Mechanisms of the Improvement in Peak VO2 With Exercise Training in Heart Failure With Reduced or Preserved Ejection Fraction

Exercise intolerance in heart failure with preserved ejection fraction: Causes, consequences and the journey towards a cure

Heart failure with preserved ejection fraction (HFpEF) accounts for over 50% of all heart failure cases nationwide and continues to rise in its prevalence. The complex, multi-organ involvement of the HFpEF clinical syndrome requires clinicians and investigators to adopt an integrative approach that considers the contribution of both cardiac and non-cardiac function to HFpEF pathophysiology. Thus, this symposium review outlines the key points from presentations covering the contributions of disease-related changes in cardiac function, arterial stiffness, peripheral vascular function, and oxygen delivery and utilization to exercise tolerance in patients with HFpEF. While many aspects of HFpEF pathophysiology remain poorly understood, there is accumulating evidence for a decline in vascular health in this patient group that may be remediable through pharmacological and lifestyle interventions and could improve outcomes and clinical status in this ever-growing patient population.

An Index for Evaluating Exercise Capacity Improvement After Cardiac Rehabilitation in Patients After Myocardial Infarction

OBJECTIVE

We investigated relationships among predictors of improvement in exercise capacity after cardiac rehabilitation programs in patients after acute myocardial infarction.

METHODS

We carried out a secondary analysis of data from 41 patients with a left ventricular ejection fraction ≥ 40% who underwent cardiac rehabilitation after the first myocardial infarction. Participants were assessed using a cardiopulmonary exercise test and stress echocardiography. A cluster analysis was performed, and the principal components were analyzed.

RESULTS

Two distinct clusters with significantly different ( P = .005) proportions of response to treatment (peak VO 2 ≥ 1 mL/kg/min) were identified among patients. The first principal component explained 28.6% of the variance. We proposed an index composed of the top 5 variables from the first component to represent the improvement in exercise capacity. The index was the average of scaled O 2 uptake and CO 2 output at peak exercise, minute ventilation at peak, load achieved at peak exercise, and exercise time. The optimal cutoff for the improvement index was 0.12, which outperformed the peak VO 2 ≥ 1 mL/kg/min criterion in recognizing the clusters, with a C-statistic of 91.7% and 72.3%, respectively.

CONCLUSION

The assessment of change in exercise capacity after cardiac rehabilitation could be improved using the composite index.

Exercise and cardiac rehabilitation in hypertensive patients with heart failure with preserved ejection fraction: A position statement on behalf of the Working Group of Arterial Hypertension of the Hellenic Society of Cardiology

Arterial hypertension is a major cause of cardiovascular morbidity and mortality and the most common cause of comorbidity in heart failure (HF) with preserved ejection fraction (HFpEF). As an adjunct to medication, healthy lifestyle modifications with emphasis on regular exercise are strongly recommended by both the hypertension and the HF guidelines of the European Society of Cardiology. Several long-term studies have shown that exercise is associated with a reduction in all-cause mortality, a favorable cardiac and metabolic risk profile, mental health, and other non-cardiovascular benefits, as well as an improvement in overall quality of life. However, the instructions for the prescriptive or recommended exercise in hypertensive patients and, more specifically, in those with HFpEF are not well defined. Moreover, the evidence is based on observational or small randomized studies, while well-designed clinical trials are lacking. Despite the proven benefit and the guidelines' recommendations, exercise programs and cardiac rehabilitation in patients with hypertensive heart disease and HFpEF are grossly underutilized. This position statement provides a general framework for exercise and exercise-based rehabilitation in patients with hypertension and HFpEF, guides clinicians' rehabilitation strategies, and facilitates clinical practice. It has been endorsed by the Working Group of Arterial Hypertension of the Hellenic Society of Cardiology and is focused on the Health Care System in Greece.

Effect of Exercise Training on Peak Aerobic Power After Heart Transplantation: A Brief Review

Heart transplantation (HTP) is a life-saving therapy for selected individuals with end-stage refractory heart failure. Despite improvements in quality of life and survival, HTP recipients' peak aerobic power (peak VO2) remains up to 50% lower than age-matched healthy control subjects owing to abnormal cardiovascular and skeletal muscle function. Currently, little is known regarding the effect of exercise training (ET) to improve peak VO2 after HTP. This brief review aims to summarise existing evidence regarding the role of ET on peak VO2 and its determinants, highlights the upper limits of endurance performance in highly trained HTP athletes, and identifies areas for future HTP exercise rehabilitation research.

Benefits of Cardiac Rehabilitation in Cardio-Renal Patients With Heart Failure With Reduced Ejection Fraction

PURPOSE

Chronic kidney disease (CKD) is common in heart failure (HF). Chronic kidney disease often worsens the prognosis and impairs the management of patients with HF. Chronic kidney disease is frequently accompanied by sarcopenia, which limits the benefits of cardiac rehabilitation (CR). The aim of this study was to evaluate the impact of CR on cardiorespiratory fitness in HF patients with reduced ejection fraction (HFrEF) according to the CKD stage.

METHODS

We conducted a retrospective study including 567 consecutive patients with HFrEF, who underwent a 4-wk CR program, and who were evaluated by cardiorespiratory exercise test before and after the program. Patients were stratified according to their estimated glomerular filtration rate (eGFR). We performed multivariate analysis looking for factors associated with an improvement of 10% in peak oxygen uptake (V˙ o2peak ).

RESULTS

Thirty-eight percent of patients had eGFR <60 mL/min/1.73m². With decreasing eGFR, we observed deterioration in V˙ o2peak , first ventilatory threshold (VT1) and workload and an increase in brain natriuretic peptide levels at baseline. After CR, there was an improvement in V˙ O2peak (15.3 vs 17.8 mL/kg/min, P < .001), VT1 (10.5 vs 12.4 mL/kg/min, P < .001), workload (77 vs 94 W, P < .001), and brain natriuretic peptide (688 vs 488 pg/mL, P < .001). These improvements were statistically significant for all stages of CKD. In a multivariate analysis predicting factors associated with V˙ o2peak improvement, renal function did not interfere with results.

CONCLUSIONS

Cardiac rehabilitation is beneficial in patients with HFrEF with CKD regardless of CKD stage. The presence of CKD should not prevent the prescription of CR in patients with HFrEF.

Exercise training affects hemodynamics and exercise capacity in cases of heart failure with preserved ejection fraction: a non-randomized controlled trial in individuals aged 65-80 years

Introduction

Exercise training is an established intervention method for improving exercise capacity and survival rates in patients with heart failure with preserved ejection fraction (HFpEF). However, most reports have focused on European and American patients, with limited data regarding the effects of exercise training on cardiac function, hemodynamics, and exercise capacity in East Asian patients. This study investigated the effects of exercise training on cardiac function, hemodynamics, and exercise capacity in Japanese patients aged 65-80 years with HFpEF.

Methods

This single-center, open-label, non-randomized, controlled trial prospectively enrolled 99 outpatients. Eligibility criteria for HFpEF patients were an HFA score ≥5 in addition to clinical symptoms of heart failure and left ventricular diastolic dysfunction. Exercise training in the intervention group consisted of aerobic exercise and strength training thrice weekly for 5 months. Patients in the control group continued the usual treatment for 5 months. Resting cardiac function was evaluated using echocardiography. Peak oxygen uptake (peakVO2), ventilatory equivalent (VE) vs. carbon dioxide output (VCO2) slope, peak cardiac output index, and arteriovenous oxygen difference were calculated using cardiopulmonary exercise testing combined with impedance cardiography.

Results

After 5 months of exercise training, remarkable interactions were observed, with peakVO2 as the primary outcome. Additionally, significant interactions were observed between hemodynamic indices and some echocardiographic parameters. The mean percentage change in peakVO2 from baseline was 8.3% in the intervention group. Fifteen study participants (30.1%) in the intervention group achieved a clinically meaningful change of 3.0 ml/min/kg (10% improvement) in peakVO2 from baseline. The group with 3.0 ml/min/kg or 10% improvement in peakVO2 from baseline had a considerably lower prevalence of diabetes mellitus and VE vs. VCO2 slope and considerably higher left atrial-global longitudinal strain values than the group without any notable improvements.

