C-reactive protein, interleukin 6, fibrinogen and risk of sudden death in European middle-aged men: the PRIME study

Cardioprotection in cardiovascular surgery

Since the invention of cardiopulmonary bypass, cardioprotective strategies have been investigated to mitigate ischemic injury to the heart during aortic cross-clamping and reperfusion injury with cross-clamp release. With advances in cardiac surgical and percutaneous techniques and post-operative management strategies including mechanical circulatory support, cardiac surgeons are able to operate on more complex patients. Therefore, there is a growing need for improved cardioprotective strategies to optimize outcomes in these patients. This review provides an overview of the basic principles of cardioprotection in the setting of cardiac surgery, including mechanisms of cardiac injury in the context of cardiopulmonary bypass, followed by a discussion of the specific approaches to optimizing cardioprotection in cardiac surgery, including refinements in cardiopulmonary bypass and cardioplegia, ischemic conditioning, use of specific anesthetic and pharmaceutical agents, and novel mechanical circulatory support technologies. Finally, translational strategies that investigate cardioprotection in the setting of cardiac surgery will be reviewed, with a focus on promising research in the areas of cell-based and gene therapy. Advances in this area will help cardiologists and cardiac surgeons mitigate myocardial ischemic injury, improve functional post-operative recovery, and optimize clinical outcomes in patients undergoing cardiac surgery.

Impact of C-reactive protein levels and role of anakinra in patients with ST-elevation myocardial infarction

BACKGROUND

Interleukin-1 blockade with anakinra reduces C-reactive protein (CRP) levels and prevents heart failure (HF) events after ST-segment myocardial infarction (STEMI). The effectiveness of anakinra according to the degree of systemic inflammation in STEMI has not been addressed.

METHODS

We analyzed 139 patients from three Virginia Commonwealth University Anakinra Response Trial randomized clinical trials to assess whether CRP levels predicted HF hospitalization or death in patients with STEMI, and if CRP levels influenced the effects of treatment with anakinra.

RESULTS

CRP cut-off levels for prediction of the composite of death or HF hospitalization for CRP at admission, 3 and 14 days were, respectively 6.45 mg/L (100% of sensitivity and 66.1% specificity), 26 mg/L (100% of sensitivity and 78% specificity) and 9.56 mg/L (100% of sensitivity and 80% specificity). More patients with elevated CRP levels died or had a HF hospitalization (5/47 [11%] vs 0/82 [0%], p = 0.004 for CRP at admission; 5/32 [15.6%] vs 0/92 [0%], p < 0.001 for day 3 and 5/26 [19%] vs 0/89 [0%], p < 0.001 for day 14). A greater number of patients treated with anakinra had low CRP levels at 3 and 14 days compared to placebo (Odds Ratio 0.11 [95% IC 0.04-0.28], p < 0.0001 and OR 0.35 [95% CI 0.14-0.86], p = 0.02, respectively). Anakinra significantly prevented death or HF hospitalization in patients with high inflammatory burden (p = 0.04 for admission, p = 0.24 for day 3, and p = 0.05 for day 14).

CONCLUSION

Patients with elevated CRP had higher incidence of HF hospitalization or death. Anakinra reduced the number of patients with elevated CRP levels and prevented death or HF hospitalization in patients with elevated CRP levels.

Elevated Interleukin-6 Levels Are Associated With an Increased Risk of QTc Interval Prolongation in a Large Cohort of US Veterans

BACKGROUND

Although accumulating data indicate that IL-6 (interleukin-6) can promote heart rate-corrected QT interval (QTc) prolongation via direct and indirect effects on cardiac electrophysiology, current evidence comes from basic investigations and small clinical studies only. Therefore, IL-6 is still largely ignored in the clinical management of long-QT syndrome and related arrhythmias. The aim of this study was to estimate the risk of QTc prolongation associated with elevated IL-6 levels in a large population of unselected subjects.

METHODS AND RESULTS

An observational study using the Veterans Affairs Informatics and Computing Infrastructure was performed. Participants were US veterans who had an ECG and were tested for IL-6. Descriptive statistics and univariate and multivariate regression analyses were performed to study the relationship between IL-6 and QTc prolongation risk. Study population comprised 1085 individuals, 306 showing normal (<5 pg/mL), 376 moderately high (5-25 pg/mL), and 403 high (>25 pg/mL) IL-6 levels. Subjects with elevated IL-6 showed a concentration-dependent increase in the prevalence of QTc prolongation, and those presenting with QTc prolongation exhibited higher circulating IL-6 levels. Stepwise multivariate regression analyses demonstrated that increased IL-6 level was significantly associated with a risk of QTc prolongation up to 2 times the odds of the reference category of QTc (e.g. QTc >470 ms men/480 ms women ms: odds ratio, 2.28 [95% CI, 1.12-4.50] for IL-6 >25 pg/mL) regardless of the underlying cause. Specifically, the mean QTc increase observed in the presence of elevated IL-6 was quantitatively comparable (IL-6 >25 pg/mL:+6.7 ms) to that of major recognized QT-prolonging risk factors, such as hypokalemia and history of myocardial infarction.

CONCLUSIONS

Our data provide evidence that a high circulating IL-6 level is a robust risk factor for QTc prolongation in a large cohort of US veterans, supporting a potentially important arrhythmogenic role for this cytokine in the general population.

The Role of Pro-Inflammatory Cytokines in the Pathogenesis of Cardiovascular Disease

With cardiovascular disease (CVD) being a primary source of global morbidity and mortality, it is crucial that we understand the molecular pathophysiological mechanisms at play. Recently, numerous pro-inflammatory cytokines have been linked to several different CVDs, which are now often considered an adversely pro-inflammatory state. These cytokines most notably include interleukin-6 (IL-6),tumor necrosis factor (TNF)α, and the interleukin-1 (IL-1) family, amongst others. Not only does inflammation have intricate and complex interactions with pathophysiological processes such as oxidative stress and calcium mishandling, but it also plays a role in the balance between tissue repair and destruction. In this regard, pre-clinical and clinical evidence has clearly demonstrated the involvement and dynamic nature of pro-inflammatory cytokines in many heart conditions; however, the clinical utility of the findings so far remains unclear. Whether these cytokines can serve as markers or risk predictors of disease states or act as potential therapeutic targets, further extensive research is needed to fully understand the complex network of interactions that these molecules encompass in the context of heart disease. This review will highlight the significant advances in our understanding of the contributions of pro-inflammatory cytokines in CVDs, including ischemic heart disease (atherosclerosis, thrombosis, acute myocardial infarction, and ischemia-reperfusion injury), cardiac remodeling (hypertension, cardiac hypertrophy, cardiac fibrosis, cardiac apoptosis, and heart failure), different cardiomyopathies as well as ventricular arrhythmias and atrial fibrillation. In addition, this article is focused on discussing the shortcomings in both pathological and therapeutic aspects of pro-inflammatory cytokines in CVD that still need to be addressed by future studies.

