71 research outputs found
A novel, personalised home-based physical activity intervention for chronic heart failure : exploring feasibility, effectiveness and patient experiences
No full textPhD ThesisHeart failure (HF) is a clinical syndrome associated with reduced cardiac output at rest and/or in response to stress. Physical activity plays an important role in reducing cardiovascular morbidity and mortality. Patients with chronic heart failure demonstrate reduced physical activity levels. Exercise based cardiac rehabilitation programmes are safe and recommended to improve symptoms and outcomes in HF. Available data suggests that less than 10% of patients with HF in the UK are referred for cardiac rehabilitation. This is secondary to lack of resources and direct exclusion of HF rehabilitation from local commissioning agreements. A personalised home-based physical activity intervention may hold great potential to improve patient outcomes and clinical practice.
This thesis firstly investigates non-invasive methods for evaluation of cardiac function (cardiac output) at rest and in response to cardiopulmonary exercise stress testing. Secondly, is explores the feasibility and physiological effects of a novel, personalised home-based physical activity intervention in HF patients (Active-at-Home-HF), and qualitatively explores barriers and facilitators to uptake and continued participation from a patient perspective.
The major findings and conclusions of the thesis suggest that i) Bioreactance and inert gas rebreathing methods show acceptable levels of agreement for estimating cardiac output at higher levels of metabolic demand. However, they cannot be used interchangeably due to strong disparity in results at rest and low-to-moderate exercise intensity; ii) Inert gas rebreathing method demonstrates acceptable level of test-retest reproducibility for estimating cardiac output at rest and during cardiopulmonary exercise testing at higher metabolic demands; iii) Active-at-Home-HF intervention is safe, feasible and acceptable for patients with chronic HF. It leads to increased daily physical activity levels and may improve quality of life and exercise tolerance; and iv) Lastly, the qualitative study emphasizes the importance of clinicians who advocate physical activity as a management option for heart failure, personalised support to increase and maintain levels of physical activity and that heart failure patients should seek social support from friends and family
Clinical validation of an artificial intelligence-based decision support system for diagnosis and risk stratification of heart failure (STRATIFYHF)
No full textIntroduction Heart failure (HF) is a complex clinical syndrome. Accurate risk stratification and early diagnosis of HF are challenging as its signs and symptoms are non-specific. We propose to address this global challenge by developing the STRATIFYHF artificial intelligence-driven decision support system (DSS), which uses novel analytical methods in determining the risk, diagnosis and prognosis of HF. The primary aim of the present study is to collect prospective clinical data to validate the STRATIFYHF DSS (in terms of diagnostic accuracy, sensitivity and specificity) as a tool to predict the risk, diagnosis and progression of HF. The secondary outcomes are the demographic and clinical predictors of risk, diagnosis and progression of HF.
Methods and analysis STRATIFYHF is a prospective, multicentre, longitudinal study that will recruit up to 1600 individuals (n=800 suspected/at risk of HF and n=800 diagnosed with HF) aged ≥45 years old, with up to 24 months of follow-up observations. Individuals suspected of HF will be divided into two categories based on current definitions and predefined inclusion criteria. All participants will have their medical history recorded, along with data on physical examination (signs and symptoms), blood tests including serum natriuretic peptides levels, ECG and echocardiogram results, as well as demographic, socioeconomic and lifestyle data, and use of complete novel technologies (cardiac output response to stress test and voice recognition biomarkers). All measurements will be recorded at baseline and at 12-month follow-up, with medical history and hospitalisation also recorded at 24-month follow-up. Cardiovascular MRI assessment will be completed in a subset of participants (n=20–40) from eligible clinical centres only at baseline. Each clinical centre will recruit a subset of participants (n=30) who will complete a 6-month home-based monitoring of clinical characteristics and accelerometry (wrist-worn monitor) to determine the feasibility and acceptability of the STRATIFYHF mobile application. Focus groups and semistructured interviews will be conducted with up to 15 healthcare professionals and up to 20 study participants (10 at risk of HF and 10 diagnosed with HF) to explore the needs of patients and healthcare professionals prior to the development of the STRATIFYHF DSS and to evaluate the acceptability of this mobile application.
Ethics and dissemination Ethical approval has been granted by the East Midlands - Leicester Central Research Ethics Committee (24/EM/0101). Dissemination activities will include journal publications and presentations at conferences, as well as development of training materials and delivery of focused training on the STRATIFYHF DSS and mobile application. We will develop and propose policy guidelines for integration of the STRATIFYHF DSS and mobile application into the standard of care in the HF care pathway.
