Improvement In Peak Oxygen Uptake Research Articles

Effects of interval training in cardiovascular disease populations: a clinical perspective.

Nearly 20 years have elapsed since the first clinical trial investigated the impact of interval training on patients with cardiovascular disease (CVD). This clinical corner discusses the health outcomes of systematic reviews and meta-analyses and appropriately powered randomized clinical trials which have tested these interval training programs across various CVDs (i.e., coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, and cardiac implantable electronic devices). The publications included in this clinical corner have shown that interval training leads to similar or superior improvements in peak oxygen uptake (V̇O2peak), functional capacity, pain free walking, quality of life, anxiety, depression, and endothelial function, but the magnitude of improvements across varying protocols (e.g., length and number of work periods, intensities of work periods, duration of exercise sessions, frequency of exercise sessions, and duration of program) and optimal dosage for males and females are unclear across CVD conditions. The heterogeneity in protocols, physical and mental health outcome measures, and lack of sex- and gender-based analyses calls for more high-quality research in this area.

Aficamten for Symptomatic Obstructive Hypertrophic Cardiomyopathy

BackgroundOne of the major determinants of exercise intolerance and limiting symptoms among patients with obstructive hypertrophic cardiomyopathy (HCM) is an elevated intracardiac pressure resulting from left ventricular outflow tract obstruction. Aficamten is an oral selective cardiac myosin inhibitor that reduces left ventricular outflow tract gradients by mitigating cardiac hypercontractility.MethodsIn this phase 3, double-blind trial, we randomly assigned adults with symptomatic obstructive HCM to receive aficamten (starting dose, 5 mg; maximum dose, 20 mg) or placebo for 24 weeks, with dose adjustment based on echocardiography results. The primary end point was the change from baseline to week 24 in the peak oxygen uptake as assessed by cardiopulmonary exercise testing. The 10 prespecified secondary end points (tested hierarchically) were change in the Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS), improvement in the New York Heart Association (NYHA) functional class, change in the pressure gradient after the Valsalva maneuver, occurrence of a gradient of less than 30 mm Hg after the Valsalva maneuver, and duration of eligibility for septal reduction therapy (all assessed at week 24); change in the KCCQ-CSS, improvement in the NYHA functional class, change in the pressure gradient after the Valsalva maneuver, and occurrence of a gradient of less than 30 mm Hg after the Valsalva maneuver (all assessed at week 12); and change in the total workload as assessed by cardiopulmonary exercise testing at week 24.ResultsA total of 282 patients underwent randomization: 142 to the aficamten group and 140 to the placebo group. The mean age was 59.1 years, 59.2% were men, the baseline mean resting left ventricular outflow tract gradient was 55.1 mm Hg, and the baseline mean left ventricular ejection fraction was 74.8%. At 24 weeks, the mean change in the peak oxygen uptake was 1.8 ml per kilogram per minute (95% confidence interval [CI], 1.2 to 2.3) in the aficamten group and 0.0 ml per kilogram per minute (95% CI, −0.5 to 0.5) in the placebo group (least-squares mean between-group difference, 1.7 ml per kilogram per minute; 95% CI, 1.0 to 2.4; P<0.001). The results for all 10 secondary end points were significantly improved with aficamten as compared with placebo. The incidence of adverse events appeared to be similar in the two groups.ConclusionsAmong patients with symptomatic obstructive HCM, treatment with aficamten resulted in a significantly greater improvement in peak oxygen uptake than placebo. (Funded by Cytokinetics; SEQUOIA-HCM ClinicalTrials.gov number, NCT05186818.)

Laryngeal widening and adequate ventilation by expiratory pressure load training improve aerobic capacity in COPD: a randomised controlled trial

RationaleDespite strategies acting on peripheral airway obstruction in chronic obstructive pulmonary disease (COPD), exercise intolerance remains inadequately improved. We hypothesised that laryngeal narrowing is a potential treatment target of expiratory...

