Ventricular assist device implantation improves skeletal muscle function, oxidative capacity, and growth hormone/insulin-like growth factor-1 axis signaling in patients with advanced heart failure

Advances in the Insulin-Heart Axis: Current Therapies and Future Directions

The insulin-heart axis plays a pivotal role in the pathophysiology of cardiovascular disease (CVD) in insulin-resistant states, including type 2 diabetes mellitus. Insulin resistance disrupts glucose and lipid metabolism, leading to systemic inflammation, oxidative stress, and atherogenesis, which contribute to heart failure (HF) and other CVDs. This review was conducted by systematically searching PubMed, Scopus, and Web of Science databases for peer-reviewed studies published in the past decade, focusing on therapeutic interventions targeting the insulin-heart axis. Studies were selected based on their relevance to insulin resistance, cardiovascular outcomes, and the efficacy of pharmacologic treatments. Key findings from the review highlight the efficacy of lifestyle modifications, such as dietary changes and physical activity, which remain the cornerstone of managing insulin resistance and improving cardiovascular outcomes. Moreover, pharmacologic interventions, such as metformin, sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and dipeptidyl peptidase-4 inhibitors, have shown efficacy in reducing cardiovascular risk by addressing metabolic dysfunction, reducing inflammation, and improving endothelial function. Furthermore, emerging treatments, such as angiotensin receptor-neprilysin inhibitors, and mechanical interventions like ventricular assist devices offer new avenues for managing HF in insulin-resistant patients. The potential of these therapies to improve left ventricular ejection fraction and reverse pathological cardiac remodeling highlights the importance of early intervention. However, challenges remain in optimizing treatment regimens and understanding the long-term cardiovascular effects of these agents. Future research should focus on personalized approaches that integrate lifestyle and pharmacologic therapies to effectively target the insulin-heart axis and mitigate the burden of cardiovascular complications in insulin-resistant populations.

[The effect of the treatmet of iron on patients with failure heart and insufficient of iron. An Meta-analisis of randomized clinical trials]

INTRODUCTION

Approximately 45% of patients with heart failure had iron deficiency for the rest of their lives.

OBJECTIVE

To determine the effect of iron treatment in patients with heart failure and iron deficiency or anemia.

MATERIALS AND METHODS

The studies were selected in: PubMed, Scopus, Cochrane and Google Scholar, from the beginning of June to July 2023. The selected articles that met the inclusion criteria, the relevant information of the studies were collected according to the selection variables and were recorded in the Revman 5.0 program of the Cochrane collaboration. The primary outcome was composed of hospitalization for heart failure or cardiovascular death.

RESULTS

Of the 7 included studies, 6717 patients were obtained, the average age was 70 years with a predominance of the male gender (57%). The primary outcome was lower in patients in the control group compared to the placebo group (OR, 0.62; 95%CI, 0.54-0.70). The 6-minute walk test (6-MWT) was improved in the iron-supplemented group compared to the placebo group (OR, 0.79; 95%CI, 0.64-0.98). Adverse events were fewer in the iron supplement group compared to the placebo group (OR, 0.78; 95%CI, 0.67-0.91).

CONCLUSION

In this meta-analysis of randomized controlled trials, the effect of iron supplementation is found to reduce the incidence rate of hospitalization for heart failure or cardiovascular death. In addition to a reduction in adverse events, such as gastrointestinal and neurological disorders, it also improves 6-MWT.

[Cardiac rehabilitation in LVAD patients : Aspects regarding exercise and rhythm]

After implantation of a left ventricular assist device (LVAD), it is strongly recommended that patients participate in an inpatient cardiac rehabilitation program (CR). Relevant topics during CR include sports and exercise therapy as well as aspects of cardiac rhythm control. Over time, LVAD patients usually regain a good quality of life and an adequate functional capacity can be observed. However, maximum performance values remain markedly reduced, in part due to the fixed LVAD pump speed and the limited total cardiac output. Therefore, structured long-term exercise training programs (even beyond CR phase II) are of particular importance in order to optimize neuromuscular control and muscle metabolism. Limitations to physical performance values may also be caused by the occurrence of supraventricular and/or ventricular arrhythmias. In both cases, the cause is an increasing hemodynamic impairment of the right heart, which may also lead to a reduced LVAD pump flow. In addition, inadequate setting of other cardiac implantable electronic devices (e.g., implantable cardioverter-defibrillator [ICD] or cardiac resynchronization therapy with defibrillator [CRT-D]) may also have a crucial impact on hemodynamics after LVAD implantation. In this article, we will discuss specific aspects of LVAD therapy related to exercise and rhythm control, particularly in the context of CR programs.

