44 research outputs found
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/
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 ...
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
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
Peak atrio-ventricular mechanics predicts exercise tolerance in heart failure patients
Full text linkPURPOSE: 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..METHODS: 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).RESULTS: 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.CONCLUSION: 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.</p
Haemodynamic determinants of quality of life in chronic heart failure
Full text linkBACKGROUND: 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. </p
