A systematic review of rehabilitation in chronic heart failure:evaluating the reporting of exercise interventions

Abstract 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 (R2 = 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

Overcoming barriers to engagement and adherence to a home-based physical activity intervention for patients with heart failure:a qualitative focus group study

Clinical 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. A qualitative focus group study was conducted. Data were analysed using thematic analysis. A purposive sample of 16 patients, 82% male, aged 68±7 years, with heart failure duration of 10±9 years were recruited. A 12-week behavioural intervention targeting physical activity was delivered once per week by telephone. Ten 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. Endorsement 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. NCT03677271. [Abstract copyright: © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ.

Haemodynamic determinants of quality of life in chronic heart failure

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 O(2) 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 O(2) consumption, but not hemodynamic response to exercise, is a significant determinant of QOL in chronic heart failure patients

Validity and reliability of short‐term heart‐rate variability from disposable electrocardiography leads

BACKGROUND AND AIMS: 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. METHODS: 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). RESULTS: 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 (ms(2)); 0.89 (0.62, 0.96), HF power (ms(2)); 0.90 (0.72, 0.96)] variables. The mean difference and upper and lower limits of agreement between disposable and reusable leads for time‐ and frequency‐domain variables were acceptable. Analysis of repeated measures using disposable leads demonstrated excellent reproducibility (ICC 95% CI) for R‐R interval (ms); 0.93 (0.85, 0.97), RMSSD (ms); 0.93 (0.85, 0.97), SDNN (ms); 0.88 (0.75, 0.95), LF power (ms(2)); 0.87 (0.72, 0.94), and HF power (ms(2)); 0.88 (0.73, 0.94) with coefficient of variation ranging from 2.2% to 5% (p > 0.37 for all variables). CONCLUSION: Single‐use Kendall DL™ ECG leads demonstrate a valid and reproducible tool for the assessment of HRV

Cardiovascular implications and physical activity in middle-aged and older adults with a history of COVID-19 (CV COVID)::a protocol for a randomised controlled trial

Background: The clinical manifestation of COVID-19 is associated with infection and inflammation of the lungs, but there is evidence to suggest that COVID-19 may also affect the structure and function of the cardiovascular system. At present, it is not fully understood to what extent COVID-19 impacts cardiovascular function in the short- and long-term following infection. The aim of the present study is twofold: (i) to define the effect of COVID-19 on cardiovascular function (i.e. arterial stiffness, cardiac systolic and diastolic function) in otherwise healthy individuals and (ii) to evaluate the effect of a home-based physical activity intervention on cardiovascular function in people with a history of COVID-19. Methods: This prospective, single-centre, observational study will recruit 120 COVID-19-vaccinated adult participants aged between 50 and 85 years, i.e. 80 with a history of COVID-19 and 40 healthy controls without a history of COVID-19. All participants will undergo baseline assessments including 12-lead electrocardiography, heart rate variability, arterial stiffness, rest and stress echocardiography with speckle tracking imaging, spirometry, maximal cardiopulmonary exercise testing, 7-day physical activity and sleep measures and quality of life questionnaires. Blood samples will be collected to assess the microRNA expression profiles, cardiac and inflammatory biomarkers, i.e. cardiac troponin T; N-terminal pro B-type natriuretic peptide; tumour necrosis factor alpha; interleukins 1, 6 and 10; C-reactive protein; d-dimer; and vascular endothelial growth factors. Following baseline assessments, COVID-19 participants will be randomised 1:1 into a 12-week home-based physical activity intervention aiming to increase their daily number of steps by 2000 from baseline. The primary outcome is change in left ventricular global longitudinal strain. Secondary outcomes are arterial stiffness, systolic and diastolic function of the heart, functional capacity, lung function, sleep measures, quality of life and well-being (depression, anxiety, stress and sleep efficiency). Discussion: The study will provide insights into the cardiovascular implications of COVID-19 and their malleability with a home-based physical activity intervention. Trial registration: ClinicalTrials.gov NCT05492552. Registered on 7 April 2022

Association between heart rate variability and haemodynamic response to exercise in chronic heart failure

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

Noninvasive Assessment of Cardiac Output in Advanced Heart Failure and Heart Transplant Candidates Using the Bioreactance Method

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