Sympathetic nervous system activation and heart failure: Current state of evidence and the pathophysiology in the light of novel biomarkers

Enhanced central sympathetic tone induces heart failure with preserved ejection fraction (HFpEF) in rats

Heart failure with preserved ejection fraction (HFpEF) is a heterogenous clinical syndrome characterized by diastolic dysfunction, concentric cardiac left ventricular (LV) hypertrophy, and myocardial fibrosis with preserved systolic function. However, the underlying mechanisms of HFpEF are not clear. We hypothesize that an enhanced central sympathetic drive is sufficient to induce LV dysfunction and HFpEF in rats. Male Sprague-Dawley rats were subjected to central infusion of either saline controls (saline) or angiotensin II (Ang II, 20 ng/min, i.c.v) via osmotic mini-pumps for 14 days to elicit enhanced sympathetic drive. Echocardiography and invasive cardiac catheterization were used to measure systolic and diastolic functions. Mean arterial pressure, heart rate, left ventricular end-diastolic pressure (LVEDP), and ± dP/dt changes in responses to isoproterenol (0.5 μg/kg, iv) were measured. Central infusion of Ang II resulted in increased sympatho-excitation with a consequent increase in blood pressure. Although the ejection fraction was comparable between the groups, there was a decrease in the E/A ratio (saline: 1.5 ± 0.2 vs Ang II: 1.2 ± 0.1). LVEDP was significantly increased in the Ang II-treated group (saline: 1.8 ± 0.2 vs Ang II: 4.6 ± 0.5). The increase in +dP/dt to isoproterenol was not significantly different between the groups, but the response in -dP/dt was significantly lower in Ang II-infused rats (saline: 11,765 ± 708 mmHg/s vs Ang II: 8,581 ± 661). Ang II-infused rats demonstrated an increased heart to body weight ratio, cardiomyocyte hypertrophy, and fibrosis. There were elevated levels of atrial natriuretic peptide and interleukin-6 in the Ang II-infused group. In conclusion, central infusion of Ang II in rats induces sympatho-excitation with concurrent diastolic dysfunction, pathological cardiac concentric hypertrophy, and cardiac fibrosis. This novel model of centrally mediated sympatho-excitation demonstrates characteristic diastolic dysfunction in rats, representing a potentially useful preclinical murine model of HFpEF to investigate various altered underlying mechanisms during HFpEF in future studies.

Combination Electroacupuncture and Guidelines Directed Medical Therapy Maintained Stability of Heart Rate and Mean Arterial Pressure in Heart Failure with Reduced Ejection Fraction

Background

Clinical studies have shown that electroacupuncture (EA) has therapeutic and modulatory effects on managing heart failure (HF) risk factors.

Objective

This study aimed to determine the impact of combination drugs and EA on chronic HF patients with reduced ejection fraction (HFrEF) to maintain a stable heart rate (HR) and mean arterial pressure (MAP).

Materials and Methods

This single-blind clinical randomized controlled trial included 42 patients with chronic HFrEF. The patients were divided into 3 groups: patients taking drugs and EA, patients taking drugs and sham EA (sham acupuncture [SA]), and patients taking drugs without EA. All patients underwent 16 sessions of therapy for 8 weeks.

Results

There was a significant difference in the average MAP based on therapy duration in the drugs + EA group, whereas there was no significant difference between drugs + SA and drugs without EA groups. There was a substantial difference between the average MAP in the drugs + EA group at the beginning of therapy compared with that at midtherapy (P < 0.05) and at the beginning of treatment and at the end of therapy (P < 0.05). There was no significant difference in the mean HR between the groups. Clinically, after 16 treatment sessions, patients receiving combined drugs and EA treatment presented with stable MAP and HR.

Conclusions

Drugs combined with EA maintained the stability of MAP and HR in patients with chronic HFrEF.

Heart failure management guided by remote multiparameter monitoring: A meta-analysis

BACKGROUND

Several implant-based remote monitoring strategies are currently tested to optimize heart failure (HF) management by anticipating clinical decompensation and preventing hospitalization. Among these solutions, the modern implantable cardioverter-defibrillator and cardiac resynchronization therapy devices have been equipped with sensors allowing continuous monitoring of multiple preclinical markers of worsening HF, including factors of autonomic adaptation, patient activity, and intrathoracic impedance.

OBJECTIVES

We aimed to assess whether implant-based multiparameter remote monitoring strategy for guided HF management improves clinical outcomes when compared to standard clinical care.

METHODS

A systematic literature research for randomized controlled trials (RCTs) comparing multiparameter-guided HF management versus standard of care was performed on PubMed, Embase, and CENTRAL databases. Incidence rate ratios (IRRs) and associated 95% confidence intervals (CIs) were calculated using the Poisson regression model with random study effects. The primary outcome was a composite of all-cause death and HF hospitalization events, whereas secondary endpoints included the individual components of the primary outcome.

RESULTS

Our meta-analysis included 6 RCTs, amounting to a total of 4869 patients with an average follow-up time of 18 months. Compared with standard clinical management, the multiparameter-guided strategy reduced the risk of the primary composite outcome (IRR 0.83, 95%CI 0.71-0.99), driven by statistically significant effect on both HF hospitalization events (IRR 0.75, 95%CI 0.61-0.93) and all-cause death (IRR 0.80, 95%CI 0.66-0.96).

CONCLUSION

Implant-based multiparameter remote monitoring strategy for guided HF management is associated with significant benefit on clinical outcomes compared to standard clinical care, providing a benefit on both hospitalization events and all-cause death.

The Importance of Optimal Hydration in Patients with Heart Failure-Not Always Too Much Fluid

Heart failure (HF) is a leading cause of morbidity and mortality and a major public health problem. Both overhydration and dehydration are non-physiological states of the body that can adversely affect human health. Congestion and residual congestion are common in patients hospitalized for HF and are associated with poor prognosis and high rates of rehospitalization. However, the clinical problem of dehydration is also prevalent in healthcare and community settings and is associated with increased morbidity and mortality. This article provides a comprehensive review of the issue of congestion and dehydration in HF, including HF guidelines, possible causes of dehydration in HF, confirmed and potential new diagnostic methods. In particular, a full database search on the relationship between dehydration and HF was performed and all available evidence in the literature was reviewed. The novel hypothesis of chronic subclinical hypohydration as a modifiable risk factor for HF is also discussed. It is concluded that maintaining euvolemia is the cornerstone of HF management. Physicians have to find a balance between decongestion therapy and the risk of dehydration.

A Serious Game to Self-Regulate Heart Rate Variability as a Technique to Manage Arousal Level Through Cardiorespiratory Biofeedback: Development and Pilot Evaluation Study

BACKGROUND

Heart rate variability biofeedback (HRVB) is an established intervention for increasing heart rate variability (HRV) in the clinical context. Using this technique, participants become aware of their HRV through real-time feedback and can self-regulate it.

OBJECTIVE

The aim of this study was 2-fold: first, to develop a serious game that applies the HRVB technique to teach participants to self-regulate HRV and, second, to test the app with participants in a pilot study.

