Molecular Mechanisms of Diaphragm Myopathy in Humans With Severe Heart Failure.

[Figure: see text].

Empagliflozin Preserves Skeletal Muscle Function in a HFpEF Rat Model.

Besides structural alterations in the myocardium, heart failure with preserved ejection fraction (HFpEF) is also associated with molecular and physiological alterations of the peripheral skeletal muscles (SKM) contributing to exercise intolerance often seen in HFpEF patients. Recently, the use of Sodium-Glucose-Transporter 2 inhibitors (SGLT2i) in clinical studies provided evidence for a significant reduction in the combined risk of cardiovascular death or hospitalization for HFpEF. The present study aimed to further elucidate the impact of Empagliflozin (Empa) on: (1) SKM function and metabolism and (2) mitochondrial function in an established HFpEF rat model. At the age of 24 weeks, obese ZSF1 rats were randomized either receiving standard care or Empa in the drinking water. ZSF1 lean animals served as healthy controls. After 8 weeks of treatment, echocardiography and SKM contractility were performed. Mitochondrial function was assessed in saponin skinned fibers and SKM tissue was snap frozen for molecular analyses. HFpEF was evident in the obese animals when compared to lean-increased E/é and preserved left ventricular ejection fraction. Empa treatment significantly improved E/é and resulted in improved SKM contractility with reduced intramuscular lipid content. Better mitochondrial function (mainly in complex IV) with only minor modulation of atrophy-related proteins was seen after Empa treatment. The results clearly documented a beneficial effect of Empa on SKM function in the present HFpEF model. These effects were accompanied by positive effects on mitochondrial function possibly modulating SKM function.

Effect of High-Intensity Interval Training, Moderate Continuous Training, or Guideline-Based Physical Activity Advice on Peak Oxygen Consumption in Patients With Heart Failure With Preserved Ejection Fraction: A Randomized Clinical Trial.

Importance: Endurance exercise is effective in improving peak oxygen consumption (peak V̇o2) in patients with heart failure with preserved ejection fraction (HFpEF). However, it remains unknown whether differing modes of exercise have different effects. Objective: To determine whether high-intensity interval training, moderate continuous training, and guideline-based advice on physical activity have different effects on change in peak V̇o2 in patients with HFpEF. Design, Setting, and Participants: Randomized clinical trial at 5 sites (Berlin, Leipzig, and Munich, Germany; Antwerp, Belgium; and Trondheim, Norway) from July 2014 to September 2018. From 532 screened patients, 180 sedentary patients with chronic, stable HFpEF were enrolled. Outcomes were analyzed by core laboratories blinded to treatment groups; however, the patients and staff conducting the evaluations were not blinded. Interventions: Patients were randomly assigned (1:1:1; n = 60 per group) to high-intensity interval training (3 × 38 minutes/week), moderate continuous training (5 × 40 minutes/week), or guideline control (1-time advice on physical activity according to guidelines) for 12 months (3 months in clinic followed by 9 months telemedically supervised home-based exercise). Main Outcomes and Measures: Primary end point was change in peak V̇o2 after 3 months, with the minimal clinically important difference set at 2.5 mL/kg/min. Secondary end points included changes in metrics of cardiorespiratory fitness, diastolic function, and natriuretic peptides after 3 and 12 months. Results: Among 180 patients who were randomized (mean age, 70 years; 120 women [67%]), 166 (92%) and 154 (86%) completed evaluation at 3 and 12 months, respectively. Change in peak V̇o2 over 3 months for high-intensity interval training vs guideline control was 1.1 vs -0.6 mL/kg/min (difference, 1.5 [95% CI, 0.4 to 2.7]); for moderate continuous training vs guideline control, 1.6 vs -0.6 mL/kg/min (difference, 2.0 [95% CI, 0.9 to 3.1]); and for high-intensity interval training vs moderate continuous training, 1.1 vs 1.6 mL/kg/min (difference, -0.4 [95% CI, -1.4 to 0.6]). No comparisons were statistically significant after 12 months. There were no significant changes in diastolic function or natriuretic peptides. Acute coronary syndrome was recorded in 4 high-intensity interval training patients (7%), 3 moderate continuous training patients (5%), and 5 guideline control patients (8%). Conclusions and Relevance: Among patients with HFpEF, there was no statistically significant difference in change in peak V̇o2 at 3 months between those assigned to high-intensity interval vs moderate continuous training, and neither group met the prespecified minimal clinically important difference compared with the guideline control. These findings do not support either high-intensity interval training or moderate continuous training compared with guideline-based physical activity for patients with HFpEF. Trial Registration: ClinicalTrials.gov Identifier: NCT02078947.

Sacubitril/Valsartan Improves Diastolic Function But Not Skeletal Muscle Function in a Rat Model of HFpEF.

