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A large body of research supports the use of exercise to improve symptoms, quality of life, and physical function in patients with chronic heart failure. Previous reviews have focused on reporting outcomes of exercise interventions such as cardiorespiratory fitness. However, none have critically examined exercise prescription. The aim of this review was to evaluate the reporting and application of exercise principles in randomised control trials of exercise training in patients with chronic heart failure. A systematic review of exercise intervention RCTs in patients with CHF, using the Consensus on Exercise Reporting Template (CERT), was undertaken. The Ovid Medline/PubMed, Embase, Scopus/Web of Science, and Cochrane Library and Health Technology Assessment Databases were searched from 2000 to June 2020. Prospective RCTs in which patients with CHF were randomized to a structured exercise programme were included. No limits were placed on the type or duration of exercise structured exercise programme or type of CHF (i.e. preserved or reduced ejection fraction). We included 143 studies, comprising of 181 different exercise interventions. The mean CERT score was 10 out of 19, with no study achieving a score of 19. Primarily, details were missing regarding motivational strategies, home‐based exercise components, and adherence/fidelity to the intervention. Exercise intensity was the most common principle of exercise prescription missing from intervention reporting. There was no improvement in the reporting of exercise interventions with time (R 2 = 0.003). Most RCTs of exercise training in CHF are reported with insufficient detail to allow for replication, limiting the translation of evidence to clinical practice. We encourage authors to provide adequate details when reporting future interventions. Where journal word counts are restrictive, we recommend using supplementary material or publishing trial protocols prior to beginning the study.

Background Heart failure patients demonstrate reduced functional capacity, hemodynamic function, and quality of life (QOL) which are associated with high mortality and morbidity rate. The aim of the present study was to assess the relationship between functional capacity, hemodynamic response to exercise and QOL in chronic heart failure. Methods A single-centre prospective study recruited 42 chronic heart failure patients (11 females, mean age 60 ± 10 years) with reduced left ventricular ejection fraction (LVEF = 23 ± 7%). All participants completed a maximal graded cardiopulmonary exercise test with non-invasive hemodynamic (bioreactance) monitoring. QOL was assessed using Minnesota Living with Heart Failure Questionnaire. Results The average value of QOL score was 40 ± 23. There was a significant negative relationship between the QOL and peak O2 consumption (r = − 0.50, p ≤ 0.01). No significant relationship between the QOL and selected exercise hemodynamic measures was found, including peak exercise cardiac power output (r = 0.15, p = 0.34), cardiac output (r = 0.22, p = 0.15), and mean arterial blood pressure (r = − 0.08, p = 0.60). Conclusion Peak O2 consumption, but not hemodynamic response to exercise, is a significant determinant of QOL in chronic heart failure patients.

Single-use electrocardiography (ECG) leads have been developed to reduce healthcare-associated infection. This study compared the validity and reliability of short-term heart rate variability (HRV) obtained from single-use disposable ECG leads.Thirty healthy subjects (33 ± 10 years; 9 females) underwent 5-min resting HRV assessments using disposable (single use) ECG cable and wire system (Kendall DL™ Cardinal Health) and a standard, reusable ECG leads (CardioExpress, Spacelabs Healthcare).Intraclass correlation coefficient (ICC) with 95% confidence interval (CI) between disposable and reusable ECG leads was for the time domain [R-R interval (ms); 0.99 (0.91, 1.00)], the root mean square of successive normal R-R interval differences (RMSSD) (ms); 0.91 (0.76, 0.96), the SD of normal-to-normal R-R intervals (SDNN) (ms); 0.91 (0.68, 0.97) and frequency domain [low-frequency (LF) normalized units (nu); 0.90 (0.79, 0.95), high frequency (HF) nu; 0.91 (0.80, 0.96), LF power (msSingle-use Kendall DL™ ECG leads demonstrate a valid and reproducible tool for the assessment of HRV.

Decline in cardiac high-energy phosphate metabolism [phosphocreatine-to-ATP (PCr/ATP) ratio] and whole body metabolism increase the risk of heart failure and metabolic diseases. The aim of the present study was to assess the relationship between PCr/ATP ratio and measures of body metabolic function. A total of 35 healthy women (56±14.0 years of age) underwent cardiac 31P magnetic resonance spectroscopy to assess PCr/ATP ratio – an index of cardiac high-energy phosphate metabolism. Fasting and 2-hour glucose levels were assessed using oral glucose tolerance test. Indirect calorimetry was performed to determine oxygen consumption and resting metabolic rate. There were no significant relationships between PCr/ATP ratio and resting metabolic rate (r=-0.09, p=0.62), oxygen consumption (r=-0.11, p=0.54), fasting glucose levels (r=-0.31, p=0.07), and 2-hour plasma glucose (r=-0.10, p=0.58). Adjusted analysis for covariates including age, body mass index, fat mass, and physical activity, had no significant influence on the relationship between PCr/ATP ratio and body metabolism. In conclusion, the lack of relationship between cardiac PCr/ATP ratio, glucose control and metabolic rate may suggest that overall metabolic function does not influence cardiac high-energy phosphate metabolism.

Objective The present study assessed agreement between resting cardiac output estimated by inert gas rebreathing (IGR) and thermodilution methods in patients with heart failure and those implanted with a left ventricular assist device (LVAD). Methods and Results Hemodynamic measurements were obtained in 42 patients, 22 with chronic heart failure and 20 with implanted continuous flow LVAD (34 males, aged 50 ± 11 years). Measurements were performed at rest using thermodilution and IGR methods. Cardiac output derived by thermodilution and IGR were not significantly different in LVAD (4.4 ± 0.9 L/min vs 4.7 ± 0.8 L/min, P = .27) or patients with heart failure (4.4 ± 1.4 L/min vs 4.5 ± 1.3 L/min, P = .75). There was a strong relationship between thermodilution and IGR cardiac index (r = 0.81, P = .001) and stroke volume index (r = 0.75, P = .001). Bland–Altman analysis showed acceptable limits of agreement for cardiac index derived by thermodilution and IGR, namely, the mean difference (lower and upper limits of agreement) for patients with heart failure –0.002 L/min/m2 (–0.65 to 0.66 L/min/m2), and –0.14 L/min/m2 (–0.78 to 0.49 L/min/m2) for patients with LVAD. Conclusions IGR is a valid method for estimating cardiac output and should be used in clinical practice to complement the evaluation and management of chronic heart failure and patients with an LVAD.