Conclusions

Although exercise training can help improve exercise intolerance in Japanese patients aged 65-80 years with HFpEF, its benefits are limited. Our results suggest that HFpEF, complicated by diabetes mellitus and decreased ventilatory efficiency during exercise, may require reconsideration of intervention strategies. This trial was registered with the University Hospital Medical Information Network, a trial registry in Japan (registration number: UMIN000045474).

Different Continuous Training Intensities Improve Echocardiographic Parameters, Quality of Life, and Functional Capacity in Heart Failure Patients with Reduced Ejection Fraction

Background

Multiple comorbidities and physiological changes play a role in a range of heart failure conditions and influence the most effective approach to exercise-based rehabilitation. This research aimed to examine and compare the outcomes of continuous training at three different intensities, focusing on left ventricular (LV) remodeling, functional capacity, and quality of life among patients with heart failure with reduced ejection fraction (HFrEF).

Methods

In this randomized control trial, a total of 60 male patients (average age: 54.33 ±2.35 years) with HFrEF were randomly allocated into three groups: 1) High-intensity continuous training group (HICT), 2) Moderate-intensity continuous training group (MICT), and 3) Low-intensity continuous training group (LICT). All the training was performed on a bicycle ergometer 3 times/week for 12 weeks. Echocardiographic parameters (left ventricular ejection fraction, left ventricular end-diastolic dimension, left ventricular end-systolic dimension, N-terminal pro-B-type natriuretic peptide (NT-proBNP), quality of life (Minnesota Living with Heart Failure Questionnaire), and functional capacity (6-minute walking test) were assessed before and the end of the study.

Results

The HICT group demonstrated the greatest improvements in all measured variables when compared to the other two groups (P < 0.05). These findings were consistent across all measured outcomes.

Conclusion

It was determined that HICT appears to yield the most favorable outcomes in enhancing echocardiographic measures, NT-proBNP levels, quality of life, and functional capacity among HFrEF patients.

Aerobic Exercise Training Response in Preterm-Born Young Adults with Elevated Blood Pressure and Stage 1 Hypertension: A Randomized Clinical Trial

Rationale: Premature birth is an independent predictor of long-term cardiovascular risk. Individuals affected are reported to have a lower rate of [Formula: see text]o2 at peak exercise intensity ([Formula: see text]o2PEAK) and at the ventilatory anaerobic threshold ([Formula: see text]o2VAT), but little is known about their response to exercise training. Objectives: The primary objective was to determine whether the [Formula: see text]o2PEAK response to exercise training differed between preterm-born and term-born individuals; the secondary objective was to quantify group differences in [Formula: see text]o2VAT response. Methods: Fifty-two preterm-born and 151 term-born participants were randomly assigned (1:1) to 16 weeks of aerobic exercise training (n = 102) or a control group (n = 101). Cardiopulmonary exercise tests were conducted before and after the intervention to measure [Formula: see text]o2PEAK and the [Formula: see text]o2VAT. A prespecified subgroup analysis was conducted by fitting an interaction term for preterm and term birth histories and exercise group allocation. Measurements and Main Results: For term-born participants, [Formula: see text]o2PEAK increased by 3.1 ml/kg/min (95% confidence interval [CI], 1.7 to 4.4), and the [Formula: see text]o2VAT increased by 2.3 ml/kg/min (95% CI, 0.7 to 3.8) in the intervention group versus controls. For preterm-born participants, [Formula: see text]o2PEAK increased by 1.8 ml/kg/min (95% CI, -0.4 to 3.9), and the [Formula: see text]o2VAT increased by 4.6 ml/kg/min (95% CI, 2.1 to 7.0) in the intervention group versus controls. No significant interaction was observed with birth history for [Formula: see text]o2PEAK (P = 0.32) or the [Formula: see text]o2VAT (P = 0.12). Conclusions: The training intervention led to significant improvements in [Formula: see text]o2PEAK and [Formula: see text]o2VAT, with no evidence of a statistically different response based on birth history. Clinical trial registered with www.clinicaltrials.gov (NCT02723552).

Reduced cardiovascular reserve capacity in long-term allogeneic stem cell transplant survivors

Premature cardiovascular mortality is increased in long-term allogeneic stem cell transplant (allo-SCT) survivors, but little information exists regarding subclinical cardiovascular dysfunction in this population. We compared peak oxygen uptake ([Formula: see text]O_2peak), a prognostic cardiovascular marker, and its determinants between long-term allo-SCT survivors and non-cancer controls. Fourteen allo-SCT survivors (mean ± SD, 44 ± 15 years, 50% male, median time since allo-SCT: 6.5 years [range 2-20]) and 14 age- and sex-matched controls (46 ± 13 years, 50% male) underwent cardiopulmonary exercise testing to quantify [Formula: see text]O_2peak. Resting echocardiography (left-ventricular ejection fraction and strain), exercise cardiac MRI (peak cardiac and stroke volume index [CI_peak, SVI_peak]), biochemistry (hemoglobin, troponin-I, B-natriuretic peptide), dual-energy x-ray absorptiometry (lean [LM] and fat [FM] mass, percent body fat [%BF]) and Fick-principal calculation (arteriovenous oxygen difference) were also performed. Survivors exhibited impaired [Formula: see text]O_2peak as compared with controls (25.9 ± 5.1 vs. 33.7 ± 6.5 ml kg^-1 min^-1, p = 0.002), which coincided with reduced CI_peak (6.6 ± 0.8 vs. 8.6 ± 1.9 L min^-1 m^-2; p = 0.001) secondary to reduced SVI_peak (48 ± 4 vs. 61 ± 8 ml m^-2; p < 0.001) rather than chronotropic impairment, and higher %BF (difference, 7.9%, p = 0.007) due to greater FM (5.8 kg; p = 0.069) and lower LM (4.3 kg, p = 0.25). All other measures were similar between groups. Despite comparable resting cardiac function and biomarker profiles, survivors exhibited reduced [Formula: see text]O_2peak and exercise cardiac function and increased %BF relative to controls. These results highlight potential therapeutic avenues and the utility of exercise-based cardiovascular assessment in unmasking cardiovascular dysfunction in allo-SCT survivors.

Self-reported engagement in exercise is associated with longer event-free survival in heart failure patients with poor functional capacity

AIMS

Despite evidence-based recommendations for clinically stable patients with heart failure (HF) to engage in unsupervised exercise, the minimum cumulative dose of exercise per week associated with improvement in HF outcomes, especially in patients with poor functional capacity, has not been examined. We examined whether patients with HF and poor functional capacity who reported engagement in a guideline-recommended minimum weekly exercise had longer event-free survival than patients who did not exercise.

METHODS AND RESULTS

This analysis included 310 patients with HF who had completed the Duke Activity Status Index (DASI) and reported their level of engagement in exercise. Patients were grouped into good and poor functional capacity using a DASI cut-point of ≥19 and then further stratified based on their self-reported exercise level: high (≥60 min/week) and low (<60 min/week). Cox regression modelling was used to predict event-free survival for the four groups after adjusting for covariates. Patients (mean age = 61.6 ± 11.4 years, 30.3% female, 44.2% NYHA Classes III-IV) were followed for a median of 362 days. There were eight deaths and 108 all-cause hospitalizations. Patients with poor functional capacity who reported high exercise engagement had a 36% lower risk of all-cause hospitalization or mortality compared with patients with poor functional capacity who reported low exercise engagement (hazard ratio: 0.64, P = 0.028).

CONCLUSION

Self-reported engagement in a minimum of 60 min of exercise per week was associated with a significant improvement in event-free survival, even in patients with HF with low functional capacity. These results provide evidence that this dose of exercise is beneficial in patients with HF and poor functional capacity.