Long-Term Changes in Estimated Glomerular Filtration Rate in Left Ventricular Assist Device Recipients: A Longitudinal Joint Model Analysis

Background Advanced kidney disease is often a relative contraindication to left ventricular assist device (LVAD) implantation because of concerns for poor outcomes including worsening kidney disease. Data are lacking on long-term changes and sex-based differences in estimated glomerular filtration rate (eGFR), with published data limited by potential bias introduced by the competing risks of death and heart transplantation. Methods and Results We conducted a longitudinal analysis of 288 adults receiving durable continuous-flow LVADs from January 2010 to December 2017 at a single center. A joint model was constructed to evaluate change in eGFR over 2 years, the prespecified primary outcome, adjusted for the competing risks of death and heart transplantation. Median baseline eGFR was 60 mL/min per 1.73 m2 (interquartile range 42-78). At 2 years, 74 patients died and 104 received a heart transplant. In unadjusted analysis, LVAD recipients had a modest initial increase in eGFR of ≈2 mL/min per 1.73 m2 within the first 6 months after implantation, followed by a decrease in eGFR below baseline values at 1 and 2 years. Men experienced an eGFR decline of 5 to 10 mL/min per 1.73 m2 over the first year which then stabilized, while women had an ≈5 mL/min per 1.73 m2 increase in eGFR within the first 6 months followed by decline towards baseline eGFR levels (interaction P=0.005). Conclusions Estimated GFR remains relatively stable in most patients following LVAD implantation. Larger studies are needed to investigate sex-based differences in eGFR and to evaluate eGFR trajectory and mortality in LVAD recipients with lower eGFR.

Insulin Receptors and Insulin Action in the Heart: The Effects of Left Ventricular Assist Devices

This year, 2022, marks the 100th anniversary of the isolation of human insulin and its administration to patients suffering from diabetes mellitus (DM). Insulin exerts many effects on the human body, including the cardiac tissue. The pathways implicated include the PKB/Akt signaling pathway, the Janus kinase, and the mitogen-activated protein kinase pathway and lead to normal cardiac growth, vascular smooth muscle regulation, and cardiac contractility. This review aims to summarize the existing knowledge and provide new insights on insulin pathways of cardiac tissue, along with the role of left ventricular assist devices on insulin regulation and cardiac function.

Isolated Left Ventricular Assist Device Implantation Produces Variable Changes to Patient Body Mass Index

BACKGROUND

Body Mass Index (BMI) is an important consideration for transplant-eligible Left Ventricular Assist Device (LVAD) recipients. LVAD therapy's impact on BMI is unclear. We evaluated BMI changes in patients who underwent LVAD implantation. The association between these patients' BMI and transplant was studied.

METHODS

This was a retrospective cohort study of patients who underwent LVAD implantation between January 1, 2012-December 31, 2018 at our institution. Patients were stratified by preoperative BMI (kg/m² ) into 4 groups: < 30, 30-34.9, 34.9-39.9, and ≥40. BMI data was collected at 12 and 6 months prior to implant, time of implantation, and 3- and 6- months post-implantation.

RESULTS

107 patients underwent LVAD implantation at our institution. Data was available for 80 patients. Baseline characteristics included mean age 56.0 years, 69% male, and mean implant BMI 29.9 ± 6.8 kg/m² . The mean BMI (kg/m² ) with each of the BMI (kg/m² ) groups <30, 30-34.9, 35-39.9, and ≥ 40 (n= 60, 25, 12, 10 respectively) was 25.1., 32.5, 36.8, and 43.8, respectively. There was no consistent pattern with weight change across differing implant BMIs. No patient with a BMI of <30 gained sufficient weight to impact transplant candidacy. 23% of patients with BMI of 30-34.9 kg/m² , 60% of patients with a BMI 35-39.9 kg/m² , and 87.5% of patients with a BMI of ≥40 had a 6-month BMI potentially affecting transplant.

CONCLUSIONS

Associated weight changes during LVAD support may significantly impact transplant candidacy. Higher BMI groups may benefit from multimodal and multidisciplinary targeted weight-loss interventions.

Sarcopenia and risk of infection in adult heart transplant recipients in Japan

AIMS

Heart transplantation (HT) is an effective therapeutic option for end-stage heart failure. Infection is a major cause of morbidity and mortality after HT. Sarcopenia, defined as the loss of muscle mass and strength, is a common comorbidity in HT candidates with end-stage heart failure. However, the effects of sarcopenia on the occurrence of post-HT infections are not well understood. Therefore, we explored the association between the skeletal muscle mass and post-transplant infections in adult HT recipients.