PURPOSE To assess the agreement between cardiac output estimated by two-dimensional echocardiography and bioreactance methods at rest and during dobutamine stress test in heart failure patients with preserved left ventricular ejection fraction (HFpEF). METHODS Hemodynamic measurements were assessed in 20 stable HFpEF patients (12 females; aged 61 ± 7 years) using echocardiography and bioreactance methods during rest and dobutamine stress test at increment dosages of 5, 10, 15, and 20 μg/kg/min until maximal dose was achieved or symptoms and sign occurred, that is, chest pain, abnormal blood pressure elevation, breathlessness, ischemic changes, or arrhythmia. RESULTS Resting cardiac output and cardiac index estimated by bioreactance and echocardiography were not significantly different. At peak dobutamine stress test, cardiac output and cardiac index estimated by echocardiography and bioreactance were significantly different (7.06 ± 1.43 vs 5.71 ± 1.59 L/min, P

We sought to determine hemodynamic mechanisms of exercise intolerance in a group of patients with the HeartWare ventricular assist device (VAD) compared to a group of heart failure patients. Twenty VAD and 22 heart failure patients underwent symptom-limited active straight leg raising exercise during right heart catheterization with thermodilution (TD), and upright cycling cardiopulmonary stress testing with cardiac output measurement by inert gas rebreathing (IGR) method. The TD and IGR exercise cardiac indexes were higher in VAD compared with heart failure group (both P < 0.05), although there was only a borderline increase in peak exercise oxygen consumption (VO2) (P = 0.06). Baseline and exercise right heart catheterization pressures were not significantly different between the two groups. The only significant independent predictors of peak VO2 in the heart failure group were exercise heart rate and cardiac index (both P < 0.05). In contrast, for the VAD group only, resting pulmonary arterial wedge and pulmonary arterial mean pressures were independently related to peak VO2 (both P < 0.05). Thus, in heart failure, exercise cardiac index is an important limitation to exercise capacity, and VADs increase exercise cardiac index. However, in VAD patients, this only produces limited benefits as increased pulmonary and pulmonary wedge pressures limit increases in exercise capacity.

Diagnostic tools available to support general practitioners diagnose heart failure (HF) are limited.(i) Determine the feasibility of the novel cardiac output response to stress (CORS) test in suspected HF patients, and (ii) Identify differences in the CORS results between (a) confirmed HF patients from non-HF patients, and (b) HF reduced (HFrEF) vs HF preserved (HFpEF) ejection fraction.Single centre, prospective, observational, feasibility study. Consecutive patients with suspected HF (N = 105; mean age: 72 ± 10 years) were recruited from specialized HF diagnostic clinics in secondary care. The consultant cardiologist confirmed or refuted a HF diagnosis. The patient completed the CORS but the researcher administering the test was blinded from the diagnosis. The CORS assessed cardiac function (stroke volume index, SVI) noninvasively using the bioreactance technology at rest-supine, challenge-standing, and stress-step exercise phases.A total of 38 patients were newly diagnosed with HF (HFrEF, n = 21) with 79% being able to complete all phases of the CORS (91% of non-HF patients). A 17% lower SVI was found in HF compared with non-HF patients at rest-supine (43 ± 15 vs 51 ± 16 mL/beat/m2, P = 0.02) and stress-step exercise phase (49 ± 16 vs 58 ± 17 mL/beat/m2, P = 0.02). HFrEF patients demonstrated a lower SVI at rest (39 ± 15 vs 48 ± 13 mL/beat/m2, P = 0.02) and challenge-standing phase (34 ± 9 vs 42 ± 12 mL/beat/m2, P = 0.03) than HFpEF patients.The CORS is feasible and patients with HF responded differently to non-HF, and HFrEF from HFpEF. These findings provide further evidence for the potential use of the CORS to improve HF diagnostic and referral accuracy in primary care.Heart failure (HF) is a global pandemic affecting 26 million people worldwide with an estimated 1 million people in the United Kingdom. Accurate early diagnosis of HF and the initiation of evidence-based treatment is essential to reduce morbidity and mortality and the associated burden on healthcare. As there are no state-of-the-art approaches, early diagnosis is challenging and often inaccurate, as initial signs and symptoms are nonspecific. We have developed an innovative test, named CORS (cardiac output response to stress test), to help general practitioners identify HF, which uses a method similar to an electrocardiogram and measures heart function at rest and during short step exercise. We recruited suspected HF patients from specialist HF diagnostic clinics in secondary care to complete the CORS test. We successfully demonstrated that 79% of patients with newly diagnosed HF (n = 38) and 91% of non-HF patients (n = 67) were able to complete all phases of the CORS test. Our findings demonstrate that newly diagnosed HF patients are able to complete this test, which provides further evidence for the potential use of the CORS test to improve HF diagnostic and referral accuracy in primary care.