The angiotensin receptor/neprilysin inhibitor Sacubitril/Valsartan (Sac/Val) has been shown to be beneficial in patients suffering from heart failure with reduced ejection fraction (HFrEF). However, the impact of Sac/Val in patients presenting with heart failure with preserved ejection fraction (HFpEF) is not yet clearly resolved. The present study aimed to reveal the influence of the drug on the functionality of the myocardium, the skeletal muscle, and the vasculature in a rat model of HFpEF. Female obese ZSF-1 rats received Sac/Val as a daily oral gavage for 12 weeks. Left ventricle (LV) function was assessed every four weeks using echocardiography. Prior to organ removal, invasive hemodynamic measurements were performed in both ventricles. Vascular function of the carotid artery and skeletal muscle function were monitored. Sac/Val treatment reduced E/é ratios, left ventricular end diastolic pressure (LVEDP) and myocardial stiffness as well as myocardial fibrosis and heart weight compared to the obese control group. Sac/Val slightly improved endothelial function in the carotid artery but had no impact on skeletal muscle function. Our results demonstrate striking effects of Sac/Val on the myocardial structure and function in a rat model of HFpEF. While vasodilation was slightly improved, functionality of the skeletal muscle remained unaffected.

Exercise training in patients with chronic heart failure promotes restoration of high-density lipoprotein functional properties.

RATIONALE: High-density lipoprotein (HDL) exerts endothelial-protective effects via stimulation of endothelial cell (EC) nitric oxide (NO) production. This function is impaired in patients with cardiovascular disease. Protective effects of exercise training (ET) on endothelial function have been demonstrated. OBJECTIVE: This study was performed to evaluate the impact of ET on HDL-mediated protective effects and the respective molecular pathways in patients with chronic heart failure (CHF). METHODS AND RESULTS: HDL was isolated from 16 healthy controls (HDL(healthy)) and 16 patients with CHF-NYHA-III (HDL(NYHA-IIIb)) before and after ET, as well as from 8 patients with CHF-NYHA-II (HDL(NYHA-II)). ECs were incubated with HDL, and phosphorylation of eNOS-Ser(1177), eNOS-Thr(495), PKC-ßII-Ser(660), and p70S6K-Ser(411) was evaluated. HDL-bound malondialdehyde and HDL-induced NO production by EC were quantified. Endothelial function was assessed by flow-mediated dilatation. The proteome of HDL particles was profiled by shotgun LC-MS/MS. Incubation of EC with HDL(NYHA-IIIb) triggered a lower stimulation of phosphorylation at eNOS-Ser(1177) and a higher phosphorylation at eNOS-Thr(495) when compared with HDL(healthy). This was associated with lower NO production of EC. In addition, an elevated activation of p70S6K, PKC-ßII by HDL(NYHA-IIIb), and a higher amount of malondialdehyde bound to HDL(NYHA-IIIb) compared with HDL(healthy) was measured. In healthy individuals, ET had no effect on HDL function, whereas ET of CHF-NYHA-IIIb significantly improved HDL function. A correlation between changes in HDL-induced NO production and flow-mediated dilatation improvement by ET was evident. CONCLUSIONS: These results demonstrate that HDL function is impaired in CHF and that ET improved the HDL-mediated vascular effects. This may be one mechanism how ET exerts beneficial effects in CHF.

Empagliflozin Improves Diastolic Function in HFpEF by Restabilizing the Mitochondrial Respiratory Chain.

BACKGROUND: Clinical studies demonstrated beneficial effects of sodium-glucose-transporter 2 inhibitors on the risk of cardiovascular death in patients with heart failure with preserved ejection fraction (HFpEF). However, underlying processes for cardioprotection remain unclear. The present study focused on the impact of empagliflozin (Empa) on myocardial function in a rat model with established HFpEF and analyzed underlying molecular mechanisms. METHODS: Obese ZSF1 (Zucker fatty and spontaneously hypertensive) rats were randomized to standard care (HFpEF, n=18) or Empa (HFpEF/Empa, n=18). ZSF1 lean rats (con, n=18) served as healthy controls. Echocardiography was performed at baseline and after 4 and 8 weeks, respectively. After 8 weeks of treatment, hemodynamics were measured invasively, mitochondrial function was assessed and myocardial tissue was collected for either molecular and histological analyses or transmission electron microscopy. RESULTS: In HFpEF Empa significantly improved diastolic function (E/é: con: 17.5±2.8; HFpEF: 24.4±4.6; P<0.001 versus con; HFpEF/Empa: 19.4±3.2; P<0.001 versus HFpEF). This was accompanied by improved hemodynamics and calcium handling and by reduced inflammation, hypertrophy, and fibrosis. Proteomic analysis demonstrated major changes in proteins involved in mitochondrial oxidative phosphorylation. Cardiac mitochondrial respiration was significantly impaired in HFpEF but restored by Empa (Vmax complex IV: con: 0.18±0.07 mmol O2/s/mg; HFpEF: 0.13±0.05 mmol O2/s/mg; P<0.041 versus con; HFpEF/Empa: 0.21±0.05 mmol O2/s/mg; P=0.012 versus HFpEF) without alterations of mitochondrial content. The expression of cardiolipin, an essential stability/functionality-mediating phospholipid of the respiratory chain, was significantly decreased in HFpEF but reverted by Empa (con: 15.9±1.7 nmol/mg protein; HFpEF: 12.5±1.8 nmol/mg protein; P=0.002 versus con; HFpEF/Empa: 14.5±1.8 nmol/mg protein; P=0.03 versus HFpEF). Transmission electron microscopy revealed a reduced size of mitochondria in HFpEF, which was restored by Empa. CONCLUSIONS: The study demonstrates beneficial effects of Empa on diastolic function, hemodynamics, inflammation, and cardiac remodeling in a rat model of HFpEF. These effects were mediated by improved mitochondrial respiratory capacity due to modulated cardiolipin and improved calcium handling.