METHODS AND RESULTS

We retrospectively examined the records of 135 patients who underwent HT between August 2007 and November 2019 at our institution. Pre-transplant computed tomography was used to calculate the skeletal muscle index (SMI) at the level of the third lumbar vertebra. Muscle wasting was defined as the SMI of the lowest sex-based tertiles. The primary endpoint was infections within 6 months of HT. The study included 109 patients (80 men, mean age: 41.6 ± 12.0 years): 37 patients in the muscle wasting group and 72 patients in the non-muscle wasting group. The mean SMI values in the muscle wasting and non-muscle wasting groups were 29.9 ± 4.8 cm² /m² and 40.7 ± 6.7 cm² /m² , respectively. Prior to HT, 108 (99.1%) patients were on left ventricular assist device support, and during that support, the rate of late right heart failure was significantly higher in the muscle wasting group than non-muscle wasting group (P = 0.012). Sixteen infections occurred within 6 months of HT. The most common infection sites included the respiratory tract (n = 5) and the upper gastrointestinal tract (n = 5), followed by the urinary tract (n = 4). Overall, 10 patients experienced infections in the muscle wasting group (27.0%) and 6 in the non-muscle wasting group (8.3%) (P = 0.009). Two patients in the muscle wasting group required intensive care unit admission, compared to none in the non-muscle wasting group. Low skeletal muscle mass was associated with infections in the univariate and multivariate logistic regression models (hazard ratio: 3.68, 95% confidence interval: 1.19-11.3; P = 0.023). However, the duration of all-cause mortality within 3 years did not differ between the groups (P = 0.56).

CONCLUSIONS

Low skeletal muscle mass is a predictor of post-HT infections within 6 months of HT.

Relationship between muscle strength and rehospitalization in ventricular assist device patients

We examined the relationship between leg extensor muscle strength (LEMS) at discharge and rehospitalization within 1 year in patients with a newly implanted ventricular assist device (VAD). This study included 28 patients who had received a VAD at our institution between October 2013 and February 2019, all of whom had been discharged for 1 year. The patients were divided into two groups according to their LEMS at discharge (higher strength [group H] and lower strength [group L]), based on the median value of the 55.2 kg-force (kgf)/body weight (BW) equation. Exercise performance parameters (e.g., grip strength, 6-min walk distance, and peak VO₂) and laboratory data concerning nutritional status were also collected. Nine patients (64.3%) in group L were rehospitalized within 1 year after discharge. The rehospitalization rate was significantly higher in group L than group H (p = 0.020). Compared with discharge, patients exhibited higher grip strength (56.3 vs. 48.6 kg/BW, respectively; p = 0.011), 6-min walk distances (588 vs. 470 m, respectively; p = 0.002), and peak VO₂ (15.4 vs. 11.9 mL/min/kg, respectively; p < 0.001) at 1 year after discharge. However, the LEMS (57.4 vs. 58.0 kgf/BW, respectively; p = 0.798) did not increase after discharge in VAD patients who avoided rehospitalization. LEMS at discharge was associated with rehospitalization after VAD surgery; a high LEMS improves the likelihood of avoiding rehospitalization.

Ambulatory advanced heart failure patients: timing of mechanical circulatory support - delaying the inevitable?

PURPOSE OF REVIEW

Current indications for continuous-flow left ventricular assist device (cfLVAD) implantation is for patients in cardiogenic shock or inotrope-dependent advanced heart failure. Risk stratification of noninotrope dependent ambulatory advanced heart failure patients is a subject of registries designed to help shared-decision making by clinicians and patients regarding the optimal timing of mechanical circulatory support (MCS).

RECENT FINDINGS

The Registry Evaluation of Vital Information for VADs in Ambulatory Life enrolled ambulatory noninotrope dependent advanced systolic heart failure patients who had 25% annualized risk of death, MCS, or heart transplantation (HT). Freedom from composite clinical outcome at 1-year follow-up was 23.5% for the entire cohort. Seattle Heart Failure Model Score and Natriuretic pepides were predictors with modest discriminatory power. Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 4 patients had the highest risk (3.7-fold) of death, MCS or HT compared to INTERMACS profile 7.

SUMMARY

We propose individualized risk stratification for noninotrope dependent ambulatory advanced heart failure patients and include serial changes in end-organ function, nutritional parameters, frailty assessment, echocardiographic and hemodynamic data. The clinical journey of a patient with advanced heart failure should be tracked and discussed at each clinic visit for shared decision-making regarding timing of cfLVAD.

