Association Between Wearable Device-Based Measures of Physical Frailty and Major Adverse Events Following Lower Extremity Revascularization

Association of Daily Step Count and Postoperative Complication among All of Us Research Participants

BACKGROUND

The association between preoperative wearable device step counts and surgical outcomes has not been examined using commercial devices linked to electronic health records (EHRs). This study measured the association between daily preoperative step counts and postoperative complications.

STUDY DESIGN

Data were obtained using the All of Us (AOU) Research program, a nationwide initiative to collect EHR and health-related data from the population. Patients who underwent a surgical procedure included in the NSQIP-targeted procedures dataset were included. Patients who did not have available physical activity FitBit data were excluded. Primary outcome was the development of a postoperative complication. All analyses were performed in the AOU researcher workbench.

RESULTS

Of 27,150 patients who underwent a surgical procedure, 475 participants with preoperative wearable data were included: 74.7% were female and 85.2% were White. The average age was 57.2 years. The overall rate of postoperative complications was 12.6%. Patients averaging less than 7,500 daily steps were at increased odds for developing a postoperative complication (odds ratio 1.83, 95% CI 1.01 to 3.31). After adjustment for age, sex, race, comorbid disease, BMI, and relative procedure risk, patients with a baseline average steps per day less than 7,500 were at increased odds for postoperative complication (adjusted odds ratio 2.06, 95% CI 1.05 to 4.06).

CONCLUSIONS

This study found an increase in overall postoperative complication rate in patients recording lower average preoperative step counts. Patients with a baseline of less than 7,500 steps per day had increased odds of postoperative complications in this cohort. These data support the use of wearable devices for surgical risk stratification and suggest step count may measure preoperative fitness.

Quantitative biomechanical analysis in validating a video-based model to remotely assess physical frailty: a potential solution to telehealth and globalized remote-patient monitoring

Assessing physical frailty (PF) is vital for early risk detection, tailored interventions, preventive care, and efficient healthcare planning. However, traditional PF assessments are often impractical, requiring clinic visits and significant resources. We introduce a video-based frailty meter (vFM) that utilizes machine learning (ML) to assess PF indicators from a 20 s exercise, facilitating remote and efficient healthcare planning. This study validates the vFM against a sensor-based frailty meter (sFM) through elbow flexion and extension exercises recorded via webcam and video conferencing app. We developed the vFM using Google's MediaPipe ML model to track elbow motion during a 20 s elbow flexion and extension exercise, recorded via a standard webcam. To validate vFM, 65 participants aged 20-85 performed the exercise under single-task and dual-task conditions, the latter including counting backward from a random two-digit number. We analyzed elbow angular velocity to extract frailty indicators-slowness, weakness, rigidity, exhaustion, and unsteadiness-and compared these with sFM results using intraclass correlation coefficient analysis and Bland-Altman plots. The vFM results demonstrated high precision (0.00-7.14%) and low bias (0.00-0.09%), showing excellent agreement with sFM outcomes (ICC(2,1): 0.973-0.999), unaffected by clothing color or environmental factors. The vFM offers a quick, accurate method for remote PF assessment, surpassing previous video-based frailty assessments in accuracy and environmental robustness, particularly in estimating elbow motion as a surrogate for the 'rigidity' phenotype. This innovation simplifies PF assessments for telehealth applications, promising advancements in preventive care and healthcare planning without the need for sensors or specialized infrastructure.

The Application of Digital Frailty Screening to Triage Nonhealing and Complex Wounds

OBJECTIVE

We investigated the association between the complexity of diabetic foot ulcers (DFUs) and frailty.

RESEARCH DESIGN AND METHODS

Individuals (n = 38) with Grade 2 Wagner DFU were classified into 3 groups based on the Society for Vascular Surgery risk-stratification for major limb amputation as Stage 1 at very low risk (n = 19), Stage 2 at low risk (n = 9), and Stage 3 to 4 at moderate-to-high risk (n = 10) of major limb amputation. Frailty status was objectively assessed using a validated digital frailty meter (FM). The FM works by quantifying weakness, slowness, rigidity, and exhaustion over a 20-second repetitive elbow flexion-extension exercise using a wrist-worn sensor. FM generates a frailty index (FI) ranging from 0 to 1; higher values indicate progressively greater severity of frailty. Skin perfusion pressure (SPP), albumin, and tissue oxygenation level (SatO2) were also measured. One-way analysis of variance (ANOVA) was used to identify group effect for wound complexity. Pearson's correlation coefficient was used to assess the associations with frailty and clinical endpoints.