The Effect of High-Intensity Interval Training on Exercise Capacity in Patients with Coronary Artery Disease: A Systematic Review and Meta-Analysis.

The optimal exercise prescription for coronary artery disease (CAD) remains under debate. The aim of our meta-analysis is to investigate the efficacy of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) of coronary artery disease patients. Electronic databases were searched from their inception date until October 23, 2021, and the articles include randomized controlled trials. The mean differences and 95% confidence intervals were calculated, and heterogeneity was assessed using the I 2 test. The study standards were met by seventeen studies. The pooled studies included 902 patients. HIIT resulted in improvement in peak oxygen uptake (1.50 ml/kg/min, 95% confidence interval: 0.48 to 2.53, n = 853 patients, and low quality evidence) compared with MICT. There was no discernible difference between the individuals in the HIIT group and the MICT group in terms of systolic/diastolic blood pressure or peak/resting heart rate. This systematic review and meta-analysis reported the superiority of HIIT versus MICT in enhancing peak oxygen uptake in CAD patients.

(766) Improvement in Peak Oxygen Uptake During First Year of Mechanical Circulatory Support in End-Stage Heart Failure Patients - Follow Up on PRO-VAD Study

(766) Improvement in Peak Oxygen Uptake During First Year of Mechanical Circulatory Support in End-Stage Heart Failure Patients - Follow Up on PRO-VAD Study

Impact of Exercise Training at Different Intensity Levels on Cardiac Function and Exercise Capacity in Patients with Chronic Heart Failure: A Prospective Cohort Study.

To investigate training at different intensity levels on cardiac function, exercise capacity, and health-related quality of life in patients with chronic heart failure. This prospective cohort study enrolled patients with chronic heart failure at Beijing Rehabilitation Hospital, Beijing, China from January 2018 to January 2020. Participants received conventional therapy (non-exercise group) or therapy plus cycle ergometer exercises at an intensity of 80% anaerobic threshold (EA group) and Δ50% power above anaerobic threshold (EB group) for 12 weeks. The primary outcome was peak oxygen uptake. Forty-five patients (15/group) completed the study without serious complications. Exercise training at an intensity of Δ50% power above anaerobic threshold had better effects on exercise capacity than exercise at an intensity of 80% anaerobic threshold, as shown by a greater improvement in peak oxygen uptake (20.3 ± 4.1 vs 16.8 ± 3.2 mL/min/kg), peak O2 pulse (12.5 ± 2.3 vs 10.1 ± 2.1 mL/beat), and peak workload (123.1 ± 26.9 vs 102.8 ± 29.5 W) in patients with chronic heart failure (all p < 0.001). Exercise improved the 6-min walk test distance (control: 394.0 ± 74.1; EA: 481.4 ± 89.4; EB: 508.9 ± 92.5 m; p < 0.001) and health-related quality of life (control: 40.7 ± 12.3; EA: 16.2 ± 8.6; EB: 11.5 ± 6.4; p < 0.001). Compared with an intensity of 80% anaerobic threshold, exercise training at an intensity of Δ 50% power above anaerobic threshold was safe and had better effects on cardiac function, exercise capacity, and health-related quality of life.

Breathing patterns and ventilatory efficiency in elderly cardiac patients with and without left ventricular dysfunction before and after exercise-based cardiac rehabilitation: the EU-CaRE study

