Advances in accelerometry for cardiovascular patients: a systematic review with practical recommendations

Decrease in accelerometer assessed physical activity during the first-year post-myocardial infarction: a prospective cohort study

OBJECTIVES

To elucidate physical activity in the first year after myocardial infarction (MI), and to explore differences in various subgroups, delineated by age, participation in exercise-based cardiac rehabilitation (exCR), or restrictions due to the covid-19 pandemic. Secondly, to explore associations between changes in physical activity variables with blood pressure and lipid levels.

METHODS

A longitudinal study in 2017-2023. Physical activity variables were assessed via accelerometers at two- and twelve months post-MI. The intensity was divided into, sedentary, light, moderate, and vigorous-intensity physical activity, according to established cut-offs. Blood pressure and lipids were measured by standardized procedures at the same time points.

RESULTS

There were 178 patients included at baseline, 81% male, mean age of 64 (9 SD) years. Patients spent 72% of their time sedentary, followed by light (19%), moderate (8%), and vigorous physical activity (1%). Patients included during covid-19 restrictions and younger patients had a higher level of moderate-intensity physical activity compared to patients included during non-pandemic restrictions and older patients. At 12-month follow-up, patients overall increased time (1%) in sedentary behavior (p = 0.03) and decreased time (0.6%) in moderate-intensity physical activity (p = 0.04), regardless of participation in exCR or age. There was a positive association between the change in mean physical activity intensity and HDL-cholesterol (p = 0.047).

CONCLUSIONS

Participants had a low fraction of time in moderate-to-vigorous-intensity physical activity two months post-MI, which deteriorated during the first year. This emphasizes the need for improved implementation of evidence-based interventions to support and motivate patients to perform regular physical activity.

Accelerometer-Measured Physical Activity in Patients with Heart Failure and Reduced Ejection Fraction: Determinants and Relationship with Patient-Reported Health Status

BACKGROUND

Accelerometer-measured physical activity is an increasingly used endpoint in heart failure (HF) trials. We investigated the determinants of accelerometer-measured physical activity and the relationship with patient-reported health status.

METHODS

Post-hoc analysis of the Empire HF trial, including outpatients with HF with reduced ejection fraction (HFrEF). Physical activity was quantified as average accelerometer counts per minute (CPM) with higher values representing higher activity. We investigated associations between activity level and clinical variables, including age, sex, and body mass index, as well as patient-reported health status assessed by Kansas City Cardiomyopathy Questionnaire (KCCQ).

RESULTS

Complete data were available in 180 (95%) patients (86% male, mean age 65 year). Baseline median physical activity level was 1318 CPM (Q1-Q3 1111-1585). Age and anemia were independently associated with activity level (β-coefficients: -10 CPM per year age increase [95% CI -16 to -5.1], p=0.00015, and -126 CPM for anemia [95% CI -9.1 to -244], p=0.035). Significant independent associations were observed between activity level and all KCCQ summary scores (β-coefficient point estimates of 3.7, 4.6, and 4.9 CPM, all p<0.02). For 12-week changes in KCCQ-summary scores, only the KCCQ-CSS was associated with activity level; mean increase of 17.5 CPM [95% CI 1.5 to 34.0], p=0.032, per 5-point increase in KCCQ-CSS. Associations were not modified by treatment allocation (interaction p-values>0.05).

CONCLUSIONS

In patients with HFrEF, older age and anemia were independently associated with lower activity. Moreover, physical activity only weakly increased with better health status, suggesting that changes in physical activity reflect improvements in patients' health status to a limited degree. This highlights the need to better understand the endpoint with regards to all other health parameters to ease interpretation in future HF trials.

Wearable Sensors to Monitor Physical Activity in Heart Failure Clinical Trials: State-of-the-Art Review

BACKGROUND

Estimation of the effects that drugs or other interventions have on patients' symptoms and functions is crucial in heart failure trials. Traditional symptoms and functions clinical outcome assessments have important limitations. Actigraphy may help to overcome these limitations due to its objective nature and the potential for continuous recording of data. However, actigraphy is not currently accepted as clinically relevant by key stakeholders.

METHODS AND RESULTS

In this state-of-the-art study, the key aspects to consider when implementing actigraphy in heart failure trials are discussed. They include which actigraphy-derived measures should be considered, how to build endpoints using them, how to measure and analyze them, and how to handle the patients' and sites' logistics of integrating devices into trials. A comprehensive recommendation based on the current evidence is provided.

CONCLUSION

Actigraphy is technically feasible in clinical trials involving heart failure, but successful implementation and use to demonstrate clinically important differences in physical functioning with drug or other interventions require careful consideration of many design choices.

Transforming the cardiometabolic disease landscape: Multimodal AI-powered approaches in prevention and management

The rise of artificial intelligence (AI) has revolutionized various scientific fields, particularly in medicine, where it has enabled the modeling of complex relationships from massive datasets. Initially, AI algorithms focused on improved interpretation of diagnostic studies such as chest X-rays and electrocardiograms in addition to predicting patient outcomes and future disease onset. However, AI has evolved with the introduction of transformer models, allowing analysis of the diverse, multimodal data sources existing in medicine today. Multimodal AI holds great promise in more accurate disease risk assessment and stratification as well as optimizing the key driving factors in cardiometabolic disease: blood pressure, sleep, stress, glucose control, weight, nutrition, and physical activity. In this article we outline the current state of medical AI in cardiometabolic disease, highlighting the potential of multimodal AI to augment personalized prevention and treatment strategies in cardiometabolic disease.

Effect of Dapagliflozin Versus Placebo on Symptoms and 6-Minute Walk Distance in Patients With Heart Failure: The DETERMINE Randomized Clinical Trials

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors reduce the risk of worsening heart failure (HF) and cardiovascular death in patients with HF irrespective of left ventricular ejection fraction. It is important to determine whether therapies for HF improve symptoms and functional capacity.