Trial registration number NCT06377319
Respiratory function and sleep parameters in adults following recovery from acute COVID-19
Full text linkThe impact of COVID-19 on lung function and sleep in otherwise healthy individuals has been subject to a limited number of studies. The aim of this study was to investigate the effect of COVID-19 on pulmonary function and sleep in adults. Participants, 50-85 years old, who had recovered from COVID-19 (COVID-19 group: n=48) and those without history of COVID-19 (control group: n=28) underwent pulmonary function assessment (Forced Vital Capacity, FVC, and Slow Vital Capacity, SVC) using spirometry. Sleep and circadian variables were measured objectively with wrist-worn actigraphy for seven days. Subjective sleep of participants was assessed using the Pittsburgh Sleep Quality Index (PSQI). There were no significant differences in age (60±6 vs 62±6 years), BMI (26.30±4.25 vs 26.48±3.60 kg/m2), or pulmonary function (FVC, 4.02± 1.04 vs 3.80 ± 0.98 L, p=0.36; and SVC, 3.82±1.09 vs 3.89±0.92 L, p=0.76) between COVID-19 and control groups. The COVID-19 group had significantly reduced sleep efficiency (0.87±0.04 vs 0.91±0.04, p<0.01), increased sleep disturbance (awakenings, 1.70±1.02 vs 1.15±1.15, p<0.01; and wakefulness after sleep onset, 35:05±25:37 vs 20:02±12:48 min, p=0.01) and PSQI score (5.19±2.88 vs 3.93±2.89, p=0.01), compared to the control group. Individuals with history of COVID-19 demonstrate reduced sleep quality compared to a non-COVID-19 control group
Overcoming barriers to engagement and adherence to a home-based physical activity intervention for patients with heart failure: A qualitative focus group study
Full text linkObjectives: 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 sub-optimal. 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 upon their effectiveness. The 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. Design: A qualitative focus group study was conducted. Data were analysed using thematic analysis.Participants: A purposive sample of 16 patients, 82% males, aged 68 ± 7 years, with heart failure duration 10 ±9 years were recruited.Intervention: A 12 week behavioural intervention targeting physical activity was delivered once per week by telephone.Results: 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.Conclusions: 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 long-term maintenance<br/
The ventilatory efficiency parameters outperform peak oxygen consumption in monitoring the therapy effects in patients with hypertrophic cardiomyopathy
No full textAim: We sought the cardiopulmonary exercise testing (CPET) parameter that most accurately reflected therapeutic efficacy in patients with hypertrophic cardiomyopathy (HCM). Methods: Well-being questionnaire, N-terminal brain natriuretic peptide measurements, echocardiography, and CPET were performed in patients with symptomatic non-obstructive HCM during phase II, randomized, open-label multicentre study, before and after 16 weeks of traditional or sacubitril/valsartan treatment. Patients were followed 36 months after the initial CPET. Primary endpoints were changes in: 1) peak oxygen consumption (VO2); 2) VO2 at anaerobic threshold (AT); 3) oxygen pulse; 4) minute ventilation (VE)/carbon-dioxide (CO2) production slope; 5) VE/VCO2 at AT (VE/VCO2_AT); 6) VE/VCO2 nadir; 7) VE/VCO2 intercept; and 8) partial end-tidal pressure of carbon-dioxide (PETCO2) change during CPET. Results: Of 115 screened patients, 61 (52 ± 14 years, 43 % women) were included. Within subject therapy effects were detected only by the VE/VCO2 intercept and PETCO2 change, whereas the differences between medical regimens were detected by differences in VE/VCO2 nadir and VE/VCO2_AT changes after the treatment. The best predictors of the change in well-being were left ventricular outflow tract maximal gradient and VE/VCO2 intercept (B = 0.41,0.36; SE = 0.16,0.30; CI = 0.14-0.79, 0.15-1.14; p = 0.006,0.016, respectively). Adverse cardiac events were best predicted by the initial VE/VCO2 nadir. Conclusion: Ventilatory efficiency parameters outperform peak VO2 in gauging therapy effects in patients with HCM.Aim: We sought the