyte necrosis and the diagnostic establishment of cardiac troponins. The assessment of biomarkers for MI is on the brink of a significant transformation due to advancements in comprehending the intricate pathophysiology of the condition. This has led to a pursuit of innovative biomarkers that could potentially overcome the limitations of current biomarkers. For individuals with a high-risk profile, this may facilitate tailoring of appropriate treatment. This review places emphasis on a diverse array of biomarkers that have the potential to offer diagnostic and prognostic information, as well as the latest clinical and preclinical evidence that is driving theoretical advancements in cardiovascular immunotherapy.

The role of interleukin-6 in the development of cardiovascular diseases: A review

Currently, the search and study of new biological markers that can provide early diagnosis of cardiovascular diseases, serve as a laboratory tool for assessing the effectiveness of treatment, or be used as prognostic markers and risk stratification criteria is ongoing. Our literature review indicates the potentially important diagnostic and prognostic value of assessing members of the interleukin-6 family. It is expected that further scientific and clinical studies will demonstrate the possibility of using members of the interleukin-6 family as an additional laboratory tool for the diagnosis, risk stratification and prediction of cardiovascular events in cardiac patients. It is necessary to evaluate in detail the possibilities of blockade of these interleukin-6 molecules in patients with cardiovascular diseases in vitro and in vivo.

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.

Characteristics and Outcomes of Early Recurrent Myocardial Infarction After Acute Myocardial Infarction

Background We aimed to understand the characteristics and outcomes of patients readmitted with a recurrent myocardial infarction (RMI) within 90 days of discharge after an acute myocardial infarction (early RMI). Methods and Results We analyzed the timing of reinfarction, etiology, and outcome for all patients admitted with an early RMI within 90 days of discharge after an acute myocardial infarction between January 1, 2010 and January 1, 2017. We identified 6626 admissions for acute myocardial infarction (index myocardial infarction) which led to 168 cases of RMI within 90 days of discharge. The mean patient age was 65.1±13.1 years, and 37% were women. The 90-day probability of readmission with an early RMI was 2.5%. Black race, medical management, higher troponin T, and shorter length of stay were independent predictors of early RMI. Medically managed group had a higher risk for early RMI compared with percutaneous coronary intervention (P=0.04) or coronary artery bypass grafting (P=0.2). Predominant mechanisms for reinfarction were stent thrombosis (17%), disease progression (12%), and unchanged coronary artery disease (11%). At 5 years, the all-cause mortality rate for patients with an early RMI was 49% (95% CI, 40%-57%) compared with 22% (95% CI, 21%-23%) for patients without an early RMI (P<0.0001). Conclusions Early RMI is a life-threatening condition with nearly 50% mortality within 5 years. Stent-related events and progression in coronary artery disease account for most early RMI. Medication compliance, aggressive risk factor management, and care transitions should be the cornerstone in preventing early RMI.

Interleukin-6 Could Be a Potential Prognostic Factor in Ambulatory Elderly Patients with Stable Heart Failure: Results from a Pilot Study

INTRODUCTION

Inflammation is a fundamental phenomenon in heart failure, but the prognostic or therapeutic role of markers such as interleukin-6 (IL-6) has not yet been clarified. The objective of this study is to describe the clinical profile of patients with elevated IL-6 and determine if they have worse clinical outcomes.

METHODS

A retrospective c.ohort observational study including 78 patients with heart failure followed up at the Heart Failure Outpatient Clinic of the Internal Medicine Department. IL-6 was determined in all patients, who were then assigned into two groups according to IL-6 level (normal or high). Clinical and prognostic data were collected to determine the differences in both groups.

RESULTS

The average age was 79 years, 60% female. A total of 53.8% of the patients had elevated IL-6 (group 2). Patients with elevated IL-6 presented more frequently with anemia mellitus (64.3% vs. 41.7%; p = 0.046), atrial fibrillation (83.3% vs. 61.9% p = 0.036), dyslipidemia (76.2% vs. 58.2%; p = 0.03), higher creatinine levels (1.35 mg/dL vs. 1.08 mg/dL; p = 0.024), lower glomerular filtration rate (43.6 mL/min/m2 vs. 59.9 mL/min/m2; p = 0.007), and anemia 25% vs. 52.4% p = 0.014. The factors independently associated with the increase in IL-6 were anemia 3.513 (1.163-10.607) and renal failure 0.963 (0.936-0.991), p < 0.05. Mortality was higher in the group with elevated IL-6 levels (16% vs. 2%; p = 0.044) with a log-rank p = 0.027 in the Kaplan-Meier curve.

CONCLUSION

Patients with heart failure and elevated IL-6 most often have atrial fibrillation, diabetes mellitus, dyslipidemia, anemia, and renal failure. In addition, mortality was higher and a tendency of higher hospital admission was observed in stable HF patients with elevated IL-6.