Abstract Introduction Coronary artery disease (CAD) may progress to left ventricular dysfunction (LVD) and chronic heart failure. A reduced ventilatory efficiency in these patients is associated with worse outcome. However, breathing patterns at rest and during exercise and their change during exercise-based cardiac rehabilitation (exCR) have been poorly described in this population. We aimed to analyse respiratory and gas-exchange parameters in elderly patients with CAD included in a multicentre study on effectiveness of exCR across seven European countries (EU-CaRE). Methods Patients aged 65 years and older with acute (ACS) and chronic coronary syndromes (CCS) who participated in exCR were included. Cardiopulmonary exercise testing (CPET) was performed before (T0) and at termination of exCR (T1), and 12 months after start of exCR (T2). Ventilation (VE), breathing frequency (BF), and end-expiratory carbon dioxide pressure (PetCO2) were measured at rest, at first ventilatory threshold and peak exercise. Ventilatory efficiency, expressed as VE/VCO2 slope and the nadir of VE/VCO2 ratio were measured during the ramp test. Peak oxygen uptake was averaged over 30 s. Breathing parameters over time were compared between patients without and with left ventricular dysfunction (LVD, defined as LV ejection fraction &amp;lt;45%) by mixed linear models corrected for age, sex and body mass index. Results 818 out of 1633 patients of the EU-CaRE study fulfilled inclusion criteria, 151 (18%) had LVD, of these, 86% were in New York Heart Association (NYHA) functional class I. Mean age was 72.5±5.4 years, 21.9% were women, and 79.8% had acute ACS. Compared to patients without LVD, in patients with LVD resting VE was increased 9%, VE/VCO2 slope 14%, and nadir VE/VCO2 ratio 9%, while PetCO2 was reduced at rest and peak exercise by 6%. From before to after exCR, resting ventilation and breathing frequency, as well as VE/VCO2 slope and nadir VE/VCO2 during exercise decreased significantly more in patients with LVD compared to patients without, while improvement in peak oxygen uptake was similar (Figure 1). Conclusions In contrast to their own perception based on NYHA class, patients with LVD had exaggerated breathing at rest and as response to exercise with consistently reduced PetCO2 and ventilatory efficiency. Abnormal breathing patterns may be an early and clinically relevant sign of LVD and linked to increased chemosensitivity and/or abnormal ergoreflex. Exercise-based CR may contribute to improvements of breathing patterns and ventilator efficiency in this population. Funding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union's Horizon 2020 research and innovation program and Swiss State Secretariat for Education, Research and Innovation for the Swiss consortium partner

Predictors of Changes in Peak Oxygen Uptake After Outpatient Cardiac Rehabilitation: Importance of Cardiac Rehabilitation Attendance

ObjectiveTo determine whether the number of cardiac rehabilitation (CR) sessions attended and selected clinical characteristics were predictive of patients who exhibited improvement in peak oxygen uptake (VO2peak) after CR. Patients and MethodsUsing the Rochester Epidemiology Project records-linkage system, we identified all consecutive patients aged 18 years or older from Olmsted County, Minnesota, who underwent cardiopulmonary exercise testing before and after CR from 1999 to 2017. Regression models were created to assess the clinical predictors of VO2peak improvement (>0% baseline) after CR. ResultsThe analysis included 671 patients, of which 524 (78%) patients exhibited VO2peak improvement after CR. The significant univariate predictors of VO2peak improvement included younger age (odds ratio [OR], 0.98; 95% CI, 0.96-0.99), lower pre-CR VO2peak (OR, 0.96; 95% CI, 0.94-0.99), and no history of peripheral artery disease (OR, 0.50; 95% CI, 0.31-0.81) (all, P<.005). The significant independent predictors of VO2peak improvement from the multivariable analysis included the number of CR sessions (OR, 1.04; 95% CI, 1.02-1.05), younger age (OR, 0.96; 95% CI, 0.94-0.98), lower pre-CR VO2peak (OR, 0.92; 95% CI, 0.89-0.95), and no history of peripheral artery disease (OR, 0.47; 95% CI, 0.28-0.78) (all, P<.005). ConclusionThese findings highlight the importance of patient participation in CR sessions and individual clinical characteristics in influencing VO2peak improvement after CR in patients with cardiovascular disease.