Rate adaptive pacing in people with chronic heart failure increases peak heart rate but not peak exercise capacity: a systematic review

Rate adaptive cardiac pacing (RAP) allows increased heart rate (HR) in response to metabolic demand in people with implantable electronic cardiac devices (IECD). The aim of this work was to conduct a systematic review to determine if RAP increases peak exercise capacity (peak VO₂) in line with peak HR in people with chronic heart failure. We conducted a systematic literature search from 1980, when IECD and RAP were first introduced, until 31 July 2021. Databases searched include PubMed, Medline, EMBASE, EBSCO, and the Clinical Trials Register. A comprehensive search of the literature produced a total of 246 possible studies; of these, 14 studies were included. Studies and subsequent analyses were segregated according to comparison, specifically standard RAP (RAPON) vs fixed rate pacing (RAPOFF), and tailored RAP (TLD RAPON) vs standard RAP (RAPON). Pooled analyses were conducted for peak VO₂ and peak HR for RAPON vs RAPOFF. Peak HR significantly increased by 15 bpm with RAPON compared to RAPOFF (95%CI, 7.98-21.97, P < 0.0001). There was no significant difference between pacing mode for peak VO₂ 0.45 ml kg^-1 min^-1 (95%CI, - 0.55-1.47, P = 0.38). This systematic review revealed RAP increased peak HR in people with CHF; however, there was no concomitant improvement in peak VO₂. Rather RAP may provide benefits at submaximal intensities by controlling the rise in HR to optimise cardiac output at lower workloads. HR may be an important outcome of CHF management, reflecting myocardial efficiency.

The Need for Breathing Training Techniques: The Elephant in the Heart Failure Cardiac Rehabilitation Room: A Randomized Controlled Trial

BACKGROUND

Although solid evidence has indicated that respiratory symptoms are common amongst patients with chronic heart failure (CHF), state-of-the-art cardiac rehabilitation (CR) programs do not typically include management strategies to address respiratory symptoms. This study investigated the effect of the addition of breathing exercises (BE) to the CR programs in CHF.

METHODS

In a two parallel-arm randomized controlled study (RCT), 40 middle-aged patients with CHF and respiratory symptoms were recruited and randomized into two equal groups (n = 20); group (A): standard CR with BE and group (B): standard CR alone. Primary outcomes were respiratory parameters and secondary outcomes included cardiovascular and cardiopulmonary outcomes. All the participants attended a program of aerobic exercise (three sessions/week, 60-75% MHR, 45-55 min) for 12 weeks, plus educational, nutritional, and psychological counseling. Group (A) patients attended the same program together with BE using inspiratory muscle training (IMT) and breathing calisthenics (BC) (six sessions/week, 15-25 min) for the same duration.

RESULTS

There was a significant improvement in the respiratory outcomes, and most of the cardiovascular and cardiopulmonary outcomes in both groups with a greater change percentage in group A (p < 0.05).

CONCLUSIONS

These results indicate that the addition of BE to the CR programs in CHF is effective and is a "patient-centered" approach.

Clinical Perspectives on Cardiac Rehabilitation After Heart Failure in Elderly Patients with Frailty: A Narrative Review

The purpose of this narrative review is to examine rehabilitation modalities for patients with heart failure and Frailty who require comprehensive intervention. Ischemic heart disease is the leading cause of death worldwide, accounting for 16% of global mortality. Due to population growing and aging, the total number of heart failure patients continues to rise, a condition known as the heart failure pandemic. Furthermore, frailty has been associated with an increased risk for heart failure and increased morbidity and mortality. The 2021 update of the 2017 ACC expert consensus decision pathway for optimization of HF treatment has become more concerning, citing frailty as one of the 10 most important issues associated with heart failure with reduced ejection fraction (HFrEF). Frailty and heart failure share common pathological mechanisms and are associated with poor clinical outcomes. Most studies of frailty in patients with heart failure primarily focus on physical frailty, and associations between psycho-psychological and social factors such as cognitive dysfunction and social isolation have also been reported. These results suggest that a more comprehensive assessment of frailty is important to determine the risk in patients with heart failure. Therefore, mechanisms of the three domains, including not only physical frailty but also cognitive, psychological, spiritual, and social aspects, should be understood. In addition to interventions in these three domains, nutritional and pharmacological interventions are also important and require tailor-made interventions for the widely varied conditions associated with heart failure and frailty. Although several studies have shown a relationship between frailty and prognosis in patients with heart failure, interventions to improve the prognosis have not yet been established. Further information is needed on frailty intervention by a multidisciplinary team to improve the prognosis.

Effects of high-intensity and moderate-intensity exercise training on cardiopulmonary function in patients with coronary artery disease: A meta-analysis

Purpose

The study aims to evaluate the effects of high-intensity and moderate-intensity exercise training on cardiopulmonary function and exercise endurance in patients with coronary artery diseases (CAD).

Methods

We performed a systematic search of the English and Chinese databases from their inception to March 2022. Randomized controlled trials (RCTs) were included to compare high-intensity and moderate-intensity exercise training on cardiopulmonary function in patients with CAD. The primary outcomes included peak oxygen uptake (peak VO₂) and anaerobic threshold (AT). The secondary outcomes included left ventricular ejection fraction (LVEF), exercises duration (ED), respiratory exchange ratio (RER), resting heart rate (RHR), peak heart rate (PHR) and oxygen pulse (O₂ pulse). The continuous variables were expressed as mean differences (MD) along with their corresponding standard deviations (SD), and the I² test was applied in the assessment of heterogeneity.

Results

After systematically literature search, 19 studies were finally selected for our meta-analysis (n = 1,036), with 511 patients in the experimental group (high-intensity exercise) and 525 patients in the control group (moderate-intensity exercise). The results showed that high-intensity exercise significantly increased patients' Peak VO₂ [MD = 2.67, 95% CI (2.24, 3.09), P < 0.00001], LVEF [MD = 3.60, 95% CI (2.17, 5.03), P < 0.00001], ED [MD = 37.51, 95% CI (34.02, 41.00), P < 0.00001], PHR [MD = 6.86, 95% CI (4.49, 9.24), P < 0.00001], and O₂ pulse [MD = 0.97, 95% CI (0.34, 1.60), P = 0.003] compared with moderate-intensity exercise. However, there were no significant differences in AT [MD = 0.49, 95% CI (−0.12, 1.10), P = 0.11], RER [MD = 0.00, 95% CI (−0.01, 0.02), P = 0.56], and RHR [MD = 1.10, 95% CI (−0.43, 2.63), P = 0.16].

Conclusion

Our results show that high-intensity exercise training has more significant positive effects compared with moderate-intensity exercise training in improving peak VO₂, LVEF, ED, PHR and O₂ pulse in patients with CAD, while no significant differences were observed in AT, RER and RHR. To sum up, high-intensity exercise training is better than moderate-intensity exercise training in improving cardiopulmonary function and exercise endurance in patients with CAD.

Systematic review registration

PROSPERO (CRD42022328475), https://www.crd.york.ac.uk/PROSPERO/.