Comparison of exercise training modalities and change in peak oxygen consumption in heart failure with preserved ejection fraction: a secondary analysis of the OptimEx-Clin trial.

AIMS: Exercise training (ET) is an effective therapy in heart failure with preserved ejection fraction (HFpEF), but the influence of different ET characteristics is unclear. We aimed to evaluate the associations between ET frequency, duration, intensity [% heart rate reserve (%HRR)] and estimated energy expenditure (EEE) with the change in peak oxygen consumption (V̇O2) over 3 months of moderate continuous training (MCT, 5×/week) or high-intensity interval training (HIIT, 3×/week) in HFpEF. METHODS AND RESULTS: ET duration and heart rate (HR) were recorded with a smartphone application. EEE was calculated using the HR data during ET and the individual HR-V̇O2 relationships during cardiopulmonary exercise testing. Differences between groups and associations between ET characteristics and peak V̇O2 change were assessed with linear regression analyses. Peak V̇O2 improved by 9.2 ± 13.2% after MCT and 8.7 ± 15.9% after HIIT (P = 0.67). The average EEE of 1 HIIT session was equivalent to ∼1.42 MCT sessions and when adjusted for EEE, the mean difference between MCT and HIIT was -0.1% (P = 0.98). For both MCT and HIIT, peak V̇O2 change was positively associated with ET frequency (MCT: R2 = 0.103; HIIT: R2 = 0.149) and duration/week (MCT: R2 = 0.120; HIIT: R2 = 0.125; all P < 0.05). Average %HRR was negatively associated with peak V̇O2 change in MCT (R2 = 0.101; P = 0.034), whereas no significant association was found in HIIT (P = 0.234). Multiple regression analyses explained ∼1/3 of the variance in peak V̇O2 change. CONCLUSION: In HFpEF, isocaloric HIIT and MCT seem to be equally effective over 3 months. Within each mode, increasing ET frequency or duration/week may be more effective to improve peak V̇O2 than increasing ET intensity.

In heart failure with preserved ejection fraction, endurance exercise training is one of the most effective treatment options to improve exercise tolerance, however, the influence of different exercise training characteristics such as training frequency, duration, intensity and energy expenditure have not yet been evaluated. A high-intensity interval training session of 38 min was associated with a ∼42% higher energy expenditure compared with a moderate continuous training session of 40 min. After taking into account the different energy expenditure, both training modes had equal effects on exercise tolerance. Therefore, patient preferences should be considered when planning an exercise program to improve treatment adherence. A higher number of exercise sessions per week or a higher weekly duration of exercise were more closely related to an increase in exercise tolerance than a higher exercise intensity. Therefore, increasing the frequency or weekly duration of exercise may be more effective in improving exercise tolerance than increasing exercise intensity.

Clinical presentation, shock severity and mortality in patients with de novo versus acute-on-chronic heart failure-related cardiogenic shock.

AIMS: Heart failure-related cardiogenic shock (HF-CS) accounts for a significant proportion of CS cases. Whether patients with de novo HF and those with acute-on-chronic HF in CS differ in clinical characteristics and outcome remains unclear. The aim of this study was to evaluate differences in clinical presentation and mortality between patients with de novo and acute-on-chronic HF-CS. METHODS AND RESULTS: In this international observational study, patients with HF-CS from 16 tertiary care centres in five countries were enrolled between 2010 and 2021. To investigate differences in clinical presentation and 30-day mortality, adjusted logistic/Cox regression models were fitted. Patients (n = 1030) with HF-CS were analysed, of whom 486 (47.2%) presented with de novo HF-CS and 544 (52.8%) with acute-on-chronic HF-CS. Traditional markers of CS severity (e.g. blood pressure, heart rate and lactate) as well as use of treatments were comparable between groups. However, patients with acute-on-chronic HF-CS were more likely to have a higher CS severity and also a higher mortality risk, after adjusting for relevant confounders (de novo HF 45.5%, acute-on-chronic HF 55.9%, adjusted hazard ratio 1.38, 95% confidence interval 1.10-1.72, p = 0.005). CONCLUSION: In this large HF-CS cohort, acute-on-chronic HF-CS was associated with more severe CS and higher mortality risk compared to de novo HF-CS, although traditional markers of CS severity and use of treatments were comparable. These findings highlight the vast heterogeneity of patients with HF-CS, emphasize that HF chronicity is a relevant disease modifier in CS, and indicate that future clinical trials should account for this.