METHODS

An HRVB app called the FitLab Game was developed for this study. To play the game, users must move the main character up and down the screen, avoiding collisions with obstacles. The wavelength that users must follow to avoid these obstacles is based on the user's basal heart rate and changes in instantaneous heart rate. To test the FitLab Game, a total of 16 participants (mean age 23, SD 0.69 years) were divided into a control group (n=8) and an experimental group (n=8). A 2 × 2 factorial design was used in each session. Participants in the experimental condition were trained in breathing techniques.

RESULTS

Changes in the frequency and time domain parameters of HRV and the game's performance features were evaluated. Significant changes in the average RR intervals and root mean square of differences between adjacent RR intervals (RMSSD) were found between the groups (P=.02 and P=.04, respectively). Regarding performance, both groups showed a tendency to increase the evaluated outcomes from baseline to the test condition.

CONCLUSIONS

The results may indicate that playing different levels leads to an improvement in the game's final score by repeated training. The tendency of changes in HRV may reflect a higher activation of the mental system of attention and control in the experimental group versus the control group. In this context, learning simple, voluntary strategies through a serious game can aid the improvement of self-control and arousal management. The FitLab Game appears to be a promising serious game owing to its ease of use, high engagement, and enjoyability provided by the instantaneous feedback.

Short-Term Mortality Associated With Hypertensive Emergencies: A Prospective Observational Cohort Study From South India

Background and aims Hypertensive emergencies are caused by acutely occurring massive elevations in blood pressure with features suggestive of acute end-organ damage and are a common complication of hypertension. About 1-2% of all patients with hypertension develop this complication in their lifetime. This study was undertaken to assess short-term outcomes associated with hypertensive emergencies in a tertiary care center. Methods We conducted a prospective cohort study and recruited 66 consenting adults with a hypertensive emergency. Sociodemographic details, clinical characteristics, blood pressure readings at different intervals, in-hospital course, and diagnosis of end-organ damage were recorded. The in-hospital outcome was noted as dead or alive. After four weeks, patients were followed up through telephonic interviews and the patient's status was then reviewed and recorded. Multiple logistic regression determined the predictors of death. Data were analyzed in SPSS version 26.0 (IBM Corp., Armonk, NY, USA). Results A total of 66 patients were enrolled, with a mean age of 54.57 (±38.18) years and a male predominance of 44 (66.35%) patients. The majority of patients were known hypertensives (n=55, 83.35%). Of the known hypertensives, 41 (74.54%) patients had discontinued their anti-hypertensive medications prior to admission. The median duration of hospitalization was 10 (7-14) days. The most common presenting complaints were dyspnea (n=35, 53.03%), pedal edema (n=29, 43.94%) and headache (n=25, 37.87%). Forty-one (62.12%) patients required ICU care, and 39 (59.09%) required ventilator support. The most common end-organ damage was acute-on-chronic kidney disease (n=21, 31.81%). The short-term mortality documented at the end of one month was 24 (36.36%). Of these, seven (10.6%) patients died in the hospital, and 17 (25.75) patients died within one month of getting discharged from the hospital. The factors that were associated with high mortality were newly-diagnosed hypertension and in-hospital hypotension. Conclusion We found high mortality associated with hypertensive emergencies. At one month follow-up, we found that more than one-third of the patients had died. Post-hospitalisation mortality was higher than in-hospital mortality. Most patients had discontinued their anti-hypertensive medication before admission. The most frequently encountered end-organ damage was acute-on-chronic kidney disease. The factors associated with high mortality were newly-diagnosed hypertension and in-hospital hypotension.

Infection as an under-recognized precipitant of acute heart failure: prognostic and therapeutic implications

As the prevalence of heart failure (HF) continues to rise, prompt diagnosis and management of various medical conditions, which may lead to HF exacerbation and result in poor patient outcomes, are of paramount importance. Infection has been identified as a common, though under-recognized, precipitating factor of acute heart failure (AHF), which can cause rapid development or deterioration of HF signs and symptoms. Available evidence indicates that infection-related hospitalizations of patients with AHF are associated with higher mortality, protracted length of stay, and increased readmission rates. Understanding the intricate interaction of both clinical entities may provide further therapeutic strategies to prevent the occurrence of cardiac complications and improve prognosis of patients with AHF triggered by infection. The purpose of this review is to investigate the incidence of infection as a causative factor in AHF, explore its prognostic implications, elucidate the underlying pathophysiological mechanisms, and highlight the basic principles of the initial diagnostic and therapeutic interventions in the emergency department.

Comparison of Hemodynamic Response between Patients with Systolic Heart Failure Differing in Serum Aldosterone Concentrations during and after a 6-Minute Walk Test

Aldosterone regulates hemodynamics, including blood pressure (BP), and is involved in the development and progression of cardiovascular diseases, including systolic heart failure (HF). While exercise intolerance is typical for HF, neither BP nor heart rate (HR) have specific characteristics in HF patients. This study compares BP and HR profiles during and after standardized exercise between patients with systolic HF with either lower or higher aldosterone concentrations. We measured BP and HR in 306 ambulatory adults with systolic HF (left ventricular ejection fraction (LVEF) <50%) during and after a 6 min walk test (6MWT). All patients underwent a resting transthoracic echocardiography, and venous blood samples were collected for biochemical analyses. The patients were also divided into tertiles of serum aldosterone concentration: T1 (<106 pg/mL), T2 (106 and 263 pg/mL) and T3 (>263 pg/mL), respectively. Individuals from T1 and T2 were combined into T1-T2 as the reference group for comparisons with patients from T3. The individuals from T3 had significantly lower systolic, mean and diastolic BPs at rest, at the end and at 1 and 3 min post-6MWT recovery, as well as a more dilated left atrium and right ventricle alongside a higher concentration of N-terminal pro-B-type natriuretic peptide (NT-proBNP). Higher serum aldosterone concentration in HF patients with an LVEF < 50% is associated with a lower 6MWT BP but not an HR profile.

Autonomic Function Recovery and Physical Activity Levels in Post-COVID-19 Young Adults after Immunization: An Observational Follow-Up Case-Control Study

Coronavirus disease 2019 (COVID-19) has detrimental multi-system consequences. Symptoms may appear during the acute phase of infection, but the literature on long-term recovery of young adults after mild to moderate infection is lacking. Heart rate variability (HRV) allows for the observation of autonomic nervous system (ANS) modulation post-SARS-CoV-2 infection. Since physical activity (PA) can help improve ANS modulation, investigating factors that can influence HRV outcomes after COVID-19 is essential to advancements in care and intervention strategies. Clinicians may use this research to aid in the development of non-medication interventions. At baseline, 18 control (CT) and 20 post-COVID-19 (PCOV) participants were observed where general anamnesis was performed, followed by HRV and PA assessment. Thus, 10 CT and 7 PCOV subjects returned for follow-up (FU) evaluation 6 weeks after complete immunization (two doses) and assessments were repeated. Over the follow-up period, a decrease in sympathetic (SNS) activity (mean heart rate: p = 0.0024, CI = -24.67--3.26; SNS index: p = 0.0068, CI = -2.50--0.32) and increase in parasympathetic (PNS) activity (mean RR: p = 0.0097, CI = 33.72-225.51; PNS index: p = 0.0091, CI = -0.20-1.47) were observed. At follow-up, HRV was not different between groups (p > 0.05). Additionally, no differences were observed in PA between moments and groups. This study provides evidence of ANS recovery after SARS-CoV-2 insult in young adults over a follow-up period, independent of changes in PA.