Synergistic role of circulating CD14++CD16+ monocytes and fibrinogen in predicting the cardiovascular events after myocardial infarction

BACKGROUND

Monocytes and fibrinogen (FIB) play important roles in driving acute and reparative inflammatory pathways after myocardial infarction (MI). In humans, there are three subsets of monocytes, namely, CD14++CD16- (Mon1), CD14++CD16+ (Mon2), and CD14+CD16++ (Mon3). During the inflammatory response, monocyte subsets express high levels of integrin α_M β₂ and protease-activated receptors 1 and 3 to interact with FIB.

HYPOTHESIS

However, whether there is a synergistic role of FIB combined with Mon2 counts in prioritizing patients at high risk of future major adverse cardiovascular events (MACEs) after MI remains unknown.

METHODS

The MI patients who treated with primary percutaneous coronary intervention were enrolled. MI patients were categorized into four groups, that is, low FIB/low Mon2, low FIB/high Mon2, high FIB/low Mon2, and high FIB/high Mon2, according to cutoff values of 3.28 g/L for FIB and 32.20 cells/μL for Mon2. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the risk of MACEs of MI patients during a median follow-up of 2.7 years. Mediating effects of high FIB levels and MACEs associated with high monocyte subsets were calculated by mediation analysis.

RESULTS

High FIB/high Mon2 group had the highest risk of MACEs during a median follow-up of 2.7 years. Moreover, mediation analysis showed that a high FIB level could explain 24.9% (p < .05) of the increased risk of MACEs associated with Mon2.

CONCLUSION

This work provides evidence indicating the translational potential of a synergistic role of FIB combined with Mon2 in prioritizing patients at high risk of future MACEs after MI.

Effects of Long-Term Intervention with Losartan, Aspirin and Atorvastatin on Vascular Remodeling in Juvenile Spontaneously Hypertensive Rats

Hypertension in adolescents is associated with adverse cardiac and vascular events. In addition to lowering blood pressure, it is not clear whether pharmacological therapy in early life can improve vascular remodeling. This study aimed to evaluate the effects of long-term administration of losartan, aspirin, and atorvastatin on vascular remodeling in juvenile spontaneously hypertensive rats (SHRs). Losartan, aspirin, and atorvastatin were administered via gavage at doses of 20, 10, and 10 mg/kg/day, respectively, on SHRs aged 6-22 weeks. Paraffin sections of the blood vessels were stained with hematoxylin-eosin (H&E) and Sirius Red to evaluate the changes in the vascular structure and the accumulation of different types of collagen. The plasma levels of renin, angiotensin II (Ang II), aldosterone (ALD), endothelin-1 (ET-1), interleukin-6 (IL-6), and neutrophil elastase (NE) were determined using ELISA kits. After the 16-week treatment with losartan, aspirin, and atorvastatin, the wall thickness of the thoracic aorta and carotid artery decreased. The integrity of the elastic fibers in the tunica media was maintained in an orderly manner, and collagen deposition in the adventitia was retarded. The plasma levels of renin, ALD, ET-1, IL-6, and NE in the SHRs also decreased. These findings suggest that losartan, aspirin, and atorvastatin could improve vascular remodeling beyond their antihypertensive, anti-inflammatory, and lipid-lowering effects. Many aspects of the protection provided by pharmacological therapy are important for the prevention of cardiovascular diseases in adults and older adults.

Circulating virome and inflammatory proteome in patients with ST-elevation myocardial infarction and primary ventricular fibrillation

Primary ventricular fibrillation (PVF) is a life-threatening complication of ST-segment elevation myocardial infarction (STEMI). It is unclear what roles viral infection and/or systemic inflammation may play as underlying triggers of PVF, as a second hit in the context of acute ischaemia. Here we aimed to evaluate whether the circulating virome and inflammatory proteome were associated with PVF development in patients with STEMI. Blood samples were obtained from non-PVF and PVF STEMI patients at the time of primary PCI, and from non-STEMI healthy controls. The virome profile was analysed using VirCapSeq-VERT (Virome Capture Sequencing Platform for Vertebrate Viruses), a sequencing platform targeting viral taxa of 342,438 representative sequences, spanning all virus sequence records. The inflammatory proteome was explored with the Olink inflammation panel, using the Proximity Extension Assay technology. After analysing all viral taxa known to infect vertebrates, including humans, we found that non-PVF and PVF patients only significantly differed in the frequencies of viruses in the Gamma-herpesvirinae and Anelloviridae families. In particular, most showed a significantly higher relative frequency in non-PVF STEMI controls. Analysis of systemic inflammation revealed no significant differences between the inflammatory profiles of non-PVF and PVF STEMI patients. Inflammatory proteins associated with cell adhesion, chemotaxis, cellular response to cytokine stimulus, and cell activation proteins involved in immune response (IL6, IL8 CXCL-11, CCL-11, MCP3, MCP4, and ENRAGE) were significantly higher in STEMI patients than non-STEMI controls. CDCP1 and IL18-R1 were significantly higher in PVF patients compared to healthy subjects, but not compared to non-PVF patients. The circulating virome and systemic inflammation were not associated with increased risk of PVF development in acute STEMI. Accordingly, novel strategies are needed to elucidate putative triggers of PVF in the setting of acute ischaemia, in order to reduce STEMI-driven sudden death burden.

Post-ischemic Myocardial Inflammatory Response: A Complex and Dynamic Process Susceptible to Immunomodulatory Therapies

Following acute occlusion of a coronary artery causing myocardial ischemia and implementing first-line treatment involving rapid reperfusion, a dynamic and balanced inflammatory response is initiated to repair and remove damaged cells. Paradoxically, restoration of myocardial blood flow exacerbates cell damage as a result of myocardial ischemia-reperfusion (MI-R) injury, which eventually provokes accelerated apoptosis. In the end, the infarct size still corresponds to the subsequent risk of developing heart failure. Therefore, true understanding of the mechanisms regarding MI-R injury, and its contribution to cell damage and cell death, are of the utmost importance in the search for successful therapeutic interventions to finally prevent the onset of heart failure. This review focuses on the role of innate immunity, chemokines, cytokines, and inflammatory cells in all three overlapping phases following experimental, mainly murine, MI-R injury known as the inflammatory, reparative, and maturation phase. It provides a complete state-of-the-art overview including most current research of all post-ischemic processes and phases and additionally summarizes the use of immunomodulatory therapies translated into clinical practice.

Sudden Cardiac Death in Patients with Heart Disease and Preserved Systolic Function: Current Options for Risk Stratification

Sudden cardiac death (SCD) is the leading cause of cardiovascular mortality in patients with coronary artery disease without severe systolic dysfunction and in heart failure with preserved ejection fraction. From a global health perspective, while risk may be lower, the absolute number of SCDs in patients with left ventricle ejection fraction >35% is higher than in those with severely reduced left ventricle ejection fraction (defined as ≤35%). Despite these observations and the high amount of available data, to date there are no clear recommendations to reduce the sudden cardiac death burden in the population with mid-range or preserved left ventricle ejection fraction. Ongoing improvements in risk stratification based on electrophysiological and imaging techniques point towards a more precise identification of patients who would benefit from ICD implantation, which is still an unmet need in this subset of patients. The aim of this review is to provide a state-of-the-art approach in sudden cardiac death risk stratification of patients with mid-range and preserved left ventricular ejection fraction and one of the following etiologies: ischemic cardiomyopathy, heart failure, atrial fibrillation or myocarditis.