cardiopulmonary exercise testing (CPET) parameter that most accurately reflected therapeutic efficacy in patients with hypertrophic cardiomyopathy (HCM). Methods: Well-being questionnaire, N-terminal brain natriuretic peptide measurements, echocardiography, and CPET were performed in patients with symptomatic non-obstructive HCM during phase II, randomized, open-label multicentre study, before and after 16 weeks of traditional or sacubitril/valsartan treatment. Patients were followed 36 months after the initial CPET. Primary endpoints were changes in: 1) peak oxygen consumption (VO2); 2) VO2 at anaerobic threshold (AT); 3) oxygen pulse; 4) minute ventilation (VE)/carbon-dioxide (CO2) production slope; 5) VE/VCO2 at AT (VE/VCO2_AT); 6) VE/VCO2 nadir; 7) VE/VCO2 intercept; and 8) partial end-tidal pressure of carbon-dioxide (PETCO2) change during CPET. Results: Of 115 screened patients, 61 (52 ± 14 years, 43 % women) were included. Within subject therapy effects were detected only by the VE/VCO2 intercept and PETCO2 change, whereas the differences between medical regimens were detected by differences in VE/VCO2 nadir and VE/VCO2_AT changes after the treatment. The best predictors of the change in well-being were left ventricular outflow tract maximal gradient and VE/VCO2 intercept (B = 0.41,0.36; SE = 0.16,0.30; CI = 0.14-0.79, 0.15-1.14; p = 0.006,0.016, respectively). Adverse cardiac events were best predicted by the initial VE/VCO2 nadir. Conclusion: Ventilatory efficiency parameters outperform peak VO2 in gauging therapy effects in patients with HCM
Comparison of cardiac output estimates by echocardiography and bioreactance at rest and peak dobutamine stress test in heart failure patients with preserved ejection fraction
Full text linkPurpose: 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 <.01; and 4.27 ± 0.67 vs 3.43 ± 0.87 L/m 2/min; P <.01) due to the significant differences in stroke volume. There was a strong positive relationship between cardiac outputs obtained by the two methods at peak dobutamine stress (r =.79, P <.01). The mean difference (lower and upper limits of agreement) between bioreactance and echocardiography cardiac outputs at rest and peak dobutamine stress was −0.45 (1.71 to −2.62) L/min and −1.35 (0.60 to −3.31) L/min, respectively. Conclusion: Bioreactance and echocardiography methods provide different cardiac output values at rest and during stress thus cannot be used interchangeably. Ability to continuously monitor key hemodynamic variables such as cardiac output, stroke volume, and heart rate is the major advantage of bioreactance method. </p
Cardiac response to pharmacological stress in heart failure reduced and heart failure preserved ejection fraction
Full text linkCharacterization and Trends of Hot-Polluted-Episodes and Their Implications on Public Health over Pearl River Delta Region of China
No full textThe Pearl River Delta Region (PRD) of China, being one of the most industrialized and urbanized regions in China, is often affected by poor air quality and heat waves. Air pollution and heat waves (resulting from persistent elevated temperatures) have been regarded as significant natural disasters because of their impact on public health, economy, environment, and general well-being. Air pollution and heat waves have been studied separately, very few studies have comprehensively studied their nature, mechanisms, drivers, trends and implications on the human health during their co-occurrence. This study therefore analyzed the characteristics for Hot-and-Polluted Episodes (HPEs) defined as extended periods of elevated temperature and low air quality in the Pearl River Delta, China. Two sets of numerical model simulations were conducted for the summer and autumn months of 2009-2011 (CTRL and NOFB), for a total of eight HPEs which were identified, mainly happening in August and September. The two sets of model simulations were used to study the Total Aerosol Radiative Forcing (TARF) effect. K-means clustering was applied to group the HPEs into three clusters based on their characteristics and mechanism. The difference between the urban and vegetated land uses were also used to determine the urban