Relationship between haemodynamic indicators and haemogram in patients with heart failure

AIMS

Pulmonary congestion, reduced cardiac output, neurohumoral factor activation, and decreased renal function associated with decreased cardiac function may have various effects on haemograms. The relationship between these factors and haemograms in patients with heart failure has not been sufficiently investigated. Recently, it was suggested that the lungs are an important site for platelet (Plt) biosynthesis and that it is necessary to study the relationship between pulmonary congestion and Plt count in heart failure in detail. In this study, we examined the relationship between various haemodynamic indicators and haemograms in detail using statistical analyses.

METHODS AND RESULTS

A total of 345 patients who underwent cardiac catheterization for the evaluation of cardiac function between 1 January 2015 and 31 December 2020 were included in the study. Haemodynamic indices, including left ventricular end-diastolic pressure (LVEDP) and cardiac index (CI), were measured. Plasma noradrenaline (Nor) concentration, estimated glomerular filtration rate (eGFR), white blood cell (WBC) count, haemoglobin (Hb) level, and Plt count were measured using blood samples collected at the same time. Structural equation modelling (SEM) was used to examine the relationship between LVEDP, CI, plasma Nor concentration, eGFR, WBC count, Hb level, and Plt count. Bayesian inference using SEM was performed for Plt count. A total of 345 patients (mean age: 66.0 ± 13.2 years) were included in this study, and 251 (73%) patients were men. After simple and multiple regression analyses, path diagrams were drawn and analysed using SEM. LVEDP showed a significant negative relationship with Plt count (standardized estimate: -0.129, P = 0.015), and CI showed a significant negative relationship with Hb level (standardized estimate: -0.263, P < 0.001). Plasma Nor concentration showed a significant positive relationship with WBC count (standardized estimate: 0.165, P = 0.003) and Plt count (standardized estimate: 0.198, P < 0.001). The eGFR had a significant positive relationship with Hb level (standardized estimate: 0.274, P < 0.001). Bayesian inference using SEM revealed no relationship between LVEDP and Hb level or WBC count but a significant negative relationship between LVEDP and Plt count.

CONCLUSIONS

LVEDP, CI, plasma Nor concentration, and eGFR were related to WBC count, Hb level, and Plt count in patients with heart failure. There was a strong relationship between elevated LVEDP and decreased Plt count, suggesting that pressure overload on the lungs may interfere with the function of the lung as a site of Plt biosynthesis.

Advances in congestive heart failure biomarkers

Congestive heart failure (CHF) is the leading cause of morbidity and mortality in the elderly worldwide. Although many biomarkers associated with in heart failure, these are generally prognostic and identify patients with moderate and severe disease. Unfortunately, the role of biomarkers in decision making for early and advanced heart failure remains largely unexplored. Previous studies suggest the natriuretic peptides have the potential to improve the diagnosis of heart failure, but they still have significant limitations related to cut-off values. Although some promising cardiac biomarkers have emerged, comprehensive data from large cohort studies is lacking. The utility of multiple biomarkers that reflect various pathophysiologic pathways are increasingly being explored in heart failure risk stratification and to diagnose disease conditions promptly and accurately. MicroRNAs serve as mediators and/or regulators of renin-angiotensin-induced cardiac remodeling by directly targeting enzymes, receptors and signaling molecules. The role of miRNA in HF diagnosis is a promising area of research and further exploration may offer both diagnostic and prognostic applications and phenotype-specific targets. In this review, we provide insight into the classification of different biochemical and molecular markers associated with CHF, examine clinical usefulness in CHF and highlight the most clinically relevant.

Stellate Ganglia and Cardiac Sympathetic Overactivation in Heart Failure

Heart failure (HF) is a major public health problem worldwide, especially coronary heart disease (myocardial infarction)-induced HF with reduced ejection fraction (HFrEF), which accounts for over 50% of all HF cases. An estimated 6 million American adults have HF. As a major feature of HF, cardiac sympathetic overactivation triggers arrhythmias and sudden cardiac death, which accounts for nearly 50–60% of mortality in HF patients. Regulation of cardiac sympathetic activation is highly integrated by the regulatory circuitry at multiple levels, including afferent, central, and efferent components of the sympathetic nervous system. Much evidence, from other investigators and us, has confirmed the afferent and central neural mechanisms causing sympathoexcitation in HF. The stellate ganglion is a peripheral sympathetic ganglion formed by the fusion of the 7th cervical and 1st thoracic sympathetic ganglion. As the efferent component of the sympathetic nervous system, cardiac postganglionic sympathetic neurons located in stellate ganglia provide local neural coordination independent of higher brain centers. Structural and functional impairments of cardiac postganglionic sympathetic neurons can be involved in cardiac sympathetic overactivation in HF because normally, many effects of the cardiac sympathetic nervous system on cardiac function are mediated via neurotransmitters (e.g., norepinephrine) released from cardiac postganglionic sympathetic neurons innervating the heart. This review provides an overview of cardiac sympathetic remodeling in stellate ganglia and potential mechanisms and the role of cardiac sympathetic remodeling in cardiac sympathetic overactivation and arrhythmias in HF. Targeting cardiac sympathetic remodeling in stellate ganglia could be a therapeutic strategy against malignant cardiac arrhythmias in HF.

Analysis of endogenous metabolites using multifunctional derivatization and capillary RPLC-MS

Heterogeneity in metabolite structure and charge state complicates their analysis in electrospray mass spectrometry (ESI-MS). Complications such as diminished signal response and quantitation can be reduced by sequential dual-stage derivatization and capillary RP LC-ESI-MS analysis. Our sequential dual-stage chemical derivatization reacts analyte primary amine and hydroxyl groups with a linear acyl chloride head containing a tertiary amine moiety. Analyte carboxylate groups are then coupled to a linear amine tag with a tertiary amine moiety. This increase in the number of tags on analytes increases analyte proton affinity and hydrophobicity. We derivatized 250 metabolite standards which on average improved signal to noise by >44-fold, with an average limit of detection of 66 nM and R² of 0.98. This system detected 107 metabolites from 18 BAECs, 111 metabolites from human urine, and 153 from human serum based on retention time, exact mass, and MS/MS matches from a derivatized standard library. As a proof of concept, aortic endothelial cells were treated with epinephrine and analyzed by the dual-stage derivatization. We observed changes in 32 metabolites with many increases related to energy metabolism, specifically in the TCA cycle. A decrease in lactate levels and corresponding increase in pyruvate levels suggest that epinephrine causes a movement away from glycolytic reliance on energy and a shift towards the more efficient TCA respiration for increasing energy.