RESULTS

Frailty index was higher in Stage 3 and 4 as compared to Stage 1 (d = 1.4, P < .01) and Stage 2 (d = 1.2, P < .01). Among assessed frailty phenotypes, exhaustion was correlated with SPP (r = -0.63, P < .01) and albumin (r = -0.5, P < .01).

CONCLUSION

Digital biomarkers of frailty may predict complexity of DFU and thus triage individuals who can be treated more simply in their primary clinic versus higher risk patients who require prompt referral to multidisciplinary, more complex care.

A systematic review of frailty assessment tools used in vascular surgery research

OBJECTIVE

Frailty is common in vascular patients and is recognized for its prognostic value. In the absence of consensus, a multitude of frailty assessment tools exist. This systematic review aimed to quantify the variety in these tools and describe their content and application to inform future research and clinical practice.

METHODS

Multiple cross-disciplinary electronic literature databases were searched from inception to August 2022. Studies describing frailty assessment in a vascular surgical population were eligible. Data extraction to a validated template included patient demographics, tool content, and analysis methods. A secondary systematic search for papers describing the psychometric properties of commonly used frailty tools was then performed.

RESULTS

Screening 5358 records identified 111 eligible studies, with an aggregate population of 5,418,236 patients. Forty-three differing frailty assessment tools were identified. One-third of these failed to assess frailty as a multidomain deficit and there was a reliance on assessing function and presence of comorbidity. Substantial methodological variability in data analysis and lack of methodological description was also identified. Published psychometric assessment was available for only 4 of the 10 most commonly used frailty tools. The Clinical Frailty Scale was the most studied and demonstrates good psychometric properties within a surgical population.

CONCLUSIONS

Substantial heterogeneity in frailty assessment is demonstrated, precluding meaningful comparisons of services and data pooling. A uniform approach to assessment is required to guide future frailty research. Based on the literature, we make the following recommendations: frailty should be considered a continuous construct and the reporting of frailty tools' application needs standardized. In the absence of consensus, the Clinical Frailty Scale is a validated tool with good psychometric properties that demonstrates usefulness in vascular surgery.

Cellular Senescence and Frailty in Transplantation

Purpose of review

To summarizes the literature on cellular senescence and frailty in solid-organ transplantation and highlight the emerging role of senotherapeutics as a treatment for cellular senescence.

Recent findings

Solid-organ transplant patients are aging. Many factors contribute to aging acceleration in this population, including cellular senescence. Senescent cells accumulate in tissues and secrete proinflammatory and profibrotic proteins which result in tissue damage. Cellular senescence contributes to age-related diseases and frailty. Our understanding of the role cellular senescence plays in transplant-specific complications such as allograft immunogenicity and infections is expanding. Promising treatments, including senolytics, senomorphics, cell-based regenerative therapies, and behavioral interventions, may reduce cellular senescence abundance and frailty in patients with solid-organ transplants.

Summary

Cellular senescence and frailty contribute to adverse outcomes in solid-organ transplantation. Continued pursuit of understanding the role cellular senescence plays in transplantation may lead to improved senotherapeutic approaches and better graft and patient outcomes.

A Remote Diet and Exercise Intervention for Surgical Patients With Prefrailty and Frailty During the COVID-19 Pandemic

Objectives: To facilitate the success of surgical patients with prefrailty and frailty in meeting diet and exercise goals in the context of the COVID-19 pandemic, and to encourage patient satisfaction with remote care. Methods: In the setting of the COVID-19 pandemic, surgical patients with prefrailty and frailty were offered remote visits with a geriatrician and a remote diet and exercise coaching program. Results: The coaching participants set a mean of 37 (±15) individualized dietary goals and 17 (±11) individualized exercise goals. 75% of the coaching participants met at least 65% of their dietary goals and 75% met at least 50% of their exercise goals. All patients met at least one diet goal and at least one exercise goal. Patients endorsed high levels of satisfaction with the program. Discussion: Diet and exercise interventions for surgical patients with prefrailty and frailty have potential for adaptation to remote formats. Such interventions may facilitate patients' meeting of individualized diet and exercise goals and may also encourage patient satisfaction.