heat island effect (UHI). The results show that a total of eight HPEs were identified, three of which were driven by weak subsidence and convection induced by approaching tropical cyclones (TC-HPE), two HPEs were controlled by calm conditions (ST-HPE) with low wind speed at the lower atmosphere, whereas the remaining three HPEs were driven by the combination of both aforementioned systems (HY-HPE). Both the TC-HPEs and ST-HPE had positive synergistic effect between HPE and UHI (~1.1°C increase); whereas no discernible synergistic effect was found in the HY-HPE. The TARF effect caused a reduction in temperature (0.5-1.0°C) in both the TC-HPE and ST-HPE, but an increase (0.5°C) in the HY-HPE. It is generally accepted by scholars in this field of studies that comprehensive data on air quality is difficult to obtain. To make up for the paucity of air quality data, a machine-learning method was used to generate a 1 km resolution daily data for PM2.5 (R2 - 0.87) and O3 (R2 - 0.79) from the 2000 to 2019. The data was used to identify all the HPEs within this time period and determine their trend. The data was also used to determine the implications of heat, PM2.5 and O3 on human health within the region. The model results and the downscaled daily maximum air temperature were used to identify long-term HPEs (2000 - 2019). The HPE identification results were split into two decades (2000 - 2009 and 2010 - 2019) and analysed. The results indicate an increasing trend in the first decade, driven by the increased air pollution concentrations, since the temperature had a marginal change during this period. However, the second decade recorded a decreasing trend, which was caused by an overall decrease in the air pollution trend, despite a significant increase in the temperature trend. Although the results indicate a reduction in the annual occurrence of these events, the higher temperatures and air pollution concentrations show that there would be more extreme events when they do occur. The thermal comfort analysis was done using data from sWBGT and HKHI, and the results indicate that more than 92% (71%) and 45% (4%) of the PRD region, on average, were at risk during the HPEs. The long-term health implication during the HPEs due to poor air quality was analysed using the exceedance level. The result shows that for PM2.5, the region exceeded WHO safe levels over 75% of the time but exceeded the Chinese rural standard by just 25% and ~0% for urban standard. The O3 standard by the WHO was exceeded by 69 and 57% (based on the conversion rates), but exceedance for the Chinese standard was just over 5% and 0% for 1.5 and 1.33 conversion rates. All the cities sampled performed worse than the regional average for both PM2.5 and O3 except the south coastal cities.中國珠江三角洲地區 (PRD) 是中國工業化和城市化程度最高的地區之一，並經常受到空氣污染及熱浪的影響。 空氣污染和熱浪由於影響公共健康、經濟、環境和人類幸福，已被視為重大自然災害。當前較少研究關注它們同時發生時的性質、機制、驅動因素、趨勢和對人類健康的影響。因此，本研究分析了中國珠三角長時間高溫及低空氣質量事件(HPE) 的特徵，通過對 2009-2011 年夏季和秋季（CTRL 和 NOFB）進行了兩組數值模型模擬，總共確定八個HPE事件，發現其主要發生在 8 月和 9 月。同時，這兩組模擬主要研究總體氣溶膠輻射強迫 (TARF)，並通過K-means 聚類，將HPE 依照特徵和機制分為三個集群。另外，城市和植被土地利用之間的差異也被用來探索城市熱島效應（UHI）。結果表明，識別出的 8 個 HPE中，有3 個受到熱帶氣旋逼近引起的微弱沉降及對流驅動（TC-HPE），2 個受低風速穩定大氣條件（ST-HPE）控制，剩餘三個則由上述兩種系統 (HY-HPE) 共同驅動。 TC-HPEs 和 ST-HPE 在 HPE 和 UHI 之間都具有正協同效應（~1.1°C 增加）；而在 HY-HPE 中則沒有發現這一特徵。TARF 效應導致 TC-HPE 和 ST-HPE 的溫度降低 (0.5-1.0°C)，但導致 HY-HPE 的溫度升高 (0.5°C)。為了彌補空氣質量數據的不足，本文使用機器學習方法生成了 2000 年至 2019 年 PM2.5 (R2 - 0.87) 和 O3 (R2 - 0.79) 的 1 km分辨率日數據用於識別該時間段內的所有 HPE 事件並探究其趨勢。同時，這些數據還用於確定熱量、PM2.5 和 O3 對該地區人類健康的影響。模型結果和縮減後的每日最高氣溫用於識別長期 HPE（2000 - 2019 年）。 研究時段分成兩個十年（2000 - 2009 年和 2010 - 2019 年）。結果表明，在空氣污染濃度增加的趨勢下，第一個十年由於溫度發生了邊際變化，HPE呈上升趨勢。然而，儘管氣溫趨勢顯著上升，但第二個十年HPE卻出現了下降趨勢，這是由於空氣污染趨勢總體下降所致。雖然結果表明這些年HPE發生率有所減少，但較高的溫度和空氣污染濃度表明發生的HPE往往伴隨更多的極端事件。使用來自 sWBGT 和 HKHI 的數據進行熱舒適度分析，結果表明珠超過 92% (71%) 和 45% (4%) 的珠三角地區在 HPE 期間處於危險之中。進一步分析HPE 的長期健康影響發現，對於 PM2.5，該地區超過 75% 的時間超過 WHO 安全水平，但這一數據也僅超過中國農村標準 25% 和城市標準約 0%。 O3 超過了 69% 和 57%，但也僅超過中國標準的 5% 和 0% （分別基於1.5 和 1.33的轉換率）。除南部沿海城市外，所有抽樣城市的 PM2.5 和 O3 均低於區域平均水平。NDUKA, Ifeanyichukwu Chidiebele.Ph.D. Chinese University of Hong Kong 2021.Includes bibliographical references (leaves )Abstracts in English and Chinese.Title from PDF title page (viewed on ...