Association between left ventricular ejection fraction, mortality and use of mechanical circulatory support in patients with non-ischaemic cardiogenic shock.

BACKGROUND: Currently, use of mechanical circulatory support (MCS) in non-ischaemic cardiogenic shock (CS) is predominantly guided by shock-specific markers, and not by markers of cardiac function. We hypothesise that left ventricular ejection fraction (LVEF) can identify patients with a higher likelihood to benefit from MCS and thus help to optimise their expected benefit. METHODS: Patients with non-ischaemic CS and available data on LVEF from 16 tertiary-care centres in five countries were analysed. Cox regression models were fitted to evaluate the association between LVEF and mortality, as well as the interaction between LVEF, MCS use and mortality. RESULTS: N = 807 patients were analysed: mean age 63 [interquartile range (IQR) 51.5-72.0] years, 601 (74.5%) male, lactate 4.9 (IQR 2.6-8.5) mmol/l, LVEF 20 (IQR 15-30) %. Lower LVEF was more frequent amongst patients with more severe CS, and MCS was more likely used in patients with lower LVEF. There was no association between LVEF and 30-day mortality risk in the overall study cohort. However, there was a significant interaction between MCS use and LVEF, indicating a lower 30-day mortality risk with MCS use in patients with LVEF ≤ 20% (hazard ratio 0.72, 95% confidence interval 0.51-1.02 for LVEF ≤ 20% vs. hazard ratio 1.31, 95% confidence interval 0.85-2.01 for LVEF > 20%, interaction-p = 0.017). CONCLUSION: This retrospective study may indicate a lower mortality risk with MCS use only in patients with severely reduced LVEF. This may propose the inclusion of LVEF as an adjunctive parameter for MCS decision-making in non-ischaemic CS, aiming to optimise the benefit-risk ratio.

Sex-related differences in patients presenting with heart failure-related cardiogenic shock.

BACKGROUND: Heart failure-related cardiogenic shock (HF-CS) accounts for a significant proportion of all CS cases. Nevertheless, there is a lack of evidence on sex-related differences in HF-CS, especially regarding use of treatment and mortality risk in women vs. men. This study aimed to investigate potential differences in clinical presentation, use of treatments, and mortality between women and men with HF-CS. METHODS: In this international observational study, patients with HF-CS (without acute myocardial infarction) from 16 tertiary-care centers in five countries were enrolled between 2010 and 2021. Logistic and Cox regression models were used to assess differences in clinical presentation, use of treatments, and 30-day mortality in women vs. men with HF-CS. RESULTS: N = 1030 patients with HF-CS were analyzed, of whom 290 (28.2%) were women. Compared to men, women were more likely to be older, less likely to have a known history of heart failure or cardiovascular risk factors, and lower rates of highly depressed left ventricular ejection fraction and renal dysfunction. Nevertheless, CS severity as well as use of treatments were comparable, and female sex was not independently associated with 30-day mortality (53.0% vs. 50.8%; adjusted HR 0.94, 95% CI 0.75-1.19). CONCLUSIONS: In this large HF-CS registry, sex disparities in risk factors and clinical presentation were observed. Despite these differences, the use of treatments was comparable, and both sexes exhibited similarly high mortality rates. Further research is necessary to evaluate if sex-tailored treatment, accounting for the differences in cardiovascular risk factors and clinical presentation, might improve outcomes in HF-CS.

Locomotor and respiratory muscle abnormalities in HFrEF and HFpEF.

Heart failure (HF) is a chronic and progressive syndrome affecting worldwide billions of patients. Exercise intolerance and early fatigue are hallmarks of HF patients either with a reduced (HFrEF) or a preserved (HFpEF) ejection fraction. Alterations of the skeletal muscle contribute to exercise intolerance in HF. This review will provide a contemporary summary of the clinical and molecular alterations currently known to occur in the skeletal muscles of both HFrEF and HFpEF, and thereby differentiate the effects on locomotor and respiratory muscles, in particular the diaphragm. Moreover, current and future therapeutic options to address skeletal muscle weakness will be discussed focusing mainly on the effects of exercise training.

Baroreflex activation therapy in patients with heart failure with reduced ejection fraction: a single-centre experience.