METHODS

The DETERMINE (Dapagliflozin Effect on Exercise Capacity Using a 6-Minute Walk Test in Patients With Heart Failure) double-blind, placebo-controlled, multicenter trials assessed the efficacy of the sodium-glucose cotransporter 2 inhibitor dapagliflozin on the Total Symptom Score (TSS) and Physical Limitation Scale (PLS) of the Kansas City Cardiomyopathy Questionnaire (KCCQ) and 6-minute walk distance (6MWD) in 313 patients with HF with reduced ejection fraction (DETERMINE-Reduced) and in 504 patients with HF with preserved ejection fraction (DETERMINE-Preserved) with New York Heart Association class II or III symptoms and elevated natriuretic peptide levels. The primary outcomes were changes in the KCCQ-TSS, KCCQ-PLS, and 6MWD after 16 weeks of treatment.

RESULTS

Among the 313 randomized patients with HF with reduced ejection fraction, the median placebo-corrected difference in KCCQ-TSS from baseline at 16 weeks was 4.2 (95% CI, 1.0, 8.2; P=0.022) in favor of dapagliflozin. The median placebo-corrected difference in KCCQ-PLS was 4.2 (95% CI, 0.0, 8.3; P=0.058). The median placebo-corrected difference in 6MWD from baseline at 16 weeks was 3.2 meters (95% CI, -6.5, 13.0; P=0.69). In the 504 patients with HF with preserved ejection fraction, the median placebo-corrected 16-week difference in KCCQ-TSS and KCCQ-PLS was 3.2 (95% CI, 0.4, 6.0; P=0.079) and 3.1 (-0.1, 5.4; P=0.23), respectively. The median 16-week difference in 6MWD was 1.6 meters (95% CI, -5.9, 9.0; P=0.67). In an exploratory post hoc analysis of both trials combined (DETERMINE-Pooled), the median placebo-corrected difference from baseline at 16 weeks was 3.7 (1.5, 5.9; P=0.005) for KCCQ-TSS, 4.0 (0.3, 4.9; P=0.036) for KCCQ-PLS, and 2.5 meters (-3.5, 8.4; P=0.50) for 6MWD.

CONCLUSIONS

Dapagliflozin improved the KCCQ-TSS in patients with HF with reduced ejection fraction but did not improve KCCQ-PLS or 6MWD. Dapagliflozin did not improve these outcomes in patients with HF with preserved ejection fraction. In a post hoc analysis including all patients across the full spectrum of ejection fraction, there was a beneficial effect of dapagliflozin on KCCQ-TSS and KCCQ-PLS but not 6MWD.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT03877237 and NCT03877224.

International Physical Activity Questionnaire Short Form and accelerometer-assessed physical activity: concurrent validity using six cut-points in HF patients

AIMS

Physical activity (PA) is an important target for improving clinical outcomes in heart failure (HF) patients. Nonetheless, assessing the daily PA profile in this population is a challenging task, traditionally performed using self-report questionnaires such as the International PA Questionnaire Short Form (IPAQ-SF). This study aimed to evaluate the concurrent validity of the IPAQ-SF and accelerometer-assessed PA using six published cut-points in patients with HF and reduced or mildly reduced ejection fraction.

METHODS AND RESULTS

The concordance between the IPAQ-SF and a hip-worn accelerometer regarding daily time spent performing moderate to vigorous PA in bouts of at least 10 min was assessed in 53 participants for seven consecutive days using six different cut-points (Barnett, Dibben, Mark, Sanders, Troiano, and Vaha-Ypya). Spearman's correlation and Bland-Altman plots were used to evaluate concurrent validity between methods. Regressions were used to study the association between patient variables, wear protocol (waking hour or 24 h), and absolute bias. The kappa index was used to evaluate the concordance between IPAQ-SF and accelerometry for classifying patients as active or non-active. All analyses were re-run using non-bouted metrics to investigate the effect of bouted versus non-bouted analysis. The IPAQ-SF and accelerometry showed low to negligible correlation (ρ = 0.12 to 0.37), depending on the cut-point used. The regression analysis showed that the absolute bias was higher in participants following the waking-hour protocol at all cut-points except Dibben's (P ≤ 0.007). The concordance between the two methods to classify patients as active and non-active was low when using Mark (κ = 0.23) and Barnett (κ = 0.34) cut-points and poor for the remaining cut-points (κ = 0.03 to 0.18). The results of the sensitivity analysis showed negligible to low correlation using non-bouted metrics (ρ = 0.27 to 0.33).

CONCLUSIONS

Moderate to vigorous PA measures using IPAQ-SF and accelerometers are not equivalent, and we do not encourage researchers to use IPAQ-SF alone when assessing PA in HF patients. Moreover, applying personalized collection and processing criteria is important when assessing PA in HF patients. We recommend following the 24 h protocol and selecting cut-points calibrated in patients with cardiovascular diseases. Finally, it is necessary to develop a new tailored questionnaire that considers walking intensity and is adjusted to the current World Health Organisation recommendations, which use non-bouted metrics.

Lifestyle Walking Intervention for Patients With Heart Failure With Reduced Ejection Fraction: The WATCHFUL Trial

BACKGROUND

Physical activity is pivotal in managing heart failure with reduced ejection fraction, and walking integrated into daily life is an especially suitable form of physical activity. This study aimed to determine whether a 6-month lifestyle walking intervention combining self-monitoring and regular telephone counseling improves functional capacity assessed by the 6-minute walk test (6MWT) in patients with stable heart failure with reduced ejection fraction compared with usual care.