Multifactorial expression of IL-6 with update on COVID-19 and the therapeutic strategies of its blockade (Review)

Interleukin 6 (IL-6), a cytokine produced by various cells of the human body (macrophages, lymphocytes, astrocytes, ischemic myocytes, endothelial cells) has both pro-inflammatory and anti-inflammatory properties, being a key component in regulating various physiologic and pathological processes. The structure of this molecule and the receptor system it possesses are important due to the different activities that IL-6 can exert; through trans-signaling pro-inflammatory activities are mediated, while through classic signaling, IL-6 is responsible for anti-inflammatory and regenerative activities. IL-6 signaling is involved in coronary artery disease and the global COVID-19 pandemic. This proatherogenic cytokine reaches elevated serum levels in the cytokine storm generated by SARS-CoV-2, and is also associated with smoking or obesity-classic cardiovascular risk factors which promote inflammatory states. IL-6 levels are proportionally correlated with dyslipidemia, hypertension and glucose dysregulation, and they are associated with poor outcomes in patients with unstable angina or acute myocardial infarction. IL-6 targeting for treatment development (not only) in cardiovascular disease and COVID-19 is still a matter of ongoing research, although tocilizumab has proven to be effective in reducing the proatherogenic effects of IL-6 and is suggested to improve COVID-19 patient survival.

Neurological Disorders and Risk of Arrhythmia

Neurological disorders including depression, anxiety, post-traumatic stress disorder (PTSD), schizophrenia, autism and epilepsy are associated with an increased incidence of cardiovascular disorders and susceptibility to heart failure. The underlying molecular mechanisms that link neurological disorders and adverse cardiac function are poorly understood. Further, a lack of progress is likely due to a paucity of studies that investigate the relationship between neurological disorders and cardiac electrical activity in health and disease. Therefore, there is an important need to understand the spatiotemporal behavior of neurocardiac mechanisms. This can be advanced through the identification and validation of neurological and cardiac signaling pathways that may be adversely regulated. In this review we highlight how dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, autonomic nervous system (ANS) activity and inflammation, predispose to psychiatric disorders and cardiac dysfunction. Moreover, antipsychotic and antidepressant medications increase the risk for adverse cardiac events, mostly through the block of the human ether-a-go-go-related gene (hERG), which plays a critical role in cardiac repolarization. Therefore, understanding how neurological disorders lead to adverse cardiac ion channel remodeling is likely to have significant implications for the development of effective therapeutic interventions and helps improve the rational development of targeted therapeutics with significant clinical implications.

CircSAMD4A aggravates H/R-induced cardiomyocyte apoptosis and inflammatory response by sponging miR-138-5p

Hypoxia/reoxygenation (H/R)‐induced myocardial cell injury is the main cause of acute myocardial infarction (AMI). Many proofs show that circular RNA plays an important role in the development of AMI. The purpose of this study was to investigate the role of circSAMD4A in H/R‐induced myocardial injury. The levels of circular SAMD4A (circSAMD4A) were detected in the heart tissues of AMI mice and H/R‐induced H9C2 cells, and the circSAMD4A was suppressed in AMI mice and H/R‐induced H9C2 cells to investigate its’ function in AMI. The levels of circSAMD4A and miR‐138‐5p were detected by real‐time quantitative PCR, and MTT assay was used to detect cell viability. TUNEL analysis and Annexin V‐FITC were used to determine apoptosis. The expression of Bcl‐2 and Bax proteins was detected by Western blot. IL‐1β, TNF‐α and IL‐6 were detected by ELISA kits. The study found that the levels of circSAMD4A were up‐regulated after H/R induction and inhibition of circSAMD4A expression would reduce the H/R‐induced apoptosis and inflammation. MiR‐138‐5p was down‐regulated in H/R‐induced H9C2 cells. circSAMD4A was a targeted regulator of miR‐138‐5p. CircSAMD4A inhibited the expression of miR‐138‐5p to promote H/R‐induced myocardial cell injury in vitro and vivo. In conclusion, CircSAMD4A can sponge miR‐138‐5p to promote H/R‐induced apoptosis and inflammatory response.

Membrane Attack Complex in Myocardial Ischemia/Reperfusion Injury: A Systematic Review for Post Mortem Applications

The complement system has a significant role in myocardial ischemia/reperfusion injury, being responsible for cell lysis and amplification of inflammatory response. In this context, several studies highlight that terminal complement complex C5b-9, also known as the membrane attack complex (MAC), is a significant contributor. The MAC functions were studied by many researchers analyzing the characteristics of its activation in myocardial infarction. Here, a systematic literature review was reported to evaluate the principal features, advantages, and limits (regarding the application) of complement components and MAC in post mortem settings to perform the diagnosis of myocardial ischemia/infarction. The review was performed according to specific inclusion and exclusion criteria, and a total of 26 studies were identified. Several methods studied MAC, and each study contributes to defining better how and when it affects the myocardial damage in ischemic/reperfusion injury. The articles were discussed, focusing on the specificity, sensibility, and post mortem stability of MAC as a marker of myocardial ischemia/infarction, supporting the usefulness in routine post mortem investigations.

Markers of Myocardial Stress, Myocardial Injury, and Subclinical Inflammation and the Risk of Sudden Death

BACKGROUND

The majority of sudden cardiac deaths (SCDs) occur in low-risk populations often as the first manifestation of cardiovascular disease (CVD). Biomarkers are screening tools that may identify subclinical cardiovascular disease and those at elevated risk for SCD. We aimed to determine whether the total to high-density lipoprotein cholesterol ratio, high-sensitivity cardiac troponin I, NT-proBNP (N-terminal pro-B-type natriuretic peptide), or high-sensitivity C-reactive protein individually or in combination could identify individuals at higher SCD risk in large, free-living populations with and without cardiovascular disease.

METHODS

We performed a nested case-control study within 6 prospective cohort studies using 565 SCD cases matched to 1090 controls (1:2) by age, sex, ethnicity, smoking status, and presence of cardiovascular disease.