Personalized remotely guided preventive exercise therapy for a healthy heart: protocol and design of the PRIORITY study

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation – Flanders (FWO) Introduction Approximately half of the heart failure population has heart failure with preserved ejection fraction (HFpEF), a chronic disease starting with cardiovascular risk factors such as hypertension, diabetes and obesity (stage A) which can further emerge in a structural heart disease without (stage B) or with (stage C) signs or symptoms. Structured exercise therapy is recommended as a Class IA intervention in national and international guidelines and, as such, should be offered to all patients. Yet, in current practice, exercise therapy is often only offered within a secondary prevention program. At present, there exists no comprehensive preventive care program that includes structured exercise for patients in the early stages of heart failure, when cardiovascular risk factors are present, but cardiac remodeling and dysfunction might still be reversible or even preventable. Purpose PRIORITY aims to investigate the use of remotely guided exercise therapy as a preventive clinical and cost-effective treatment in the HFpEF continuum. This includes both prevention of progression of asymptomatic diastolic dysfunction towards symptomatic HFpEF (= primary prevention) and delaying progression of symptomatic HFpEF (= secondary prevention). Methods A randomized controlled multicenter trial will be conducted in 450 patients (men and women, aged 35-80 years) with heart failure (n = 180 stage A, 180 stage B, 90 stage C). Participants are being recruited from 3 different hospitals and the general population during a 16-month period which started in September 2021. Patients will be randomized (1:1) to usual care or to the PRIORITY exercise intervention (i.e. a combination of supervised with remotely guided home-based training sessions). Training prescription is based on the EXPERT tool and includes person-tailored endurance and dynamic strength training. During one year, participants will receive 18 supervised exercise sessions supplemented with a structured progressive home-based exercise program. Outcomes will be assessed at baseline, 4 months, one and two-years. Primary outcome is the proportion of patients with a clinically relevant improvement in peak oxygen uptake at one-year. Secondary outcomes include vascular health, muscle metabolism, change in electrocardiographic parameters and physical fitness parameters (muscle strength, body composition). Further, big data of physical activity collected during the trial will be used to develop models using machine-learning algorithms which can predict physical activity uptake and changes in fitness to facilitate the creation of more personalized interventions and better tailored exercise prescription. Conclusion We anticipate that the PRIORITY study will contribute to better prevention of heart failure thanks to an early easily accessible person-tailored exercise intervention.

Exercise-Based Cardiac Rehabilitation Improves Exercise Capacity Regardless of the Response to Cardiac Resynchronization Therapy in Patients With Heart Failure and Reduced Ejection Fraction.

In patients with chronic heart failure with reduced ejection fraction (HFrEF), cardiac resynchronization therapy (CRT) improves left ventricular ejection fraction (LVEF) and exercise-based cardiac rehabilitation (ECR) enhances exercise capacity. This study examined the relationship between the 2 responses. Sixty-four consecutive HFrEF patients who participated in a 3-month ECR program after CRT were investigated. Patients were categorized according to a median improvement in peak oxygen uptake (PV̇O2) after ECR of 7% as either good (n=32; mean percentage change in PV̇O2[%∆PV̇O2]=23.2%) or poor (n=32; mean %∆PV̇O2=2.5%) responders. There was no significant difference in baseline characteristics between the good and poor responders, except for PV̇O2(51% vs. 59%, respectively; P=0.01). The proportion of good CRT responders was similar between the good and poor responders (%∆LVEF ≥10%; 53% vs. 47%, respectively; P=NS). Overall, there was no significant correlation between %∆LVEF after CRT and %∆PV̇O2after ECR. Notably, among poor CRT responders (n=32), the prevalence of atrial fibrillation (0% vs. 29%; P<0.03) and baseline PV̇O2(48% vs. 57%; P<0.05) were significantly lower among those with a good (n=15) than poor (n=17) response to ECR. In patients with HFrEF, good ECR and CRT responses are unrelated. A good PV̇O2response to ECR can be achieved even in poor CRT responders, particularly in those with a sinus rhythm or low baseline PV̇O2.

High-Intensity Interval Training and Cardiometabolic Risk Factors in Children: A Meta-analysis.