METHODS

The WATCHFUL trial (Pedometer-Based Walking Intervention in Patients With Chronic Heart Failure With Reduced Ejection Fraction) was a 6-month multicenter, parallel-group randomized controlled trial recruiting patients with heart failure with reduced ejection fraction from 6 cardiovascular centers in the Czech Republic. Eligible participants were ≥18 years of age, had left ventricular ejection fraction <40%, and had New York Heart Association class II or III symptoms on guidelines-recommended medication. Individuals exceeding 450 meters on the baseline 6MWT were excluded. Patients in the intervention group were equipped with a Garmin vívofit activity tracker and received monthly telephone counseling from research nurses who encouraged them to use behavior change techniques such as self-monitoring, goal-setting, and action planning to increase their daily step count. The patients in the control group continued usual care. The primary outcome was the between-group difference in the distance walked during the 6MWT at 6 months. Secondary outcomes included daily step count and minutes of moderate to vigorous physical activity as measured by the hip-worn Actigraph wGT3X-BT accelerometer, NT-proBNP (N-terminal pro-B-type natriuretic peptide) and high-sensitivity C-reactive protein biomarkers, ejection fraction, anthropometric measures, depression score, self-efficacy, quality of life, and survival risk score. The primary analysis was conducted by intention to treat.

RESULTS

Of 218 screened patients, 202 were randomized (mean age, 65 years; 22.8% female; 90.6% New York Heart Association class II; median left ventricular ejection fraction, 32.5%; median 6MWT, 385 meters; average 5071 steps/day; average 10.9 minutes of moderate to vigorous physical activity per day). At 6 months, no between-group differences were detected in the 6MWT (mean 7.4 meters [95% CI, -8.0 to 22.7]; P=0.345, n=186). The intervention group increased their average daily step count by 1420 (95% CI, 749 to 2091) and daily minutes of moderate to vigorous physical activity by 8.2 (95% CI, 3.0 to 13.3) over the control group. No between-group differences were detected for any other secondary outcomes.

CONCLUSIONS

Whereas the lifestyle intervention in patients with heart failure with reduced ejection fraction improved daily steps by about 25%, it failed to demonstrate a corresponding improvement in functional capacity. Further research is needed to understand the lack of association between increased physical activity and functional outcomes.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03041610.

Accelerometer Use to Measure Physical Activity in Older Adults With Coronary Artery Disease: An Integrative Review

BACKGROUND

Physical activity is necessary for improved health outcomes among older adults with coronary artery disease (CAD), and device-based assessment of physical activity is preferred for accurate measurement. Many previous studies have applied accelerometry to examine physical activity in this population, but no reviews have systematically examined the application of various accelerometers to measure physical activity in older adults with CAD.

OBJECTIVE

This integrative review aimed to examine accelerometry application to measure physical activity in older adults with CAD and provide guidance for accelerometer selection and settings.

METHODS

Six databases-CINAHL, PubMed, PsycINFO, Scopus, EMBASE, and Google Scholar-were searched for information sources. Authors of selected studies applied accelerometers to measure physical activity and included adults 60 years or older with CAD.

RESULTS

Among 12 studies reviewed, 5 were randomized controlled trials, and most used an age cutoff of 65 years for older adults. The most frequently used accelerometer was the RT3, and the most common device placement was the waist/hip. Data collection duration was typically 3 consecutive days. However, many study authors did not report epoch length, sampling frequency, number of valid hours of data required per day, total number of valid days of data needed, or criteria for nonwear time.

CONCLUSIONS

On the basis of data synthesis and previous study results, triaxial research-grade accelerometers, waist/hip placement, and a 5- to 7-day monitoring period are recommended for measuring physical activity in older adults with CAD. However, the study purpose, device and participant characteristics, and physical activity outcomes of interest should be considered during device selection.

Physical activity measurements in individuals with interstitial lung disease: a systematic review and meta-analysis

BACKGROUND

Physical activity (PA) measurements are becoming common in interstitial lung disease (ILD); however, standardisation has not been achieved. We aimed to systematically review PA measurement methods, present PA levels and provide practical recommendations on PA measurement in ILD.

METHODS

We searched four databases up to November 2022 for studies assessing PA in ILD. We collected information about the studies and participants, the methods used to measure PA, and the PA metrics. Studies were scored using 12 items regarding PA measurements to evaluate the reporting quality of activity monitor use.

RESULTS

In 40 of the included studies, PA was measured using various devices or questionnaires with numerous metrics. Of the 33 studies that utilised activity monitors, a median of five out of 12 items were not reported, with the definition of nonwear time being the most frequently omitted. The meta-analyses showed that the pooled means (95% CI) of steps, time spent in moderate to vigorous PA, total energy expenditure and sedentary time were 5215 (4640-5791) steps·day^-1, 82 (58-106) min·day^-1, 2130 (1847-2412) kcal·day^-1 and 605 (323-887) min·day^-1, respectively, with considerable heterogeneity.

CONCLUSION

The use of activity monitors and questionnaires in ILD lacks consistency. Improvement is required in the reporting quality of PA measurement methods using activity monitors.

Measurement properties of device-based physical activity instruments in ambulatory adults with physical disabilities and/or chronic diseases: a scoping review

BACKGROUND

People with physical disabilities and/or chronic diseases tend to have an inactive lifestyle. Monitoring physical activity levels is important to provide insight on how much and what types of activities people with physical disabilities and/or chronic diseases engage in. This information can be used as input for interventions to promote a physically active lifestyle. Therefore, valid and reliable physical activity measurement instruments are needed. This scoping review aims 1) to provide a critical mapping of the existing literature and 2) directions for future research on measurement properties of device-based instruments assessing physical activity behavior in ambulant adults with physical disabilities and/or chronic diseases.

METHODS

Four databases (MEDLINE, CINAHL, Web of Science, Embase) were systematically searched from 2015 to April 16th 2023 for articles investigating measurement properties of device-based instruments assessing physical activity in ambulatory adults with physical disabilities and/or chronic diseases. For the majority, screening and selection of eligible studies were done in duplicate. Extracted data were publication data, study data, study population, device, studied measurement properties and study outcome. Data were synthesized per device.