Exercise intolerance is a cardinal symptom of patients with heart failure (HF). We hypothesized that patients with HF with preserved ejection fraction (HFpEF) in comparison with those with reduced ejection fraction (HFrEF) have disproportionate exercise-induced impairment of left atrial (LA) function that may explain the effort intolerance.Total 40 HFpEF patients, 40 HFrEF patients, and 20 matched healthy controls underwent resting and exercise stress transthoracic echocardiography using modified Bruce protocol with speckle-tracking derived assessments of peak atrial longitudinal strain (PALS) and left ventricular global longitudinal strain (LVGLS).In comparison to controls, PALS and LVGLS were reduced in HFpEF and HFrEF patients (P 0.01); however, the strain magnitudes were significantly lower in HFrEF than in HFpEF (P 0.01). Both HFpEF and HFrEF showed a 28% and 30% reduction in exercise time in comparison with controls (HFpEF, 363 ± 152, HFrEF 352 ± 91, controls, 505 ± 42 s, P 0.01) and exercise-related rise in E/E' in HFpEF patients. However, during exercise PALS reduced from resting values by 26% (resting 23.1 ± 4.7 and peak 18.5 ± 3.5, P 0.01) in HFpEF but only 8% in HFrEF (resting 11.5 ± 1.4 and peak 10.5 ± 1.5, P 0.01), and remained unchanged in controls (resting 34 ± 1.9 and peak 34.4 ± 1.2, P = 0.4). Regression analysis of the combined data from the HF patients and controls revealed that PALS was independently associated with exercise time such that a 1% reduction in PALS was associated with a 10 s reduction in exercise duration (p 0.01). PALS at baseline and peak exercise differentiated normal from HF patients. LVGLS at baseline and peak exercise differentiated HFpEF from HFrEF and patients of HFpEF showed abnormality of both PALS and LVGLS.Although left ventricle and LA strain are lower in HFrEF than HFpEF at rest and exercise compared to healthy controls, patients with HFpEF show more profound deterioration of LA reservoir function with exercise which appears to contribute to exercise intolerance.

The present study evaluated the effect of age on glucose tolerance and cardiac function and assessed the relationship between metabolic control and cardiac function and performance. Thirty-four healthy women aged 40 to 81 years were divided into two age groups: younger (≤50 years of age, N = 19) and older (≥60 years of age, N = 15). Participants performed an oral glucose tolerance test and a graded cardiopulmonary exercise test with non-invasive haemodynamic measurements. Compared to younger, older women demonstrated significantly higher 2-hour glucose (4.67 ± 1.01 vs 6.08 ± 1.54 mmol/l, P < 0.01), but lower peak exercise O2 consumption (1.96 ± 0.44 vs 1.38 ± 0.26 l/min, P < 0.01) and cardiac power output (4.06 ± 0.76 vs 3.35 ± 0.73 W, P = 0.01). When data from all study participants were combined, there was a significant negative relationship between 2-hour glucose and peak cardiac power (r = -0.39, P = 0.02), and peak O2 consumption (r = -0.40, P = 0.02). The strength of these relationships was affected by age, with moderate negative relationship identified between 2-hour glucose and peak cardiac power output in younger compared to older participants (r = -0.38, P = 0.11 vs. r = -0.09, P = 0.75). Metabolic control and cardiac function decline with age. The lack of relationship between glucose control and cardiac power may suggest that metabolic control does not influence cardiac function and performance in older women.

Funding Acknowledgements Type of funding sources: None. Objective Cardiovascular autonomic function, represented by heart rate variability (HRV) is a simple, non-invasive measure used to determine alteration of sympathetic and parasympathetic control. The aim of the present study was firstly to evaluate the effect of age and gender on HRV measures, and secondly to determine the relationship between measures of HRV and functional capacity in healthy individuals Methods This was a retrospective, single centre, cross-sectional, observational study. Data were collected between January 2018 and July 2019. Sixty-eight healthy participants (age range: 19-78 years) were stratified according to age into the younger age group (55 years of age, N = 25, males, N = 14; females, N = 11). Frequency domain HRV measures (i.e. absolute and normalised low frequency power (LF), high frequency power HF and their ration i.e. LF/HF ratio) were derived from RR interval and recorded at rest (supine position) for 30 minutes. Simultaneous non-invasive gas-exchange and central haemodynamic measurements (bioimpedance) were collected at rest and during maximal graded cardiopulmonary exercise stress test using semi-recumbent cycle ergometer. Results The mean age of the younger group was 26 ± 6 years and older 64 ± 6 years. Cardiorespiratory fitness (i.e. peak oxygen consumption) was significantly reduced in older compared to younger age group (1.60 ± 0.57 vs. 2.38 ± 0.74 L/min, p Conclusions High frequency power of the heart rate variability declines with age more in men but not women. Gender difference in high frequency power is apparent in older but not younger age, with older women showing nearly one third higher HF than older men. Measures of heart rate variability do not predict cardiorespiratory fitness

Although left ventricular assist device (LVAD) improves functional capacity, on average LVAD patients are unable to achieve the aerobic capacity of normal healthy subjects or mild heart failure patients. The aim of this study was to examine if markers of right ventricular (RV) function influence maximal exercise capacity. This was a single-center prospective study that enrolled 20 consecutive HeartWare ventricular assist device patients who were admitted at the Freeman Hospital (Newcastle upon Tyne, United Kingdom) for a heart transplant assessment from August 2017 to October 2018. Mean peak oxygen consumption (Peak VO2) was 14.0 ± 5.0 ml/kg/min, and mean peak age and gender-adjusted percent predicted oxygen consumption (%VO2) was 40.0% ± 11.5%. Patients were subdivided into two groups based on the median peak VO2, so each group consisted of 10 patients (50%). Right-sided and pulmonary pressures were consistently higher in the group with poorer exercise tolerance. Patients with poor exercise tolerance (peak VO2 below the median) had higher right atrial pressures at rest (10.6 ± 6.4 vs. 4.3 mmHg ± 3.2; p = 0.02) and the increase with passive leg raising was significantly greater than those with preserved exercise tolerance (peak VO2 above the median). Patients with poor functional capacity also had greater RV dimensions (4.4 cm ± 0.5 vs. 3.7 cm ± 0.5; p = 0.02) and a higher incidence of significant tricuspid regurgitation (moderate or severe tricuspid regurgitation in five patients in the poor exercise capacity group vs. none in the preserved exercise capacity group; p = 0.03). In conclusion, echocardiographic and hemodynamic markers of RV dysfunction discriminate between preserved and nonpreserved exercise capacity in HeartWare ventricular assist device patients.