Biomarkers of acute myocardial infarction: diagnostic and prognostic value. Part 2 (Literature review)

In the second part of the review, we continue the discussion of biomarkers that have a diagnostic and prognostic significance in acute myocardial infarction (AMI). The study of the AMI pathophysiology through the experimental and clinical research contributes to the discovery of new regulatory molecules and pathogenetic mechanisms underlying AMI. At the same time, many molecules involved in the pathogenesis of AMI can be used as effective biomarkers for the diagnosis and prediction of AMI. This article discusses in detail the diagnostic and prognostic value of inflammatory biomarkers of AMI (C-reactive protein, interleukin-6, tumor necrosis factor-alpha, myeloperoxidase, matrix metalloproteinases, soluble form of CD40 ligand, procalcitonin, placental growth factor) and a number of recently discovered new biomarkers of AMI (microribonucleic acids, galectin-3, stimulating growth factor expressed by gene 2, growth differentiation factor 15, proprotein convertase of subtilisin-kexin type 9).

Differential clusterization of soluble and extracellular vesicle-associated cytokines in myocardial infarction

A proinflammatory dysregulation of cytokine release is associated with various diseases, in particular with those of infectious etiology, as well as with cardiovascular diseases (CVD). We showed earlier that cytokines are released in two forms, soluble and in association with extracellular vesicles (EVs). Here, we investigated the patterns of expression and clustering of soluble and EV-associated cytokines in patients with ST-elevation myocardial infarction (STEMI). We collected plasma samples from 48 volunteers without CVD and 62 patients with STEMI, separated soluble and EV fractions, and analyzed them for 33 cytokines using a multiplexed bead-based assay. We identified soluble and EV-associated cytokines that are upregulated in STEMI and form correlative clusters. Several clustered soluble cytokines were expressed almost exclusively in patients with STEMI. EV-associated cytokines were largely not affected by STEMI, except for pro-inflammatory cytokines IL-6, IL-18, and MIG, as well as anti-inflammatory IL-2 that were upregulated in a correlated fashion. Our results demonstrated that soluble cytokines in patients with STEMI are upregulated in a coordinated fashion in contrast to the mainly unaffected system of EV-associated cytokines. Identification of cytokine clusters affected differently by STEMI now permits investigation of their differential contributions to this pathology.

Post-Myocardial Infarction Ventricular Remodeling Biomarkers-The Key Link between Pathophysiology and Clinic

Studies in recent years have shown increased interest in developing new methods of evaluation, but also in limiting post infarction ventricular remodeling, hoping to improve ventricular function and the further evolution of the patient. This is the point where biomarkers have proven effective in early detection of remodeling phenomena. There are six main processes that promote the remodeling and each of them has specific biomarkers that can be used in predicting the evolution (myocardial necrosis, neurohormonal activation, inflammatory reaction, hypertrophy and fibrosis, apoptosis, mixed processes). Some of the biomarkers such as creatine kinase-myocardial band (CK-MB), troponin, and N-terminal-pro type B natriuretic peptide (NT-proBNP) were so convincing that they immediately found their place in the post infarction patient evaluation protocol. Others that are related to more complex processes such as inflammatory biomarkers, atheroma plaque destabilization biomarkers, and microRNA are still being studied, but the results so far are promising. This article aims to review the markers used so far, but also the existing data on new markers that could be considered, taking into consideration the most important studies that have been conducted so far.

Interleukin-6 level is a powerful predictor of long-term cardiovascular mortality in patients with acute coronary syndrome

BACKGROUND

The interleukin-6 (IL-6) pathway has a crucial role in the pathogenesis of atherosclerosis, the main cause of cardiovascular diseases. We aimed to characterize the predictive value of inflammatory biomarkers on long-term cardiovascular mortality in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI).

METHODS

This prospective observational study included 322 consecutive patients with ACS undergoing PCI. Blood-derived biomarkers IL-6 and high-sensitivity C-reactive protein (hsCRP) were assessed at the time point of ACS. Patients were followed-up for 6 years. Long-term cardiovascular mortality was our primary endpoint. Adjusted Cox-regression analysis was used for prediction of events.

RESULTS

Elevated IL-6 values (≥3.3 pg/mL) emerged as an independent and the most powerful predictor for cardiovascular mortality: the ROC analysis showed that IL-6 was more accurate for cardiovascular mortality prediction as compared to hsCRP (IL-6: AUC = 0.72; 95%CI: 0.62-0.81; p = 0.009 vs hsCRP: AUC = 0.56; 95%CI: 0.41-0.72; p = 0.445). The positive predictive value of IL-6 for mortality was 9%, the negative predictive value 99%, sensitivity 94% and specificity 48%. The primary endpoint of long-term cardiovascular death occurred more frequently in patients with high vs low IL-6 (9.0% vs 0.5%, p = 0.001). The multivariate Cox regression analysis revealed that patients with high IL-6 (≥3.3 pg/mL) values were at 8.6-fold higher hazard to die than those with low IL-6 (<3.3 pg/mL) levels (adj. hazard ratio [HR] = 8.60, 95%CI: 1.07-69.32; p = 0.043).