Skeletal muscle atrophy in heart failure with diabetes: from molecular mechanisms to clinical evidence

Two highly prevalent and growing global diseases impacted by skeletal muscle atrophy are chronic heart failure (HF) and type 2 diabetes mellitus (DM). The presence of either condition increases the likelihood of developing the other, with recent studies revealing a large and relatively poorly characterized clinical population of patients with coexistent HF and DM (HFDM). HFDM results in worse symptoms and poorer clinical outcomes compared with DM or HF alone, and cardiovascular-focused disease-modifying agents have proven less effective in HFDM indicating a key role of the periphery. This review combines current clinical knowledge and basic biological mechanisms to address the critical emergence of skeletal muscle atrophy in patients with HFDM as a key driver of symptoms. We discuss how the degree of skeletal muscle wasting in patients with HFDM is likely underpinned by a variety of mechanisms that include mitochondrial dysfunction, insulin resistance, inflammation, and lipotoxicity. Given many atrophic triggers (e.g. ubiquitin proteasome/autophagy/calpain activity and supressed IGF1-Akt-mTORC1 signalling) are linked to increased production of reactive oxygen species, we speculate that a higher pro-oxidative state in HFDM could be a unifying mechanism that promotes accelerated fibre atrophy. Overall, our proposal is that patients with HFDM represent a unique clinical population, prompting a review of treatment strategies including further focus on elucidating potential mechanisms and therapeutic targets of muscle atrophy in these distinct patients.

Exercise Tolerance in Patients Treated With a Durable Left Ventricular Assist Device: Importance of Myocardial Recovery

The number of patients supported with left ventricular assist devices (LVADs) is growing and support times are increasing. This has led to a greater focus on functional capacity of these patients. LVADs greatly improve heart failure symptoms, but surprisingly, improvement in peak oxygen uptake (pVO₂) is small and remains decreased at approximately 50% of normal values. Inadequate increase in cardiac output during exercise is the main responsible factor for the low pVO₂ in LVAD recipients. Some patients experience LV recovery during mechanical unloading and these patients have a higher pVO₂. Here we review the various components determining exercise cardiac output in LVAD recipients and discuss the potential impact of cardiac recovery on these components. LV recovery may affect several components, leading to improved hemodynamics during exercise and, in turn, physical capacity in patients with advanced heart failure undergoing LVAD implantation.

Adiponectin in heart failure

The adipose tissue, apart from storing energy, plays a role of an endocrine organ. One of the most important adipokines secreted by adipose tissue is adiponectin, which is also produced by cardiomyocytes and connective tissue cells within the heart. Adiponectin is known for its beneficial effect on the metabolism and cardiovascular system and its low level is a factor of development of many cardiovascular diseases. Paradoxically, in the course of heart failure, adiponectin level gradually increases with the severity of the disease and higher adiponectin level is a factor of poor prognosis. As a result, there is a growing interest in adiponectin as a marker of heart failure progression and a predictor of prognosis in the course of this disease.

Anabolism to Catabolism: Serologic Clues to Nutritional Status in Heart Failure

PURPOSE OF REVIEW

Malnutrition, sarcopenia, and cachexia are areas of increasing interest in the management of patients with heart failure (HF). This review aims to examine the serological markers useful in guiding the physician in identification of these patients.

RECENT FINDINGS

Traditional nutritional biomarkers including albumin/prealbumin, iron, and vitamin D deficiencies predict poor prognosis in malnutrition and HF. Novel biomarkers including ghrelin, myostatin, C-terminal agrin fragment, and adiponectin have been identified as possible substrates and/or therapeutic targets in cardiac patients with sarcopenia and cachexia, though clinical trial data is limited to date. Increased focus on nutritional deficiency syndromes in heart failure has led to the use of established markers of malnutrition as well as the identification of novel biomarkers in the management of these patients, though to date, their usage has been confined to the academic domain and further research is required to establish their role in the clinical setting.

Relation of Pretransplant Peak Oxygen Consumption to Outcomes After Heart Transplantation

Peak exercise oxygen consumption (pVO₂) is an important predictor of prognosis in patients with heart failure (HF). The association between pretransplant pVO₂ and post-transplantation outcomes in HF patients has not been previously studied. We identified adult OHT recipients with available pVO₂ in the United Network for Organ Sharing registry (2000 to 2015). Patients were divided into 3 categories using Weber classification: class B (pVO₂ 16 to 20 ml/kg/min), class C (pVO₂ 10 to 16 ml/kg/min), and class D (pVO₂ <10 ml/kg/min). Postoperative outcomes (mortality, renal failure, rejection) were compared between the groups. A total of 9,623 patients were included in this analysis; the mean age was 54 ± 11 years, 74% were male, 75% were white and 59% had nonischemic etiology of HF. The mean pVO₂ was 11.7 ± 3.6 ml/kg/min: 1,202 (12.5%) in class B, 6,055 (62.9%) in class C, and 2,366 (24.6%) were in class D. At a median follow-up of 6.1 years, 2,730 (28.4%) died. Post-transplantation survival decreased with decreasing pVO₂; 1 and 5-year survival: B (92%, 80%), C (90%, 79%), and D (87%, 75%), p <0.001 by log-rank. After multiple adjustments, patients in class D had significantly higher post-transplantation mortality compared with class C (Hazard Ratio (HR) 1.21 [1.03 to 1.43], p = 0.02). When analyzed as a continuous variable, each 1 ml/kg/min increase in pVO₂ was associated with 2% decrease in mortality during follow-up (adjusted HR 0.98 [0.96 to 0.99], p <0.001). Patients in class D had significantly prolonged (>14 days) hospitalization (adjusted Odds Ratio (OR) 1.42 [1.20 to 1.68], p <0.001) and a trend toward increased need for dialysis (adjusted OR 1.36 [1.00 to 1.84], p = 0.05) compared with patients in class B. In this large cohort, lower pretransplant pVO₂ was associated with greater mortality and morbidity after OHT. These results suggest that earlier transplantation might improve post-transplantation outcomes in advanced HF patients.