AIMS: Heart failure with reduced ejection fraction (HFrEF) is associated with excessive sympathetic and impaired parasympathetic activity. The Barostim Neo™ device is used for electronical baroreflex activation therapy (BAT) to counteract autonomic nervous system dysbalance. Randomized trials have shown that BAT improves walking distance and reduces N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels at least in patients with only moderate elevation at baseline. Its impact on the risk of heart failure hospitalization (HFH) and death is not yet established, and experience in clinical routine is limited. METHODS AND RESULTS: We report on patient characteristics and clinical outcome in a retrospective, non-randomized single-centre registry of BAT in HFrEF. Patients in the New York Heart Association (NYHA) Classes III and IV with a left ventricular ejection fraction (LVEF) <35% despite guideline-directed medical therapy were eligible. Symptom burden, echocardiography, and laboratory testing were assessed at baseline and after 12 months. Clinical events of HFH and death were recorded at routine clinical follow-up. Data are shown as number (%) or median (inter-quartile range). Between 2014 and 2020, 30 patients were treated with BAT. Median age was 67 (63-77) years, and 27 patients (90%) were male. Most patients (83%) had previous HFH. Device implantation was successful in all patients. At 12 months, six patients had died and three were alive but did not attend follow-up. NYHA class was III/IV in 26 (87%)/4 (13%) patients at baseline, improved in 19 patients, and remained unchanged in 5 patients (P < 0.001). LVEF improved from 25.5 (20.0-30.5) % at baseline to 30.0 (25.0-36.0) % at 12 months (P = 0.014). Left ventricular end-diastolic diameter remained unchanged. A numerical decrease in NT-proBNP [3165 (880-8085) vs. 1001 (599-3820) pg/mL] was not significant (P = 0.526). Median follow-up for clinical events was 16 (10-33) months. Mortality at 1 (n = 6, 20%) and 3 years (n = 10, 33%) was as expected by the Meta-Analysis Global Group in Chronic Heart Failure risk score. Despite BAT, event rate was high in patients with NYHA Class IV, NT-proBNP levels >1600 pg/mL, or estimated glomerular filtration rate (eGFR) <30 mL/min at baseline. NYHA class and eGFR were independent predictors of mortality. CONCLUSIONS: Patients with HFrEF who are selected for BAT are in a stage of worsening or even advanced heart failure. BAT appears to be safe and improves clinical symptoms and-to a modest degree-left ventricular function. The risk of death remains high in advanced disease stages. Patient selection seems to be crucial, and the impact of BAT in earlier disease stages needs to be established.

Trajectory and correlates of pulmonary congestion by lung ultrasound in patients with acute myocardial infarction: insights from PARADISE-MI.

AIM: PARADISE-MI examined the efficacy of sacubitril/valsartan in acute myocardial infarction (AMI) complicated by reduced left ventricular ejection fraction (LVEF), pulmonary congestion, or both. We sought to assess the trajectory of pulmonary congestion using lung ultrasound (LUS) and its association with cardiac structure and function in a pre-specified substudy. METHODS AND RESULTS: Patients without prior heart failure (HF) underwent eight-zone LUS and echocardiography at baseline (±2 days of randomization) and after 8 months. B-lines were quantified offline, blinded to treatment, clinical findings, time point, and outcomes. Among 152 patients (median age 65, 32% women, mean LVEF 41%), B-lines were detectable in 87% at baseline [median B-line count: 4 (interquartile range 2-8)]. Among 115 patients with LUS data at baseline and follow-up, B-lines decreased significantly from baseline (mean ± standard deviation: -1.6 ± 7.3; P = 0.018). The proportion of patients without pulmonary congestion at follow-up was significantly higher in those with fewer B-lines at baseline. Adjusted for baseline, B-lines at follow-up were on average 6 (95% confidence interval: 3-9) higher in patients who experienced an intercurrent HF event vs. those who did not (P = 0.001). A greater number of B-lines at baseline was associated with larger left atrial size, higher E/e' and E/A ratios, greater degree of mitral regurgitation, worse right ventricular systolic function, and higher tricuspid regurgitation velocity (P-trend <0.05 for all). CONCLUSION: In this AMI cohort, B-lines, indicating pulmonary congestion, were common at baseline and, on average, decreased significantly from baseline to follow-up. Worse pulmonary congestion was associated with prognostically important echocardiographic markers.

Impact of educational attainment on preventive efforts after myocardial infarction: results of the IPP and NET-IPP trials.