RESULTS

One hundred three of 21566 Studies were included. 55 Consumer-grade and 23 research-grade devices were studied on measurement properties, using 14 different physical activity outcomes, in 23 different physical disabilities and/or chronic diseases. ActiGraph (n = 28) and Fitbit (n = 39) devices were most frequently studied. Steps (n = 68) was the most common used physical activity outcome. 97 studies determined validity, 11 studies reliability and 6 studies responsiveness.

CONCLUSION

This scoping review shows a large variability in research on measurement properties of device-based instruments in ambulatory adults with physical disabilities and/or chronic diseases. The variability highlights a need for standardization of and consensus on research in this field. The review provides directions for future research.

Effects of a Dedicated Cardiac Rehabilitation Program for Patients With Obesity on Body Weight, Physical Activity, Sedentary Behavior, and Physical Fitness: The OPTICARE XL Randomized Controlled Trial

OBJECTIVE

Previously published results of the OPTICARE XL open label randomized controlled trial showed no added value of OPTICARE XL CR, a dedicated cardiac rehabilitation (CR) program for patients with obesity, with respect to health-related quality of life (primary outcome). This clinical trial studied the effects of OPTICARE XL CR on several secondary outcomes, which included body weight, physical activity, sedentary behavior, and physical fitness.

METHODS

Patients with coronary artery disease or atrial fibrillation and body mass index ≥ 30 were randomized to OPTICARE XL CR (n = 102) or standard CR (n = 99). OPTICARE XL CR was a 1-year group intervention, specifically designed for patients with obesity that included aerobic and strength exercise, behavioral coaching, and an aftercare program. Standard CR consisted of a 6- to 12-week group aerobic exercise program, supplemented with cardiovascular lifestyle education. Study end points included body weight, physical activity, sedentary behavior (accelerometer), and physical fitness (6-Minute Walk Test and handgrip strength), which were evaluated 6 months after the end of CR (primary endpoint) and 3 months after the start of CR.

RESULTS

Six months after completion of either program, improvements in body weight, physical activity, sedentary behavior, and physical fitness were similar between the groups. Three months after CR start, patients randomized to OPTICARE XL CR showed greater weight loss (mean change = -3.6 vs -1.8 kg) and a larger improvement in physical activity (+880 vs +481 steps per day) than patients randomized to standard CR.

CONCLUSION

Patients allocated to OPTICARE XL CR lost significantly more body weight and showed promising results with respect to physical activity 3 months after the start of CR; however, these short-term results were not expanded or sustained in the longer term.

IMPACT

Patients with obesity do not benefit from standard CR programs. The new OPTICARE XL CR program showed its effects in the short term on weight loss and physical activity, and, therefore, redesign of the aftercare phase is recommended.

Statistical analysis plan for a randomized controlled trial examining pedometer-based walking intervention in patients with heart failure with reduced ejection fraction: the WATCHFUL trial

BACKGROUND

Physical activity is an effective management strategy for heart failure with reduced ejection fraction, but patients' compliance is challenging. Walking is a suitable form of physical activity due to its convenience and sustainability, and it can potentially improve functional capacity in heart failure patients.

OBJECTIVES

The WATCHFUL trial aims to determine whether a pedometer-based walking intervention combined with face-to-face sessions and regular telephone contact improves functional capacity in heart failure patients.

METHODS

The WATCHFUL trial is a 6-month multicenter, parallel-group, randomized, controlled, superiority trial with a 6-month follow-up. A total of 202 patients were recruited for the trial. The primary analysis will evaluate the change in distance walked during the 6-min walk test from baseline to 6 months based on the intention-to-treat population; the analysis will be performed using a linear mixed-effect model adjusted for baseline values. Missing data will be imputed using multiple imputations, and the impact of missing data will be assessed using a sensitivity analysis. Adverse events are monitored and recorded throughout the trial period.

DISCUSSION

The trial has been designed as a pragmatic trial with a scalable intervention that could be easily translated into routine clinical care. The trial has been affected by the COVID-19 pandemic, which slowed patients' recruitment and impacted their physical activity patterns.

CONCLUSIONS

The present publication provides details of the planned statistical analyses for the WATCHFUL trial to reduce the risks of reporting bias and erroneous data-driven results.

TRIAL REGISTRATION

ClinicalTrials.gov (identifier: NCT03041610, registered: 3/2/2017).

Assessing Physical Activity Levels among Chinese College Students by BMI, HR, and Multi-Sensor Activity Monitors

We investigated the use of multi-sensor physical activity monitors, body mass index (BMI), and heart rate (HR) to measure energy expenditure (EE) of various physical activity levels among Chinese collegiate students, compared with portable indirect calorimetry.

METHODS

In a laboratory experiment, 100 college students, 18-25 years old, wore the SenseWear Pro3 Armband™ (SWA; BodyMedia, Inc., Pittsburg, PA, USA) and performed 7 different physical activities. EE was measured by indirect calorimetry, while body motion and accelerations were measured with an SWA accelerometer. Special attention was paid to the analysis of unidirectional and three-directional accelerometer output.

RESULTS

Seven physical activities were recorded and distinguished by SWA, and different physical activities demonstrated different data features. The mean values of acceleration ACz (longitudinal accel point, axis Z) and VM (vector magnitude) were significantly different (p = 0.000, p < 0.05) for different physical activities, whereas no significant difference was found in one single physical activity with varied speeds (p = 0.9486, p > 0.05). When all physical activities were included in a correlation regression analysis, a strong linear correlation between the EE and accelerometer reporting value was found. According to the correlation analysis, sex, BMI, HR, ACz, and VM were independent variables, and the EE algorithm model demonstrated a high correlation coefficient R² value of 0.7.