Isolated knee extensor exercise training improves skeletal muscle vasodilation, blood flow, and functional capacity in patients with HFpEF

Patients with HFpEF experience severe exercise intolerance due in part to peripheral vascular and skeletal muscle impairments. Interventions targeting peripheral adaptations to exercise training may reverse vascular dysfunction, increase peripheral oxidative capacity, and improve functional capacity in HFpEF. Determine if 8 weeks of isolated knee extension exercise (KE) training will reverse vascular dysfunction, peripheral oxygen utilization, and exercise capacity in patients with HFpEF. Nine HFpEF patients (66 ± 5 years, 6 females) performed graded IKE exercise (5, 10, and 15 W) and maximal exercise testing (cycle ergometer) before and after IKE training (3x/week, 30 min/leg). Femoral blood flow (ultrasound) and leg vascular conductance (LVC; index of vasodilation) were measured during graded IKE exercise. Peak pulmonary oxygen uptake (V̇O2 ; Douglas bags) and cardiac output (QC ; acetylene rebreathe) were measured during graded maximal cycle exercise. IKE training improved LVC (pre: 810 ± 417, post: 1234 ± 347 ml/min/100 mmHg; p = 0.01) during 15 W IKE exercise and increased functional capacity by 13% (peak V̇O2 during cycle ergometry; pre:12.4 ± 5.2, post: 14.0 ± 6.0 ml/min/kg; p = 0.01). The improvement in peak V̇O2 was independent of changes in Q̇c (pre:12.7 ± 3.5, post: 13.2 ± 3.9 L/min; p = 0.26) and due primarily to increased a-vO2 difference (pre: 10.3 ± 1.6, post: 11.0 ± 1.7; p = 0.02). IKE training improved vasodilation and functional capacity in patients with HFpEF. Exercise interventions aimed at increasing peripheral oxidative capacity may be effective therapeutic options for HFpEF patients.

Effects of Exercise on Heart Failure with Preserved Ejection Fraction: An Updated Review of Literature

Heart failure with preserved ejection fraction (HFpEF) represents the most common HF phenotype of patients aged > 65 years, with an incidence and a prevalence that are constantly growing. The HFpEF cardinal symptom is exercise intolerance (EI), defined as the impaired ability to perform physical activity and to reach the predicted age-related level of exercise duration in the absence of symptoms—such as fatigue or dyspnea—and is associated with a poor quality of life, a higher number of hospitalizations, and poor outcomes. The evidence of the protective effect between exercise and adverse cardiovascular outcomes is numerous and long-established. Regular exercise is known to reduce cardiovascular events and overall mortality both in apparently healthy individuals and in patients with established cardiovascular disease, representing a cornerstone in the prevention and treatment of many cardio-metabolic conditions. Several studies have investigated the role of exercise in HFpEF patients. The present review aims to dwell upon the effects of exercise on HFpEF. For this purpose, the relevant data from a literature search (PubMed, EMBASE, and Medline) were reviewed. The analysis of these studies underlines the fact that exercise training programs improve the cardiorespiratory performance of HFpEF patients in terms of the increase in peak oxygen uptake, the 6 min walk test distance, and the ventilatory threshold; on the other hand, diastolic or systolic functions are generally unchanged or only partially modified by exercise, suggesting that multiple mechanisms contribute to the improvement of exercise tolerance in HFpEF patients. In conclusion, considering that exercise training programs are able to improve the cardiorespiratory performance of HFpEF patients, the prescription of exercise training programs should be encouraged in stable HFpEF patients, and further research is needed to better elucidate the pathophysiological mechanisms underpinning the beneficial effects described.

The impact of type-2 diabetes mellitus on cardiac rehabilitation outcomes: a meta-analysis

OBJECTIVE

To determine the impact of cardiac rehabilitation (CR) on changes in functional capacity (FC) among patients with CVD and a type-2 diabetes mellitus (T2DM) co-morbidity compared to non-T2DM patients.

DATA SOURCE

A systematic review and meta-analysis of randomized control trials were completed using PubMed, CINAHL, and Web of Science in January 2021.

STUDY SELECTION

Articles were included if they compared CR patients with T2DM to those without T2DM (non-T2DM).

DATA EXTRACTION

The primary outcome variable was FC change from pre to post CR reported as maximal or peak oxygen consumption (VO₂max, VO₂peak), and peak metabolic equivalent (METs). Risk of bias was assessed using the Cochrane risk of bias tool. A random-effects model sub-group meta-analysis was conducted. A diabetes co-morbidity was selected for the subgroup analysis with CVD patients being reported as T2DM or non-T2DM.

DATA SYNTHESIS

Twelve studies with total sample of 15,672 patients were extracted. Average change in peak METs was 1.41±1.76 among non-T2DM and 1.08±1.57 among T2DM patients after CR. Change in FC was significantly lower among T2DM patients (Z-value=2.14; g = -0.42; 95% CI [-0.86 - 0.01]; p=0.03).

CONCLUSION

CVD patients with T2DM experience less robust improvements in FC in response to CR compared to patients with CVD alone. A better understanding of the relationship between T2DM and FC vital step in informing exercise prescription in CR for patients with T2DM and CVD. The lack of understanding the role of T2DM onset and progression is a limitation to this study.

Changes in Fat Oxidation and Body Composition after Combined Exercise Intervention in Sedentary Obese Chinese Adults

(1) Background: Evidence suggests that aerobic exercise and high-intensity interval training (HIIT) might increase fat oxidation and reduce fat. However, limited research has examined the effects of combining progressive aerobic exercise and HIIT interventions in sedentary adults with overweight and obesity, and differences in its effects between men and women remain unclear. The purpose of this study was to investigate the effects of combined progressive aerobic exercise and HIIT (CAEH) on fat oxidation and fat reduction in sedentary Chinese adults and compare sex differences in sedentary adults after seven weeks. (2) Methods: Eighty-four sedentary obese adults were enrolled and allocated to two groups in baseline (experimental (EXP) group:42; control (CON) group:42), and fifty-six subjects (EXP:31; CON:25) completed the experiments and were included in the final analysis. Subjects in the EXP group performed CAEH three times per week for seven weeks. Subjects in the CON group were advised to continue with their normal daily activities. Anthropometric, lipid profile, cardiorespiratory fitness, and fat oxidation outcomes were assessed before and after the intervention. (3) Results: After seven weeks of the CAEH intervention, compared with the CON group, the EXP group showed significant increases in fat oxidation at rest (FO_rest) (+0.03 g/min, p < 0.01), maximal fat oxidation (MFO) (+0.05 g/min, p < 0.01), and maximal oxygen intake (VO₂max) (+3.2 mL/kg/min, p < 0.01). The changes in the percentages of the FO_rest (+57%) and the VO₂max (+16%) were significantly greater (+20%, +6%) in males than in females (p < 0.05, p < 0.05). The body mass index (BMI) (−1.2 kg/m², p < 0.01), body fat percentage (−3.2%, p < 0.001), visceral fat area (−12.8 cm², p < 0.001), and total cholesterol (TC) levels (−0.4 mmol/L, p < 0.05) were significantly decreased in the EXP group. (4) Conclusions: Seven weeks of the CAEH intervention effectively improved FO_rest, MFO, and VO₂max in sedentary obese adults, and the improvements in FO_rest and VO₂max were more pronounced in males than in females. CAEH also improved body composition and TC levels in sedentary obese adults.

Comparison of Cardiorespiratory Fitness in Black or African American Versus Caucasian Patients With Heart Failure

PURPOSE

Cardiopulmonary exercise testing (CPX) is a well-established assessment with important insight into prognosis and therapeutic efficacy in patients with heart failure (HF). Prior studies have identified several clinical differences between Black or African American (B-AA) and Caucasian patients with HF. Differences in key CPX responses between these two groups require further investigation.

METHODS

Using a database consisting of subjects with symptomatic HF who had undergone CPX for inclusion in various prospective randomized clinical trials, we identified 198 (n = 94 [47%] B-AA; n = 105 [53%] Caucasian) patients with a qualifying baseline CPX. Significant univariate predictors of peak oxygen uptake (V˙o2peak) were included in a multivariate linear regression model.