RESULTS

The median study follow-up time until SCD was 11.3 years. When examined as quartiles or continuous variables in conditional logistic regression models, each of the biomarkers was significantly and independently associated with SCD risk after mutually controlling for cardiac risk factors and other biomarkers. The mutually adjusted odds ratios for the top compared with the bottom quartile were 1.90 (95% CI, 1.30-2.76) for total to high-density lipoprotein cholesterol ratio, 2.59 (95% CI, 1.76-3.83) for high-sensitivity cardiac troponin I, 1.65 (95% CI, 1.12-2.44) for NT-proBNP, and 1.65 (95% CI, 1.13-2.41) for high-sensitivity C-reactive protein. A biomarker score that awarded 1 point when the concentration of any of those 4 biomarkers was in the top quartile (score range, 0-4) was strongly associated with SCD, with an adjusted odds ratio of 1.56 (95% CI, 1.37-1.77) per 1-unit increase in the score.

CONCLUSIONS

Widely available measures of lipids, subclinical myocardial injury, myocardial strain, and vascular inflammation show significant independent associations with SCD risk in apparently low-risk populations. In combination, these measures may have utility to identify individuals at risk for SCD.

Cardiac Arrest Risk During Acute Infections: Systemic Inflammation Directly Prolongs QTc Interval via Cytokine-Mediated Effects on Potassium Channel Expression

BACKGROUND

During acute infections, the risk of malignant ventricular arrhythmias is increased, partly because of a higher propensity to develop QTc prolongation. Although it is generally believed that QTc changes almost exclusively result from concomitant treatment with QT-prolonging antimicrobials, direct effects of inflammatory cytokines on ventricular repolarization are increasingly recognized. We hypothesized that systemic inflammation per se can significantly prolong QTc during acute infections, via cytokine-mediated changes in K⁺ channel expression.

METHODS

We evaluated (1) the frequency of QTc prolongation and its association with inflammatory markers, in patients with different types of acute infections, during active disease and remission; (2) the prevalence of acute infections in a cohort of consecutive patients with Torsades de Pointes; (3) the relationship between K⁺ channel mRNA levels in ventricles and peripheral blood mononuclear cells and their changes in patients with acute infection over time.

RESULTS

In patients with acute infections, regardless of concomitant QT-prolonging antimicrobial treatments, QTc was significantly prolonged but rapidly normalized in parallel to CRP (C-reactive protein) and cytokine level reduction. Consistently in the Torsades de Pointes cohort, concomitant acute infections were highly prevalent (30%), despite only a minority (25%) of these cases were treated with QT-prolonging antimicrobials. KCNJ2 K⁺ channel expression in peripheral blood mononuclear cell, which strongly correlated to that in ventricles, inversely associated to CRP and IL (interleukin)-1 changes in acute infection patients.

CONCLUSIONS

During acute infections, systemic inflammation rapidly induces cytokine-mediated ventricular electrical remodeling and significant QTc prolongation, regardless concomitant antimicrobial therapy. Although transient, these changes may significantly increase the risk of life-threatening ventricular arrhythmia in these patients. It is timely and warranted to transpose these findings to the current coronavirus disease 2019 (COVID-19) pandemic, in which both increased amounts of circulating cytokines and cardiac arrhythmias are demonstrated along with a frequent concomitant treatment with several QT-prolonging drugs. Graphic Abstract: A graphic abstract is available for this article.

Wide QRS-T angles are associated with markers of increased inflammatory activity independently of hypertension and diabetes

Background

Wide QRS‐T angles and inflammatory activity are markers of future cardiovascular events including sudden cardiac death (SCD). The association between wide QRS‐T angles and inflammatory activation is however not fully understood.

Methods

1,094 study participants of both sexes, 50–64 years old, were included from a randomly selected population‐based cohort as a part of the Swedish CArdioPulmonary bioImage Study (SCAPIS) pilot study. Serum samples were analyzed for markers of inflammation, cardiac wall stress/injury, and the metabolic syndrome. Wide QRS‐T angles were defined using Frank vectorcardiography. Variables were analyzed through unsupervised principal component analysis (PCA) as well as Orthogonal Projections to Latent Structures (OPLS) modeling. In addition, a subset of study participants was analyzed in a post hoc matched group design.

Results

Wide QRS‐T angles correlated positively with markers of inflammation, cardiac wall stress/injury, the metabolic syndrome, and male sex in both PCA and OPLS models. In the matched post hoc analysis, participants with wide QRS‐T angles had significantly higher counts of white blood cells (WBC) and neutrophils in comparison with matched controls. WBC as well as the number of neutrophils, monocytes, basophils, eosinophils and levels of C‐reactive protein, IL‐1, IL‐4, IL‐6, TNF‐α, and NT‐pro‐BNP were also significantly higher in comparison with healthy controls.

Conclusions

Markers of inflammatory activation and cardiac injury/wall stress were significantly higher in the presence of wide QRS‐T angles. These results corroborate an association between abnormal electrophysiological function and inflammatory activation and may have implications for the prediction of SCD.

Inflammation as the Common Biological Link Between Depression and Cardiovascular Diseases: Can Carnosine Exert a Protective Role?

Several epidemiological studies have clearly shown the high co-morbidity between depression and Cardiovascular Diseases (CVD). Different studies have been conducted to identify the common pathophysiological events of these diseases such as the overactivation of the hypothalamic- pituitary-adrenal axis and, most importantly, the dysregulation of immune system which causes a chronic pro-inflammatory status. The biological link between depression, inflammation, and CVD can be related to high levels of pro-inflammatory cytokines, such as IL-1β, TNF-α, and IL-6, released by macrophages which play a central role in the pathophysiology of both depression and CVD. Pro-inflammatory cytokines interfere with many of the pathophysiological mechanisms relevant to depression by upregulating the rate-limiting enzymes in the metabolic pathway of tryptophan and altering serotonin metabolism. These cytokines also increase the risk to develop CVD, because activation of macrophages under this pro-inflammatory status is closely associated with endothelial dysfunction and oxidative stress, a preamble to atherosclerosis and atherothrombosis. Carnosine (β-alanyl-L-histidine) is an endogenous dipeptide which exerts a strong antiinflammatory activity on macrophages by suppressing reactive species and pro-inflammatory cytokines production and altering pro-inflammatory/anti-inflammatory macrophage polarization. This dipeptide exhibits antioxidant properties scavenging reactive species and preventing oxidative stress-induced pathologies such as CVD. In the present review we will discuss the role of oxidative stress and chronic inflammation as common pathophysiological events both in depression and CVD and the preclinical and clinical evidence on the protective effect of carnosine in both diseases as well as the therapeutic potential of this dipeptide in depressed patients with a high co-morbidity of cardiovascular diseases.

The role of implantable cardioverter-defibrillators and sudden cardiac death prevention: indications, device selection, and outcome

Multiple randomized multicentre clinical trials have established the role of the implantable cardioverter-defibrillator (ICD) as the mainstay in the treatment of ventricular tachyarrhythmias and sudden cardiac death (SCD) prevention. These trials have focused mainly on heart failure patients with advanced left ventricular dysfunction and were mostly conducted two decades ago, whereas a more recent trial has provided conflicting results. Therefore, much remains to be determined on how best to balance the identification of patients at high risk of SCD together with who would benefit most from ICD implantation in a contemporary setting. Implantable cardioverter-defibrillators have also evolved from the simple, defibrillation-only devices implanted surgically to more advanced technologies of multi-chamber devices, with physiologic bradycardic pacing, including cardiac resynchronization therapy, atrial and ventricular therapeutic pacing algorithms, and subcutaneous ICDs. These multiple options necessitate individualized approach to device selection and programming. This review will focus on the current knowledge on selection of patients for ICD treatment, device selection and programming, and future directions of implantable device therapy for SCD prevention.