Frailty in People with Chronic Limb Threatening Ischemia and Diabetes-Related Foot Ulcers: A Systematic Review

BACKGROUND

Frailty represents a state of multisystem impairment that may adversely impact people presenting with chronic limb-threatening ischemia (CLTI) and diabetes-related foot ulcers (DFUs). The aim of this systematic review was to explore the association between frailty and outcomes from CLTI and DFUs.

METHODS

We performed a systematic literature search of electronic databases to find studies using a validated measure of frailty in individuals with CLTI and/or DFUs. The primary outcomes were the impact of frailty on the severity of initial clinical presentation and unfavorable follow-up outcomes including readmissions, major limb amputation, cardiovascular events, revascularization, and wound healing.

RESULTS

Ten cohort studies were included. Two studies had a low risk of bias, 1 was unable to be assessed, 5 had moderate risk of bias, and 2 high risk of bias. The prevalence of frailty in people presenting with CLTI ranged from 27% to 88% and was 71% in people with DFUs. The presence of frailty in both people with CLTI and DFUs was associated with substantially increased severity at presentation (severity of ischemia and tissue loss) and poorer outcomes at follow-up (risk of readmission, limb amputation, and all-cause mortality).

CONCLUSIONS

The presence of frailty in both people with CLTI and DFUs is likely associated with substantially higher complexity at presentation followed by a greater risk for readmission, amputation, and death during follow-up. Heterogeneity in the tools used to screen for frailty, poor definition of frailty, and unclear evaluation of exposure and outcomes limit further interpretation of findings.

Frailty predicts poor longer-term outcomes in patients following lower limb open surgical revascularization

BACKGROUND

Frailty in vascular surgery patients is increasingly recognized as a marker of poor outcome. This provides particular challenges for patients with lower limb peripheral arterial disease who require surgical revascularization. This study aimed to assess the impact of frailty on short- and long-term outcome in this specific patient group using a specialty specific frailty score.

METHODS

Patients undergoing open surgical revascularization for chronic limb ischemia (January 2015-December 2016) were assessed. Demographics, mode of admission, diagnosis, and site of surgery were recorded alongside a variety of frailty-specific characteristics. We calculated the previously validated Addenbrookes Vascular Frailty Score (AVFS) and Long AVFS (LAVFS). Primary outcome was 3-year mortality.

RESULTS

Two hundred and sixty-one patients (75% men, median age 69 years) were studied. The median length of stay was 6 days with a 3-year mortality of 23%. The predictive power of vascular frailty scores showed that for 3-year mortality, area under the receiver operator curve values (AUROC) were specific for both the AVFS score (AUROC: 0.724, 95% CI: 0.654-0.794) and LAVFS Score (AUROC: 0.741, 95%CI: 0.670-0.813). Furthermore, the cumulative AVFS and LAVFS scores both predicted mortality over the follow-up period (P=0.0001) with increased mortality among patients with higher scores.

CONCLUSIONS

Incremental worsening of frailty, determined using a specialty specific frailty score, predicts mortality risk in patients undergoing lower limb surgical revascularization.

Digital health in older adults for the prevention and management of cardiovascular diseases and frailty. A clinical consensus statement from the ESC Council for Cardiology Practice/Taskforce on Geriatric Cardiology, the ESC Digital Health Committee and the ESC Working Group on e-Cardiology

Digital health technology is receiving increasing attention in cardiology. The rise of accessibility of digital health tools including wearable technologies and smart phone applications used in medical practice has created a new era in healthcare. The coronavirus pandemic has provided a new impetus for changes in delivering medical assistance across the world. This Consensus document discusses the potential implementation of digital health technology in older adults, suggesting a practical approach to general cardiologists working in an ambulatory outpatient clinic, highlighting the potential benefit and challenges of digital health in older patients with, or at risk of, cardiovascular disease. Advancing age may lead to a progressive loss of independence, to frailty, and to increasing degrees of disability. In geriatric cardiology, digital health technology may serve as an additional tool both in cardiovascular prevention and treatment that may help by (i) supporting self-caring patients with cardiovascular disease to maintain their independence and improve the management of their cardiovascular disease and (ii) improving the prevention, detection, and management of frailty and supporting collaboration with caregivers. Digital health technology has the potential to be useful for every field of cardiology, but notably in an office-based setting with frequent contact with ambulatory older adults who may be pre-frail or frail but who are still able to live at home. Cardiologists and other healthcare professionals should increase their digital health skills and learn how best to apply and integrate new technologies into daily practice and how to engage older people and their caregivers in a tailored programme of care.