RESULTS

When compared with Caucasian patients, B-AA were younger (mean ± SD = 54.8 ± 10.0 vs 57.9 ± 9.6 yr, P = .03), had higher C-reactive protein (CRP) (median [IQR] = 4.9 [2.3, 8.8] vs 1.9 [0.6, 5.5] mg/L, P < .0001), lower hemoglobin (13.0 ± 1.8 vs 13.8 ± 1.6 g/dL, P = .003), and lower left ventricular ejection fraction (LVEF) (40 [32, 51] vs 53 [43, 59]%, P < .00010). During CPX, B-AA patients also had lower V˙o2peak (14.6 ± 3.9 vs 17.6 ± 4.8 mL·kg-1·min-1, P < .0001). No differences were observed between B-AA and Caucasian in the minute ventilation/carbon dioxide production (V˙e/V˙co2) slope (P = .14). The difference in V˙o2peak between B-AA and Caucasian was largely attenuated after adjusting for age, body mass index, CRP, N-terminal pro-brain natriuretic peptide, hemoglobin, LVEF, and peak HR (14.1: 95% CI, 13.2-14.9 vs 15.6: 95% CI, 14.4-16.8 mL·kg-1·min-1, P = .053).

CONCLUSIONS

Directly measured V˙o2peak was significantly lower in B-AA than in Caucasians with HF. This is largely explained by differences in clinical characteristics, whereas no significant differences were observed in the V˙e/V˙co2 slope.

Mechanisms of Exercise Capacity Improvement after Cardiac Rehabilitation Following Myocardial Infarction Assessed with Combined Stress Echocardiography and Cardiopulmonary Exercise Testing

Cardiac rehabilitation (CR) is indicated in all patients after acute myocardial infarction (AMI) to improve prognosis and exercise capacity (EC). Previous studies reported that up to a third of patients did not improve their EC after CR (non-responders). Our aim was to assess the cardiac and peripheral mechanisms of EC improvement after CR using combined exercise echocardiography and cardiopulmonary exercise testing (CPET-SE). The responders included patients with an improved EC assessed as a rise in peak oxygen uptake (VO₂) ≥ 1 mL/kg/min. Peripheral oxygen extraction was calculated as arteriovenous oxygen difference (A-VO₂Diff). Out of 41 patients (67% male, mean age 57.5 ± 10 years) after AMI with left ventricular ejection fraction (LVEF) ≥ 40%, 73% improved their EC. In responders, peak VO₂ improved by 27% from 17.9 ± 5.2 mL/kg/min to 22.7 ± 5.1 mL/kg/min, p < 0.001, while non-responders had a non-significant 5% decrease in peak VO₂. In the responder group, the peak exercise heart rate, early diastolic myocardial velocity at peak exercise, LVEF at rest and at peak exercise, and A-VO₂Diff at peak exercise increased, the minute ventilation to carbon dioxide production slope decreased, but the stroke volume and cardiac index were unchanged after CR. Non-responders had no changes in assessed parameters. EC improvement after CR of patients with preserved LVEF after AMI is associated with an increased heart rate response and better peripheral oxygen extraction during exercise.

Exercise Intolerance in Heart Failure with Preserved Ejection Fraction

Exercise intolerance represents a typical feature of heart failure with preserved ejection fraction (HFpEF), and is associated with a poor quality of life, frequent hospitalizations, and increased all-cause mortality. The cardiopulmonary exercise test is the best method to quantify exercise intolerance, and allows detection of the main mechanism responsible for the exercise limitation, influencing treatment and prognosis. Exercise training programs improve exercise tolerance in HFpEF. However, studies are needed to identify appropriate type and duration. This article discusses the pathophysiology of exercise limitation in HFpEF, describes methods of determining exercise tolerance class, and evaluates prognostic implications and potential therapeutic strategies.

The importance of physical activity and cardiorespiratory fitness for patients with heart failure

The present review highlights current research on the importance of PA and fitness for patients with heart failure and recommendations with respect to heart failure phenotypes and special populations. Furthermore, the evidence for various exercise types and intensities/doses as an "exercise prescription", are discussed. The strong association between heart failure and traditional risk factors, physical inactivity and low fitness, underlines the importance of regular PA and exercise for prevention and treatment of heart failure. This is illustrated by cardiac stiffness which typically accelerates in middle-life and could be reversed by aerobic exercise. In patients with HFpEF, regular PA counteracts many of the changes observed, both metabolic and functional. Indeed, exercise-based cardiac rehabilitation has received a class 1A recommendation in current guidelines [1], in order to improve functional capacity, quality of life and lower the risk of rehospitalization. An individually tailored plan based on risk stratification, clinical assessment and cardiopulmonary exercise testing is encouraged before initiation of exercise training in patients with heart failure. In general, a combination of aerobic exercise and resistance training protocols is recommended (Table 1) [2], preferably throughout life. More studies are needed, regarding the role of PA and exercise in specific populations, such as frail patients with heart failure.

Cellular and molecular pathobiology of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) affects half of all patients with heart failure worldwide, is increasing in prevalence, confers substantial morbidity and mortality, and has very few effective treatments. HFpEF is arguably the greatest unmet medical need in cardiovascular disease. Although HFpEF was initially considered to be a haemodynamic disorder characterized by hypertension, cardiac hypertrophy and diastolic dysfunction, the pandemics of obesity and diabetes mellitus have modified the HFpEF syndrome, which is now recognized to be a multisystem disorder involving the heart, lungs, kidneys, skeletal muscle, adipose tissue, vascular system, and immune and inflammatory signalling. This multiorgan involvement makes HFpEF difficult to model in experimental animals because the condition is not simply cardiac hypertrophy and hypertension with abnormal myocardial relaxation. However, new animal models involving both haemodynamic and metabolic disease, and increasing efforts to examine human pathophysiology, are revealing new signalling pathways and potential therapeutic targets. In this Review, we discuss the cellular and molecular pathobiology of HFpEF, with the major focus being on mechanisms relevant to the heart, because most research has focused on this organ. We also highlight the involvement of other important organ systems, including the lungs, kidneys and skeletal muscle, efforts to characterize patients with the use of systemic biomarkers, and ongoing therapeutic efforts. Our objective is to provide a roadmap of the signalling pathways and mechanisms of HFpEF that are being characterized and which might lead to more patient-specific therapies and improved clinical outcomes.

The impact of exercise training for chronic heart failure patients with cardiac resynchronization therapy: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Systematically review the current published literature on the impact of exercise training (ET) in chronic heart failure (CHF) patients who were conducted cardiac resynchronization therapy (CRT).

METHODS

PubMed, EMBASE, and the Cochrane Library of Controlled Trails databases were searched for trials comparing the additional effects of ET in CHF patients after CRT implantation with no exercise or usual care control up until 2020.03.07. We independently screened the literature, extracted data, employed the tool for the assEssment of Study qualiTy and reporting in EXercise (TESTEX) to evaluate study quality and risk of bias, and performed meta-analysis with Revman 5.3 software.

RESULTS

Eight trials were identified for qualitative analysis and 7 randomized controlled trails (RCTs) included 235 participants (120 ET; 115 controls) for quantitative analysis. The results showed that the maximal workload (mean difference [MD] 26.32 W, 95% CI 19.41-33.23; P < .00001, I2 = 0%) and the exercise duration (MD 68.95 seconds, 95% CI 15.41-122.48; P = .01, I2 = 76%) had significant improvement in the ET group versus control. Subgroup analysis showed that compared with control, the change in peak oxygen uptake (VO2) (MD 3.05 ml/kg/minute, 95% CI 2.53-3.56; P < .00001, I2 = 0%), left ventricular ejection fraction (LVEF) (MD 4.97%, 95% CI 1.44-8.49; P = .006, I2 = 59%), and health related quality of life (HRQoL) (the change in Minnesota living with heart failure questionnaire [MLHFQ]: MD -19.96, 95% CI -21.57 to -18.34; P < .00001, I2 = 0%) were significantly improved in the light to moderate intensity training (non-HIT) group, while there seemed no statistical difference of above endpoints in the high intensity training (HIT) group.

CONCLUSION

During the short term (up to 6 months), non-HIT could improve exercise capacity, cardiac function, and HRQoL in CHF patients with CRT. However, due to the small number of participants, a high-quality large-sample multicenter trial is demanded.