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Sudden Cardiac Death (SCD) - risk stratification and prediction with molecular biomarkers

Sudden cardiac death (SCD) is a sudden, unexpected death that is caused by the loss of heart function. While SCD affects many patients suffering from coronary artery diseases (CAD) and heart failure (HF), a considerable number of SCD events occur in asymptomatic individuals. Certain risk factors for SCD have been identified and incorporated in different clinical scores, however, risk stratification using such algorithms is only useful for health management rather than for early detection and prediction of future SCD events in high-risk individuals. In this review, we discuss different molecular biomarkers that are used for early detection of SCD. This includes genetic biomarkers, where the majority of them are genomic variants for genes that encode for ion channels. Meanwhile, protein biomarkers often denote proteins that play roles in pathophysiological processes that lead to CAD and HF, notably (i) atherosclerosis that involves oxidative stress and inflammation, as well as (ii) cardiac tissue damage that involves neurohormonal and hemodynamic regulation and myocardial stress. Finally, we outline existing challenges and future directions including the use of OMICS strategy for biomarker discovery and the multimarker panels.

Inflammation-Nature's Way to Efficiently Respond to All Types of Challenges: Implications for Understanding and Managing "the Epidemic" of Chronic Diseases

Siloed or singular system approach to disease management is common practice, developing out of traditional medical school education. Textbooks of medicine describe a huge number of discrete diseases, usually in a systematic fashion following headings like etiology, pathology, investigations, differential diagnoses, and management. This approach suggests that the body has a multitude of ways to respond to harmful incidences. However, physiology and systems biology provide evidence that there is a simple mechanism behind this phenotypical variability. Regardless if an injury or change was caused by trauma, infection, non-communicable disease, autoimmune disorders, or stress, the typical physiological response is: an increase in blood supply to the area, an increase in white cells into the affected tissue, an increase in phagocytic activity to remove the offending agent, followed by a down-regulation of these mechanisms resulting in healing. The cascade of inflammation is the body's unique mechanism to maintain its integrity in response to macroscopic as well as microscopic injuries. We hypothesize that chronic disease development and progression are linked to uncontrolled or dysfunctional inflammation to injuries regardless of their nature, physical, environmental, or psychological. Thus, we aim to reframe the prevailing approach of management of individual diseases into a more integrated systemic approach of treating the "person as a whole," enhancing the patient experience, ability to a make necessary changes, and maximize overall health and well-being. The first part of the paper reviews the local immune cascades of pro- and anti-inflammatory regulation and the interconnected feedback loops with neural and psychological pathways. The second part emphasizes one of nature's principles at work-system design and efficiency. Continually overwhelming this finely tuned system will result in systemic inflammation allowing chronic diseases to emerge; the pathways of several common conditions are described in detail. The final part of the paper considers the implications of these understandings for clinical care and explore how this lens could shape the physician-patient encounter and health system redesign. We conclude that healthcare professionals must advocate for an anti-inflammatory lifestyle at the patient level as well as at the local and national levels to enhance population health and well-being.

Classical Risk Factors and Inflammatory Biomarkers: One of the Missing Biological Links between Cardiovascular Disease and Major Depressive Disorder

BACKGROUND

Cardiovascular disorders (CVD) and major depressive disorder (MDD) are the most frequent diseases worldwide responsible for premature death and disability. Behavioral and immunological variables influence the pathophysiology of both disorders. We therefore determined frequency and severity of MDD in CVD and studied whether MDD without CVD or other somatic diseases influences classical and inflammatory biomarkers of cardiovascular risk. In addition, we investigated the influence of proinflammatory cytokines on antidepressant treatment outcome.

METHODS

In a case-control design, 310 adults (MDD patients without CVD, CVD patients, and cardiologically and psychiatrically healthy matched controls) were investigated. MDD patients were recruited after admission in a psychiatric university hospital. Primary outcome criteria were clinical depression ratings (HAM-D scale), vital signs, classical cardiovascular risk factors and inflammatory biomarkers which were compared between MDD patients and healthy controls.

RESULTS

We detected an enhanced cardiovascular risk in MDD. Untreated prehypertension and signs directing to a metabolic syndrome were detected in MDD. Significantly higher inflammatory biomarkers such as the high sensitivity C-reaktive protein (hsCRP) and proinflammatory acute phase cytokines interleukine-1β (IL-1β) and interleukine-6 (IL-6) underlined the higher cardiovascular risk in physically healthy MDD patients. Surprisingly, high inflammation markers before treatment were associated with better clinical outcome and faster remission. The rate of MDD in CVD patients was high.

CONCLUSIONS

Patients suffering from MDD are at specific risk for CVD. Precise detection of cardiovascular risks in MDD beyond classical risk factors is warranted to allow effective prophylaxis and treatment of both conditions. Future studies of prophylactic interventions may help to provide a basis for prophylactic treatment of both MDD and CVD. In addition, the high risk for MDD in CVD patients was confirmed and underlines the requirement for clinical attention.

Systemic inflammation and arrhythmic risk: lessons from rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic immuno-mediated disease primarily affecting the joints, characterized by persistent high-grade systemic inflammation. Cardiovascular morbidity and mortality are significantly increased in RA, with >50% of premature deaths attributable to cardiovascular disease. In particular, RA patients were twice as likely to experience sudden cardiac death compared with non-RA subjects, pointing to an increased propensity to develop malignant ventricular arrhythmias. Indeed, ventricular repolarization (QT interval) abnormalities and cardiovascular autonomic nervous system dysfunction, representing two well-recognized risk factors for life-threatening ventricular arrhythmias in the general population, are commonly observed in RA. Moreover, large population-based studies seem to indicate that also the prevalence of atrial fibrillation is significantly higher in RA subjects than in the general population, thus suggesting that these patients are characterized by an abnormal diffuse myocardial electrical instability. Although the underlying mechanisms accounting for the pro-arrhythmogenic substrate in RA are probably intricate, the leading role seems to be played by chronic systemic inflammatory activation, able to promote arrhythmias both indirectly, by accelerating the development of ischaemic heart disease and congestive heart failure, and directly, by affecting cardiac electrophysiology. In this integrated mechanistic view, lowering the inflammatory burden through an increasingly tight control of disease activity may represent the most effective intervention to reduce arrhythmic risk in these patients. Intriguingly, these considerations could be more generally applicable to all the diseases characterized by chronic systemic inflammation, and could help elucidate the link between low-grade chronic inflammation and arrhythmic risk in the general population.