Objectives: The aim of the present study was to assess the validity and trending ability of the bioreactance method in estimating cardiac output at rest and in response to stress in advanced heart failure patients and heart transplant candidates. Design: This was a prospective single-center study. Setting: This study was conducted at the heart transplant center at the Freeman Hospital, Newcastle upon Tyne, UK. Participants: Eighteen patients with advanced chronic heart failure due to reduced left ventricular ejection fraction (19 ± 7%), and peak oxygen consumption 12.3 ± 3.9 mL/kg/min. Interventions: Participants underwent right heart catheterization using the Swan-Ganz catheter. Measurements and Main Results: Cardiac output was measured simultaneously using thermodilution and bioreactance at rest and during active straight leg raise test to volitional exertion. There was no significant difference in cardiac index values obtained by the thermodilution and bioreactance methods (2.26 ± 0.59 v 2.38 ± 0.50 L/min, p > 0.05) at rest and peak straight leg raise test (2.92 ± 0.77 v 3.01 ± 0.66 L/min, p > 0.05). In response to active leg raise test, thermodilution cardiac output increased by 22% and bioreactance by 21%. There was also a strong relationship between cardiac outputs from both methods at rest (r = 0.88, p < 0.01) and peak straight leg raise test (r = 0.92, p < 0.01). Cartesian plot analysis showed good trending ability of bioreactance compared with thermodilution (concordance rate = 93%) Conclusions: `Cardiac output measured by the bioreactance method is comparable to that from the thermodilution method. Bioreactance method may be used in clinical practice to assess hemodynamics and improve management of advanced heart failure patients undergoing heart transplant assessment.

Coronavirus disease 2019 (COVID‐19) is caused by severe acute respiratory syndrome coronavirus‐2. The clinical presentation of this virus mainly manifests in the respiratory system but may also lead to severe complications in the cardiovascular system. The global burden of COVID‐19 has led to an unprecedented need to gain further insight into patient outcomes, management, and clinical practice. This review aims to provide an overview of the current literature on heart failure (HF) hospitalizations, management, and care pathways for supporting patients during and beyond this pandemic. A literature review of five areas of interest was conducted and included: (i) HF hospitalization; (ii) recognizing the needs and supporting HF patients during COVID‐19; (iii) supporting rehabilitation services; (iv) transitioning to a telehealth framework; and (v) the need for evidence. Patients with new‐onset or existing HF are particularly vulnerable, but a significant reduction in HF hospital admissions has been reported. During these periods of uncertainty, the current care pathways for acute and elective cardiac patients have had to change with the relocation of HF services to protect the vulnerable and reduce transmission of COVID‐19. Optimizing community HF services has the potential to reduce the pressures on secondary care during the recovery from this pandemic. Telemedicine and virtual health care are emerging technologies and overcome the risk of in‐person exposure. Successful remote delivery of cardiac rehabilitation services has been reported during the pandemic. Delivery of a robust telehealth framework for HF patients will improve communication between clinician and patient. The reduction in HF admissions is a concern for the future and may result in unintended mortality. New‐onset and current HF patients must understand their diagnosis and future prognosis and seek help and support using the appropriate platform when needed. Realigning HF services and the use of telemedicine and virtual health care has great potential but needs to be carefully understood to ensure engagement and approval in this population to overcome barriers and challenges.

ObjectivesClinical guidelines recommend regular physical activity for patients with heart failure to improve functional capacity and symptoms and to reduce hospitalisation. Cardiac rehabilitation programmes have demonstrated success in this regard; however, uptake and adherence are suboptimal. Home-based physical activity programmes have gained popularity to address these issues, although it is acknowledged that their ability to provide personalised support will impact on their effectiveness. This study aimed to identify barriers and facilitators to engagement and adherence to a home-based physical activity programme, and to identify ways in which it could be integrated into the care pathway for patients with heart failure.DesignA qualitative focus group study was conducted. Data were analysed using thematic analysis.ParticipantsA purposive sample of 16 patients, 82% male, aged 68±7 years, with heart failure duration of 10±9 years were recruited.InterventionA 12-week behavioural intervention targeting physical activity was delivered once per week by telephone.ResultsTen main themes were generated that provided a comprehensive overview of the active ingredients of the intervention in terms of engagement and adherence. Fear of undertaking physical activity was reported to be a significant barrier to engagement. Influences of family members were both barriers and facilitators to engagement and adherence. Facilitators included endorsement of the intervention by clinicians knowledgeable about physical activity in the context of heart failure; ongoing support and personalised feedback from team members, including tailoring to meet individual needs, overcome barriers and increase confidence.ConclusionsEndorsement of interventions by clinicians to reduce patients’ fear of undertaking physical activity and individual tailoring to overcome barriers are necessary for long-term adherence. Encouraging family members to attend consultations to address misconceptions and fear about the contraindications of physical activity in the context of heart failure should be considered for adherence, and peer-support for long-term maintenance.Trial registration numberNCT03677271.

Background Physical activity plays an important role in the prevention of cardio-metabolic diseases. The present study evaluated the effect of habitual physical activity on body composition, peak oxygen consumption, cardiac and metabolic function. Methods This was a retrospective study. Data was collected between February 2014 and November 2015. Thirty-six healthy women (age 50±16 years) were stratified according to daily number of steps into low- ( 12500 steps/day, n=19). All participants underwent body composition assessment, oral glucose tolerance test and non-invasive gas-exchange and haemodynamic (bioreactance) measurements at rest and in response to maximal graded cardiopulmonary exercise test. Results The high active group averaged 16280±3205 steps/day and the low active group averaged 6285±943 steps/day (difference p=0.00). High-active women (vs. low active) demonstrated significantly lower body weight (62.1±12.3 vs. 71.2±9.1 kg, p=0.02), body fat (27.2±9.1 vs 37.7±6.4 %, p=0.00), but increased lean body mass (72.8±9.1 vs. 62.3±6.4 %, p=0.00). Peak oxygen consumption was significantly higher in high- versus low active women (2.0±0.5 vs. 1.5±0.2 l/min, p=0.00). There were no significant differences between the groups in fasting- and 2-hour glucose levels (4.9±0.6 vs. 4.8±0.5, p=0.45 and 4.8±1.3 vs. 5.5±1.4 mmol/L, p=0.16) haemodynamic measures of cardiac function including cardiac power output, cardiac output, stroke volume and arterial blood pressure at rest and in response to exercise stress test (p>0.05). Conclusions Increased levels of habitual physical activity improve body composition and peak oxygen consumption but appears to have limited effect cardio-metabolic function in middle-aged women.

BackgroundHypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disease that affects approximately one in 500 people. HCM is a recognized genetic disorder most often caused by mutations involving myosin-binding protein C (MYBPC3) and β-myosin heavy chain (MYH7) which are responsible for approximately three-quarters of the identified mutations.MethodsAs a part of the international multidisciplinary SILICOFCM project (www.silicofcm.eu) the present study evaluated the association between underlying genetic mutations and clinical phenotype in patients with HCM. Only patients with confirmed single pathogenic mutations in either MYBPC3 or MYH7 genes were included in the study and divided into two groups accordingly. The MYBPC3 group was comprised of 48 patients (76%), while the MYH7 group included 15 patients (24%). Each patient underwent clinical examination and echocardiography.ResultsThe most prevalent symptom in patients with MYBPC3 was dyspnea (44%), whereas in patients with MYH7 it was palpitations (33%). The MYBPC3 group had a significantly higher number of patients with a positive family history of HCM (46% vs. 7%;p = 0.014). There was a numerically higher prevalence of atrial fibrillation in the MYH7 group (60% vs. 35%,p = 0.085). Laboratory analyses revealed normal levels of creatinine (85.5 ± 18.3 vs. 81.3 ± 16.4 µmol/l;p = 0.487) and blood urea nitrogen (10.2 ± 15.6 vs. 6.9 ± 3.9 mmol/l;p = 0.472) which were similar in both groups. The systolic anterior motion presence was significantly more frequent in patients carrying MYH7 mutation (33% vs. 10%;p = 0.025), as well as mitral leaflet abnormalities (40% vs. 19%;p = 0.039). Calcifications of mitral annulus were registered only in MYH7 patients (20% vs. 0%;p = 0.001). The difference in diastolic function, i.e. E/e′ ratio between the two groups was also noted (MYBPC3 8.8 ± 3.3, MYH7 13.9 ± 6.9,p = 0.079).ConclusionsMajor findings of the present study corroborate the notion that MYH7 gene mutation patients are presented with more pronounced disease severity than those with MYBPC3.

SummaryPurpose This study assessed the agreement between cardiac output estimated by inert gas rebreathing and bioreactance methods at rest and during exercise. Methods Haemodynamic measurements were assessed in 20 healthy individuals (11 females, nine males; aged 32 ± 10 years) using inert gas rebreathing and bioreactance methods. Gas exchange and haemodynamic data were measured simultaneously under rest and different stages (i.e. 30, 60, 90, 120, 150 and 180 W) of progressive graded cardiopulmonary exercise stress testing using a bicycle ergometer. Results At rest, bioreactance produced significantly higher cardiac output values than inert gas rebreathing (7·8 ± 1·4 versus 6·5 ± 1·7 l min−1, P = 0·01). At low-to-moderate exercise intensities (i.e. 30–90 W), bioreactance produced significantly higher cardiac outputs compared with rebreathing method (P

Background The prevalence of prediabetes is rapidly rising in the UK, largely associated with an increase in obesity. Lifestyle programmes that provide support to make and sustain dietary and physical activity behavioural changes are necessary to initiate and maintain weight loss. However, these programmes are often intensive and time consuming. Given the magnitude of the problem, there is a need for behavioural interventions that can be delivered at scale. Digital interventions can address some of the aforementioned issues. The primary aim of the present study is to assess the feasibility and acceptability of a digital intervention called Changing Health that provides structured education and lifestyle behaviour change support to adults with prediabetes. Methods A single-group pilot study will be undertaken. We aim to recruit 40 participants with prediabetes defined by HbA1c or fasting plasma glucose (FPG), aged between 18 and 75 years with a BMI ≥ 25. Participants will receive the digital intervention (a mobile phone app incorporating structured education and behavioural tools to support lifestyle behaviour change) with the aim of losing and maintaining 5–6% of their baseline body weight. Each participant will receive 100 min of lifestyle coaching over the 9-month intervention period and will have continued access to the digital intervention. Clinical outcome measures will be collected during four visits to our clinical research facility: two visits at baseline, one visit at month 3, and one visit at month 9. These secondary outcome measures will include diet, physical activity, sleep, metabolic control, body composition, cardiorespiratory fitness, and cardiovascular function. To measure primary outcomes, an embedded qualitative study will be conducted to obtain data on feasibility and acceptability of the intervention. Discussion This pilot study will establish whether Changing Health is feasible and acceptable to adults with prediabetes. Clinical outcome measures will provide estimates of variability to inform sample size calculations, and qualitative data generated will inform any necessary refinements to the intervention. This will provide a platform for a larger evaluation to assess the effectiveness of Changing Health for changing diet and physical activity to initiate and maintain weight loss in adults with prediabetes. Trial registration ISRCTN Registry: ISRCTN69270299.