Selection of the optimal respiratory muscle training mode in patients with class II-III chronic heart failure

Aim To study the effect of various types of respiratory muscle training (RMT) in patients with functional class (FC) II-III chronic heart failure (CHF) and more than 70% preserved diaphragm muscle mass.Material and methods 53 patients (28 men and 25 women) aged 50-75 years with NYHA FC II-III ischemic heart disease (IHD) and arterial hypertension with more than 70% preserved diaphragm muscle mass of &gt;70% were randomized to one of four RMT types: static loads, dynamic loads, their combination, and breathing without applied resistance as a control. Peak oxygen consumption (VO2 peak) and maximum inspiratory pressure (MIP) were evaluated at baseline and in 6 months.Results All study groups showed significant improvement of physical endurance indexes compared to baseline values (р&lt;0.05). In pairwise comparison, the groups significantly differed (р&lt;0.01). The greatest improvement was observed for patients of dynamic and combined training groups. Furthermore, in the combined training group, results were significantly higher than in the group of isolated dynamic loads. The most significant (р &lt;0.01), positive changes in the force of inspiratory muscles were observed in groups of dynamic and combined trainings with the best results displayed by patients of the combined training group.Conclusion With preserving more than 70 % of diaphragm muscle tissue (as determined by MIP &gt;60 cm H2O), a combination of static and dynamic RMT is most effective for patients with FC II-III CHF.

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.

Supported progressive resistance exercise training to counter the adverse side effects of robot-assisted radical prostatectomy: a randomised controlled trial

PURPOSE

To investigate the effects of a supported home-based progressive resistance exercise training (RET) programme on indices of cardiovascular health, muscular strength and health-related quality of life (HR-QoL) in prostate cancer (PCa) patients after treatment with robot-assisted radical prostatectomy (RARP).

METHODS

This study was a single-site, two-arm randomised controlled trial, with 40 participants randomised to either the intervention or control group over a 10-month period. In addition to receiving usual care, the intervention group completed three weekly RET sessions using resistance bands for 6 months. Participants performed 3 sets of 12-15 repetitions for each exercise, targeting each major muscle group. The control group received usual care only. Brachial artery flow-mediated dilatation (FMD) was the primary outcome and assessed at baseline, 3 and 6 months. Secondary outcomes included body weight, body fat, aerobic fitness, strength and blood-borne biomarkers associated with cardiometabolic risk.

RESULTS

There was no significant difference between the groups in FMD at 3 or 6 months. However, there were improvements in aerobic exercise capacity (P < 0.01) and upper- (P < 0.01) and lower-limb (P = 0.01) strength in favour of the RET group at 6 months, accompanied by greater weight loss (P = 0.04) and a reduction in body fat (P = 0.02). Improvements in HRQoL were evident in the RET group at 3 and 6 months via the PCa-specific component of the FACT-P questionnaire (both P < 0.01). Five adverse events and one serious adverse event were reported throughout the trial duration.

CONCLUSION

This study demonstrates that home-based RET is an effective and safe mode of exercise that elicits beneficial effects on aerobic exercise capacity, muscular strength and HR-QoL in men who have undergone RARP.

TRIAL REGISTRATION

ISRCTN10490647.

Young Adult Cancer Survivorship: Recommendations for Patient Follow-up, Exercise Therapy, and Research

Survivors of adolescent and young adult cancers (AYAs) often live 50 to 60 years beyond their diagnosis. This rapidly growing cohort is at increased risk for cancer- and treatment-related 'late effects' that persist for decades into survivorship. Recognition of similar issues in pediatric cancer survivors has prompted the development of evidence-based guidelines for late effects screening and care. However, corresponding evidence-based guidelines for AYAs have not been developed. We hosted an AYA survivorship symposium for a large group of multidisciplinary AYA stakeholders (approximately 200 were in attendance) at Princess Margaret Cancer Centre (Toronto, Ontario, Canada) to begin addressing this disparity. The following overview briefly summarizes and discusses the symposium's stakeholder-identified high-priority targets for late effects screening and care and highlights knowledge gaps to direct future research in the field of AYA survivorship. This overview, although not exhaustive, is intended to stimulate clinicians to consider these high-priority screening and care targets when seeing survivors in clinical settings and, ultimately, to support the development of evidence-based late effects screening and care guidelines for AYAs.

Effect of ivabradine on exercise capacity in individuals with heart failure with preserved ejection fraction

The prevalence of heart failure with preserved ejection fraction (HFpEF) is about 30-75% of the patients living with heart failure. A hallmark symptom of these patients is exercise intolerance. Ivabradine can, eventually, increase exercise capacity by heart rate control. However, clinical trials show conflicting results about the effects of ivabradine on exercise capacity, an important prognostic variable. The aim of this study was to investigate the effects of ivabradine on exercise capacity in individuals with HFpEF. This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and supplemented by guidance from the Cochrane Collaboration Handbook for Systematic Reviews of Interventions. For the meta-analysis, a forest plot was used to graphically present the effect sizes and the 95% CIs. Four randomized controlled trials were included. Ivabradine did not change exercise capacity expressed by peak VO₂ and 6MWT (MD = 0.8; 95% CI - 2.5 to 4.3; P = 0.62) (Fig. 4a). In our secondary analysis, the ivabradine group showed a significant resting HR reduction when compared with placebo (MD = - 13.2; 95% CI - 16.6 to -9.8; P < 0.00001) and ivabradine showed increased values of E/e' ratio compared with placebo (MD = 0.8; 95% CI 0.0 to 1.6; P = 0.04). Current available evidence suggests that there is no effect of ivabradine on exercise capacity in patients with HFpEF. Also, questions about negative effects on E/e' values and adverse events associated with ivabradine treatment need to be considered in future studies.

Beyond the myocardium? SGLT2 inhibitors target peripheral components of reduced oxygen flux in the diabetic patient with heart failure with preserved ejection fraction

Recent cardiovascular outcome trials have highlighted the propensity of the antidiabetic agents, SGLT2 inhibitors (SGLT2is or -flozin drugs), to exert positive clinical outcomes in patients with cardiovascular disease at risk for major adverse cardiovascular events (MACEs). Of interest in cardiac diabetology is the physiological status of the patient with T2DM and heart failure with preserved ejection fraction (HFpEF), a well-examined association. Underlying this pathologic tandem are the effects that long-standing hyperglycemia has on the ability of the HFpEF heart to adequately deliver oxygen. It is believed that shortcomings in oxygen diffusion or utilization and the resulting hypoxia thereafter may play a role in underlying the clinical sequelae of patients with T2DM and HFpEF, with implications in the long-term decline of extra-cardiac tissue. Oxygen consumption is one of the most critical factors in indexing heart failure disease burden, warranting a probe into the role of SGLT2i on oxygen utility in HFpEF and T2DM. We investigated the role of oxygen flux in the patient with T2DM and HFpEF extending beyond the heart with focuses on cellular metabolism, perivascular fibrosis with endothelial dysfunction, hematologic changes, and renal effects with neurohormonal considerations in the patient with HFpEF and T2DM. Moreover, we give a commentary on potential therapeutic targets of these components with SGLT2i to gain insight into disease burden amelioration in patients with HFpEF and T2DM.

Exercise Intolerance in Patients With Heart Failure: JACC State-of-the-Art Review

Exercise intolerance is the cardinal symptom of heart failure (HF) and is of crucial relevance, because it is associated with a poor quality of life and increased mortality. While impaired cardiac reserve is considered to be central in HF, reduced exercise and functional capacity are the result of key patient characteristics and multisystem dysfunction, including aging, impaired pulmonary reserve, as well as peripheral and respiratory skeletal muscle dysfunction. We herein review the different modalities to quantify exercise intolerance, the pathophysiology of HF, and comorbid conditions as they lead to reductions in exercise and functional capacity, highlighting the fact that distinct causes may coexist and variably contribute to exercise intolerance in patients with HF.