Suppression of Cardiogenic Edema with Sodium-Glucose Cotransporter-2 Inhibitors in Heart Failure with Reduced Ejection Fraction: Mechanisms and Insights from Pre-Clinical Studies

In heart failure with reduced ejection fraction (HFrEF), cardiogenic edema develops from impaired cardiac function, pathological remodeling, chronic inflammation, endothelial dysfunction, neurohormonal activation, and altered nitric oxide-related pathways. Pre-clinical HFrEF studies have shown that treatment with sodium-glucose cotransporter-2 inhibitors (SGLT-2i) stimulates natriuretic and osmotic/diuretic effects, improves overall cardiac function, attenuates maladaptive cardiac remodeling, and reduces chronic inflammation, oxidative stress, and endothelial dysfunction. Here, we review the mechanisms and effects of SGLT-2i therapy on cardiogenic edema in various models of HFrEF. Overall, the data presented suggest a high translational importance of these studies, and pre-clinical studies show that SGLT-2i therapy has a marked effect on suppressing the progression of HFrEF through multiple mechanisms, including those that affect the development of cardiogenic edema.

Integrative physiological study of adaptations induced by aerobic physical training in hypertensive hearts

Aerobic physical training reduces arterial pressure in patients with hypertension owing to integrative systemic adaptations. One of the key factors is the decrease in cardiac sympathetic influence. Thus, we hypothesized that among other causes, cardiac sympathetic influence reduction might be associated with intrinsic cardiac adaptations that provide greater efficiency. Therefore, 14 spontaneously hypertensive rats (SHR group) and 14 normotensive Wistar Kyoto rats (WKY group) were used in this study. Half of the rats in each group were trained to swim for 12 weeks. All animals underwent the following experimental protocols: double blockade of cardiac autonomic receptors with atropine and propranolol; echocardiography; and analysis of coronary bed reactivity and left ventricle contractility using the Langendorff technique. The untrained SHR group had a higher sympathetic tone, cardiac hypertrophy, and reduced ejection fraction compared with the untrained WKY group. In addition, reduced coronary bed reactivity due to increased flow, and less ventricular contractile response to dobutamine and salbutamol administration were observed. The trained SHR group showed fewer differences in echocardiographic parameters as the untrained SHR group. However, the trained SHR group showed a reduction in the cardiac sympathetic influence, greater coronary bed reactivity, and increased left intraventricular pressure. In conclusion, aerobic physical training seems to reduce cardiac sympathetic influence and increase contractile strength in SHR rats, besides the minimal effects on cardiac morphology. This reduction suggests intrinsic cardiac adaptations resulting in beneficial adjustments of coronary bed reactivity associated with greater left ventricular contraction.

Biomarkers of Volume Overload and Edema in Heart Failure With Reduced Ejection Fraction

From a pathogenetic point of view, heart failure (HF) is characterized by the activation of several neurohumoral pathways with a role in maintaining the cardiac output and the adequate perfusion pressure in target organs and tissues. Decreased cardiac output in HF with reduced ejection fraction causes activation of the sympathetic nervous system, the renin angiotensin aldosterone system, arginine-vasopressin system, natriuretic peptides, and endothelin, all of which cause water and salt retention in the body. As a result, patients will present clinically as the main symptoms: dyspnea and peripheral edema caused by fluid redistribution to the lungs and/or by fluid overload. By studying these pathophysiological mechanisms, biomarkers with a prognostic and therapeutic role in the management of edema were identified in patients with HF with low ejection fraction. This review aims to summarize the current data from the specialty literature of such biomarkers with a role in the pathogenesis of edema in HF with low ejection fraction. These biomarkers may be the basis for risk stratification and the development of new therapeutic means in the treatment of edema in these patients.

Biomarkers in heart failure: Relevance in the clinical practice

Early detection and risk stratification of patients with heart failure (HF) are crucial to improve outcomes. Given the complexity of the pathophysiological processes of HF and the involvement of multi-organ systems in different stages of HF, clinical prognostication of HF can be challenging. In this regard, several biomarkers have been investigated for diagnosis, screening, and risk stratification of HF patients. These biomarkers can be classified as biomarkers of myocardial stretch such as B-type natriuretic peptide, biomarkers of neurohormonal activation, biomarkers of inflammation and oxidative stress and biomarkers of cardiac hypertrophy, fibrosis and remodeling. In this paper, we summarize current evidence supporting the use of selected biomarkers in HF. We review their diagnostic, prognostic and therapeutic role in the management of HF. We also discuss potential factors limiting the use of these novel biomarkers in the clinical practice and highlight the challenges of adopting a multi-biomarker strategy.

Calpains as Potential Therapeutic Targets for Myocardial Hypertrophy

Despite advances in its treatment, heart failure remains a major cause of morbidity and mortality, evidencing an urgent need for novel mechanism-based targets and strategies. Myocardial hypertrophy, caused by a wide variety of chronic stress stimuli, represents an independent risk factor for the development of heart failure, and its prevention constitutes a clinical objective. Recent studies performed in preclinical animal models support the contribution of the Ca²⁺-dependent cysteine proteases calpains in regulating the hypertrophic process and highlight the feasibility of their long-term inhibition as a pharmacological strategy. In this review, we discuss the existing evidence implicating calpains in the development of cardiac hypertrophy, as well as the latest advances in unraveling the underlying mechanisms. Finally, we provide an updated overview of calpain inhibitors that have been explored in preclinical models of cardiac hypertrophy and the progress made in developing new compounds that may serve for testing the efficacy of calpain inhibition in the treatment of pathological cardiac hypertrophy.

Influence of diet and sport on the risk of sleep apnea in patients with metabolic syndrome associated with hypothyroidism - a 4-year survey

Apnea is a common problem observed among obese individuals, affecting the quality of sleep and increasing cardiovascular risk and mortality. The current study monitored the risk of obstructive sleep apnea (OSA) following diet therapy and sports-associated diet therapy in patients with metabolic syndrome (MS) and hypothyroidism. The subjects included in the study were divided into 3 groups: control group (CG) (n=36), diet therapy group (DG) (including patients following a personalized diet therapy program) (n=76), and diet therapy and sports group (DSG) (which considered patients doing sports in addition to following a personalized diet therapy program) (n=80). The evaluation methods included body analysis (body mass index, fat mass, and visceral fat), paraclinical analysis (homeostasis model assessment of insulin resistance), assessment of difficulty in breathing, stress monitoring, hypothyroidism, and risk of OSA. The OSA index was assessed using the Berlin Questionnaire of Sleep Apnea and Epworth Sleepiness Scale. The correlation between OSA with body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR) index, fat mass, and visceral fat showed a statistically significant positive ratio (p<0.05; F=3.871). The obtained results indicated that diet therapy and physical activity reduced the OSA risk by 78.72%.

Implantable vagus nerve stimulation system performance is not affected by internal or external defibrillation shocks

PURPOSE

Autonomic regulation therapy (ART) for heart failure (HF) is delivered using vagus nerve stimulation (VNS), and has been associated with improvement in cardiac function and HF symptoms. VNS is delivered using an implantable pulse generator (IPG) and a lead placed around the cervical vagus nerve. Because HF patients may receive concomitant cardiac defibrillation therapy, testing was conducted to determine the effect of defibrillation (DF) on VNS system performance.