Physical Activity Is Higher in Patients with Left Ventricular Assist Device Compared with Chronic Heart Failure

PURPOSE

Left ventricular assist devices (LVAD) are associated with an increased aerobic capacity in patients with chronic heart failure (CHF). However, studies evaluating the impact of LVAD implantation on physical activity (PA) are lacking. The aim of this study was to compare daily PA levels in participants with LVAD with well-matched CHF participants.

METHODS

Sixteen participants with an LVAD (age, 59.1 ± 10.8 yr) were case-matched to 16 participants with advanced CHF (age, 58.3 ± 8.7 yr), who were listed or being considered for cardiac transplantation. Participants underwent a cardiopulmonary exercise test to determine peak oxygen consumption (V˙O2 peak). Physical activity was monitored continuously for seven consecutive days with an Actiheart monitor.

RESULTS

V˙O2 peak in the CHF group (12.3 ± 3.5 mL·kg·min) was not significantly different to the LVAD group before LVAD implantation (10.4 ± 2.1 mL·kg·min), but was lower than in the LVAD group after implantation (15.8 ± 4.3 mL·kg·min; P < 0.05). Physical activity was higher in the LVAD (19.7 ± 6.4 kJ·kg·d) compared with the CHF group (11.6 ± 6.9 kJ·kg·d; P = 0.001). The LVAD participants spent more time performing moderate-intensity PA than their CHF counterparts (median, 26 min·d; interquartile range, 24-40 min·d vs median, 12 min·d; interquartile range, 9-16 min·d; P < 0.001). Physical activity was correlated with V˙O2 peak (r = 0.582; P = 0.001) across participants in the CHF and LVAD groups.

CONCLUSIONS

Higher levels of PA were observed in participants with LVAD compared with patients with advanced CHF. This may be due to a higher V˙O2 peak, resulting in an improved capacity to perform activities of daily living with less symptoms.

Frailty in the End-Stage Lung Disease or Heart Failure Patient: Implications for the Perioperative Transplant Clinician

The syndrome of frailty for patients undergoing heart or lung transplantation has been a recent focus for perioperative clinicians because of its association with postoperative complications and poor outcomes. Patients with end-stage cardiac or pulmonary failure may be under consideration for heart or lung transplantation along with bridging therapies such as ventricular assist device implantation or venovenous extracorporeal membrane oxygenation, respectively. Early identification of frail patients in an attempt to modify the risk of postoperative morbidity and mortality has become an important area of study over the last decade. Many quantification tools and risk prediction models for frailty have been developed but have not been evaluated extensively or standardized in the cardiothoracic transplant candidate population. Heightened awareness of frailty, coupled with a better understanding of distinct cellular mechanisms and biomarkers apart from end-stage organ disease, may play an important role in potentially reversing frailty related to organ failure. Furthermore, the clinical management of these critically ill patients may be enhanced by waitlist and postoperative physical rehabilitation and nutritional optimization.

Prognostic Implications of Changes in Albumin Following Left Ventricular Assist Device Implantation in Patients With Severe Heart Failure

Mechanical assist devices have emerged as an established therapeutic option for patients with end-stage heart failure. Because preimplant hypoalbuminemia is a known risk factor for adverse outcomes, we hypothesized that change in albumin may be a prognostic indicator in patients with continuous-flow left ventricular assist devices (cfLVADs). This is a retrospective single-center study of patients who underwent cfLVAD implantation (HeartMate II and HeartWare HVAD) at an academic center from 2008 to 2014. After excluding those who died, were transplanted, or hospitalized during the first 3 months post-implant, albumin values were obtained and stratified by an increase or a decrease from pre-implant to 3 months post-implant on 171 (81% male, mean age 57 ± 16 years) patients (139 for the survival analysis and 90 for the hospitalization analysis). Decrease in albumin from pre-implant to 3 months after implant correlated with increased mortality (hazard ratio 2.93, confidence interval 1.57 to 5.44, p <0.01) and reduced time to next hospitalization (hazard ratio 1.70, confidence interval 1.03 to 2.81, p = 0.04). The Kaplan-Meier survival curve estimated a 49.43% 2-year survival rate in those whose albumin decreased versus 83.62% in those whose albumin increased over 3 months (p <0.01). Improved outcomes were seen in patients whose albumin normalized versus patients whose albumin remained normal over 3 months. In conclusion, our study is the first to demonstrate the importance of change in albumin from pre- to postimplant on the prognosis of cfLVAD patients. Future studies are needed to determine whether therapeutic intervention to improve albumin post-implant will prevent hospitalizations and improve outcomes.