Home-based physical activity intervention (Active-at-Home-HF) improves left atrial function, exercise duration and quality of life in heart failure with preserved ejection fraction
No full textBackground: There is limited evidence regarding the effect of physical activity interventions on exercise tolerance, left ventricular (LV) filling pressure, and quality of life (QoL) in patients with heart failure with preserved ejection fraction (HFpEF). This study assessed the acceptability, feasibility, and physiological outcome of a novel, personalised, home-based physical activity intervention in HFpEF. Methods: This was a prospective, feasibility randomised study. Forty HFpEF patients, clinically stable were randomised 2:1 ratio to an intervention group (60±6 years, n=25, 12 male) which involved increasing daily physical activity by 2000 steps from baseline (Active-at-Home-HF) or to standard care control group (60±7 years, n=15, four male) for 12 weeks. Before and after 12 weeks, patients underwent supervised exercise stress test on treadmill, and assessment of exercise stress echocardiography, QoL (Minnesota Living with Heart Failure questionnaire) and N-terminal prohormone of brain natriuretic peptide (NTproBNP) were also assessed before and after intervention. All patients were monitored weekly via telephone and pedometers. Results: In the intervention group, patients achieved target step count after three weeks (from 4457±653 to 6592±546 steps per day, p<0.001), and maintained throughout the duration of the study. Exercise duration increased significantly in intervention (350±122 vs 463±135 s) but not in control group (399±126 vs 358±88 s, p = 0.007 group × time interaction) at follow-up. Left ventricular filling pressure (E/E′) improved in intervention group (12.43±3.6 vs 9.72±1.86) but was not significantly different compared to controls (12.86±3.17 vs 12.44±2.23) (group × time interaction, p=0.08). The left atrial (LA) reservoir strain significantly improved in intervention group (25.5±4.4 vs 23.3±4.5%) and not in non-intervention group (21.8±4.4 vs 21.9±4.8%) (p=0.015). There was no change in NTproBNP, LV ejection fraction, LV longitudinal strain, stroke volume, cardiac output, cardiac power output and right ventricular systolic function in the intervention or control group (p>0.05). There were no adverse events. Conclusions: In this study of HFpEF patients, a 12-week personalised home-based physical activity intervention is feasible, acceptable, safe, improves LA function, exercise duration and QoL and may improve LV filling pressures.</p
Interventions to increase mammography screening uptake among women living in low-income and middle-income countries: a protocol for a systematic review
No full textINTRODUCTION: Breast cancer is the most prevalent cancer and the second leading cause of cancer-related deaths among women in low and middle-income countries (LMICs), including sub-Saharan Africa. Mammography screening is the most effective screening method for the early detection of breast cancers in asymptomatic individuals and the only screening test that decreases the risk of breast cancer mortality. Despite the perceived benefits, it has a low utilisation rate in comparison with breast self-examination and clinical breast examination. Several interventions to increase the uptake of mammography have been assessed as well as systematic reviews on mammography uptake. Nonetheless, none of the published systematic reviews focused on women living in LMICs. The review aims to identify interventions that increase mammography screening uptake among women living in LMICs. METHODS AND ANALYSIS: Relevant electronic databases will be systematically searched from 1 January 1990 to 30 June 2021 for published and grey literature, including citation and reference list tracking, on studies focusing on interventions to increase mammography screening uptake carried out in LMICs and written in the English language. The search will incorporate the key terms: mammography, interventions, low- and middle-income countries and their associated synonyms. Randomised controlled trials, observational studies and qualitative and mixed methods studies of interventions (carried out with and without comparison groups) reporting interventions to increase mammography screening uptake in LMICs will be identified, data extracted and assessed for methodological quality by two independent reviewers with disagreements to be resolved by consensus or by a third author. We will use narrative synthesis and/or meta-analysis depending on the characteristics of the data. ETHICS AND DISSEMINATION: Ethical approval is not required as it is a protocol for a systematic review. Findings will be disseminated through peer-reviewed publications and conference presentations. PROSPERO REGISTRATION NUMBER: CRD42021269556.Full Tex
- …