Introduction Left Ventricular Assist Devices (LVAD) improve survival and functional capacity in patients with advanced heart failure (HF). However, there are potential complications. Purpose We sought to determine parameters of exercise intolerance in a group of patients with the HeartWare LVAD (HVAD) compared to a group of HF patients. Methods This was a single-centre parallel prospective group-study. Briefly, echocardiograms, right heart catheterisation (RHC) and cardiopulmonary exercise tests were performed in forty-two patients admitted for a heart transplant assessment between August2017 and October2018.Of them 20 belonged to the HVAD group and 22 to the HF group. Results In our study, HVAD patients had a better exercise capacity than HF patients, although no significant differences were noted (14.0±5.0 ml/kg/min vs 11.3±3.9 ml/kg/min, p=0.06). To determine exercise tolerance, both HVAD and HF groups were subdivided into 2 groups based on the median peak exercise oxygen consumption (peakVO2) for that group. The table shows the comparison between preserved and non-preserved exercise tolerance in HF and HVADpatients. First of all, in the HVADgroup, all resting RHC pressures were significantly lower in the preserved exercise capacity group. However, in HFpatients there were no statistically significant differences between both subgroups in right-sided pressures, but Thermodilution exercise-induced change in cardiac output (ΔCO) and cardiac index (ΔCI) was significantly higher in the patients with preserved exercise tolerance. Secondly, in the HVADgroup the right ventricle was significantly larger in the reduced exercise tolerance subgroup. Moreover, patients with lower peak VO2 had more significant tricuspid regurgitation. Nevertheless, in HFpatients none of the echocardiographic parameters were related to the exercise capacity. HF HVAD > Median Peak V02 < Median Peak V02 p > Median Peak V02 < Median Peak V02 p Thermodilution CO, l/min: • Rest 4.3±1.0 4.4±1.8 0.82 4.8±0.8 4.2±1.2 0.21 • Exercise 5.6±1.7 4.8±1.8 0.36 7.1±3.2 4.8±0.8 0.05 • ΔCO 1.26±1.0 0.26±0.7 0.02 2.2±2.5 0.4±0.7 0.05 Right Atrium pressure, mmHg 7.0±4.5 6.8±4.10 0.92 4.3±3.2 10.6±6.40 0.02 Mean Pulmonary Artery pressure, mmHg 26.4±12.6 26.5±10.9 0.97 16.8±5.4 30.5±12.5 0.01 Tricuspid Regurgitation, n (%): • None 1 (9) 1 (9) 1 (12) 0 (0) • Mild 7 (64) 8 (73) 7 (88) 4 (44) • Moderate 2 (18) 0 (0) 0 (0) 4 (44) • Severe 1 (9) 2 (18) 0.36 0 (0) 1 (12) 0.03 Right Ventricle Basal Diastolic Diameter, cm 4.0±1.0 4.1±1.0 0.83 3.7±0.5 4.4±0.5 0.02 Conclusion Right-sided parameters in the echocardiogram and RHC pressures discriminate between preserved and non-preserved exercise capacity in HVADpatients, but not in HFpatients. In these last patients only ΔCO and ΔCI were statistically correlated with peak exercise oxygen consumption Acknowledgement/Funding N. Bouzas-Cruz would like to thank the Spanish Society of Cardiology (Sociedad Española de Cardiología), for her research grant and fellowship

Objectives. Heart rate variability (HRV) and haemodynamic response to exercise (i.e. peak cardiac power output) are strong predictors of mortality in heart failure. The present study assessed the relationship between measures of HRV and peak cardiac power output. Design. In a prospective observational study of 33 patients (age 54 ± 16 years) with chronic heart failure with reduced left ventricular ejection fraction (29 ± 11%), measures of the HRV (i.e. R-R interval and standard deviation of normal R-R intervals, SDNN) were recorded in a supine position. All patients underwent maximal graded cardiopulmonary exercise testing with non-invasive (inert gas rebreathing) cardiac output assessment. Cardiac power output, expressed in watts, was calculated as the product of cardiac output and mean arterial blood pressure. Results. The mean RR and SDNN were 837 ± 166 and 96 ± 29 ms, peak exercise cardiac power output 2.28 ± 0.85 watts, cardiac output 10.34 ± 3.14 L/min, mean arterial blood pressure 98 ± 14 mmHg, stroke volume 91.43 ± 40.77 mL/beat, and oxygen consumption 19.0 ± 5.6 mL/kg/min. There was a significant but only moderate relationship between the RR interval and peak exercise cardiac power output (r = 0.43, p =.013), cardiac output (r = 0.35, p =.047), and mean arterial blood pressure (r = 0.45, p =.009). The SDNN correlated with peak cardiac power output (r = 0.42, p =.016), mean arterial blood arterial (r = 0.41, p =.019), and stroke volume (r = 0.35, p =.043). Conclusions. Moderate strength of the relationship between measures of HRV and cardiac response to exercise suggests that cardiac autonomic function is not good indicator of overall function and pumping capability of the heart in chronic heart failure.

Background: Referrals to physical activity and exercise programmes for patients with heart failure is suboptimal with high dropout rates in hospital-based programmes. Home-based programmes have gained popularity and help address this issue. The aim of the present study was to explore patients’ experiences of participating in a personalised homebased physical activity intervention programme and to explore whether experiences corresponded with physiological changes post intervention. Methods: Twenty patients (68±7 years) with chronic heart failure (13±11 years) due to reduced ejection fraction underwent a 12-week personalised home-based physical activity programme. This involved increasing daily pedometer step count by 2000 steps from baseline. Patients completed exercise, cardiac function and quality of life tests pre-post intervention. Sixteen of the 20 patients attended one of three focus group discussions to provide their views around the decision to participate in the programme and their experience of the programme when enrolled. Results: Seventeen patients (85%) completed the intervention, and 15 patients achieved the daily target step count which increased from baseline to 3 weeks by 2546 (5108±3064 to 7654±3849, p=0.03), and maintained until week 12 (9022±3942). On completion of the intervention, quality of life improved by 15% (26±18 vs. 22±19), cardiac index and stroke volume increased by 11% and 19% respectively (6.8±1.5 vs. 7.6±2.0 L/min/m2; and 127 ± 34 vs 151 ± 34, P=0.05). Workload and O2 consumption at anaerobic threshold increased by 16% (49±16 vs. 59±14 watts, p=0.01) and 10% (11.5±2.9 vs 12.8±2.2 ml/kg/min). Thematic analyses identified 10 themes influencing participation and maintenance. These included patient’s fear of engaging in physical activity, family influences on engagement with physical activity, support from clinicians and research staff, and increased confidence as a result of participating in a personalised programme. Conclusion: A personalised home-based physical activity intervention programme is feasible and for patients with stable chronic heart failure and led to improved quality of life and submaximal exercise capacity. However, qualitative findings suggest that outcomes are likely to be contingent on personalised feedback and support from suitably trained team members to increase confidence and self-efficacy, family support, and endorsement of the programme from a clinician.