CONCLUSIONS

The predictive energy consumption model of physical activity based on multi-sensor physical activity monitors, BMI, and HR demonstrated high accuracy and can be applied to daily physical activity monitoring among Chinese collegiate students.

Preliminary results of the cross-sectional associations of sedentary behavior and physical activity with serum brain-derived neurotrophic factor in adults with coronary heart disease

This is the first study to analyze the association of accelerometer-measured patterns of habitual physical activity (PA) and sedentary behavior (SB) with serum BDNF in individuals with coronary heart disease. A total of 30 individuals (M = 69.5 years; 80% men) participated in this pre-post study that aimed to test a multi-behavioral intervention. All participants underwent standardized measurement of anthropometric variables, blood collection, self-administered survey, and accelerometer-based measurement of PA and SB over seven days. Serum BDNF concentrations were measured using enzyme-linked immunosorbent assay kit. We applied separate multiple linear regression analysis to estimate the associations of baseline SB pattern measures, light and moderate-to-vigorous PA with serum BDNF (n = 29). Participants spent 508.7 ± 76.5 min/d in SB, 258.5 ± 71.2 min/d in light PA, and 21.2 ± 15.2 min/d in moderate-to-vigorous PA. Per day, individuals had 15.5 ± 3.2 numbers of 10-to-30 min bouts of SB (average length: 22.2 ± 2.1 min) and 3.4 ± 1.2 numbers of > 30 min bouts of SB (average length: 43.8 ± 2.4 min). Regression analysis revealed no significant associations between any of the accelerometer-based measures and serum BDNF. The findings of this study did not reveal an association of accelerometer-measured PA and SB pattern variables with serum BDNF in individuals with coronary heart disease. In addition, our data revealed a considerable variation of PA and SB which should be considered in future studies.

Individually tailored home-based physiotherapy program makes sustainable improvement in exercise capacity and daily physical activity in patients with pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a rare, chronic, progressive, and life-threatening cardiopulmonary disease. This study investigated the impact of an individually tailored 12 weeks home-based physiotherapy program in PAH patients, with the aim to evaluate change in exercise capacity and daily physical activity level.

METHODS

This was an analysis of secondary outcomes from a prospective, randomized, controlled intervention study. Twenty-one participants were recruited from the Latvian PH registry based on inclusion criteria and randomized in a training group (TG) and control group (CG). Both groups continued a medical target therapy, but for TG, the individually tailored home-based physiotherapy program was added including physical exercises, relaxation, self-control, education, and supervision with telehealth elements. Outcomes included a 6-min walk test (6MWT) (m) and daily physical activity based on accelerometry results assessed at baseline, after 12 weeks, and at follow-up 6 months after commencement of intervention.

RESULTS

6MWT distance significantly (p < 0.05) and clinically (>33 m) increased within TG after 12 weeks (51.8 m, 95% CI = 25.7-77.9 m, Cohen's d = 1.7) and at follow-up (75.5 m, 95% CI = 46.1-104.8 m, Cohen's d = 2.1). A significant difference in 6MWT results between the groups at 12 weeks and follow-up was approved. In TG, low-intensity activities significantly (p < 0.05) increased both after 12 weeks (Cohen's d = 1.6) and at follow-up (Cohen's d = 1.2), moderate-intensity activities significantly (p < 0.05) increased at follow-up (Cohen's d = 1.3), and no significant improvements were present in CG.

CONCLUSION

The individually tailored 12 weeks home-based physiotherapy program comprising comprehensive physical exercise training, relaxation, self-control skills training, and education, added to stable medical target therapy and supervised by physiotherapist through telehealth elements, is effective in improving exercise capacity and increasing daily time in low or moderate physical activities 6 months after commencement of the intervention in patients with PAH.

Convergent validity of commonly used questions assessing physical activity and sedentary time in Swedish patients after myocardial infarction

BACKGROUND

Guidelines recommend regular physical activity (PA) and decreased sedentary time (SED) for patients after myocardial infarction (MI). Therefore, valid self-assessment of PA is vital in clinical practice. The purpose of this study was to assess the convergent validity of commonly used PA and SED questions recommended by the National Board of Health and welfare (NBHW) and national SWEDEHEART-registry using accelerometers as the reference method in patients after MI.

METHODS

Data were obtained 2017-2021 among Swedish men and women (180 assessments). Participants answered five commonly used PA and SED-questions (by NBHW and SWEDEHEART) and wore an accelerometer (Actigraph GT3X) for seven days. Convergent validity was assessed gradually by; Kruskall Wallis-, Sperman rho, Weighted Kappa- and ROC-analyses. Misclassification was explored by Chi-square analyses with Benjamini-Hochberg adjustment.

RESULTS

The strongest correlation (r = 0.37) was found for the SED-GIH question (NBHW). For PA, no specific question stood out, with correlations of r = 0.31 (NBWH), and r = 0.24-0.30 (SWEDEHEART). For all questions (NBHW and SWEDEHEART), there was a high degree of misclassification (congruency 12-30%) affecting the agreement (0.09-0.32) between self-report and accelerometer assessed time. The SED-GIH, PA-index and SWEDEHEART-VPA had the strongest sensitivity for identifying individuals with high SED (0.72) or low PA (0.77 and 0.75).

CONCLUSION

The studied PA and SED questions may provide an indication of PA and SED level among patients with MI in clinical practice and could be used to form a basis for further dialogue and assessment. Further development is needed, since practical assessment tools of PA and SED are desirable.