In women with PCOS, waist circumference is a better surrogate of glucose and lipid metabolism than disease status per se

OBJECTIVE

Cardiometabolic abnormalities are recognized in polycystic ovary syndrome (PCOS). However, over-emphasis on PCOS as a risk factor potentially results in over-investigation and treatment of some women with and under-recognition of cardiometabolic risk in obese women without PCOS. Our objective was to explore the association between waist circumference (WC) and indices of glucose and lipid metabolism in women with and without PCOS.

DESIGN, PATIENTS AND MEASUREMENTS

(i) An exploratory cross-sectional study investigating association of potential cardiometabolic risk markers (PCOS status, anthropometric measures, hsCRP, HOMA-IR, SHBG, testosterone) with indices of glucose (frequently sampled intravenous glucose tolerance test) and lipid metabolism (postprandial studies and lipoprotein particle size) in 61 women with (n = 29) and without (n = 32) PCOS; (ii) a cross-sectional study in 103 PCOS women and 102 BMI-matched controls to explore if between-group differences in indices of lipid and glucose metabolism persist after adjusting for WC. NIH criteria were used for PCOS diagnosis.

RESULTS

Study 1: Univariate correlations and stepwise regression modelling identified waist circumference (WC), as a better surrogate than PCOS status, independently predicting multiple variables of glucose and lipid metabolism. Study 2: Fasting insulin and triglyceride, hsCRP and insulin resistance (according to HOMA-IR and SiM [Avignon index]) were greater, while fasting HDL was lower in women with PCOS compared to BMI-matched women without PCOS. None of these differences persisted when a subset of 80 women with PCOS was compared with 80 women without PCOS, pair-matched for WC.

CONCLUSION

Some cardiometabolic abnormalities in PCOS are related to central obesity, and following adjustment for WC does not differ from normal subjects. Waist circumference measurement has potential to take precedence over PCOS status as part of the assessment of cardiometabolic risk in reproductive-age women.

Ischemia/reperfusion injury in male guinea pigs: An efficient model to investigate myocardial damage in cardiovascular complications

Myocardial ischemia/reperfusion (I/R) injury is the major problem that aggravates cardiac damage. Several established animal models fail to explain the similarity in disease mechanism and progression as seen in humans; whereas guinea pig shows high similarity in cardiovascular parameters. Hence, current study is aimed to develop an animal model using guinea pigs that may best correlate with disease mechanism of human myocardial I/R injury. Male guinea pigs were randomized into three groups: normal diet (ND), high fat diet (HFD) and sham; fed with respective diets for 90 days. Myocardial infarction (MI) was induced by ligating left anterior descending artery (LAD) for 30 min followed by 24 h and 7 days of reperfusion in ND and HFD groups. Electrocardiogram (ECG) showed the alterations in electrical conduction during myocardial I/R injury. Elevated levels of lactate dehydrogenase (LDH) and creatine kinase-MB ((CK-MB)) were higher in HFD compared to ND. Inflammatory markers such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were up-regulated in I/R injury animals compared to sham. Fold change of these protein expression levels were higher in HFD compared to ND. Elevated lipid profile and increased aortic wall thickness in HFD animals depicts the risk of developing cardiovascular complications. ECG analysis strongly confirmed MI through changes in sinus rhythm that are reflected in infarcted tissue as verified through TTC staining. Thus the combination of HFD followed by I/R injury proved to be an efficient model to study pathophysiology of myocardial I/R injury with minimal tissue damage and surgical mortality.

Inflammation following acute myocardial infarction: Multiple players, dynamic roles, and novel therapeutic opportunities

Acute myocardial infarction (AMI) and the heart failure that often follows, are major causes of death and disability worldwide. As such, new therapies are required to limit myocardial infarct (MI) size, prevent adverse left ventricular (LV) remodeling, and reduce the onset of heart failure following AMI. The inflammatory response to AMI, plays a critical role in determining MI size, and a persistent pro-inflammatory reaction can contribute to adverse post-MI LV remodeling, making inflammation an important therapeutic target for improving outcomes following AMI. In this article, we provide an overview of the multiple players (and their dynamic roles) involved in the complex inflammatory response to AMI and subsequent LV remodeling, and highlight future opportunities for targeting inflammation as a therapeutic strategy for limiting MI size, preventing adverse LV remodeling, and reducing heart failure in AMI patients.

Biomarkers to Predict Cardiovascular Death

This article reviews biomarkers that have been shown to identify subjects at increased risk for cardiovascular death within the general population, in those with established coronary artery disease, and in those with heart failure. Use of biomarkers for risk stratification for sudden cardiac death continues to evolve. It seems that a multimarker strategy for risk stratification using simple measures of circulating proteins and usual clinical risk factors, particularly in patients with known coronary artery disease, can be used to identify patients at near-term risk of death. Whether similar strategies in the general population will prove to be cost-effective needs to be investigated.

Resetting the Abnormal Circadian Cortisol Rhythm in Adrenal Incidentaloma Patients With Mild Autonomous Cortisol Secretion

CONTEXT

Adrenal incidentalomas (AIs) are found commonly on axial imaging. Around 30% exhibit autonomous cortisol secretion (ACS) associated with increased cardiovascular events and death.

OBJECTIVE

We hypothesized that AI/ACS patients have an abnormal cortisol rhythm that could be reversed by use of carefully timed short-acting cortisol synthesis blockade, with improvement in cardiovascular disease markers.

DESIGN, SETTING, AND PARTICIPANTS

In a phase 1/2a, prospective study (Eudract no. 2012-002586-35), we recruited six patients with AI/ACS and two control groups of six sex-, age-, and body mass index-matched individuals: (1) patients with AI and no ACS (AI/NoACS) and (2) healthy volunteers with no AI [healthy controls (HC)]. Twenty-four-hour circadian cortisol analysis was performed to determine any differences between groups and timing of intervention for cortisol lowering using the 11β-hydroxylase inhibitor metyrapone. Circadian profiles of serum interleukin-6 (IL-6) were assessed.

RESULTS

Serum cortisol levels in group AI/ACS were significantly higher than both group AI/NoACS and group HC from 6 pm to 10 pm [area under the curve (AUC) difference: 0.81 nmol/L/h; P = 0.01] and from 10 pm to 2 am (AUC difference: 0.86 nmol/L/h; P < 0.001). In light of these findings, patients with ACS received metyrapone 500 mg at 6 pm and 250 mg at 10 pm, and cortisol rhythms were reassessed. Postintervention evening serum cortisol was lowered, similar to controls [6 pm to 10 pm (AUC difference: -0.06 nmol/L/h; P = 0.85); 10 pm to 2 am (AUC difference: 0.10 nmol/L/h; P = 0.76)]. Salivary cortisone showed analogous changes. IL-6 levels were elevated before treatment [10 pm to 2 pm (AUC difference: 0.42 pg/mL/h; P = 0.01)] and normalized post treatment.