Mediating Effect of Physical Activity in the Association between Low 25-Hydroxyvitamin D and Frailty Trajectories: The English Longitudinal Study of Ageing

BACKGROUND: Frailty is associated with adverse health outcomes, and vitamin D (VD) deficiency may be a risk factor. We aimed to identify frailty trajectories and examine the mediating effect of physical activity (PA) on the association between VD deficiency and frailty trajectories. METHODS: We included 2997 participants aged 60 to 85 years from ELSA. VD was measured using serum 25-hydroxyvitamin D [25(OH)D] (sufficient: >50; insufficient: 30−50; deficient: <30 nmol/L). Frailty was assessed by a 60-item frailty index, and PA was measured on the basis of total energy expenditure. Frailty trajectories were identified using group-based trajectory modeling, and the mediation effect of PA was tested using causal mediation analysis. RESULTS: Three distinct frailty trajectories emerged: “Non-frail” (66.48%), “Pre-frail to frail” (25.67%) and “Frail to severely frail” (7.85%). VD deficiency was associated with the “Pre-frail to frail” (OR = 1.51, 95% CI: 1.14, 1.98) and “Frail to severely frail” trajectories (OR = 2.29, 95% CI: 1.45, 3.62). PA only mediated 48.4% (95% CI: 17.1%−270.8%) of the association between VD deficiency and the “Pre-frail to frail” trajectory. CONCLUSIONS: Vitamin D deficiency is associated with the onset and worsening of frailty in older adults, and reduced PA may mediate its impact on the transition from pre-frailty to frailty.

Major Adverse Events in Patients with Peripheral Artery Disease after Endovascular Revascularization: A Retrospective Study

OBJECTIVE

For peripheral artery disease (PAD) patients, after endovascular revascularization, it is crucial to manage associated factors that can affect the risk of major adverse events. We aimed to investigate the associated factors of major adverse events in these patients.

MATERIALS AND METHODS

We conducted a retrospective longitudinal analysis using the electronic medical records from a tertiary hospital in Korea and included the data of 1263 patients. Eligible patients were categorized into four groups based on diabetes mellitus (DM) and regular exercise. The major adverse events included major adverse limb events and major adverse cardiovascular events. Major adverse events-free survival was assessed using the Kaplan-Meier method, and associated factors of major adverse events were analyzed using Cox proportional hazards analyses.

RESULTS

Kaplan-Meier survival curves showed that patients with DM and non-regular exercise had a shorter major adverse events-free survival. The Cox regression analysis showed that for patients with critical limb ischemia or chronic kidney disease, the risk of major adverse events increased, while group variables were not significant.

CONCLUSION

Target management of patients with DM, critical limb ischemia, and chronic kidney disease is essential to reduce major adverse events after endovascular revascularization in patients with PAD.

Harnessing Digital Health to Objectively Assess Functional Performance in Veterans with Chronic Obstructive Pulmonary Disease

INTRODUCTION

An early detection of impaired functional performance is critical to enhance symptom management for patients with chronic obstructive pulmonary disease (COPD). However, conventional functional measures based on walking assessments are often impractical for small clinics where the available space to administrate gait-based test is limited. This study examined the feasibility and effectiveness of an upper-extremity frailty meter (FM) in identifying digital measures of functional performance and assessing frailty in COPD patients.

METHODS

Forty-eight patients with COPD (age = 68.8 ± 8.5 years, body mass index [BMI] = 28.7 ± 5.8 kg/m2) and 49 controls (age = 70.0 ± 3.0 years, BMI = 28.7 ± 6.1 kg/m2) were recruited. All participants performed a 20-s repetitive elbow flexion-extension test using a wrist-worn FM sensor. Functional performance was quantified by FM metrics, including speed (slowness), range of motion (rigidity), power (weakness), flexion and extension time (slowness), as well as speed and power reduction (exhaustion). Conventional functional measures, including timed-up-and-go test, gait and balance tests, and 5 repetition sit-to-stand test, were also performed.

RESULTS

Compared to controls, COPD patients exhibited deteriorated performances in all conventional functional assessments (d = 0.64-1.26, p < 0.010) and all FM metrics (d = 0.45-1.54, p < 0.050). FM metrics had significant agreements with conventional assessment tools (|r| = 0.35-0.55, p ≤ 0.001). FM metrics efficiently identified COPD patients with pre-frailty and frailty (d = 0.82-2.12, p < 0.050).