AIMS: Educational attainment might impact secondary prevention after myocardial infarction (MI). The purpose of the present study was to compare the rate of risk factors and the efficacy of an intensive prevention program (IPP), performed by prevention assistants and supervised by physicians, in patients with MI and different levels of education. METHODS: In this post hoc analysis of the multicenter IPP and NET-IPP trials, patients with MI were stratified into two groups according to educational attainment: no "Abitur" (no A) vs. "Abitur" or university degree (AUD). The groups were compared at the time of index MI and after 12-month IPP vs. usual care. RESULTS: Out of n = 462 patients with MI, 76.0% had no A and 24.0% had AUD. At the time of index, MI rates of obesity (OR 2.4; 95%CI 1.4-4.0), smoking (OR 2.2, 95%CI 1.4-3.6), and physical inactivity (OR 1.6; 95%CI 1.0-2.5) were significantly elevated in patients with no A. At 12 months after index MI, larger improvements of the risk factors smoking and physical inactivity were observed in patients with IPP and no A than in patients with IPP and AUD or with usual care. LDL cholesterol levels were reduced by IPP compared to usual care, with no difference between no A vs. AUD. A matched-pair analysis revealed that high baseline risk was an important reason for the large risk factor reductions in patients with IPP and no A. CONCLUSION: The study demonstrates that patients with MI and lower educational level have an increased rate of lifestyle-related risk factors and a 12-month IPP, which is primarily performed by non-physician prevention assistants, is effective to improve prevention in this high-risk cohort.

Impact of Different Training Modalities on Molecular Alterations in Skeletal Muscle of Patients With Heart Failure With Preserved Ejection Fraction: A Substudy of the OptimEx Trial.

BACKGROUND: Exercise intolerance is a cardinal feature of heart failure with preserved ejection fraction and so far exercise training (ET) is the most effective treatment. Since the improvement in exercise capacity is only weakly associated with changes in diastolic function other mechanisms, like changes in the skeletal muscle, contribute to improvement in peak oxygen consumption. The aim of the present study was to analyze molecular changes in skeletal muscle of patients with heart failure with preserved ejection fraction performing different ET modalities. METHODS: Skeletal muscle biopsies were taken at study begin and after 3 and 12 months from patients with heart failure with preserved ejection fraction randomized either into a control group (guideline based advice for ET), a high-intensity interval training group (HIIT) or a moderate continuous training group. The first 3 months of ET were supervised in-hospital followed by 9 months home-based ET. Protein and mRNA expression of atrophy-related proteins, enzyme activities of enzymes linked to energy metabolism and satellite cells (SCs) were quantified. RESULTS: Exercise capacity improved 3 months after moderate continuous exercise training and HIIT. This beneficial effect was lost after 12 months. HIIT mainly improved markers of energy metabolism and the amount and function of SC, with minor changes in markers for muscle atrophy. Only slight changes were observed after moderate continuous exercise training. The molecular changes were no longer detectable after 12 months. CONCLUSIONS: Despite similar improvements in exercise capacity by HIIT and moderate continuous exercise training after 3 months, only HIIT altered proteins related to energy metabolism and amount/function of SC. These effects were lost after switching from in-hospital to at-home-based ET. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02078947.

Impact of different training modalities on high-density lipoprotein function in HFpEF patients: a substudy of the OptimEx trial.

AIMS: In heart failure with preserved ejection fraction (HFpEF), the reduction of nitric oxide (NO)-bioavailability and consequently endothelial dysfunction leads to LV stiffness and diastolic dysfunction of the heart. Besides shear stress, high-density lipoprotein (HDL) stimulates endothelial cells to increased production of NO via phosphorylation of endothelial nitric oxide synthase (eNOS). For patients with heart failure with reduced ejection fraction, earlier studies demonstrated a positive impact of exercise training (ET) on HDL-mediated eNOS activation. The study aims to investigate the influence of ET on HDL-mediated phosphorylation of eNOS in HFpEF patients. METHODS AND RESULTS: The present study is a substudy of the OptimEx-Clin trial. The patients were randomized to three groups: (i) HIIT (high-intensity interval training; (ii) MCT (moderate-intensity continuous training); and (iii) CG (control group). Supervised training at study centres was offered for the first 3 months. From months 4-12, training sessions were continued at home with the same exercise protocol as performed during the in-hospital phase. Blood was collected at baseline, after 3, and 12 months, and HDL was isolated by ultracentrifugation. Human aortic endothelial cells were incubated with isolated HDL, and HDL-induced eNOS phosphorylation at Ser1177 and Thr495 was assessed. Subsequently, the antioxidative function of HDL was evaluated by measuring the activity of HDL-associated paraoxonase-1 (Pon1) and the concentration of thiobarbituric acid-reactive substances (TBARS). After 3 months of supervised ET, HIIT resulted in increased HDL-mediated eNOS-Ser1177 phosphorylation. This effect diminished after 12 months of ET. No effect of HIIT was observed on HDL-mediated eNOS-Thr495 phosphorylation. MCT had no effect on HDL-mediated eNOS phosphorylation at Ser1177 and Thr495 . HIIT also increased Pon1 activity after 12 months of ET and reduced the concentration of TBARS in the serum after 3 and 12 months of ET. A negative correlation was observed between TBARS concentration and HDL-associated Pon1 activity in the HIIT group (r = -0.61, P < 0.05), and a trend was evident for the correlation between the change in HDL-mediated eNOS-Ser1177 phosphorylation and the change in peak V̇O2 after 3 months in the HIIT group (r = 0.635, P = 0.07). CONCLUSIONS: The present study documented that HIIT but not MCT exerts beneficial effects on HDL-mediated eNOS phosphorylation and HDL-associated Pon1 activity in HFpEF patients. These beneficial effects of HIIT were reduced as soon as the patients switched to home-based ET.