CONCLUSIONS

In AI/ACS, the evening and nocturnal cortisol exposure is increased. Use of timed evening doses of metyrapone resets the cortisol rhythm to normal. This unique treatment paradigm is associated with a reduction in the cardiovascular risk marker IL-6.

Long Term High Fat Diet Treatment: An Appropriate Approach to Study the Sex-Specificity of the Autonomic and Cardiovascular Responses to Obesity in Mice

Obesity-related cardiovascular disease (CVD) involves increased sympathetic activity in men and male animals. Although women exhibit increased visceral fat, metabolic disorders, inflammation and CVD with obesity, whether body weight gain affects autonomic control of cardiovascular function in females remain unknown. Due to the lack of adequate model to mimic the human pathology, this study aimed to develop a murine model, which would allow studying the sex-specificity of the response of the autonomic nervous system to obesity and identifying the origin of potential sex-differences. We tested the hypothesis that sexual dimorphisms in the autonomic response to obesity disappear in mice matched for changes in body weight, metabolic and inflammatory disorders. Male and female C57Bl/6 mice were submitted to control (CD) or high fat diet (HFD) for 24 weeks. Female mice gained more adipose mass and lost more lean mass than males but reached similar visceral adipose mass and body weight, as males, at the end of the diet. 24 weeks of HFD matched male and female mice for visceral adiposity, glycaemia, plasma insulin, lipids, and inflammatory cytokines levels, demonstrating the suitability of the model to study human pathology. HFD did not elevate BP, but similarly increased heart rate (HR) in males (CD: 571 ± 9 vs. HFD: 631 ± 14 bpm, P < 0.05) and females (CD: 589 ± 19 vs. HFD: 642 ± 6 bpm, P < 0.05). Indices of autonomic control of BP and HR were obtained by measuring BP and HR response to ganglionic blockade, β-adrenergic, and muscarinic receptors antagonists. HFD increased vascular but reduced cardiac sympathetic drive in males (CD: -43 ± 4 and HFD: -60 ± 7% drop in BP, P < 0.05). HFD did not alter females' vascular or cardiac sympathetic drive. HFD specifically reduced aortic α-adrenergic constriction in males and lowered HR response to muscarinic receptor antagonism in females. These data suggest that obesity-associated increases in HR could be caused by a reduced cardiac vagal tone in females, while HR increases in males may compensate for the reduced vascular adrenergic contractility to preserve baseline BP. These data suggest that obesity impairs autonomic control of cardiovascular function in males and females, via sex-specific mechanisms and independent of fat distribution, metabolic disorder or inflammation.

Iron participated in breast cancer chemoresistance by reinforcing IL-6 paracrine loop

Chemotherapeutic efficacy is also regulated by the tumor microenvironment. IL-6 produced by TAMs and downstream IL-6/STAT3 signaling pathway is central regulator in chemotherapeutic response. The M2-like phenotype of TAMs is characterized by elevated iron uptake. Whether iron participates in chemo-resistance need to be elucidated. In the present study, we found that IL-6 participated in breast cancer chemoresistance. Local IL-6 paracrine loop acted as exogenous IL-6 rich niche for chemo-sensitive breast cancer cells, leading to de novo acquired drug resistance. Furthermore, Iron reinforced the IL-6 paracrine loop between TAMs and tumor cells resulting in enhanced chemo-resistance. Targeting iron metabolism could disturb the reciprocal interaction between tumor cells and TAMs, breaking the local IL-6 rich niche and blocking IL-6 signaling pathway, which could be promising strategy to overcome chemo-resistance.

Reduced acute myocardial ischemia-reperfusion injury in IL-6-deficient mice employing a closed-chest model

Objective and design

We examined the role of IL-6 in the temporal development of cardiac ischemia–reperfusion injury employing a closed-chest I/R model.

Materials/methods

Infarction, local and systemic inflammation, neutrophil infiltration, coagulation and ST elevation/resolution were compared between wild-type (WT) and IL-6-deficient (IL-6^−/−) mice after 1 h ischemia and 0, ½, 3, and 24 h reperfusion.

Results

IL-6 deficiency reduced infarct size at 3 h reperfusion (28.8 ± 4.5 % WT vs 17.6 ± 2.5 % IL-6^−/−), which reduction persisted and remained similar at 24 h reperfusion (25.1 ± 3.0 % WT vs 14.6 ± 4.4 % IL-6^−/−). Serum Amyloid A was reduced at 24 h reperfusion only (57.5 ± 4.9 WT vs 24.8 ± 5.6 ug/ml IL-6^−/− mice). Cardiac cytokines (IL-6, IL-1β and TNFα) peaked at 3 h reperfusion, but IL-1β and TNFα levels were unaffected by IL-6 deficiency. Significant neutrophil influx was only detected at 24 h reperfusion and was similar for WT and IL-6^−/−. Tissue factor peaked at 24 h reperfusion, whereas fibrin/fibrinogen peaked at 3 h reperfusion and was completely resolved at 24 h reperfusion; both coagulation factors were unaltered by IL-6 deficiency. Prolonged ST elevation was observed during ischemia that completely resolved for both genotypes at early reperfusion.

Conclusions

The data suggest that, in the absence of major surgical intervention, IL-6 contributes to the development of infarct size in the early phase of reperfusion; this contribution did not depend on neutrophil influx, IL-1β and TNFα, tissue factor and fibrin.

Expression of Tumor-Related Macrophages and Cytokines After Surgery of Triple-Negative Breast Cancer Patients and its Implications

Background

Triple-negative breast cancer (TNBC) has negative expression of progesterone receptor (PR) and estrogen receptor (ER), and low expression of human epithelial growth factor receptor-2 (HER-2). This study aimed to investigate the expressional profile of cytokines in TNBC patients with significant expression of macrophages.

Material/Methods

Immunohistochemical (IHC) S-P staining method was used to detect the tumor-associated macrophages (TAMs) marker CD68 expression in 48 cases of TNBC samples. The correlation between CD68 expression and prognosis was analyzed. Expressions of key cytokines – interleukin-6 (IL-6), IL-10, IL-12, IL-1β, chemokine (C-C motif) ligand-5 (CCL-5), and macrophage inflammatory protein-2 (MIP-2) – were quantified by RT-PCR and enzyme-linked immunosorbent assay (ELISA).

Results

Thirty-four out of 48 TNBC samples (71.4%) had CD68-positive expression. IL-6 and CCL-5 were up-regulated in high-infiltrated tumors when compared to low-infiltrated samples. Other cytokines had no significant difference regarding the expression level across groups.

Conclusions

TAMs were up-regulated in most TNBC patients after the surgery. Its expression suggested unfavorable prognosis, especially in the high-infiltrated group. Those tumors with more macrophage also had elevated expression of cytokine IL-6 and chemotactic factor CCL-5, both of which have potency to be clinical index and drug target for TNBC.