METHODS

Normal swine (n = 4) with VNS system implants on the right cervical vagus nerve received sequential defibrillation shocks with three defibrillation systems: an implantable cardioverter defibrillator (ICD), a subcutaneous ICD (S-ICD), and an external cardioverter defibrillator (ECD). Each system delivered a series of bipolar high-energy shocks and reverse-polarity high-energy shocks.

RESULTS

The specified cardiac defibrillation shocks were delivered successfully from each of the three defibrillation systems to all animals. After each shock series, interrogation of the IPG confirmed that software and data were unchanged from pre-programmed values. After all of the defibrillation shocks were delivered, the IPGs underwent and passed comprehensive electrical testing demonstrating proper system function. No shifts in IPG parameters or ART system failures were observed, and histologic evaluation of the vagus nerve revealed no anatomic changes.

CONCLUSIONS

Implantable VNS systems were tested in vivo for immunity to defibrillation via ICD, S-ICD, and ECD, and were found to be unaffected by a series of high-energy defibrillation shocks. These results confirm that ART systems are capable of continuing to function after defibrillation and the cervical vagus nerve is anatomically unaffected.

ALM Fluid Therapy Shifts Sympathetic Hyperactivity to Parasympathetic Dominance in the Rat Model of Non-Compressible Hemorrhagic Shock

ABSTRACT

Excessive sympathetic outflow following trauma can lead to cardiac dysfunction, inflammation, coagulopathy, and poor outcomes. We previously reported that buprenorphine analgesia decreased survival after hemorrhagic trauma. Our aim is to examine the underlying mechanisms of mortality in a non-compressible hemorrhage rat model resuscitated with saline or adenosine, lidocaine, magnesium (ALM). Anesthetized adult male Sprague-Dawley rats were randomly assigned to Saline control group or ALM therapy group (both n = 10). Hemorrhage was induced by 50% liver resection. After 15 min, 0.7 mL/kg 3% NaCl ± ALM intravenous bolus was administered, and after 60 min, 0.9% NaCl ± ALM was infused for 4 h (0.5 mL/kg/h) with 72 h monitoring. Animals received 6-12-hourly buprenorphine for analgesia. Hemodynamics, heart rate variability, echocardiography, and adiponectin were measured. Cardiac tissue was analyzed for adrenergic/cholinergic receptor expression, inflammation, and histopathology. Four ALM animals and one Saline control survived to 72 h. Mortality was associated with up to 97% decreases in adrenergic (β-1, α-1A) and cholinergic (M2) receptor expression, cardiac inflammation, myocyte Ca2+ loading, and histopathology, indicating heart ischemia/failure. ALM survivors had higher cardiac output and stroke volume, a 30-fold increase in parasympathetic/sympathetic receptor expression ratio, and higher circulating adiponectin compared to Saline controls. Paradoxically, Saline cardiac adiponectin hormone levels were higher than ALM, with no change in receptor expression, indicating intra-cardiac synthesis. Mortality appears to be a "systems failure" associated with CNS dysregulation of cardiac function. Survival involves an increased parasympathetic dominance to support cardiac pump function with reduced myocardial inflammation. Increased cardiac α-1A adrenergic receptor in ALM survivors may be significant, as this receptor is highly protective during heart dysfunction/failure.

The Role of Exercise-Induced Molecular Processes and Vitamin D in Improving Cardiorespiratory Fitness and Cardiac Rehabilitation in Patients With Heart Failure

Heart failure (HF) still affects millions of people worldwide despite great advances in therapeutic approaches in the cardiovascular field. Remarkably, unlike pathological hypertrophy, exercise leads to beneficial cardiac hypertrophy characterized by normal or enhanced contractile function. Exercise-based cardiac rehabilitation improves cardiorespiratory fitness and, as a consequence, ameliorates the quality of life of patients with HF. Particularly, multiple studies demonstrated the improvement in left ventricular ejection fraction (LVEF) among patients with HF due to the various processes in the myocardium triggered by exercise. Exercise stimulates IGF-1/PI3K/Akt pathway activation involved in muscle growth in both the myocardium and skeletal muscle by regulating protein synthesis and catabolism. Also, physical activity stimulates the activation of the mitogen-activated protein kinase (MAPK) pathway which regulates cellular proliferation, differentiation and apoptosis. In addition, emerging data pointed out the anti-inflammatory effects of exercises as well. Therefore, it is of utmost importance for clinicians to accurately evaluate the patient’s condition by performing a cardiopulmonary exercise test and/or a 6-min walking test. Portable devices with the possibility to measure exercise capacity proved to be very useful in this setting as well. The aim of this review is to gather together the molecular processes triggered by the exercise and available therapies in HF settings that could ameliorate heart performance, with a special focus on strategies such as exercise-based cardiac rehabilitation.

Full-Length Transcriptome Sequencing: An Insight Into the Dog Model of Heart Failure

Heart failure (HF) leads to a progressive increase in morbidity and mortality rates. This study aimed to explore the transcriptional landscape during HF and identify differentially expressed transcripts (DETs) and alternative splicing events associated with HF. We generated a dog model of HF (n = 3) using right ventricular pacemaker implantation. We performed full-length transcriptome sequencing (based on nanopore platform) on the myocardial tissues and analyzed the transcripts using differential expression analysis and functional annotation methods [Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses]. Additionally, we estimated the expression of the selected genes by quantitative real-time PCR (qRT-PCR) and detected the proportion of immune cells using flow cytometry. We found that increased B-type natriuretic peptide reduced ejection fraction, and apparent clinical signs were observed in the dog model of HF. We identified 67,458 transcripts using full-length transcriptome sequencing. A total of 785 DETs were obtained from the HF and control groups. These DETs were mainly enriched in the immune responses, especially Th1, Th2, and Th17 cell differentiation processes. Furthermore, flow cytometry results revealed that the proportion of Th1 and Th17 cells increased in patients with HF compared to controls, while the proportion of Th2 cells decreased. Differentially expressed genes in the HF and control groups associated with Th1, Th2, and Th17 cell differentiation were quantified using qRT-PCR. We also identified variable splicing events of sarcomere genes (e.g., MYBPC3, TNNT2, TTN, FLNC, and TTNI3). In addition, we detected 4,892 transcription factors and 406 lncRNAs associated with HF. Our analysis based on full-length transcript sequencing provided an analysis perspective in a dog model of HF, which is valuable for molecular research in an increasingly relevant large animal model of HF.