Using Consumer-Wearable Activity Trackers for Risk Prediction of Life-Threatening Heart Arrhythmia in Patients with an Implantable Cardioverter-Defibrillator: An Exploratory Observational Study

Ventricular arrhythmia (VA) is a leading cause of sudden death and health deterioration. Recent advances in predictive analytics and wearable technology for behavior assessment show promise but require further investigation. Yet, previous studies have only assessed other health outcomes and monitored patients for short durations (7−14 days). This study explores how behaviors reported by a consumer wearable can assist VA risk prediction. An exploratory observational study was conducted with participants who had an implantable cardioverter-defibrillator (ICD) and wore a Fitbit Alta HR consumer wearable. Fitbit reported behavioral markers for physical activity (light, fair, vigorous), sleep, and heart rate. A case-crossover analysis using conditional logistic regression assessed the effects of time-adjusted behaviors over 1−8 weeks on VA incidence. Twenty-seven patients (25 males, median age 59 years) were included. Among the participants, ICDs recorded 262 VA events during 8093 days monitored by Fitbit (median follow-up period 960 days). Longer light to fair activity durations and a higher heart rate increased the odds of a VA event (p < 0.001). In contrast, lengthier fair to vigorous activity and sleep durations decreased the odds of a VA event (p < 0.001). Future studies using consumer wearables in a larger population should prioritize these outcomes to further assess VA risk.

The Relationship Between Objectively Measured Step Count, Clinical Characteristics, and Quality of Life Among Depressed Patients Recently Hospitalized With Systolic Heart Failure

OBJECTIVE

Physical activity (PA) can improve symptoms of both depression and heart failure (HF), but objective activity data among recently hospitalized HF patients with comorbid depression are lacking. We examined PA and the relationship between daily step counts and mood, health-related quality of life (HRQoL), and heart health among patients enrolled in a clinical trial treating HF and comorbid depression.

METHODS

We screened hospitalized patients with systolic HF (left ventricular ejection fraction [LVEF] ≤45%) and New York Heart Association class II-IV symptoms for depression using the two-item Patient Health Questionnaire (PHQ-2) and telephoned screen-positive patients to administer the PHQ-9 2 weeks after discharge. If the patient scored PHQ-9 ≥10 and agreed to continue in our study, we administered our baseline assessment and mailed them an armband accelerometer. We instructed patients to wear the armbands for 7 days before returning them and classified their data as "usable" if they wore it ≥10 hours per day on ≥4 separate days.

RESULTS

We mailed accelerometers to 531 depressed HF patients, and 222 (42%) returned them with usable data. Their median age was 64 years, 54% were women, 23% were non-White, and they walked a median of 1170 steps daily. Higher median daily step counts were associated with lower New York Heart Association class and better physical- and HF-specific HRQoL, but not mood symptoms, mental HRQoL, or LVEF.

CONCLUSIONS

Patients with HF and comorbid depression are generally sedentary after hospital discharge. Although mood symptoms and LVEF were unrelated to objective PA, patients with higher step counts self-reported better HRQoL.Trial Registration:ClinicalTrials.gov identifier NCT02044211.

Living with heart failure: patient experiences and implications for physical activity and daily living

AIMS

Heart failure (HF) substantially limits the ability of patients to engage in physical activities. A detailed understanding of how patients experience these limitations is required to develop valid and sensitive measures for use in clinical research. This qualitative study was designed to provide a thorough description of how HF patients experience physical activity limitations in their daily lives.

METHODS AND RESULTS

Semi-structured interviews were conducted with 40 HF patients. Interview transcripts were coded with the aim of identifying key aspects of physical activity. Patients were divided between HF with preserved ejection fraction (n = 21, 52.5%) and HF with reduced ejection fraction (n = 19, 47.5%); the majority of patients were New York Heart Association Class II (n = 22, 52.5%) or Class III (n = 16, 40.0%). Relevant physical activity themes, including mobility and broader daily function areas, were identified. The most frequently reported mobility limitations involved difficulty walking (up a steep incline, up steps, and long distances), limited walking speed, difficulty standing for long periods of time, and difficulty carrying and lifting objects. These limitations were principally related to three HF symptoms: dyspnoea, tiredness/fatigue, and peripheral oedema. Patients adapted to their symptoms and related mobility limitations in several ways, including taking rests during an activity, doing an activity more slowly, and avoiding/refraining from an activity altogether. The broader daily function areas most commonly impacted by the mobility limitations were housework, exercising or playing sports, and going shopping.

CONCLUSIONS

Heart failure patients report numerous physical activity limitations. These specific mobility and daily function areas can be measured using clinical outcome assessments (e.g. patient-reported outcomes and performance outcomes) in clinical trials and observational research. Accelerometry can be used to contribute to a holistic picture of patient functioning by passively collecting this type of data.

Considerations to address missing data when deriving clinical trial endpoints from digital health technologies

Digital health technologies (DHTs) enable us to measure human physiology and behavior remotely, objectively and continuously. With the accelerated adoption of DHTs in clinical trials, there is an unmet need to identify statistical approaches to address missing data to ensure that the derived endpoints are valid, accurate, and reliable. It is not obvious how commonly used statistical methods to handle missing data in clinical trials can be directly applied to the complex data collected by DHTs. Meanwhile, current approaches used to address missing data from DHTs are of limited sophistication and focus on the exclusion of data where the quantity of missing data exceeds a given threshold. High-frequency time series data collected by DHTs are often summarized to derive epoch-level data, which are then processed to compute daily summary measures. In this article, we discuss characteristics of missing data collected by DHT, review emerging statistical approaches for addressing missingness in epoch-level data including within-patient imputations across common time periods, functional data analysis, and deep learning methods, as well as imputation approaches and robust modeling appropriate for handling missing data in daily summary measures. We discuss strategies for minimizing missing data by optimizing DHT deployment and by including the patients' perspective in the study design. We believe that these approaches provide more insight into preventing missing data when deriving digital endpoints. We hope this article can serve as a starting point for further discussion among clinical trial stakeholders.