Sedentary Behavior, Exercise, and Cardiovascular Health

Sedentary behavior and physical inactivity are among the leading modifiable risk factors worldwide for cardiovascular disease and all-cause mortality. The promotion of physical activity and exercise training (ET) leading to improved levels of cardiorespiratory fitness is needed in all age groups, race, and ethnicities and both sexes to prevent many chronic diseases, especially cardiovascular disease. In this state-of-the-art review, we discuss the negative impact of sedentary behavior and physical inactivity, as well as the beneficial effects of physical activity /ET and cardiorespiratory fitness for the prevention of chronic noncommunicable diseases, including cardiovascular disease. We review the prognostic utility of cardiorespiratory fitness compared with obesity and the metabolic syndrome, as well as the increase of physical activity /ET for patients with heart failure as a therapeutic strategy, and ET dosing. Greater efforts at preventing sedentary behavior and physical inactivity while promoting physical activity, ET, and cardiorespiratory fitness are needed throughout the healthcare system worldwide and particularly in the United States in which the burden of cardiometabolic diseases remains extremely high.

Weight loss in heart failure is associated with increased mortality only in non-obese patients without diabetes

BACKGROUND

Weight loss (WL) is an independent predictor of mortality in patients with heart failure (HF). Moderate WL is recommended for overweight or obese patients with type 2 diabetes mellitus (DM). The aim of this study was to assess the prognostic impact of body weight reduction on survival in patients with both HF with reduced ejection fraction (HFrEF) and DM.

METHODS

The study comprised patients with HFrEF at the outpatient clinic. WL was defined as a body weight reduction of at least 7.5% during at least 6 months. Clinical features and 1 year mortality were analysed in WL and DM groups. Multivariate regression model was chosen to assess the predictive role of WL in HF patients with and without DM. The analysis regarding obesity before HF was also performed.

RESULTS

The study comprised 777 patients with HFrEF. Mean age was 53.2 ± 9.2, 12.0% were women, mean EF was 23.7 ± 6.0 %, and New York Heart Association III or IV class, DM, and WL were found in 60.5%, 33.3%, and 47.1% patients, respectively. WL was more prevalent in diabetic patients, comparing with those without DM (53.7% vs. 43.8%, respectively, 0.01), and was associated with higher 1 year mortality only in non-diabetic group (17.6% for WL vs. 8.2% for non-WL, log-rank 0.001). In the multivariate analysis, WL was associated with a higher risk of 1 year mortality in non-diabetic patients: HR 1.76 (1.05-2.95), 0.03 and only in the subgroup without obesity: HR 2.35 (1.28-4.32), 0.006. In non-diabetic patients with obesity and in diabetic patients regardless of weight status, WL was not associated with worse prognosis (thereof, WL was excluded from the multivariate models).

CONCLUSIONS

Overall, WL in HFrEF has emerged as a predictor of unfavourable outcomes only in non-obese patients without DM. More importantly, this study has identified that the presence of DM (irrespective of weight status) or the presence of obesity in non-diabetic patients abolished the unfavourable impact of WL on long-term outcomes.

Effect of Aerobic Exercise on Peak Oxygen Consumption, VE/VCO2 Slope, and Health-Related Quality of Life in Patients with Heart Failure with Preserved Left Ventricular Ejection Fraction: a Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

The aim of this study was to determine the effects of aerobic exercise on peak oxygen uptake (peak VO₂), minute ventilation/carbon dioxide production (VE/VCO₂ slope), and health-related quality of life (HRQoL) among patients with heart failure (HF) and preserved ejection fraction (HFpEF).

RECENT FINDINGS

We conducted a Cochrane Library, MEDLINE/PubMed, Physiotherapy Evidence Database, and SciELO search (from 1985 to May 2019) for randomized controlled trials that evaluated the effects of aerobic exercise in HFpEF patients. We calculated the mean differences (MD) and 95% confidence interval (CI). Ten intervention studies were included providing a total of 399 patients. Compared with control, aerobic exercise resulted in improvement in peak VO₂ MD 1.9 mL kg^-1 min^-1 (95% CI 1.3 to 2.5; N = 314) and HRQoL measured by Minnesota Living with Heart Failure MD 5.4 (95% CI - 10.5 to - 0.2; N = 256). No significant difference in VE/VCO₂ slope was found between participants in the aerobic exercise group and the control group. The quality of evidence for peak VO₂ and HRQoL was assessed as being moderate. Aerobic exercise moderately improves peak VO₂ and HRQoL and should be considered a strategy of rehabilitation of HFpEF individuals.

Therapy for heart failure with preserved ejection fraction: current status, unique challenges, and future directions

Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF. Among elderly women, HFpEF comprises more than 80% of incident HF cases. Adverse outcomes-exercise intolerance, poor quality of life, frequent hospitalizations, and reduced survival-approach those of classic HF with reduced EF (HFrEF). However, despite its importance, our understanding of the pathophysiology of HFpEF is incomplete, and despite intensive efforts, optimal therapy remains uncertain, as most trials to date have been negative. This is in stark contrast to management of HFrEF, where dozens of positive trials have established a broad array of effective, guidelines-based therapies that definitively improve a range of clinically meaningful outcomes. In addition to providing an overview of current management status, we examine evolving data that may help explain this paradox, overcome past challenges, provide a roadmap for future success, and that underpin a wave of new trials that will test novel approaches based on these insights.

Noninvasive imaging assessment of rehabilitation therapy in heart failure with preserved and reduced left ventricular ejection fraction (IMAGING-REHAB-HF): design and rationale

Background:

Studies have shown significant benefits of exercise therapy in heart failure (HF) with a reduced ejection fraction (HFrEF) and HF with a preserved ejection fraction (HFpEF). The mechanisms responsible for the beneficial effect of exercise in HFrEF and HFpEF are still unclear. We hypothesized that the effect of exercise on myocardial remodeling may explain its beneficial effect.

Methods:

IMAGING-REHAB-HF is a single-center, randomized, controlled clinical trial using cardiac magnetic resonance imaging, vasomotor endothelial function, cardiac sympathetic activity imaging and serum biomarkers to compare the effect of exercise therapy in HFpEF (LVEF ≥ 45%) and HFrEF (LVEF < 45%). Subjects will be assessed at baseline and after 4 months. The exercise program will consist of three 60-min exercise sessions/week. The primary endpoints are the effect of exercise on myocardial extracellular volume (ECV), left ventricular (LV) systolic function, LV mass, LV mass-to-volume and LV cardiomyocyte volume. Secondary endpoints include the effect of exercise on vasomotor endothelial function, cardiac sympathetic activity and plasmatic biomarkers. Patients will be allocated in a 2:1 fashion to supervised exercise program or usual care. A total sample size of 90 patients, divided into two groups according to LVEF:HFpEF group (45 patients:30 in the intervention arm and 15 in the control arm) and HFrEF group (45 patients:30 in the intervention arm and 15 in the control arm) – will be necessary to achieve adequate power.

Conclusion:

This will be the first study to evaluate the benefits of a rehabilitation program on cardiac remodeling in HF patients. The unique design of our study may provide unique data to further elucidate the mechanisms involved in reverse cardiac remodeling after exercise in HFpEF and HFrEF patients.

Impaired Exercise Tolerance in Heart Failure: Role of Skeletal Muscle Morphology and Function

PURPOSE OF REVIEW

To discuss the impact of deleterious changes in skeletal muscle morphology and function on exercise intolerance in patients with heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF), as well as the utility of exercise training and the potential of novel treatment strategies to preserve or improve skeletal muscle morphology and function.