High-intensity interval training (HIIT) has been widely used to prevent and treat cardiovascular risk factors in adolescents and adults; nevertheless, the available evidence in children is scarce. To synthesize evidence regarding the effectiveness of HIIT interventions on improving cardiovascular risk factors and cardiorespiratory fitness (CRF) in children from 5 to 12 years old. We searched 5 databases, Medline, Embase, SPORTDiscus, the Cochrane Library, and Web of Science. Randomized controlled trials (RCTs) evaluating the effectiveness of HIIT interventions on cardiometabolic risk factors and CRF in children were included. Meta-analyses were conducted to determine the effect of HIIT on body composition, cardiometabolic and CRF variables in comparison with nontraining control groups. A total of 11 RCTs and 512 participants were included. The results of the meta-analysis revealed a significant improvement in peak oxygen uptake (standardized mean difference [SMD] = 0.70, 95% confidence interval [CI] = 0.28 to 1.12; P = 0.001], in total cholesterol [SMD = -1.09, 95% CI = -1.88 to -0.30; P = 0.007], in low-density lipoprotein cholesterol [SMD = -1.28, 95% CI = -2.34 to -0.23; P = 0.017] and triglycerides [SMD = -0.71, 95% CI = -1.15 to -0.28; P = 0.001) levels. Because of the small number of available RCTs, it was not possible to conduct a subgroup analysis or a linear meta-regression analysis. HIIT is a feasible and time-efficient approach for improving CRF, total cholesterol, low-density lipoprotein cholesterol, and triglycerides levels in children.

Home-based training program in patients with chronic heart failure and reduced ejection fraction: a randomized pilot study

OBJECTIVES:We aimed to compare the effects of home-and center-based exercise training programs on functional capacity, inspiratory muscle strength, daily physical activity level, and quality of life (QoL) in patients with chronic heart failure (CHF) over a 12-week period.METHODS:This study included 23 patients with CHF (left ventricular ejection fraction 31±6%) randomized to a home-based (n=11) or center-based (n=12) program. Patients underwent 12 weeks of aerobic training (60%-70% heart rate reserve): walking for the home-based and supervised cycling for the center-based group, both combined with resistance training (50% of 1 maximum repetition). At baseline and after 12 weeks of training, we assessed cardiopulmonary test variables, 6-min walk test distance (6 MWD), steps/day with accelerometry, and QoL (Minnesota Living with Heart Failure questionnaire). Maximal inspiratory pressure and handgrip strength were measured at baseline and after 4, 8, and 12 weeks of training. ClinicalTrials.gov: NCT03615157.RESULTS:There were no adverse events during training in either group. The home- and center-based training groups obtained similar improvements in peak oxygen uptake, maximal ventilation, and 6 MWD. However, there were significant between-group differences: center-based training was more effective in improving maximal inspiratory pressure (p=0.042), number of steps/day (p=0.001), and QoL (p=0.039).CONCLUSIONS:Home-based training is safe and can be an alternative to improve the exercise capacity of patients with stable CHF. However, center-based training was superior in improving inspiratory muscle strength, QoL, and daily physical activity.

Determinants of Functional Capacity and Quality of Life After Implantation of a Durable Left Ventricular Assist Device.

Continuous-flow left ventricular assist devices (LVAD) are increasingly used as destination therapy in patients with end-stage heart failure and, with recent improvements in pump design, adverse event rates are decreasing. Implanted patients experience improved survival, quality of life (QoL) and functional capacity (FC). However, improvement in FC and QoL after implantation is not unequivocal, and this has implications for patient selection and preimplantation discussions with patients and relatives. This article identifies preimplantation predictors of lack of improvement in FC and QoL after continuous-flow LVAD implantation and discusses potential mechanisms, allowing for the identification of potential factors that can be modified. In particular, the pathophysiology behind insufficient improvement in peak oxygen uptake is discussed. Data are included from 40 studies, resulting in analysis of >700 exercise tests. Mean peak oxygen uptake was 13.4 ml/kg/min (equivalent to 48% of predicted value; 259 days after implantation, range 31–1,017 days) and mean 6-minute walk test distance was 370 m (182 days after implantation, range 43–543 days). Finally, the interplay between improvement in FC and QoL is discussed.