CONCLUSION

This study proposes the feasibility of using a 20-s repetitive elbow flexion-extension test and wrist-worn sensor-derived frailty metrics as an alternative and practical solution to evaluate functional performance in COPD patients. Its simplicity and low risk for test administration may also facilitate its application for remote patient monitoring. Furthermore, in settings where the administration of walking test is impractical, for example, when ventilator support is needed or space is limited, FM may be used as an alternative solution. Future studies are encouraged to use the FM to quantitatively monitor the progressive decline in functional performance and quantify outcomes of rehabilitation interventions.

A Wrist-Worn Sensor-Derived Frailty Index Based on an Upper-Extremity Functional Test in Predicting Functional Mobility in Older Adults

INTRODUCTION

Preoperative frailty is an independent risk factor for postoperative complications across surgical specialties. Functional mobility such as gait, timed up and go (TUG), and 5 times sit-to-stand (5-STS) are popular preoperative frailty measurements but are not suitable for patients with severe mobility impairment. A wrist-worn sensor-derived frailty index based on an upper-extremity functional test (20-s repetitive elbow flexion-extension task; UEFI) was developed previously; however, its association with functional mobility remained unexplored. We aimed to investigate the predictive power of the UEFI in predicting functional mobility.

METHODS

We examined correlation between the UEFI and gait speed, TUG duration, and 5-STS duration in 100 older adults (≥ 65 years) using multivariate regression analysis. The UEFI was calculated using slowness, weakness, exhaustion, and flexibility of the sensor-based 20-s repetitive elbow flexion-extension task.

RESULTS

The UEFI was a significant predictor for gait speed and TUG duration and 5-STS duration (all R ≥ 0.60; all p < 0.001) with the variance (adjusted R2) of 35-37% for the dependent variables. The multivariate regression analysis revealed significant associations between the UEFI and gait speed (β = -0.84; 95% confidence interval [95% CI] = [-1.19, -0.50]; p < 0.001) and TUG duration (β = 16.2; 95% CI = [9.59, 22.8]; p < 0.001) and 5-STS duration (β = 33.3; 95% CI = [23.6, 43.2]; p < 0.001), found after accounting for confounding variables (e.g., age and fear of falling scale).

CONCLUSIONS

Our findings suggest that the UEFI can be performed with a wrist-worn sensor and has been validated with other established measures of preoperative frailty. The UEFI can be applied in a wide variety of patients, regardless of mobility limitations, in an outpatient setting.

Incorporating Outcomes that Matter to Older Adults into Surgical Research

This editorial comments on the article by Thillainadesan et al. in this issue.

Remote Physical Frailty Monitoring-The Application of Deep Learning-Based Image Processing in Tele-Health

Remote screening physical frailty (PF) may assist in triaging patients with chronic obstructive pulmonary disease (COPD) who are in clinical priorities to visit a clinical center for preventive care. Conventional PF assessment tools have however limited feasibility for remote patient monitoring applications. To improve the safety of PF assessment, we previously developed and validated a quick and safe PF screening tool called Frailty Meter (FM). FM works by quantifying weakness, slowness, rigidity, and exhaustion during a 20-second repetitive elbow flexion/extension task using a wrist-worn sensor and generates a frailty index (FI) ranging from zero to one; higher values indicate progressively greater severity of frailty. However, the use of wrist-sensor limits its applications in telemedicine and remote patient monitoring. In this study, we developed a sensor-less FM based on deep learning-based image processing, which can be easily integrated into mobile health and enables remote assessment of physical frailty. The sensor-less FM extracts kinematic features of the forearm motion from the video of 20-second elbow flexion and extension recorded by a tablet camera, and then calculates frailty phenotypes and FI. To test the validity of sensor-less FM, 11 COPD patients admitted to a Telehealth pulmonary rehabilitation clinic and 10 healthy young volunteers (controls) were recruited. All participants completed the test indicating high feasibility. Strong correlations (0.72 < r < 0.99) were observed between the sensor-based FM and sensor-less FM to extract all frailty phenotypes and FI. After adjusting with age and body mass index(BMI), sensor-less FM enables distinguishing COPD group from controls (p<0.050) with the largest effect sizes observed for weakness (Cohen's effect size d=2.24), frailty index (d=1.70), and slowness (d=1.70). These pilot findings suggest feasibility and proof of concept validity of this sensor-less FM toward remote assessment of PF in COPD patients.