RECENT FINDINGS

Both HFrEF and HFpEF patients exhibit a reduction in percent of type I (oxidative) muscle fibers and oxidative enzymes coupled with abnormal mitochondrial respiration. These skeletal muscle abnormalities contribute to impaired oxidative metabolism with an earlier shift towards glycolytic metabolism during exercise that is strongly associated with exercise intolerance. In both HFrEF and HFpEF patients, peripheral "non-cardiac" factors are important determinants of the improvement in exercise tolerance following aerobic exercise training. Adjunctive strategies that include nutritional supplementation with amino acids and/or anabolic drugs to stimulate anabolic molecular pathways in skeletal muscle show great promise for improving exercise tolerance and treating heart failure-associated sarcopenia, but these efforts remain early in their evolution, with no immediate clinical applications. There is consistent evidence that heart failure is associated with multiple skeletal muscle abnormalities which impair oxygen uptake and utilization and contribute greatly to exercise intolerance. Exercise training induces favorable adaptations in skeletal muscle morphology and function that contribute to improvements in exercise tolerance in patients with HFrEF. The contribution of skeletal muscle adaptations to improved exercise tolerance following exercise training in HFpEF remains unknown and warrants further investigation.

Heart Failure With Preserved Ejection Fraction: A Review of Cardiac and Noncardiac Pathophysiology

Heart failure with preserved ejection fraction (HFpEF) is one of the largest unmet clinical needs in 21st-century cardiology. It is a complex disorder resulting from the influence of several comorbidities on the endothelium. A derangement in nitric oxide bioavailability leads to an intricate web of physiological abnormalities in the heart, blood vessels, and other organs. In this review, we examine the contribution of cardiac and noncardiac factors to the development of HFpEF. We zoom in on recent insights on the role of comorbidities and microRNAs in HFpEF. Finally, we address the potential of exercise training, which is currently the only available therapy to improve aerobic capacity and quality of life in HFpEF patients. Unraveling the underlying mechanisms responsible for this improvement could lead to new biomarkers and therapeutic targets for HFpEF.

Influence of Baseline Physical Activity Level on Exercise Training Response and Clinical Outcomes in Heart Failure: The HF-ACTION Trial

OBJECTIVES

This study sought to evaluate the influence of baseline physical activity (PA) on responses to aerobic exercise training and clinical events in outpatients with chronic systolic heart failure (HF) from the multicenter HF-ACTION (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure) trial.

BACKGROUND

The influence of baseline PA on exercise capacity, responses to exercise training and clinical outcomes in patients with chronic HF is unclear.

METHODS

Of 2,130 participants who provided consent for this analysis, 1,494 patients (64%) had complete baseline PA data, using a modified version of the International Physical Activity Questionnaire-Short Form questionnaire and were included in the analysis; 742 received usual care and 752 were allocated to the exercise training group. Changes in exercise capacity, all-cause mortality and hospitalization, cardiovascular (CV) mortality and hospitalization, and CV mortality and HF hospitalization were evaluated as a function of baseline PA tertile.

RESULTS

At baseline, the highest PA tertile showed greater peak oxygen uptake, cardiopulmonary exercise test duration, and 6-min walk test distance than the other 2 PA tertiles, as well as lower New York Heart Association functional class, lower Beck depression score, and lower atrial fibrillation prevalence than the lowest PA tertile. Compared to the lowest PA tertile, the middle tertile had 18% lower risk of CV death/CV hospitalizations, and the upper tertile showed 23% lower risk of CV death/HF hospitalizations. Exercise capacity and clinical outcome responses to training were similar and largely nonsignificant across baseline PA tertiles with significant benefit of training on exercise test duration for all tertiles.

CONCLUSIONS

In patients with chronic systolic HF, aerobic exercise training significantly improves exercise test duration to a similar extent across baseline PA tertiles. Although higher baseline PA was associated with lower risk of clinical events, no significant differences in event rates within each PA tertile were seen between subgroups randomized to exercise training versus usual care. (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure [HF-ACTION]; NCT00047437).

Skeletal Muscle Myopathy in Heart Failure: the Role of Ejection Fraction

PURPOSE OF REVIEW

This review summarizes: (1) the structural and functional features coupled with pathophysiological factors responsible of skeletal muscle myopathy (SMM) in both heart failure with reduced (HFrEF) and preserved (HFpEF) ejection fraction and (2) the role of exercise as treatment of SMM in these HF-related phenotypes.

RECENT FINDINGS

The recent literature showed two main phenotypes of heart failure (HF): (1) HFrEF primarily due to a systolic dysfunction of the left ventricle and (2) HFpEF, mainly related to a diastolic dysfunction. Exercise intolerance is one of most disabling symptoms of HF and it is shown that persists after the normalization of the central hemodynamic impairments by therapy and/or cardiac surgery including heart transplant. A specific skeletal muscle myopathy (SMM) has been defined as one of the main causes of exercise intolerance in HF. The SMM has been well described in the last 20 years in the HFrEF; on the contrary, few studies are available in HFpEF. Recent evidences have revealed that exercise training counteracts HF-related SMM and in turn ameliorates exercise intolerance.

Effect of exercise therapy on established and emerging circulating biomarkers in patients with heart failure: a systematic review and meta-analysis

Background

Biomarkers are important in the diagnosis, risk stratification and management of patients with heart failure (HF). The established biomarkers of myocardial stretch, brain natriuretic peptide (BNP) and amino (N) portion of BNP (NT-proBNP) have been extensively studied, and early analyses have demonstrated response to exercise training. Several other biomarkers have been identified over the last decade and may provide valuable and complementary information which may guide treatment strategies, including exercise therapy.

Methods

A systematic search of PubMed, EMBASE and Cochrane Trials Register to 31 October 2017 was conducted for exercise-based rehabilitation trials in HF. Randomised and controlled trials that reported biomarkers, BNP, NT-proBNP, soluble ST2, galectin-3, mid-regional atrial natriuretic peptide, mid-regional adrenomedullin and copeptin, were included.

Results

Forty-three studies were included in the systematic review, with 27 studies suitable for meta-analyses. Data pooling was only possible for NT-proBNP and BNP. Meta-analyses of conventional training studies demonstrated a statistically significant improvement in NT-proBNP (pmol/L); mean difference (MD) −32.80 (95% CI −56.19 to −9.42), p=0.006 and in BNP (pmol/L); MD −17.17 (95% CI −29.56 to −4.78), p=0.007. Pooled data of non-conventional training failed to demonstrate any statistically significant improvements.

Conclusion

Pooled data indicated a favourable effect of conventional exercise therapy on the established biomarkers, NT-proBNP and BNP; however, this was in contrast to a number of studies that could not be pooled. Limited evidence exists as to the effect of exercise training on emerging biomarkers.

High intensity interval training versus moderate intensity continuous training on exercise capacity and quality of life in patients with heart failure with reduced ejection fraction: A systematic review and meta-analysis

OBJECTIVE

The aim of this study was to investigate the effects of high intensity interval training (HIIT) versus moderate intensity continuous training (MICT) in heart failure patients with reduced ejection fraction (HFrEF).

BACKGROUND

Despite the well-known positive effects of exercise in heart failure patients, the best mode of exercise is still under discussion.

METHODS

We searched Pubmed/MEDLINE, Cochrane Central Register of Controlled Trials, PEDro data base, and SciELO (from the earliest date available to October 2017) for randomized controlled trials that evaluated the effects of HIIT versus MICT in HFrEF patients. Weighted mean differences (WMD) with 95% confidence interval (CI) were calculated, and heterogeneity was assessed using the I² test.

RESULTS

13 studies met the study criteria, including 411 patients. Compared to MICT, HIIT resulted in improvement in Peak VO₂ WMD (1.35 mL·kg^-1·min^-1 95% CI: 0.03 to 2.64 N = 411). HIIT resulted in no difference in VE/VCO₂ slope WMD (-1.21 95% CI: -3.0 to 0.58 N = 135), and quality of life measured by Minnesota Living with Heart Failure questionnaire WMD (1.19 95% CI: -5.81 to 8.19 N = 79). Sub-group analyses comparing studies with and without isocaloric exercise training protocol also showed a nonsignificant difference in peak VO₂ for participants in the HIIT group compared with MICT group.

CONCLUSIONS

HIIT improves peak VO₂ and should be considered as a component of care of HFrEF patients. However, its superiority versus MICT disappears when isocaloric protocols are compared. An important caveat is uncertainty and variation of actual training intensities compared to program targets.