Current Insights into Exercise-based Cardiac Rehabilitation in Patients with Coronary Heart Disease and Chronic Heart Failure.

Cardiac rehabilitation is a package of lifestyle secondary prevention strategies designed for patients with coronary heart disease and chronic heart failure. A community-based cardiac rehabilitation programme provides patients with a structured exercise training intervention alongside educational support and psychological counselling. This review provides an update regarding the clinical benefits of community-based cardiac rehabilitation from a psycho-physiological perspective, and also focuses on the latest epidemiological evidence regarding potential survival benefits. Behaviour change is key to long-term adoption of a healthy and active lifestyle following a cardiac event. In order for lifestyle interventions such as structured exercise interventions to be adopted by patients, practitioners need to ensure that behaviour change programmes are mapped against patient's priorities and values, and adapted to their level of readiness and intention to engage with the target behaviour. We review the evidence regarding behaviour change strategies for cardiac patients and provide practitioners with the latest guidance. The 'dose' of exercise training delivered to patients attending exercise-based cardiac rehabilitation is an important consideration because an improvement in peak oxygen uptake requires an adequate physiological stimulus to invoke positive physiological adaptation. We conclude by critically reviewing the latest evidence regarding exercise dose for cardiac patients including the role of traditional and more contemporary training interventions including high intensity interval training.

Mitochondrial oxygen affinity increases after sprint interval training and is related to the improvement in peak oxygen uptake

The body responds to exercise training by profound adaptations throughout the cardiorespiratory and muscular systems, which may result in improvements in maximal oxygen consumption (VO2 peak) and mitochondrial capacity. By convenience, mitochondrial respiration is often measured at supra-physiological oxygen levels, an approach that ignores any potential regulatory role of mitochondrial affinity for oxygen (p50mito ) at physiological oxygen levels. In this study, we examined the p50mito of mitochondria isolated from the Vastus lateralis and Triceps brachii in 12 healthy volunteers before and after a training intervention with seven sessions of sprint interval training using both leg cycling and arm cranking. The changes in p50mito were compared to changes in whole-body VO2 peak. We here show that p50mito is similar in isolated mitochondria from the Vastus (40±3.8Pa) compared to Triceps (39±3.3) but decreases (mitochondrial oxygen affinity increases) after seven sessions of sprint interval training (to 26±2.2Pa in Vastus and 22±2.7Pa in Triceps, both P<.01). The change in VO2 peak modelled from changes in p50mito was correlated to actual measured changes in VO2 peak (R2 =.41, P=.002). Together with mitochondrial respiratory capacity, p50mito is a critical factor when measuring mitochondrial function, it can decrease with sprint interval training and should be considered in the integrative analysis of the oxygen cascade from lung to mitochondria.

Exercise Interventions and Cardiovascular Health in Childhood Cancer: A Meta-analysis.

This study analyzed the effects of physical exercise interventions on cardiovascular endpoints in childhood cancer survivors. Relevant articles were systematically searched in PubMed, CINAHL, and Web of Science databases (since inception to 11th September 2019). We performed a meta-analysis (random effects) to determine the mean difference (expressed together with 95% confidence intervals) between pre- and post-intervention values for those cardiovascular endpoints reported in more than three studies. Twenty-seven studies (of which 16 were controlled studies) comprising 697 participants were included. Only three studies reported adverse events related to exercise interventions. Exercise resulted in an increased performance on the 6-minute walk distance test (mean difference=111 m, 95% confidence interval=39-183, p=0.003) and a non-significant trend (mean difference=1.97 ml∙kg-1∙min-1, 95% confidence interval=-0.12-4.06, p=0.065) for improvement in peak oxygen uptake. Furthermore, left ventricular ejection fraction was preserved after exercise interventions (mean difference=0.29%, 95% confidence interval=-1.41-1.99, p=0.738). In summary, exercise interventions might exert a cardioprotective effect in childhood cancer survivors by improving - or attenuating the decline of - physical capacity and cardiovascular function. Further studies, particularly randomized controlled trials, are needed to confirm these benefits.