Central Hemodynamic Adjustments during Post-Exercise Hypotension in Hypertensive Patients with Ischemic Heart Disease: Concurrent Circuit Exercise versus High-Intensity Interval Exercise. A Preliminary Study

Concurrent aerobic plus resistance exercise (RAE) and high-intensity interval exercise (HIIE) are both effective at inducing post-exercise hypotension (PEH) in patients with hypertension. However, central hemodynamic changes associated with PEH in hypertensive subjects with underlying ischemic heart disease (IHD) have been poorly investigated. The study aim was to compare the acute effects produced by these two exercise modalities on left ventricular diastolic function and left atrial function. Twenty untrained male patients with a history of hypertension and IHD under stable pharmacological therapy were enrolled. Each patient underwent three exercise sessions: RAE, HIIE and a control session without exercise, each lasting 45 min. An echocardiography examination was performed before and between 30 min and 40 min from the end of the exercise sessions. Following the exercise sessions, BP values decreased in a similar way in RAE and HIIE and were unchanged after the control session. Compared to pre-session, the ratio between early filling velocity (E) and mitral annulus early diastolic velocity (E’). E/E’ increased after HIIE and remained unchanged after both RAE and control sessions (between-sessions p 0.002). Peak atrial longitudinal strain (PALS) increased slightly after RAE (+1.4 ± 1.1%), decreased after HIIE (−4.6 ± 2.4%) and was unchanged after the control session (between-sessions p 0.03). Peak atrial contraction strain (PACS) was mildly increased after RAE, was reduced after HIIE and was unchanged after the control session. Atrial volume was unchanged after both exercise sessions. Left ventricular and left atrial stiffness increased significantly after HIIE, but remained unchanged after the RAE and control sessions. Stroke volume and cardiac output increased after RAE, decreased after HIIE, and were unchanged after the control session. In conclusion, single session of RAE and HIIE brought about similar PEH in hypertensive subjects with IHD, while they evoked different central hemodynamic adjustments. Given its neutral effects on diastolic and atrial functions, RAE seems more suitable for reducing blood pressure in hypertensive patients with IHD.

Milestones in Heart Failure: How Far We Have Come and How Far We Have Left to Go

Heart failure is a clinically complex syndrome that results due to the failure of the ventricles to function as pump and oxygenate end organs. The repercussions of inadequate perfusion are seen in the form of sympathetic overactivation and third spacing, leading to clinical signs of increased blood pressure, dyspnea, fatigue, palpitations, etc. This article provided a brief overview of the clinical syndrome of heart failure; its epidemiology, risk factors, symptoms, and staging; and the mechanisms involved in disease progression. This article also described several landmark trials in heart failure that tested the efficacy of first-line drugs such as beta-blockers, angiotensin receptor blockers, angiotensin-converting enzyme inhibitors, and the latest drugs in the field of heart failure: angiotensin receptor neprilysin inhibitors. Most studies described in this article were guideline-setting trials that revolutionized the practice of medicine and cardiology.

Catestatin as a Biomarker of Cardiovascular Diseases: A Clinical Perspective

Accounting for almost one-third of the global mortality, cardiovascular diseases (CVDs) represent a major global health issue. Emerging data suggest that most of the well-established mechanistic explanations regarding the cardiovascular pathophysiology are flawed, and cannot fully explain the progression and long-term effects of these diseases. On the other hand, dysregulation of the sympathetic nervous system (SNS) has emerged as an important player in the pathophysiology of CVDs. Even though upregulated SNS activity is an essential compensatory response to various stress conditions, in the long term, it becomes a major contributor to both cardiac dysfunction and vascular damage. Despite the fact that the importance of SNS hyperactivity in the setting of CVDs has been well-appreciated, its exact quantification and clinical application in either diagnostics or therapy of CVDs is still out of reach. Nevertheless, in recent years a number of novel laboratory biomarkers implicated in the pathophysiology of SNS activation have been explored. Specifically, in this review, we aimed to discuss the role of catestatin, a potent physiological inhibitor of catecholamine spillover that offers cardioprotective effects. Limited data indicate that catestatin could also be a reliable indirect marker of SNS activity and it is likely that high CST levels reflect advanced CV disease burden. Consequently, large-scale studies are required to validate these observations in the upcoming future.

The sympathies of the body: functional organization and neuronal differentiation in the peripheral sympathetic nervous system

During the last 30 years, our understanding of the development and diversification of postganglionic sympathetic neurons has dramatically increased. In parallel, the list of target structures has been critically extended from the cardiovascular system and selected glandular structures to metabolically relevant tissues such as white and brown adipose tissue, lymphoid tissues, bone, and bone marrow. A critical question now emerges for the integration of the diverse sympathetic neuron classes into neural circuits specific for these different target tissues to achieve the homeostatic regulation of the physiological ends affected.

How COVID-19 can cause autonomic dysfunctions and postural orthostatic syndrome? A Review of mechanisms and evidence

Coronavirus disease 2019 (COVID-19) is a viral disease spread by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Because the recent pandemic has resulted in significant morbidity and mortality, understanding various aspects of this disease has become critical. SARS-CoV-2 can affect a variety of organs and systems in the body. The autonomic nervous system plays an important role in regulating body functions, and its dysfunction can cause a great deal of discomfort for patients. In this study, we focused on the effect of COVID-19 on the autonomic system and syndromes associated with it, such as postural orthostatic syndrome (POTS).

Arguments for Using Direct Oral Anticoagulants in Cancer-Related Venous Thromboembolism

(1) Background: Patients with cancer with a hypercoagulable state present an increased incidence of venous thromboembolism (VTE). Neoplastic patients with concurrent VTE undergoing anticoagulant treatment face a series of issues. (2) The aim of the present paper is to systematically summarize current VTE management in patients with neoplasia and to review the current clinical evidence from meta-analyses of randomized controlled trials and guidelines regarding the administration of direct oral anticoagulants (DOACs) for cancer-associated VTE. (3) Search Strategy: We performed a review on meta-analyses of randomized controlled trials and guidelines in favor of the administration of DOACs in patients with cancer-associated VTE published in the last 6 years in the Medline (PubMed) and Embase databases. (4) Results: 21 meta-analyses, 14 randomized controlled studies comparing DOACs to VKAs and LMWH, and 7 national and international guidelines were identified. We identified five studies that show the antineoplastic effect of DOAC on experimental models. (5) Conclusions: DOACs can be seen as the first choice for VTE treatment in neoplastic patients who have a low risk of bleeding, who do not have severe renal impairment, and who are not undergoing treatments that could interact with DOAC's mechanism of action.

Assessment of ECG during hybrid comprehensive telerehabilitation in heart failure patients-Subanalysis of the Telerehabilitation in Heart Failure Patients (TELEREH-HF) randomized clinical trial

BACKGROUND

Exercise training in heart failure (HF) patients should be monitored to ensure patients' safety. Electrocardiographic (ECG) telemonitoring was used to assess the safety of hybrid comprehensive telerehabilitation (HCTR).

OBJECTIVE

Analysis of ECG recorded during HCTR in HF patients.

METHODS

The TELEREH-HF multicenter, randomized, controlled trial enrolled 850 HF patients with New York Heart Association class I-III and left ventricular ejection fraction of ≤40%. This subanalysis focuses on 386 patients (aged 62 ± 11 years, LVEF 31 ± 7%) randomized to HCTR. HCTR was telemonitored with a device allowing to record 16-s fragments of ECG and to transmit the data via mobile phone network to the monitoring center. ResultsIn 386 patients, 16,622 HCTR sessions were recorded and 66,488 ECGs fragments were evaluated. Sinus rhythm was present in 320 (83%) and permanent atrial fibrillation (AF) in 66 (17%) patients, respectively. The most common arrhythmias were ventricular and atrial premature beats, recorded in 76.4% and 27.7% of the patients, respectively. Non-sustained ventricular tachycardia (21 episodes in 8 patients) and paroxysmal AF episodes (6 in 4 patients) were rare. None of the analyzed demographic and clinical characteristics was predictive for onset of the new arrhythmias on exercise.