Sudden Cardiac Death Risk Stratification - An Update

Sudden cardiac death (SCD) remains a major public health problem worldwide, yet current methods to identify those at greatest risk are inadequate. High-risk individuals may benefit from potentially life-saving treatment, such as insertion of an implantable-cardioverter defibrillator (ICD). However, such treatments are expensive and have their own associated risks. Furthermore, most cases of SCD occur in the general adult population who may be relatively asymptomatic but yet have an underlying predisposition to SCD. Hence, there is great interest and clinical need in improving methods for risk stratification of SCD to identify those at greatest risk and implement the most appropriate treatment. This review provides an update on current risk-stratification methods for SCD in high-risk groups, in particular patients with reduced left ventricular function following acute myocardial infarction and those with non-ischaemic dilated cardiomyopathy, and highlights some novel methods that may have a role to play in future risk-stratification schemes. Approaches and challenges for SCD risk stratification among the general public are also discussed.

Sudden cardiac death risk stratification

Arrhythmic sudden cardiac death (SCD) may be caused by ventricular tachycardia/fibrillation or pulseless electric activity/asystole. Effective risk stratification to identify patients at risk of arrhythmic SCD is essential for targeting our healthcare and research resources to tackle this important public health issue. Although our understanding of SCD because of pulseless electric activity/asystole is growing, the overwhelming majority of research in risk stratification has focused on SCD-ventricular tachycardia/ventricular fibrillation. This review focuses on existing and novel risk stratification tools for SCD-ventricular tachycardia/ventricular fibrillation. For patients with left ventricular dysfunction or myocardial infarction, advances in imaging, measures of cardiac autonomic function, and measures of repolarization have shown considerable promise in refining risk. Yet the majority of SCD-ventricular tachycardia/ventricular fibrillation occurs in patients without known cardiac disease. Biomarkers and novel imaging techniques may provide further risk stratification in the general population beyond traditional risk stratification for coronary artery disease alone. Despite these advances, significant challenges in risk stratification remain that must be overcome before a meaningful impact on SCD can be realized.

Prerace aspirin to protect susceptible runners from cardiac arrest during marathons: is opportunity knocking?

While endurance exercise such as marathon training is cardioprotective, an increasing frequency of race-related cardiac arrests and sudden death has been observed in middle-aged men since the year 2000. An evidence-based strategy for prevention is considered based on identifying atherothrombosis as the underlying cause in this susceptible subgroup. Review of all articles on PubMed related to acute cardiac events during marathons. Male gender and the marathon compared with the half-marathon were identified as significant risk factors for race-related cardiac arrests, which events increased 2.3-fold in the latter half of a 10-year prospective registry beginning in the year 2000. There were 50 cardiac arrests in runners who were 86% male with a mean age of 42 years. The main cause of sudden death was atherosclerotic heart disease in those over the age of 40 including myocardial infarction in 12 of 13 (93%) cases over the age of 45 as assessed retrospectively. Inflammatory biomarkers predicting acute cardiac events and hypercoagulability with in vivo platelet activation were demonstrated in same-aged asymptomatic middle-aged men during marathons. Excess cardiac morbidity and mortality in middle-aged men during marathons is mediated by atherothrombosis which may render non-obstructive coronary atherosclerotic plaques vulnerable to rupture. Prerace low-dose aspirin usage is prudent to protect susceptible runners from a high, if transient, risk for cardiac arrest during races as evidence-based to prevent first myocardial infarctions in same-aged healthy men.

Decreased prevalence of cardiac arrhythmias during and after vigorous and prolonged exercise in healthy male marathon runners

BACKGROUND

Vigorous exercise such as marathon running results in an increased risk of sudden cardiac death. Malignant arrhythmias seem to be the primary cause. However, continuous electrocardiographic monitoring for detection of arrhythmias during a marathon race has not been performed yet.

METHODS

Twenty male marathon runners (age 45 ± 8 years) free of cardiovascular disease underwent 24-hour Holter monitoring 5 weeks before a marathon race (baseline). Subsequently, wireless Holter monitoring started immediately before the race, recorded up to 70 hours postrace. Electrocardiograms were analyzed for the presence of arrhythmias. Additionally, cardiac troponin, interleukin-6 (IL-6), and electrolytes were assessed prerace and postrace.

RESULTS

At baseline Holter recordings, runners showed a median of 9 (interquartile range 3-25) atrial premature complexes (APCs) and 4 (2-16) ventricular premature complexes (VPCs) per 100,000 beats. Compared to baseline, the number of APCs decreased significantly during and 1 hour after the marathon race (0 [0-3] and 0 [0-0], all P < .001) as well as the number of VPCs during the race (0 [0-0], P = .008). No malignant arrhythmias occurred. Mean postrace levels for troponin and IL-6 were significantly augmented after the race (prerace to postrace: troponin 4 times, IL-6 17 times, all P < .001); however, no significant influence of these biomarkers or electrolytes on the prevalence of arrhythmias was observed (all P > .05).

CONCLUSIONS

In this cohort of male runners free of cardiovascular disease, the prevalence of arrhythmias during and after a marathon race was decreased. Arrhythmogenic risk was independent of changes in biomarkers assessing cardiac injury, inflammation, and changes in electrolytes.

Biomarkers in electrophysiology: role in arrhythmias and resynchronization therapy

Circulating biomarkers related to inflammation, neurohormones, myocardial stress, and necrosis have been associated with commonly encountered arrhythmic disorders such as atrial fibrillation (AF) and more malignant processes including ventricular arrhythmias (VA) and sudden cardiac death (SCD). Both direct and indirect biomarkers implicated in the heart failure cascade have potential prognostic value in patients undergoing cardiac resynchronization therapy (CRT). This review will focus on the role of biomarkers in AF, history of SCD, and CRT with an emphasis to improve clinical risk assessment for arrhythmias and patient selection for device therapy. Notably, information obtained from biomarkers may supplement traditional diagnostic and imaging techniques, thus providing an additional benefit in the management of patients.

[High sensitivity C protein as an independent risk factor in people with and without history of cardiovascular disease]

Among the new cardiovascular event (CVE) risk biomarkers, C-reactive protein detected using high sensitive techniques (hs-CRP) has been one of the most commonly evaluated. In this review, the available evidence on the usefulness of hs-CRP was explored as an independent risk event factor in subjects with no cardiovascular history and as prognosis in case of chronic or acute cardiovascular condition. An overview (revision of revisions) was carried out searching in the main bibliographic databases and in other general Internet search engines. During the first stage, systematic reviews, clinical practice guidelines, health technology assessments and coverage policies were found and, during the second stage primary studies published after the systematic review search dates were added. Seven hundred and seventy four quotes were found, including 36 papers assessing the role of hs-CRP in healthy populations or with cardiovascular history. High quality evidence was found pointing out hs-CRP, both as risk factor in the general population and as prognostic factor in those with CVE, in all the populations assessed. It was most useful in subjects with a history of CVE and intermediate risk of events at 10 years; where adding hs-CRP to the classical models for event risk estimation improves risk staging. There was no consensus on its clinical usefulness as a prognostic marker in subjects with chronic or acute disease.