P6325Gas exchange improvements during exercise correlate with hemodynamic changes in heart failure patients with a left ventricular assist device

Abstract Background The implantation of left ventricular assist devices (LVAD) has established its role in therapy for patients with end stage heart failure. Benefits in survival as well as an improved quality of life, compared to optimized medical therapy (OMT) alone, has been proven. There are limited data in the literature on the metabolic changes during exercise in LVAD patients, and in most studies no increase in peak oxygen consumption on cardiopulmonary exercise test (CPET) could be shown early after surgery. However, recent data suggests an improvement in peak oxygen uptake (VO2) as a late effect after rehabilitation. To further investigate these findings we sought to analyse CPET data from patients before LVAD implantation as well as in the early and late follow up in correlation with hemodynamic changes at these times. Methods We collected and retrospectively analysed data of heart failure patients who had undergone LVAD implantation, and in whom a right heart catheterization, a cardiopulmonary exercise test and an echocardiography had been performed at time before, as well as 6 Months and 12 months after LVAD implantation, respectively. Results Data of 43 patients implanted with an LVAD between 2011 and 2017 were analysed. There was significant improvement in cardiac output (3,2 vs 4,3 L/min, p&lt;0,001) and VE/VCO2 slope (46 vs 38, p=0,001) 6 months after LVAD implant as well as a significant reduction in PCWP (26 vs 11 mmHg, p&lt;0,001), PAP mean (40 vs 22 mmHg, p&lt;0,001), RA mean (12 vs 8 mmHg, p=0,002) and PVR (4,2 vs 2,5 WU, p&lt;0,001). However, there was no significant increase in peak VO2 after 6 months. 12 months after LVAD implantation there were no further significant changes in cardiac output, intracardiac pressures or VE/VCO2 slope, which all remained similar to the 6 months follow up. However, at that point, a significant increase in peak VO2 was seen, compared to baseline (1060 vs 1410ml/min, p=0,001) and to 6 months after surgery (Figure 1). Conclusion Cardiac output increases in heart failure patients early after LVAD implantation. Consequently, permanent ventricular off loading results in the reduction of intracardiac pressures and improvement in the VE/VCO2 slope 6 months after surgery. However, a significant rise in peak oxygen consumption could only be noted 12 months after surgery, suggesting either a delayed long-term effect of improved hemodynamics or other causes such as enhanced mobility or training due to improved quality of life.

Home‐Based Cardiac Rehabilitation Alone and Hybrid With Center‐Based Cardiac Rehabilitation in Heart Failure: A Systematic Review and Meta‐Analysis

BackgroundCenter‐based cardiac rehabilitation (CBCR) has been shown to improve outcomes in patients with heart failure (HF). Home‐based cardiac rehabilitation (HBCR) can be an alternative to increase access for patients who cannot participate in CBCR. Hybrid cardiac rehabilitation (CR) combines short‐term CBCR with HBCR, potentially allowing both flexibility and rigor. However, recent data comparing these initiatives have not been synthesized.Methods and ResultsWe performed a meta‐analysis to compare functional capacity and health‐related quality of life (hr‐QOL) outcomes in HF for (1) HBCR and usual care, (2) hybrid CR and usual care, and (3) HBCR and CBCR. A systematic search in 5 standard databases for randomized controlled trials was performed through January 31, 2019. Summary estimates were pooled using fixed‐ or random‐effects (when I2>50%) meta‐analyses. Standardized mean differences (95% CI) were used for distinct hr‐QOL tools. We identified 31 randomized controlled trials with a total of 1791 HF participants. Among 18 studies that compared HBCR and usual care, participants in HBCR had improvement of peak oxygen uptake (2.39 mL/kg per minute; 95% CI, 0.28–4.49) and hr‐QOL (16 studies; standardized mean difference: 0.38; 95% CI, 0.19–0.57). Nine RCTs that compared hybrid CR with usual care showed that hybrid CR had greater improvements in peak oxygen uptake (9.72 mL/kg per minute; 95% CI, 5.12–14.33) but not in hr‐QOL (2 studies; standardized mean difference: 0.67; 95% CI, −0.20 to 1.54). Five studies comparing HBCR with CBCR showed similar improvements in functional capacity (0.0 mL/kg per minute; 95% CI, −1.93 to 1.92) and hr‐QOL (4 studies; standardized mean difference: 0.11; 95% CI, −0.12 to 0.34).Conclusions HBCR and hybrid CR significantly improved functional capacity, but only HBCR improved hr‐QOL over usual care. However, both are potential alternatives for patients who are not suitable for CBCR.