The use of accelerometer-based wearable activity monitors in clinical settings: current practice, barriers, enablers, and future opportunities

Background

Wearable activity monitors (WAMs, e.g. Fitbits and research accelerometers) show promise for helping health care professionals (HCPs) measure and intervene on patients’ activity patterns. This study aimed to describe the clinical use of WAMs within South Australia, barriers and enablers, and future opportunities for large-scale clinical use.

Methods

A descriptive qualitative study was undertaken using semi-structured interviews. Participants were HCPs with experience using WAMs in South Australian clinical settings. Commencing with participants identified through the research team’s professional networks, snowball recruitment continued until all identified eligible HCPs had been invited. Semi-structured interviews were used to explore the research aims, with quantitative data analysed descriptively, and qualitative data analysed thematically.

Results

18 participants (physiotherapists n = 8, exercise physiologists n = 6, medical consultants n = 2, and research personnel recommended by medical consultants n = 2), represented 12 discrete “hubs” of WAM use in clinical practice, spanning rehabilitation, orthopaedics, geriatrics, intensive care, and various inpatient-, outpatient-, community-based hospital and private-practice settings. Across the 12 hubs, five primarily used Fitbits® (various models), four used research-grade accelerometers (e.g. GENEActiv, ActivPAL and StepWatch accelerometers), one used Whoop Bands® and another used smartphone-based step counters. In three hubs, WAMs were used to observe natural activity levels without intervention, while in nine they were used to increase (i.e. intervene on) activity. Device selection was typically based on ease of availability (e.g. devices borrowed from another department) and cost-economy (e.g. Fitbits® are relatively affordable compared with research-grade devices). Enablers included device characteristics (e.g. accuracy, long battery life, simple metrics such as step count) and patient characteristics (e.g. motivation, rehabilitation population, tech-savvy), whilst barriers included the HCPs’ time to download and interpret the data, multidisciplinary team attitudes and lack of protocols for managing the devices.

Conclusions

At present, the use of WAMs in clinical practice appears to be fragmented and ad hoc, though holds promise for understanding patient outcomes and enhancing therapy. Future work may focus on developing protocols for optimal use, system-level approaches, and generating cost-benefit data to underpin continued health service funding for ongoing/wide-spread WAM use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-07096-7.

Assessment of Physical Activity Using Waist-Worn Accelerometers in Hospitalized Heart Failure Patients and Its Relationship with Kansas City Cardiomyopathy Questionnaire

The health benefits of physical activity have been widely recognized, yet there is limited information on associations between accelerometer-related parameters and established patient-reported health status. This study investigated the association between the waist-worn accelerometer measurements, cardiopulmonary exercise testing (CPX), and results of the Kansas City Cardiomyopathy Questionnaire (KCCQ) in heart failure (HF) patients hospitalized for acute decompensation. A total of 31 patients were enrolled and wore a validated three-axis accelerometer for 2 weeks and completed the short version of the KCCQ after removing the device. Daily step counts, exercise time (metabolic equivalents × hours), and %sedentary time (sedentary time/device-equipped time) were measured. Among the measured parameters, the best correlation was observed between %sedentary time and the KCCQ overall and clinical summary scores (r = -0.65 and -0.65, each p < 0.001). All of the individual domains of the KCCQ (physical limitation, symptom frequency, and quality of life), with the exception of the social limitation domain, showed moderate correlations with %sedentary time. Finally, oxygen consumption assessed by CPX demonstrated only weak associations with the accelerometer-measured parameters. An accelerometer could complement the KCCQ results in accurately assessing the physical activity in HF patients immediately after hospitalization, albeit its correlation with CPX was at most moderate.

Associations between physical activity, sedentary behaviour and left ventricular structure and function from the Echocardiographic Study of Latinos (ECHO-SOL)

OBJECTIVE

The cross-sectional association between accelerometer-measured physical activity (PA), sedentary behaviour (SB) and cardiac structure and function is less well described. This study's primary aim was to compare echocardiographic measures of cardiac structure and function with accelerometer measured PA and SB.

METHODS

Participants included 1206 self-identified Hispanic/Latino men and women, age 45-74 years, from the Echocardiographic Study of Latinos. Standard echocardiographic measures included M-mode, two-dimensional, spectral, tissue Doppler and myocardial strain. Participants wore an Actical accelerometer at the hip for 1 week.

RESULTS

The mean±SE age for the cohort was 56±0.4 years, 57% were women. Average moderate to vigorous PA (MVPA) was 21±1.1 min/day, light PA was 217±4.2 min/day and SB was 737±8.1 min/day. Both higher levels of light PA and MVPA (min/day) were associated with lower left ventricular (LV) mass index (LVMI)/end-diastolic volume and a lower E/e' ratio. Higher levels of MVPA (min/day) were associated with better right ventricular systolic function. Higher levels of SB were associated with increased LVMI. In a multivariable linear regression model adjusted for demographics and cardiovascular disease modifiable factors, every 10 additional min/day of light PA was associated with a 0.03 mL/m2 increase in left atrial volume index (LAVI) (p<0.01) and a 0.004 cm increase in tricuspid annular plane systolic excursion (p<0.01); every 10 additional min/day of MVPA was associated with a 0.18 mL/m2 increase in LAVI (p<0.01) and a 0.24% improvement in global circumferential strain (p<0.01).

CONCLUSIONS

Our findings highlight the potential positive association between the MVPA and light PA on cardiac structure and function.