Targeting MuRF1 by small molecules in a HFpEF rat model improves myocardial diastolic function and skeletal muscle contractility.

BACKGROUND: About half of heart failure (HF) patients, while having preserved left ventricular function, suffer from diastolic dysfunction (so-called HFpEF). No specific therapeutics are available for HFpEF in contrast to HF where reduced ejection fractions (HFrEF) can be treated pharmacologically. Myocardial titin filament stiffening, endothelial dysfunction, and skeletal muscle (SKM) myopathy are suspected to contribute to HFpEF genesis. We previously described small molecules interfering with MuRF1 target recognition thereby attenuating SKM myopathy and dysfunction in HFrEF animal models. The aim of the present study was to test the efficacy of one small molecule (MyoMed-205) in HFpEF and to describe molecular changes elicited by MyoMed-205. METHODS: Twenty-week-old female obese ZSF1 rats received the MuRF1 inhibitor MyoMed-205 for 12 weeks; a comparison was made to age-matched untreated ZSF1-lean (healthy) and obese rats as controls. LV (left ventricle) function was assessed by echocardiography and by invasive haemodynamic measurements until week 32. At week 32, SKM and endothelial functions were measured and tissues collected for molecular analyses. Proteome-wide analysis followed by WBs and RT-PCR was applied to identify specific genes and affected molecular pathways. MuRF1 knockout mice (MuRF1-KO) SKM tissues were included to validate MuRF1-specificity. RESULTS: By week 32, untreated obese rats had normal LV ejection fraction but augmented E/e' ratios and increased end diastolic pressure and myocardial fibrosis, all typical features of HFpEF. Furthermore, SKM myopathy (both atrophy and force loss) and endothelial dysfunction were detected. In contrast, MyoMed-205 treated rats had markedly improved diastolic function, less myocardial fibrosis, reduced SKM myopathy, and increased SKM function. SKM extracts from MyoMed-205 treated rats had reduced MuRF1 content and lowered total muscle protein ubiquitination. In addition, proteomic profiling identified eight proteins to respond specifically to MyoMed-205 treatment. Five out of these eight proteins are involved in mitochondrial metabolism, dynamics, or autophagy. Consistent with the mitochondria being a MyoMed-205 target, the synthesis of mitochondrial respiratory chain complexes I + II was increased in treated rats. MuRF1-KO SKM controls also had elevated mitochondrial complex I and II activities, also suggesting mitochondrial activity regulation by MuRF1. CONCLUSIONS: MyoMed-205 improved myocardial diastolic function and prevented SKM atrophy/function in the ZSF1 animal model of HFpEF. Mechanistically, SKM benefited from an attenuated ubiquitin proteasome system and augmented synthesis/activity of proteins of the mitochondrial respiratory chain while the myocardium seemed to benefit from reduced titin modifications and fibrosis.

Cardiovascular risk factors, exercise capacity and health literacy in patients with chronic ischaemic heart disease and type 2 diabetes mellitus in Germany: Baseline characteristics of the Lifestyle Intervention in Chronic Ischaemic Heart Disease and Type 2 Diabetes study.

BACKGROUND: Lifestyle interventions are a cornerstone in the treatment of chronic ischaemic heart disease (CIHD) and type 2 diabetes mellitus (T2DM). This study aimed at identifying differences in clinical characteristics between categories of the common lifestyle intervention targets BMI, exercise capacity (peak V̇O2) and health literacy (HL). METHODS: Cross-sectional baseline characteristics of patients enrolled in the LeIKD trial (Clinicaltrials.gov NCT03835923) are presented in total, grouped by BMI, %-predicted peak V̇O2 and HL (HLS-EU-Q16), and compared to other clinical trials with similar populations. RESULTS: Among 499 patients (68.3±7.7 years; 16.2% female; HbA1c, 6.9±0.9%), baseline characteristics were similar to other trials and revealed insufficient treatment of several risk factors (LDL-C 92±34 mg/dl; BMI, 30.1±4.8 kg/m2; 69.6% with peak V̇O2<90% predicted). Patients with lower peak V̇O2 showed significantly higher (p < 0.05) CIHD and T2DM disease severity (HbA1c, CIHD symptoms, coronary artery bypass graft). Obese patients had a significantly higher prevalence of hypertension and higher triglyceride levels, whereas in patients with low HL both quality of life components (physical, mental) were significantly reduced. CONCLUSIONS: In patients with CIHD and T2DM, peak V̇O2, BMI and HL are important indicators of disease severity, risk factor burden and quality of life, which reinforces the relevance of lifestyle interventions.