CONCLUSION

In the setting of ACS, high IL-6 values are associated with substantial long-term cardiovascular mortality. Further, IL-6 performs as a superior predictor for cardiovascular death as compared to hsCRP.

The clinical significance of interleukin-6 in heart failure: results from the BIOSTAT-CHF study

AIMS

Inflammation is a central process in the pathophysiology of heart failure (HF), but trials targeting tumour necrosis factor (TNF)-α were largely unsuccessful. Interleukin (IL)-6 is an important inflammatory mediator and might constitute a potential pharmacologic target in HF. However, little is known regarding the association between IL-6 and clinical characteristics, outcomes and other inflammatory biomarkers in HF. We thus aimed to identify and characterize these associations.

METHODS AND RESULTS

Interleukin-6 was measured in 2329 patients [89.4% with a left ventricular ejection fraction (LVEF) ≤ 40%] of the BIOSTAT-CHF cohort. The primary outcome was all-cause mortality and HF hospitalization during 2 years, with all-cause, cardiovascular (CV), and non-CV death as secondary outcomes. Approximately half (56%) of all included patients had plasma IL-6 values greater than the previously determined 95th percentile of normal values at baseline. Elevated N-terminal pro-brain natriuretic peptide, procalcitonin and hepcidin, younger age, TNF-α/IL-1-related biomarkers, or having iron deficiency, atrial fibrillation and LVEF > 40% independently predicted elevated IL-6 levels. IL-6 independently predicted the primary outcome [HR (95% confidence interval) per doubling: 1.16 (1.11-1.21), P < 0.001], all-cause mortality [1.22 (1.16-1.29), P < 0.001] and CV as well as non-CV mortality [1.16 (1.09-1.24), P < 0.001; 1.31 (1.18-1.45), P < 0.001], but did not improve discrimination in previously published risk models.

CONCLUSIONS

In a large, heterogeneous cohort of HF patients, elevated IL-6 levels were found in more than 50% of patients and were associated with iron deficiency, reduced LVEF, atrial fibrillation and poorer clinical outcomes. These findings warrant further investigation of IL-6 as a potential therapeutic target in specific HF subpopulations.

Omega-3 intake is associated with attenuated inflammatory response and cardiac remodeling after myocardial infarction

BACKGROUND

Myocardial infarction (MI) elicits an intense acute inflammatory response that is essential for cardiac repair. However, an excessive inflammatory response also favors myocardial apoptosis, cardiac remodeling, and cardiovascular mortality. Omega-3 polyunsaturated fatty acids (ω-3) bear anti-inflammatory effects, which may mitigate the inflammatory response during MI. This study investigated whether ω-3 intake is associated with attenuation of the MI-related inflammatory response and cardiac remodeling.

METHODS

ST-elevation MI (STEMI) patients (n = 421) underwent clinical, biochemical, nutritional, 3D echocardiogram, Cardiac Magnetic Resonance imaging (CMRi) at 30 days and 3D echocardiogram imaging at six months after the MI. Blood tests were performed at day one (D1) and day five (D5) of hospitalization. Changes in inflammatory markers (ΔD5-D1) were calculated. A validated food frequency questionnaire estimated the nutritional consumption and ω-3 intake in the last 3 months before admission.

RESULTS

The intake of ω-3 below the median (< 1.7 g/day) was associated with a short-term increase in hs-C-reactive protein [OR:1.96(1.24-3.10); p = 0.004], Interleukin-2 [OR:2.46(1.20-5.04); p = 0.014], brain-type natriuretic peptide [OR:2.66(1.30-5.44); p = 0.007], left-ventricle end-diastolic volume [OR:5.12(1.11-23.52)]; p = 0.036] and decreases in left-ventricle ejection fraction [OR:2.86(1.47-6.88); p = 0.017] after adjustment for covariates. No differences were observed in the extension of infarcted mass obtained by CMRi.

CONCLUSION

These findings suggest that a reduced daily intake of ω-3 may intensify outcome-determining mechanisms after STEMI, such as acute inflammatory response and late left ventricular remodeling.

TRIAL REGISTRATION

Clinical Trial Registry number and website: NCT02062554 .