The present study evaluated reproducibility of the inert gas rebreathing method to estimate cardiac output at rest and during cardiopulmonary exercise testing. Thirteen healthy subjects (10 males, 3 females, ages 23–32 years) performed maximal graded cardiopulmonary exercise stress test using a cycle ergometer on 2 occasions (Test 1 and Test 2). Participants cycled at 30-watts/3-min increments until peak exercise. Hemodynamic variables were assessed at rest and during different exercise intensities (i. e., 60, 120, 150, 180 watts) using an inert gas rebreathing technique. Cardiac output and stroke volume were not significantly different between the 2 tests at rest 7.4 (1.6) vs. 7.1 (1.2) liters min−1, p=0.54; 114 (28) vs. 108 (15) ml beat−1, p=0.63) and all stages of exercise. There was a significant positive relationship between Test 1 and Test 2 cardiac outputs when data obtained at rest and during exercise were combined (r=0.95, p

Aim The present study assessed the effect of high intensity interval training on cardiac function during prolonged submaximal exercise in patients with type 2 diabetes. Methods Twenty-six patients with type 2 diabetes were randomized to a 12 week of high intensity interval training (3 sessions/week) or standard care control group. All patients underwent prolonged (i.e. 60 min) submaximal cardiopulmonary exercise testing (at 50% of previously assess maximal functional capacity) with non-invasive gas-exchange and haemodynamic measurements including cardiac output and stroke volume before and after the intervention. Results At baseline (prior to intervention) there was no significant difference between the intervention and control group in peak exercise oxygen consumption (20.3 ± 6.1 vs. 21.7 ± 5.5 ml/kg/min, p = 0.21), and peak exercise heart rate (156.3 ± 15.0 vs. 153.8 ± 12.5 beats/min, p = 0.28). During follow-up assessment both groups utilized similar amount of oxygen during prolonged submaximal exercise (15.0 ± 2.4 vs. 15.2 ± 2.2 ml/min/kg, p = 0.71). However, cardiac function i.e. cardiac output during submaximal exercise decreased significantly by 21% in exercise group (16.2 ± 2.7–12.8 ± 3.6 L/min, p = 0.03), but not in the control group (15.7 ± 4.9–16.3 ± 4.1 L/min, p = 0.12). Reduction in exercise cardiac output observed in the exercise group was due to a significant decrease in stroke volume by 13% (p = 0.03) and heart rate by 9% (p = 0.04). Conclusion Following high intensity interval training patients with type 2 diabetes demonstrate reduced cardiac output during prolonged submaximal cardiopulmonary exercise testing. Ability of patients to maintain prolonged increased metabolic demand but with reduced cardiac output suggests cardiac protective role of high intensity interval training in type 2 diabetes. Trial registration ISRCTN78698481. Registered 23 January 2013, retrospectively registered.

Purpose Less than 10% of heart failure patients in the UK participate in cardiac rehabilitation programmes. The present pilot study evaluated feasibility, acceptability and physiological effects of a novel, personalised, home-based physical activity intervention in chronic heart failure. Methods Twenty patients (68 ± 7 years old, 20% females) with stable chronic heart failure due to reduced left ventricular ejection fraction (31 ± 8 %) participated in a single-group, pilot study assessing the feasibility and acceptability of a 12-week personalised home-based physical activity intervention aiming to increase daily number of steps by 2000 from baseline (Active-at-Home-HF). Patients completed cardiopulmonary exercise testing with non-invasive gas exchange and haemodynamic measurements and quality of life questionnaire pre- and post-intervention. Patients were supported weekly via telephone and average weekly step count data collected using pedometers. Results Forty-three patients were screened and 20 recruited into the study. Seventeen patients (85%) completed the intervention, and 15 (75%) achieved the target step count. Average step count per day increased significantly from baseline to 3 weeks by 2546 (5108 ± 3064 to 7654 ± 3849, P = 0.03, n = 17) and was maintained until week 12 (9022 ± 3942). Following completion of the intervention, no adverse events were recorded and quality of life improved by 4 points (26 ± 18 vs. 22 ± 19). Peak exercise stroke volume increased by 19% (127 ± 34 vs. 151 ± 34 m/beat, P = 0.05), while cardiac index increased by 12% (6.8 ± 1.5 vs. 7.6 ± 2.0 L/min/m2, P = 0.19). Workload and oxygen consumption at anaerobic threshold also increased by 16% (49 ± 16 vs. 59 ± 14 watts, P = 0.01) and 10% (11.5 ± 2.9 vs. 12.8 ± 2.2 ml/kg/min, P = 0.39). Conclusion The Active-at-Home-HF intervention is feasible, acceptable and effective for increasing physical activity in CHF. It may lead to improvements in quality of life, exercise tolerance and haemodynamic function. Trial Registration www.clinicaltrials.gov NCT0367727. Retrospectively registered on 17 September 2018.

Purpose Although Left Ventricular Assist Device (LVAD) improves functional capacity, on average LVAD patients are unable to achieve the aerobic capacity of normal healthy subjects or mild heart failure patients. The aim of this study was to examine if markers of right ventricular (RV) function influence maximal exercise capacity. Methods This was a single-centre prospective study that enrolled 20 consecutive HeartWare ventricular assist device (HVAD) patients who were admitted at the Freeman Hospital (Newcastle upon Tyne, United Kingdom) for a heart transplant assessment from August 2017 to October 2018. Results Mean peak oxygen consumption (Peak VO2) was 14.0 ± 5.0 ml/kg/min, and mean peak age and gender-adjusted percent predicted oxygen consumption (%VO2) was 40.0 ± 11.5 %. Patients were subdivided into 2 groups based on the median peak VO2, so each group consisted of 10 patients (50%). Right-sided and pulmonary pressures were consistently higher in the group with poorer exercise tolerance. Patients with poor exercise tolerance (peak VO2 below the median) had higher right atrial pressures at rest (10.6mmHg ± 6.4 versus 4.3mmHg ± 3.2, p= 0.02) and the increase with passive leg raising was significantly greater than those with preserved exercise tolerance (peak VO2 above the median). Patients with poor functional capacity also had greater RV dimensions (4.4 cm ± 0.5 versus 3.7 cm ± 0.5, p= 0.02) and a higher incidence of significant tricuspid regurgitation (TR) (moderate or severe TR in 5 patients in the poor exercise capacity group versus none in the preserved exercise capacity group, p=0.03). Conclusion Echocardiographic and hemodynamic markers of RV dysfunction discriminate between preserved and non-preserved exercise capacity in HVAD patients.