Increased Cardiopulmonary Fitness Is Associated with a Greater Reduction in Depression among People Who Underwent Bariatric Surgery

The aim of this study was to determine the effect of changes in cardiopulmonary fitness on the mental health of patients with severe obesity who underwent gastric bypass surgery (prior to and 1, 3, and 6 months after surgery). Study participants were recruited from among patients of a regional hospital in Czechia who underwent gastric bypass surgery between April 2018 and October 2019. They were eligible if they (a) were between 18 and 65 years old, (b) provided written informed consent, and (c) were able to walk independently. Twenty-six patients (age 45.4 ± 9.0 years, body mass index 45.1 ± 7.4 kg·m⁻², body fat 43.8 ± 4.8%) were included in the analysis. The key finding revealed that the greater the increase in cardiopulmonary fitness (i.e., longer distance walked in the six-minute walk test, 6MWT), the better the improvement in depression score among patients who underwent bariatric surgery. In particular, increments of 10 m in the 6MWT lead to the improvement of 0.5 points on the depression subscale of the Hospital Anxiety and Depression Scale (HADS) questionnaire. As the main implication, these results suggest that patients should participate in exercise training programs to increase their fitness status for optimal physical and mental outcomes of bariatric surgery.

Measuring physical activity with activity monitors in patients with heart failure: from literature to practice. A position paper from the Committee on Exercise Physiology and Training of the Heart Failure Association of the European Society of Cardiology

The aims of this paper were to provide an overview of available activity monitors used in research in patients with heart failure and to identify the key criteria in the selection of the most appropriate activity monitor for collecting, reporting, and analysing physical activity in heart failure research. This study was conducted in three parts. First, the literature was systematically reviewed to identify physical activity concepts and activity monitors used in heart failure research. Second, an additional scoping literature search for validation of these activity monitors was conducted. Third, the most appropriate criteria in the selection of activity monitors were identified. Nine activity monitors were evaluated in terms of size, weight, placement, costs, data storage, water resistance, outcomes and validation, and cut‐off points for physical activity intensity levels were discussed. The choice of a monitor should depend on the research aims, study population and design regarding physical activity. If the aim is to motivate patients to be active or set goals, a less rigorously tested tool can be considered. On the other hand, if the aim is to measure physical activity and its changes over time or following treatment adjustment, it is important to choose a valid activity monitor with a storage and battery longevity of at least one week. The device should provide raw data and valid cut‐off points should be chosen for analysing physical activity intensity levels. Other considerations in choosing an activity monitor should include data storage location and ownership and the upfront costs of the device.

The detrimental effect of COVID-19 nationwide quarantine on accelerometer-assessed physical activity of heart failure patients

AIMS

A reduction of habitual physical activity due to prolonged COVID-19 quarantine can have serious consequences for patients with cardiovascular diseases, such as heart failure. This study aimed to explore the effect of COVID-19 nationwide quarantine on accelerometer-assessed physical activity of heart failure patients.

METHODS AND RESULTS

We analysed the daily number of steps in 26 heart failure patients during a 6-week period that included 3 weeks immediately preceding the onset of the quarantine and the first 3 weeks of the quarantine. The daily number of steps was assessed using a wrist-worn accelerometer worn by the patients as part of an ongoing randomized controlled trial. Multilevel modelling was used to explore the effect of the quarantine on the daily step count adjusted for weather conditions. As compared with the 3 weeks before the onset of the quarantine, the step count was significantly lower during each of the first 3 weeks of the quarantine (P < 0.05). When the daily step count was averaged across the 3 weeks before and during the quarantine, the decrease amounted to 1134 (SE 189) steps per day (P < 0.001), which translated to a 16.2% decrease.

CONCLUSIONS

The introduction of the nationwide quarantine due to COVID-19 had a detrimental effect on the level of habitual physical activity in heart failure patients, leading to an abrupt decrease of daily step count that lasted for at least the 3-week study period. Staying active and maintaining sufficient levels of physical activity during the COVID-19 pandemic are essential despite the unfavourable circumstances of quarantine.

Advances in accelerometry for cardiovascular patients: a systematic review with practical recommendations

Aims

Accelerometers are becoming increasingly commonplace for assessing physical activity; however, their use in patients with cardiovascular diseases is relatively substandard. We aimed to systematically review the methods used for collecting and processing accelerometer data in cardiology, using the example of heart failure, and to provide practical recommendations on how to improve objective physical activity assessment in patients with cardiovascular diseases by using accelerometers.

Methods and results

Four electronic databases were searched up to September 2019 for observational, interventional, and validation studies using accelerometers to assess physical activity in patients with heart failure. Study and population characteristics, details of accelerometry data collection and processing, and description of physical activity metrics were extracted from the eligible studies and synthesized. To assess the quality and completeness of accelerometer reporting, the studies were scored using 12 items on data collection and processing, such as the placement of accelerometer, days of data collected, and criteria for non‐wear of the accelerometer. In 60 eligible studies with 3500 patients (of those, 536 were heart failure with preserved ejection fraction patients), a wide variety of accelerometer brands (n = 27) and models (n = 46) were used, with Actigraph being the most frequent (n = 12), followed by Fitbit (n = 5). The accelerometer was usually worn on the hip (n = 32), and the most prevalent wear period was 7 days (n = 22). The median wear time required for a valid day was 600 min, and between two and five valid days was required for a patient to be included in the analysis. The most common measures of physical activity were steps (n = 20), activity counts (n = 15), and time spent in moderate‐to‐vigorous physical activity (n = 14). Only three studies validated accelerometers in a heart failure population, showing that their accuracy deteriorates at slower speeds. Studies failed to report between one and six (median 4) of the 12 scored items, with non‐wear time criteria and valid day definition being the most underreported items.

Conclusions

The use of accelerometers in cardiology lacks consistency and reporting on data collection, and processing methods need to be improved. Furthermore, calculating metrics based on raw acceleration and machine learning techniques is lacking, opening the opportunity for future exploration. Therefore, we encourage researchers and clinicians to improve the quality and transparency of data collection and processing by following our proposed practical recommendations for using accelerometers in patients with cardiovascular diseases, which are outlined in the article.