Diagnostic and prognostic value of biomarkers in acute myocardial infarction

The incidence of acute myocardial infarction (AMI) has been increasing rapidly in recent years, seriously endangering human health. Cardiac biomarkers play critical roles in the diagnosis and prognosis of AMI. Troponin is a highly sensitive and specific biomarker for AMI diagnosis and can independently predict adverse cardiac events. Other biomarkers such as N-terminal B-type natriuretic peptide and C reactive protein are also valuable predictors of cardiovascular prognosis. Recently, several novel biomarkers have been identified for the diagnosis and risk assessment in patients with AMI. A multibiomarker approach can potentially enhance the diagnostic accuracy and provide more information for the early risk stratification of AMI. In this review, we will summarise the biomarkers discovered in recent years and focus on their diagnostic and prognostic value for patients with AMI.

Association of serum cystatin C levels with acute coronary syndrome in patients of advanced age

Objective

This study was performed to investigate the relationship between the serum cystatin C (Cys C) level and acute coronary syndrome (ACS) in patients of advanced age.

Methods

The study included 184 patients with ACS and 46 healthy control subjects. Statistical analysis was performed using SPSS version 14.0 (SPSS Inc., Chicago, IL, USA).

Results

The serum Cys C level was significantly higher in patients with than without ACS (1.24 ± 0.30 vs. 1.42 ± 0.46 mg/L, respectively). Patients with more stenotic coronary arteries were significantly more likely to have higher median serum Cys C and creatinine levels and a lower estimated glomerular filtration rate. The multivariate logistic regression analysis demonstrated that the serum Cys C level was independently associated with the presence of ACS and the quantity of stenotic coronary arteries after adjustment for confounding factors. Additionally, the serum Cys C level was positively correlated with age, the creatinine level, and the N-terminal pro-B-type natriuretic peptide level in all patients but was negatively correlated with the estimated glomerular filtration rate.

Conclusion

A high serum Cys C level was independently associated with ACS and the quantity of stenotic coronary arteries in patients of advanced age regardless of renal function.

Association of serum cystatin C levels with mortality in patients with acute type A aortic dissection

Increased serum cystatin C levels are related to the prognosis of cardiovascular diseases. This study aims to investigate the effect of admission serum cystatin C levels on short- and long-term mortality in patients with acute type A aortic dissection (ATAAD). From 2010 to 2014, 136 consecutive patients with ATAAD were enrolled and followed up. Clinical data and laboratory assays including were measured. During a median follow-up of 198.7 days, the short-term mortality (30-days) was 20.6%, whereas the long-term death rate was 10.2%. We identified that the expression of cystatin C and high-sensitivity C-reactive protein (hs-CRP) in the dying patients was higher than in the surviving patients (P < 0.01). Hs-CRP (HR = 1.41, 95% CI: 1.03–2.59, P = 0.037) was an independent risk factor of short-term death determined by univariate and multivariate Cox analyses. No impact of cystatin C was observed on the short-term mortality. For long-term mortality, cystatin C (HR = 1.49, 95% CI: 1.10–7.36, P = 0.013) was identified as an independent predictor at above the cut-off value ≥ 1.10 mg/L. ROC analysis showed the AUC values of cystatin C and hs-CRP were 0.772 (95% CI, 0.692–0.839) and 0.640 (95% CI, 0.574–0.739), respectively, in the prediction of long-term death. The combined AUC value of cystatin C and hs-CRP was 0.883 (95% CI, 0.826–0.935; P < 0.01). Taken together, high cystatin C levels (≥ 1.10 mg/L) on admission are independently associated with the long-term mortality in patients with ATAAD.

Toward a Blood-Borne Biomarker of Chronic Hypoxemia: Red Cell Distribution Width and Respiratory Disease

Hypoxemia (systemic oxygen desaturation) marks the presence, risk, and progression of many diseases. Episodic or nocturnal hypoxemia can be challenging to detect and quantify. A sensitive, specific, and convenient marker of recent oxygen desaturation represents an unmet medical need. Observations of acclimatization to high altitude in humans and animals reveals several proteosomic, ventilatory, and hematological responses to low oxygen tension. Of these, increased red cell distribution width (RDW) appears to have the longest persistence. Literature review and analyses of a 2M patient database across the full disease pathome revealed that increased RDW is predictive of poor outcome for certain diseases including many if not all hypoxigenic conditions. Comprehensive review of diseases impacting the respiratory axis show many are associated with increased RDW and no apparent counterexamples. The mechanism linking RDW to outcome is unknown. Conjectural roles for iron deficiency, inflammation, and oxidative stress have not been born out experimentally. Sports-doping studies show that erythropoietin (EPO) injection can induce formation of unusually large red blood cells (RBC) in sufficient numbers to increase RDW. Because endogenous EPO responds strongly to hypoxemia, this molecule could potentially mediate a long-lived RDW response to low oxygenation. RDW may be a guidepost signaling that unexploited information is embedded in subtle RBC variation. Applying modern techniques of measurement and analysis to certain RBC characteristics may yield a more specific and sensitive marker of chronic pulmonary and circulatory diseases, sleep apnea, and opioid inhibition of breathing.