CONCLUSION

Telerehabilitation in HF patients was safe without the evidence for symptomatic arrhythmias requiring discontinuation of telerehabilitation. Only one mildly symptomatic paroxysmal AF episode led to the short-term suspension of the training program. The most common arrhythmias were atrial and ventricular premature beats. These arrhythmias did not result in any changes in rehabilitation and therapy regimens.

Aggressive beta-blocker titration in stabilized acute heart failure patients with low left ventricular ejection fraction

Objectives

A beta-blocker should be initiated in patients with stable acute heart failure (AHF). Beta-blocker titration should be conducted after a two-week interval. The benefits of aggressive beta-blocker titration are still unclear. This study aimed to investigate the aggressive beta-blocker titration outcomes in stabilized AHF patients with low left ventricular ejection fraction (LVEF).

Methods

In this retrospective cohort study, we analysed clinical data from the heart failure (HF) registry. AHF Patients with LVEF <40% were divided into aggressive and guideline-directed beta-blocker titration groups. The composite of worsening HF, ventricular arrhythmia, and mortality during hospitalization were defined as the primary outcomes. We considered secondary outcomes as the components of primary outcomes and also the outcomes during a 90-day follow-up after hospital discharge, including HF readmission and mortality.

Results

The primary outcomes between both groups were not significantly different (12.3% vs 24.4%; relative risk [RR] 0.51; 95% confidence interval [CI] 0.25–1.01; p = 0.055). However, the aggressive beta-blocker titration reduced ventricular arrhythmia events (5.7% vs 17.8%; RR 0.32; 95% CI 0.12–0.84; p = 0.016). The 90-day HF readmission rate (2.6% vs 7.5%; RR 0.35; 95% CI 0.07–1.66; p = 0.179) and mortality rate (4.3% vs 5%; RR 0.87; 95% CI 0.18–4.31; p = 1.000) between both groups were not found to be significantly different.

Conclusion

Compared to the guideline-directed beta-blocker titration, the aggressive beta-blocker titration was safe in low LVEF AHF patients who have been previously stabilized. Additionally, aggressive beta-blocker titration effectively reduced ventricular arrhythmia events.

Current concept in the diagnosis, treatment and rehabilitation of patients with congestive heart failure

Heart failure (HF) is a major public health problem with a prevalence of 1%-2% in developed countries. The underlying pathophysiology of HF is complex and as a clinical syndrome is characterized by various symptoms and signs. HF is classified according to left ventricular ejection fraction (LVEF) and falls into three groups: LVEF ≥ 50% - HF with preserved ejection fraction (HFpEF), LVEF < 40% - HF with reduced ejection fraction (HFrEF), LVEF 40%-49% - HF with mid-range ejection fraction. Diagnosing HF is primarily a clinical approach and it is based on anamnesis, physical examination, echocardiogram, radiological findings of the heart and lungs and laboratory tests, including a specific markers of HF - brain natriuretic peptide or N-terminal pro-B-type natriuretic peptide as well as other diagnostic tests in order to elucidate possible etiologies. Updated diagnostic algorithms for HFpEF have been recommended (H2FPEF, HFA-PEFF). New therapeutic options improve clinical outcomes as well as functional status in patients with HFrEF (e.g., sodium-glucose cotransporter-2 - SGLT2 inhibitors) and such progress in treatment of HFrEF patients resulted in new working definition of the term "HF with recovered left ventricular ejection fraction". In line with rapid development of HF treatment, cardiac rehabilitation becomes an increasingly important part of overall approach to patients with chronic HF for it has been proven that exercise training can relieve symptoms, improve exercise capacity and quality of life as well as reduce disability and hospitalization rates. We gave an overview of latest insights in HF diagnosis and treatment with special emphasize on the important role of cardiac rehabilitation in such patients.

Fibrosis, the Bad Actor in Cardiorenal Syndromes: Mechanisms Involved

Cardiorenal syndrome is a term that defines the complex bidirectional nature of the interaction between cardiac and renal disease. It is well established that patients with kidney disease have higher incidence of cardiovascular comorbidities and that renal dysfunction is a significant threat to the prognosis of patients with cardiac disease. Fibrosis is a common characteristic of organ injury progression that has been proposed not only as a marker but also as an important driver of the pathophysiology of cardiorenal syndromes. Due to the relevance of fibrosis, its study might give insight into the mechanisms and targets that could potentially be modulated to prevent fibrosis development. The aim of this review was to summarize some of the pathophysiological pathways involved in the fibrotic damage seen in cardiorenal syndromes, such as inflammation, oxidative stress and endoplasmic reticulum stress, which are known to be triggers and mediators of fibrosis.

Relaxin increased blood pressure and sympathetic activity in paraventricular nucleus of hypertensive rats via enhancing oxidative stress

Relaxin, an ovarian polypeptide hormone, is found in the hypothalamic paraventricular nucleus (PVN) which is an important central integrative site for the control of blood pressure and sympathetic outflow. The aim of this study was to determine if superoxide anions modulate the effects of relaxin in the PVN. Experiments were performed in normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs). Relaxin mRNA and protein, and its receptor, relaxin family peptide receptor 1 (RXFP1) levels in PVN were 3.24, 3.17, and 3.64 times higher in SHRs than in WKY rats, respectively. Microinjection of relaxin-2 into the PVN dose-dependently increased mean arterial pressure (MAP), renal sympathetic nerve activity (RSNA) and heart rate (HR) in both WKY rats and SHRs, although the effects on MAP (16.87 ± 1.99 vs. 8.97 ± 1.48 mm Hg in 100 nmol), RSNA (22.60 ± 2.15 vs. 11.77 ± 1.43 % in 100 nmol) and HR (22.85 ± 3.13 vs. 12.62 ± 2.83 beats/min in 100 nmol) were greater in SHRs. Oxidative stress level was enhanced after relaxin-2 microinjection into the PVN. Pretreatment with superoxide anion scavengers or NADPH oxidase inhibitor blocked, and superoxide dismutase inhibitor potentiated the effects of relaxin-2 on MAP, RSNA and HR. RXFP1 knockdown significantly attenuated the blood pressure of SHRs, and inhibited the increases of atrial natriuretic peptide, brain natriuretic peptide, collagen I, collagen III and fibronectin in the heart of SHRs. These results demonstrated that relaxin is expressed in the PVN, and contributes to hypertension and sympathetic overdrive via oxidative stress. Down-regulation of RXFP1 in the PVN could attenuate hypertension and cardiac remodeling.