Integrated analysis of differential expression and alternative splicing of non-small cell lung cancer based on RNA sequencing

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, with high morbidity and mortality rates. Numerous diagnosis and treatment methods have been proposed, and the prognosis of NSCLC has improved to a certain extent. However, the mechanisms of NSCLC remain largely unknown, and additional studies are required. In the present study, the RNA sequencing dataset of NSCLC was downloaded from the Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/). The clean reads obtained from the raw data were mapped to the University of California Santa Cruz human genome (hg19), based on TopHat, and were assembled into transcripts via Cufflink. The differential expression (DE) and differential alternative splicing (DAS) genes were screened out through Cuffdiff and rMATS, respectively. The significantly enriched gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes pathways were obtained through the Database of Annotation, Visualization and Integrated Discovery (DAVID). Different numbers of DE and DAS genes were identified in different types of NSCLC samples, but a number of common functions and pathways were obtained, including biological processes associated with abnormal immune and cell activity. GO terms and pathways associated with substance metabolism, including the insulin signaling pathway and oxidative phosphorylation, were enriched in DAS genes rather than DE genes. Integrated analysis of differential expression and alternative splicing may be helpful in understanding the mechanisms of NSCLC, in addition to its early diagnosis and treatment.

Frailty in Advanced Heart Failure

Frailty is defined as a biological syndrome reflecting impaired physiologic reserve and heightened vulnerability to stressors. The evolving profile of heart failure (HF), increased survival of aging patients with complex comorbidities in parallel with the growing population undergoing mechanical circulatory support as lifetime therapy, means that advanced HF specialists are becoming aware of the burden of frailty and its downstream consequences on postintervention outcomes in these patients. The limited data available to date suggest that frailty is highly prevalent in patients with advanced HF and appears to provide prognostic information not captured by traditional risk assessment.

Angiotensin-II-induced Muscle Wasting is Mediated by 25-Hydroxycholesterol via GSK3β Signaling Pathway

While angiotensin II (ang II) has been implicated in the pathogenesis of cardiac cachexia (CC), the molecules that mediate ang II's wasting effect have not been identified. It is known TNF-α level is increased in patients with CC, and TNF-α release is triggered by ang II. We therefore hypothesized that ang II induced muscle wasting is mediated by TNF-α. Ang II infusion led to skeletal muscle wasting in wild type (WT) but not in TNF alpha type 1 receptor knockout (TNFR1KO) mice, suggesting that ang II induced muscle loss is mediated by TNF-α through its type 1 receptor. Microarray analysis identified cholesterol 25-hydroxylase (Ch25h) as the down stream target of TNF-α. Intraperitoneal injection of 25-hydroxycholesterol (25-OHC), the product of Ch25h, resulted in muscle loss in C57BL/6 mice, accompanied by increased expression of atrogin-1, MuRF1 and suppression of IGF-1/Akt signaling pathway. The identification of 25-OHC as an inducer of muscle wasting has implications for the development of specific treatment strategies in preventing muscle loss.

•

Ang II induced muscle wasting is mediated by TNF-α, which in turn up regulates Ch25h

•

Knockout of TNFR1 inhibits the production of 25-OHC and blocks ang II induced muscle loss in mice

•

25-OHC injection induces muscle wasting in mice by activating GSK3β

•

A GSK3β inhibitor blocks ang II induced muscle atrophy, which paves the way for targeted therapy to treat muscle wasting

Cardiac cachexia (CC), a condition characterized by weight loss and muscle wasting, is a serious complication that occurs in patients with chronic heart failure. This condition impairs patient's daily physical activity and their quality of life. Specific therapy for CC is currently unavailable because the pathogenesis remains unknown. Previous studies have identified angiotensin II (ang II) as an important mediator of CC. We now report a previously unrecognized role of 25-hydroxycholesterol (25-OHC) in mediating ang II induced muscle loss. The identification of 25-OHC as a muscle wasting inducer has implications for the development of therapeutic intervention in preserving muscle mass.