Effects of exercise training in heart failure with preserved ejection fraction: an updated systematic literature review.

Physical activity is associated with a lower risk of adverse cardiovascular outcomes, including heart failure (HF). Exercise training is a class IA level recommendation in patients with stable HF, but its impact is less clear in heart failure with preserved ejection fraction (HFpEF). The aim of this study was to analyze the effects of the exercise training on cardiovascular outcomes in patients with HFpEF. A systematic literature search was conducted on the main electronic databases, proceedings of major meetings, and reference lists of the identified studies, using specific terms for only English language studies published between 2000 and 2018. We followed the PRISMA to perform our review. Quality of studies was also assessed. The systematic review identified 9 studies on 348 patients, of moderate (n = 2) to good (n = 7) quality. The training consisted of a combination of supervised in-hospital and home-based outpatient programs, including aerobic exercise, endurance and resistance training, walking, and treadmill and bicycle ergometer. Most of the protocols ranged 12-16weeks, with a frequency of 2-3 sessions weekly, lasting 20-60min per session. There were significant improvements in peak oxygen uptake, 6-min walking test distance, and ventilatory threshold, whereas quality of life and echocardiographic parameters improved only in some studies. Endothelial function/arterial stiffness remained unchanged. No adverse events were reported. Appropriate exercise programs are able to get a favorable cardiovascular outcome in patients with HFpEF. This could also benefit in terms of quality of life, even if more controversial. Further researches are necessary.

Short-term effects of a 3-week interval training program on heart rate variability in chronic heart failure. A randomised controlled trial.

Exaggerated sympathetic nervous system activity associated with low heart rate variability (HRV) is considered to trigger cardiac arrhythmias and sudden death. Regular exercise training is efficient to improve autonomic balance. We aimed to verify the superiority of high-intensity interval training (HIIT) to enhance HRV, cardiorespiratory fitness and cardiac function as compared with moderate intensity continuous training (MICT) in a short, intense cardiac rehabilitation program. This was a prospective, monocentric, evaluator-blinded, randomised (1:1) study with a parallel two-group design. Overall, 31 individuals with voluntary chronic heart failure (CHF) (left ventricular ejection fraction [LVEF]<45%) were allocated to MICT (n=15) or HIIT (n=16) for a short rehabilitation program (mean [SD] 27 [4] days). Participants underwent 24-hr electrocardiography, echocardiography and a cardiopulmonary exercise test at entry and at the end of the study. High-frequency power in normalized units (HFnu%) measured as HRV increased with HIIT (from 21.2% to 26.4%, P<0.001) but remained unchanged with MICT (from 23.1% to 21.9%, P=0.444, with a significant intergroup difference, P=0.003). Resting heart rate (24-hr Holter electrocardiography) decreased significantly for both groups (from 68.2 to 64.6 bpm and 66.0 to 63.5 bpm for MICT and HIIT, respectively, with no intergroup difference, P=0.578). The 2 groups did not differ in premature ventricular contractions. Improvement in peak oxygen uptake was greater with HIIT than MICT (+21% vs. +5%, P=0.009). LVEF improved with only HIIT (from 36.2% to 39.5%, P=0.034). In this short rehabilitation program, HIIT was significantly superior to the classical MICT program for enhancing parasympathetic tone and peak oxygen uptake. CLINICALTRIALS. NCT03603743.