Purpose To determine parameters of exercise intolerance in a group of patients with HeartWare Ventricular Assist Device(HVAD) compared to a group of heart failure(HF)patients Methods This was a single-centre parallel prospective group-study.Echocardiograms,right heart catheterisation(RHC) and cardiopulmonary exercise tests were performed in 42patients admitted for a heart transplant assessment between August2017 and October2018:20 belonged to the HVAD group and 22 to the HF group Results HVADpatients had a better exercise capacity than HFpatients, although no significant differences were noted(14.0±5.0ml/kg/min vs 11.3±3.9ml/kg/min, p=0.06).To determine exercise tolerance,both HVAD and HFgroups were subdivided into 2 groups based on the median peakVO2.The table shows the comparison between preserved and non-preserved exercise tolerance in HF and HVADpatients. In the HVAD group,all resting RHC pressures were significantly lower in the preserved exercise capacity group.However,in HFpatients there were no statistically significant differences between both subgroups in right-sided pressures,but Thermodilution exercise-induced change in cardiac output(ΔCO) and cardiac index(ΔCI) was significantly higher in the patients with preserved exercise tolerance.In the HVADgroup the right ventricle was significantly larger in the reduced exercise tolerance subgroup.Patients with lower peakVO2 had more significant tricuspid regurgitation.Nevertheless,in HFpatients none of the echocardiographic parameters were related to the exercise capacity Conclusion Right-sided parameters in the echocardiogram and RHC pressures discriminate between preserved and non-preserved exercise capacity in HVADpatients,but not in HFpatients.In these last patients only ΔCO and ΔCI were statistically correlated with peak exercise oxygen consumption.

Aims N‐terminal prohormone of brain natriuretic peptide (NT‐proBNP) plays an important role in diagnosis and management of heart failure. The aim of the present study was to assess haemodynamic response to exercise and to evaluate the relationship between NT‐proBNP, cardiac function, and exercise tolerance in chronic heart failure. Methods and results A single‐centre, cross‐sectional pilot study recruited 17 patients with chronic heart failure with reduced left ventricular ejection fraction (age 67 ± 7 years) and 20 healthy volunteers (age 65 ± 12 years). The NT‐proBNP was measured in the heart failure group. All participants completed maximal graded cardiopulmonary exercise stress testing coupled with gas exchange (using metabolic analyser for determination of exercise tolerance, i.e. peak O2 consumption) and continuous haemodynamic measurements (i.e. cardiac output and cardiac power output) using non‐invasive bioreactance technology. Heart failure patients demonstrated significantly lower peak exercise cardiac function and exercise tolerance than healthy controls, i.e. cardiac power output (5.0 ± 2.0 vs. 3.2 ± 1.2 W, P

BackgroundPrimary care physicians lack access to an objective cardiac function test during diagnostic testing for suspected heart failure.AimTo determine the role of the novel Cardiac Output Response to Stress (CORS) test in the current diagnostic pathway for heart failure and the opportunities and challenges to potential implementation in primary care.MethodQualitative study using semi-structured in-depth interviews which were audiorecorded and transcribed verbatim. Data from the interviews were analysed thematically using an inductive approach. Fourteen healthcare professionals (six males, eight females) from primary (GPs, nurses, healthcare assistants, and practice managers) and secondary care (consultant cardiologists) participated.ResultsFour themes relating to opportunities and challenges surrounding the implementation of the new diagnostic technology were identified. These reflected that adoption of CORS test would be an advantage to primary care but the test had barriers to implementation which include establishment of clinical utility, suitability for immobile patients, and cost implication to GP practices.ConclusionThe development of a simple non-invasive clinical test to accelerate the diagnosis of heart failure in primary care maybe helpful to reduce unnecessary referrals to secondary care. The CORS test has the potential to serve this purpose however, factors such as cost-effectiveness, diagnostic accuracy, and seamless implementation in primary care have to be fully explored.

BackgroundWe developed a simple non-invasive Cardiac Output Response to Stress (CORS) Test to improve diagnosis and monitoring of heart failure in primary care.AimThe aim of the present study was to assess test-retest reproducibility of the CORS test.MethodThirty-two healthy volunteers (age, 64±10, female n=18) were recruited. Cardiac output was measured continuously using bioreactance method in supine and standing position, and during a two 3-min stages of a step-exercise protocol (10 and 15 steps per minute) using a 15-cm height bench. The CORS test was performed twice i.e. Test 1 and Test 2.ResultsCardiac output and stroke volume were not significantly different between the two tests at supine (6.2±1.4 versus 6.3±1.7 L/min, P = 0.84; 102±24 versus 108±32 ml/beat, P = 0.36), standing (5.7±2.1 versus 5.7±1.9 L/min, P = 0.99; 82±32 versus 83±29 ml/beat, P = 0.93), stage one step-exercise (8.5± 1.8 versus 8.2±1.9 L/min, P = 0.56; 104±26 versus 104±27 ml/beat, P = 0.99) and stage two step-exercise (9.9±1.7 versus 9.6±2.0 L/min, P = 0.51; 109±29 versus 111±26 ml/beat, P = 0.76). There was a significant positive relationship between Test 1 and Test 2 cardiac outputs (r=0.92, PConclusionThe CORS test demonstrates acceptable reproducibility and can potentially be used in primary care to identify and monitor heart failure.