Signaling and function of cardiac autonomic nervous system receptors: Insights from the GPCR signalling universe

The two branches of the autonomic nervous system (ANS), adrenergic and cholinergic, exert a multitude of effects on the human myocardium thanks to the activation of distinct G protein-coupled receptors (GPCRs) expressed on the plasma membranes of cardiac myocytes, cardiac fibroblasts, and coronary vascular endothelial cells. Norepinephrine (NE)/epinephrine (Epi) and acetylcholine (ACh) are released from cardiac ANS terminals and mediate the biological actions of the ANS on the heart via stimulation of cardiac adrenergic or muscarinic receptors, respectively. In addition, several other neurotransmitters/hormones act as facilitators of ANS neurotransmission in the heart, taking part in the so-called nonadrenergic noncholinergic (NANC) part of the ANS's control of cardiac function. These NANC mediators also use several different cell membrane-residing GPCRs to exert their effects in the myocardium. Cardiac ANS dysfunction and an imbalance between the activities of its two branches underlie a variety of cardiovascular diseases, from heart failure and hypertension to coronary artery disease, myocardial ischemia, and arrhythmias. In this review, we present the main well-established signaling modalities used by cardiac autonomic GPCRs, including receptors for salient NANC mediators, and we also highlight the latest developments pertaining to cardiac cell type-specific signal transduction, resulting in cell type-specific cardiac effects of each of these autonomic receptors.

Plasma Catestatin Levels and Advanced Glycation End Products in Patients on Hemodialysis

Catestatin (CST) is a pleiotropic peptide involved in cardiovascular protection with its antihypertensive and angiogenic effects. Considering that patients with end-stage renal disease (ESRD) who are undergoing hemodialysis (HD) are associated with higher cardiovascular risk, the aim of this study was to investigate plasma CST levels in HD patients, compare them to healthy controls and evaluate possible CST associations with advanced glycation end products (AGEs) and laboratory, anthropometric and clinical parameters. The study included 91 patients on HD and 70 healthy controls. Plasma CST levels were determined by an enzyme-linked immunosorbent assay in a commercially available diagnostic kit, while AGEs were determined using skin autofluorescence. Plasma CST levels were significantly higher in the HD group compared to the controls (32.85 ± 20.18 vs. 5.39 ± 1.24 ng/mL, p < 0.001) and there was a significant positive correlation between CST and AGEs (r = 0.492, p < 0.001). Furthermore, there was a significant positive correlation between plasma CST levels with both the Dialysis Malnutrition Score (r = 0.295, p = 0.004) and Malnutrition-Inflammation Score (r = 0.290, p = 0.005). These results suggest that CST could be playing a role in the complex pathophysiology of ESRD/HD and that it could affect the higher cardiovascular risk of patients on HD.

Effect of defibrillation on the performance of an implantable vagus nerve stimulation system

BACKGROUND

Vagus Nerve Stimulation (VNS) delivers Autonomic Regulation Therapy (ART) for heart failure (HF), and has been associated with improvement in cardiac function and heart failure symptoms. VNS is delivered using an implantable pulse generator (IPG) and lead with electrodes placed around the cervical vagus nerve. Because HF patients may receive concomitant cardiac defibrillation therapy, testing was conducted to determine the effect of defibrillation (DF) on the VNS system.

METHODS

DF testing was conducted on three ART IPGs (LivaNova USA, Inc.) according to international standard ISO14708-1, which evaluated whether DF had any permanent effects on the system. Each IPG was connected to a defibrillation pulse generator and subjected to a series of high-energy pulses.

RESULTS

The specified series of pulses were successfully delivered to each of the three devices. All three IPGs passed factory electrical tests, and interrogation confirmed that software and data were unchanged from the pre-programmed values. No shifts in parameters or failures were observed.

CONCLUSIONS

Implantable VNS systems were tested for immunity to defibrillation, and were found to be unaffected by a series of high-energy defibrillation pulses. These results suggest that this VNS system can be used safely and continue to function after patients have been defibrillated.

Why Do We Not Assess Sympathetic Nervous System Activity in Heart Failure Management: Might GRK2 Serve as a New Biomarker?

Heart failure (HF) represents the end-stage condition of several structural and functional cardiovascular diseases, characterized by reduced myocardial pump function and increased pressure load. The dysregulation of neurohormonal systems, especially the hyperactivity of the cardiac adrenergic nervous system (ANS), constitutes a hallmark of HF and exerts a pivotal role in its progression. Indeed, it negatively affects patients’ prognosis, being associated with high morbidity and mortality rates, with a tremendous burden on global healthcare systems. To date, all the techniques proposed to assess the cardiac sympathetic nervous system are burdened by intrinsic limits that hinder their implementation in clinical practice. Several biomarkers related to ANS activity, which may potentially support the clinical management of such a complex syndrome, are slow to be implemented in the routine practice for several limitations due to their assessment and clinical impact. Lymphocyte G-protein-coupled Receptor Kinase 2 (GRK2) levels reflect myocardial β-adrenergic receptor function in HF and have been shown to add independent prognostic information related to ANS overdrive. In the present manuscript, we provide an overview of the techniques currently available to evaluate cardiac ANS in HF and future perspectives in this field of relevant scientific and clinical interest.

Neurohumoral, cardiac and inflammatory markers in the evaluation of heart failure severity and progression

Heart failure is common in adult population, accounting for substantial morbidity and mortality worldwide. The main risk factors for heart failure are coronary artery disease, hypertension, obesity, diabetes mellitus, chronic pulmonary diseases, family history of cardiovascular diseases, cardiotoxic therapy. The main factor associated with poor outcome of these patients is constant progression of heart failure. In the current review we present evidence on the role of established and candidate neurohumoral biomarkers for heart failure progression management and diagnostics. A growing number of biomarkers have been proposed as potentially useful in heart failure patients, but not one of them still resembles the characteristics of the “ideal biomarker.” A single marker will hardly perform well for screening, diagnostic, prognostic, and therapeutic management purposes. Moreover, the pathophysiological and clinical significance of biomarkers may depend on the presentation, stage, and severity of the disease. The authors cover main classification of heart failure phenotypes, based on the measurement of left ventricular ejection fraction, including heart failure with preserved ejection fraction, heart failure with reduced ejection fraction, and the recently proposed category heart failure with mid-range ejection fraction. One could envisage specific sets of biomarker with different performances in heart failure progression with different left ventricular ejection fraction especially as concerns prediction of the future course of the disease and of left ventricular adverse/reverse remodeling. This article is intended to provide an overview of basic and additional mechanisms of heart failure progression will contribute to a more comprehensive knowledge of the disease pathogenesis.

Clinical Implications of Uric Acid in Heart Failure: A Comprehensive Review

Affecting more than 26 million people worldwide and with rising prevalence, heart failure (HF) represents a major global health problem. Hence, further research is needed in order to abate poor HF outcomes and mitigate significant expenses that burden health care systems. Based on available data, experts agree that there is an urgent need for a cost-effective prognostic biomarker in HF. Although a significant number of biomarkers have already been investigated in this setting, the clinical utility of adding biomarker evaluation to routine HF care still remains ambiguous. Specifically, in this review we focused on uric acid (UA), a purine metabolism detriment whose role as cardiovascular risk factor has been exhaustingly debated for decades. Multiple large population studies indicate that UA is an independent predictor of mortality in acute and chronic HF, making it a significant prognostic factor in both settings. High serum levels have been also associated with an increased incidence of HF, thus expanding the clinical utility of UA. Importantly, emerging data suggests that UA is also implicated in the pathogenesis of HF, which sheds light on UA as a feasible therapeutic target. Although to date clinical studies have not been able to prove the benefits of xanthine oxidase in HF patients, we discuss the putative role of UA and xanthine oxidase in the pathophysiology of HF as a therapeutic target.