Frailty and cardiac rehabilitation: A call to action from the EAPC Cardiac Rehabilitation Section

Frailty is a geriatric syndrome characterised by a vulnerability status associated with declining function of multiple physiological systems and loss of physiological reserves. Two main models of frailty have been advanced: the phenotypic model (primary frailty) or deficits accumulation model (secondary frailty), and different instruments have been proposed and validated to measure frailty. However measured, frailty correlates to medical outcomes in the elderly, and has been shown to have prognostic value for patients in different clinical settings, such as in patients with coronary artery disease, after cardiac surgery or transvalvular aortic valve replacement, in patients with chronic heart failure or after left ventricular assist device implantation. The prevalence, clinical and prognostic relevance of frailty in a cardiac rehabilitation setting has not yet been well characterised, despite the increasing frequency of elderly patients in cardiac rehabilitation, where frailty is likely to influence the onset, type and intensity of the exercise training programme and the design of tailored rehabilitative interventions for these patients. Therefore, we need to start looking for frailty in elderly patients entering cardiac rehabilitation programmes and become more familiar with some of the tools to recognise and evaluate the severity of this condition. Furthermore, we need to better understand whether exercise-based cardiac rehabilitation may change the course and the prognosis of frailty in cardiovascular patients.

Epigallocatechin Gallate Reduces Slow-Twitch Muscle Fiber Formation and Mitochondrial Biosynthesis in C2C12 Cells by Repressing AMPK Activity and PGC-1α Expression

Epigallocatechin gallate (EGCG) is a major active compound in green tea polyphenols. EGCG acts as an antioxidant to prevent the cell damage caused by free radicals and their derivatives. In skeletal muscle, exercise causes the accumulation of intracellular reactive oxygen species (ROS) and promotes the formation of slow-type muscle fiber. To determine whether EGCG, as a ROS scavenger, has any effect on skeletal muscle fiber type, we applied different concentrations (0, 5, 25, and 50 μM) of EGCG in the culture medium of differentiated C2C12 cells for 2 days. The fiber-type composition, mitochondrial biogenesis-related gene expression, antioxidant and glucose metabolism enzyme activity, and ROS levels in C2C12 cells were then detected. According to our results, 5 μM EGCG significantly decreased the cellular activity of SDH, 25 μM EGCG significantly downregulated the MyHC I, PGC-1α, NRF-1, and p-AMPK levels and SDH activity while enhancing the CAT and GSH-Px activity and decreasing the intracellular ROS levels, and 50 μM EGCG significantly downregulated MyHC I, PGC-1α, and NRF-1 expression and HK and SDH activity while increasing LDH activity. Furthermore, 300 μM H2O2 and 0.5 mM AMPK agonist (AICAR) improved the expression of MyHC I, PGC-1α, and p-AMPK, which were all reversed by 25 μM EGCG. In conclusion, the effect of EGCG on C2C12 cells may occur through the reduction of the ROS level, thereby decreasing both AMPK activity and PGC-1α expression and eventually reducing slow-twitch muscle fiber formation and mitochondrial biosynthesis.

Insulin Signaling and Heart Failure

Heart failure is associated with generalized insulin resistance. Moreover, insulin-resistant states such as type 2 diabetes mellitus and obesity increases the risk of heart failure even after adjusting for traditional risk factors. Insulin resistance or type 2 diabetes mellitus alters the systemic and neurohumoral milieu, leading to changes in metabolism and signaling pathways in the heart that may contribute to myocardial dysfunction. In addition, changes in insulin signaling within cardiomyocytes develop in the failing heart. The changes range from activation of proximal insulin signaling pathways that may contribute to adverse left ventricular remodeling and mitochondrial dysfunction to repression of distal elements of insulin signaling pathways such as forkhead box O transcriptional signaling or glucose transport, which may also impair cardiac metabolism, structure, and function. This article will review the complexities of insulin signaling within the myocardium and ways in which these pathways are altered in heart failure or in conditions associated with generalized insulin resistance. The implications of these changes for therapeutic approaches to treating or preventing heart failure will be discussed.

Cardiac cachexia: hic et nunc

Cardiac cachexia (CC) is the clinical entity at the end of the chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely, the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. A better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia, and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.

Adiponectin resistance in skeletal muscle: pathophysiological implications in chronic heart failure

Skeletal muscle wasting is a common complication of chronic heart failure (CHF) and linked to poor patient prognosis. In recent years, adiponectin was postulated to be centrally involved in CHF-associated metabolic failure and muscle wasting. This review discusses current knowledge on the role of adiponectin in CHF. Particular emphasis will be given to the complex interaction mechanisms and the intracellular pathways underlying adiponectin resistance in skeletal muscle of CHF patients. In this review, we propose that the resistance process is multifactorial, integrating abnormalities emanating from insulin signalling, mitochondrial biogenesis, and ceramide metabolism.

Effects of intravenous iron therapy in iron-deficient patients with systolic heart failure: a meta-analysis of randomized controlled trials

AIMS

The aim of this study was to assess the net clinical and prognostic effects of intravenous (i.v.) iron therapy in patients with systolic heart failure (HF) and iron deficiency (ID).