Moderate continuous or high intensity interval exercise in heart failure with reduced ejection fraction: Differences between ischemic and non-ischemic etiology.

Background: Exercise for heart failure (HF) with reduced ejection fraction (HFrEF) is recommended by guidelines, but exercise mode and intensities are not differentiated between HF etiologies. We, therefore, investigated the effect of moderate or high intensity exercise on left ventricular end-diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF) and maximal exercise capacity (peak VO2) in patients with ischemic cardiomyopathy (ICM) and non-ischemic cardiomyopathy (NICM). Methods: The Study of Myocardial Recovery after Exercise Training in Heart Failure (SMARTEX-HF) consecutively enrolled 231 patients with HFrEF (LVEF ≤ 35 %, NYHA II-III) in a 12-weeks supervised exercise program. Patients were stratified for HFrEF etiology (ICM versus NICM) and randomly assigned (1:1:1) to supervised exercise thrice weekly: a) moderate continuous training (MCT) at 60-70 % of peak heart rate (HR), b) high intensity interval training (HIIIT) at 90-95 % peak HR, or c) recommendation of regular exercise (RRE) according to guidelines. LVEDD, LVEF and peak VO2 were assessed at baseline, after 12 and 52 weeks. Results: 215 patients completed the intervention. ICM (59 %; n = 126) compared to NICM patients (41 %; n = 89) had significantly lower peak VO2 values at baseline and after 12 weeks (difference in peak VO2 2.2 mL/(kg*min); p < 0.0005) without differences between time points (p = 0.11) or training groups (p = 0.15). Etiology did not influence changes of LVEDD or LVEF (p = 0.30; p = 0.12), even when adjusting for sex, age and smoking status (p = 0.54; p = 0.12). Similar findings were observed after 52 weeks. Conclusions: Etiology of HFrEF did not influence the effects of moderate or high intensity exercise on cardiac dimensions, systolic function or exercise capacity. Clinical Trial Registration­URL: http://www.clinicaltrials.gov. Unique identifier: NCT00917046.

Peak O2 -pulse predicts exercise training-induced changes in peak V̇O2 in heart failure with preserved ejection fraction.

AIMS: Exercise training (ET) has been consistently shown to increase peak oxygen consumption (V̇O2 ) in patients with heart failure with preserved ejection fraction (HFpEF); however, inter-individual responses vary significantly. Because it is unlikely that ET-induced improvements in peak V̇O2 are significantly mediated by an increase in peak heart rate (HR), we aimed to investigate whether baseline peak O2 -pulse (V̇O2  × HR-1 , reflecting the product of stroke volume and arteriovenous oxygen difference), not baseline peak V̇O2 , is inversely associated with the change in peak V̇O2 (adjusted by body weight) following ET versus guideline control (CON) in patients with HFpEF. METHODS AND RESULTS: This was a secondary analysis of the OptimEx-Clin (Optimizing Exercise Training in Prevention and Treatment of Diastolic Heart Failure, NCT02078947) trial, including all 158 patients with complete baseline and 3 month cardiopulmonary exercise testing measurements (106 ET, 52 CON). Change in peak V̇O2 (%) was analysed as a function of baseline peak V̇O2 and its determinants (absolute peak V̇O2 , peak O2 -pulse, peak HR, weight, haemoglobin) using robust linear regression analyses. Mediating effects on change in peak V̇O2 through changes in peak O2 -pulse, peak HR and weight were analysed by a causal mediation analysis with multiple correlated mediators. Change in submaximal exercise tolerance (V̇O2 at the ventilatory threshold, VT1) was analysed as a secondary endpoint. Among 158 patients with HFpEF (66% female; mean age, 70 ± 8 years), changes in peak O2 -pulse explained approximately 72% of the difference in changes in peak V̇O2 between ET and CON [10.0% (95% CI, 4.1 to 15.9), P = 0.001]. There was a significant interaction between the groups for the influence of baseline peak O2 -pulse on change in peak V̇O2 (interaction P = 0.04). In the ET group, every 1 mL/beat higher baseline peak O2 -pulse was associated with a decreased mean change in peak V̇O2 of -1.45% (95% CI, -2.30 to -0.60, P = 0.001) compared with a mean change of -0.08% (95% CI, -1.11 to 0.96, P = 0.88) following CON. None of the other factors showed significant interactions with study groups for the change in peak V̇O2 (P > 0.05). Change in V̇O2 at VT1 was not associated with any of the investigated factors (P > 0.05). CONCLUSIONS: In patients with HFpEF, the easily measurable peak O2 -pulse seems to be a good indicator of the potential for improving peak V̇O2 through exercise training. While changes in submaximal exercise tolerance were independent of baseline peak O2 -pulse, patients with high O2 -pulse may need to use additional therapies to significantly increase peak V̇O2 .