METHODS AND RESULTS

We performed an aggregate data meta-analysis (random effects model) of randomized controlled trials that evaluated the effects of i.v. iron therapy in iron-deficient patients with systolic HF. We searched electronic databases up to September 2014. We identified five trials which fulfilled the inclusion criteria (509 patients received i.v. iron therapy in comparison with 342 controls). Intravenous iron therapy has been shown to reduce the risk of the combined endpoint of all-cause death or cardiovascular hospitalization [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.30-0.64, P < 0.0001], and the combined endpoint of cardiovascular death or hospitalization for worsening HF (OR 0.39, 95% CI 0.24-0.63, P = 0.0001). Intravenous iron therapy resulted in a reduction in NYHA class (data are reported as a mean net effect with 95% CIs for all continuous variables) (-0.54 class, 95% CI -0.87 to -0.21, P = 0.001); an increase in 6-min walking test distance (+31 m, 95% CI 18-43, P < 0.0001); and an improvement in quality of life [Kansas City Cardiomyopathy Questionnaire (KCCQ) score +5.5 points, 95% CI 2.8-8.3, P < 0.0001; European Quality of Life-5 Dimensions (EQ-5D) score +4.1 points, 95% CI 0.8-7.3, P = 0.01; Minnesota Living With Heart Failure Questionnaire (MLHFQ) score -19 points, 95% CI:-23 to -16, P < 0.0001; and Patient Global Assessment (PGA) +0.70 points, 95% CI 0.31-1.09, P = 0004].

CONCLUSION

The evidence indicates that i.v. iron therapy in iron-deficient patients with systolic HF improves outcomes, exercise capacity, and quality of life, and alleviates HF symptoms.

Sleep-disordered breathing and cardiovascular disease

Sleep-disordered breathing (SDB) is a common comorbidity in a number of cardiovascular diseases, and mounting clinical evidence demonstrates that it has important implications in the long-term outcomes of patients with cardiovascular disease (CVD). While recognition among clinicians of the role of SDB in CVD is increasing, it too often remains neglected in the routine care of patients with CVD, and therefore remains widely undiagnosed and untreated. In this article, we provide an overview of SDB and its relationship to CVD, with the goal of helping cardiovascular clinicians better recognize and treat this important comorbidity in their patients. We will describe the two major types of SDB and discuss the pathophysiologic, diagnostic, and therapeutic considerations of SDB in patients with CVD.

Evidence for partial pharmaceutical reversal of the cancer anorexia-cachexia syndrome: the case of anamorelin

A major component of the cancer anorexia-cachexia syndrome is a decline in food intake. Up until now none of the drugs that improve appetite also improve skeletal muscle. Recent studies have suggested that the oral ghrelin-analog, anamorelin, increased food intake and muscle mass. Unfortunately, it does not increase muscle power. Its regulatory future is uncertain, although it has important clinical effects.

Cardiac cachexia: hic et nunc: "hic et nunc" - here and now

Cardiac cachexia (CC) is the clinical entity at the end of chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. Better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick-up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.

The wasting continuum in heart failure: from sarcopenia to cachexia

Sarcopenia (muscle wasting) and cachexia share some pathophysiological aspects. Sarcopenia affects approximately 20 %, cachexia <10 % of ambulatory patients with heart failure (HF). Whilst sarcopenia means loss of skeletal muscle mass and strength that predominantly affects postural rather than non-postural muscles, cachexia means loss of muscle and fat tissue that leads to weight loss. The wasting continuum in HF implies that skeletal muscle is lost earlier than fat tissue and may lead from sarcopenia to cachexia. Both tissues require conservation, and therapies that stop the wasting process have tremendous therapeutic appeal. The present paper reviews the pathophysiology of muscle and fat wasting in HF and discusses potential treatments, including exercise training, appetite stimulants, essential amino acids, growth hormone, testosterone, electrical muscle stimulation, ghrelin and its analogues, ghrelin receptor agonists and myostatin antibodies.

Frailty in Advanced Heart Failure: A Consequence of Aging or a Separate Entity?

There are over 5 million Americans with heart failure (HF), the majority of whom are over age 65. Frailty is a systemic syndrome associated with aging that produces subclinical dysfunction across multiple organ systems and leads to an increased risk for morbidity and mortality. The prevalence of frailty is about 10% in community-dwelling elderly and 20% in those with advanced HF, and increases in both cohorts with age. Yet the relationship between the primary frailty of aging and frailty secondary to HF remains poorly defined. Whether the frailty of these two populations share similar etiologies or exist as separate entities is unknown. Teasing apart potential molecular, cellular, and functional differences between the frailty of aging and that of advanced HF has implications for risk stratification, quality of life, and pharmacological and therapeutic interventions for advanced HF patients.