Frailty, Physical Activity, and Mobility in Patients With Cardiac Implantable Electrical Devices

The prevalence of frailty and its effect on the outcome in cardiac resynchronization therapy patients

Frailty is a complex clinical syndrome associated with aging and comorbidities, which correlates with unfavorable outcomes. However, in heart failure patients, frailty is very common, data is scarce about those, who are eligible for Cardiac Resynchronization Therapy (CRT) implantation. We investigated the incidence of frailty and the association of Frailty Index (FI) with the outcome. Thirty baseline clinical parameters were used by the Rockwood cumulative deficit method to determine patients' FI in our single-center cohort. Based on previous studies, patients with FI ≤ 0.210 were considered as non-frail, those with FI 0.10-0.210 were classified in Frail-1, with FI > 0.10 in Frail-2 groups, respectively. Echocardiographic response after 12 months and all-cause mortality were investigated by frailty groups. Among 1004 included patients, 75 (7%) were considered Non-frail, 271 (27%) grouped in Frail-1, and 658 (66%) in Frail-2 with a median FI of 0.36 (0.28-0.43). Patients in Frail-2 group were older, with more comorbidities compared with non-frail patients or those in Group Frail-1. During the median follow-up time of 4.8 years, 29 (39%) patients died in the Non-frail, 140 (52%) in Frail-1, and 471 (72%) in the Frail-2 groups (log-rank p < 0.001). Group Frail-2 showed an unfavorable outcome compared to the non-frail (HR 2.49, 95%CI 1.92-3.22; p < 0.001) and the Frail-1 group (1.83, 95%CI 1.55-2.16; p < 0.001). In our HFrEF patients eligible for CRT implantation, patients were exceedingly vulnerable with a high prevalence of frailty. The calculated frailty index was associated with outcome and proved to be prevalent in individual risk stratification.

EHRA expert consensus document on the management of arrhythmias in frailty syndrome, endorsed by the Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), Latin America Heart Rhythm Society (LAHRS), and Cardiac Arrhythmia Society of Southern Africa (CASSA)

There is an increasing proportion of the general population surviving to old age with significant chronic disease, multi-morbidity, and disability. The prevalence of pre-frail state and frailty syndrome increases exponentially with advancing age and is associated with greater morbidity, disability, hospitalization, institutionalization, mortality, and health care resource use. Frailty represents a global problem, making early identification, evaluation, and treatment to prevent the cascade of events leading from functional decline to disability and death, one of the challenges of geriatric and general medicine. Cardiac arrhythmias are common in advancing age, chronic illness, and frailty and include a broad spectrum of rhythm and conduction abnormalities. However, no systematic studies or recommendations on the management of arrhythmias are available specifically for the elderly and frail population, and the uptake of many effective antiarrhythmic therapies in these patients remains the slowest. This European Heart Rhythm Association (EHRA) consensus document focuses on the biology of frailty, common comorbidities, and methods of assessing frailty, in respect to a specific issue of arrhythmias and conduction disease, provide evidence base advice on the management of arrhythmias in patients with frailty syndrome, and identifies knowledge gaps and directions for future research.

The impacts of preoperative frailty on readmission after cardiac implantable electrical device implantation

Cardiac implantable electrical devices (CIED) such as pacemakers, implantable cardioverter defibrillators, and cardiac resynchronization therapies are generally recommended for older patients and those with severe heart failure (HF). However, there is currently a lack of evidence on the relationship between frailty and readmission rates among patients with CIED. This study investigated whether preoperative frailty influenced readmission rates among patients with CIED over a one-year period following implantation. The study retrospectively analyzed 101 patients who underwent CIED implantations. To compare frailty-based differences in their characteristics and readmission rates, these participants were categorized into frailty and non-frailty groups via the modified frailty index (mFI). The frailty group had a significantly higher readmission rate than the non-frailty group (non-frailty group vs. frailty group = 1 vs. 8 patients: P < 0.05). Further, a multivariate analysis showed that frailty was a significant readmission factor. Based on individual analyses with/without histories of HF, the readmission rate also tended to be higher among individuals considered frail via the mFI (readmission rate in HF patients: non-frailty group vs. frailty group = 1 vs. 5 patients: P = 0.65; non-HF patients: non-frailty group vs. frailty group = 0 vs. 3 patients: P = 0.01). Participants with preoperative frailty showed higher readmission rates within a one-year period following implantation compared to those without preoperative frailty. This tendency was consistent regardless of HF history. The mFI may thus help predict readmission among patients with CIED.

A Proposed Method of Converting Gait Speed and TUG Test in Older Subjects

Sarcopenia is one of the most important health problems in advanced age. In 2019, the European Working Group of Sarcopenia in Older People (EWGSOP) updated the operational diagnostic criteria for identification of people with sarcopenia (EWGSOP2). Among the two proposed low performance measures of sarcopenia are gait speed and the Timed Up and Go (TUG) test. Usage of any of those tools requires recalculation for the second one for eventual comparisons. The simple linear regression has been used for such comparisons in several previous studies, but the appropriateness of such an approach has not been verified. The aim of this study is to find the most appropriate model describing the relationship between these two popular measures of physical function. The study was performed in 450 consecutive outpatients of the Geriatric Clinic of the Medical University of Lodz, Poland, aged 70 to 92 years who volunteered to participate in the study. The TUG test and gait speed at 4 m to assess physical function were used. Different alternative models were compared to obtain the highest R-squared values. A Reciprocal-Y model (R-squared = 71.9%) showed the highest performance, followed by a Logarithmic-Y square root-X model (R-squared = 69.3%) and a Reciprocal-Y square root-X model (R-squared = 69.1%). The R-squared for the linear model was 49.5%. For the selected reciprocal model, the correlation coefficient was 0.85 and the equation of the fitted model was: Gait speed (m/s) = 1/(-0.0160767 + 0.101386 × TUG). In conclusion, in independent community-dwelling older adults, the relationship between gait speed and the TUG test in older subjects is nonlinear. The proposed reciprocal model may be useful for recalculations of gait speed or TUG in future studies.

Multiple mediating effects of self-efficacy and physical activity on the relationship between frailty and health-related quality of life in adults with CVD

AIMS

Poor health-related quality of life is prevalent among individuals with cardiovascular disease (CVD) and may be associated with frailty as well as low levels of self-efficacy and physical activity. This study aimed to identify the multiple mediating effects of exercise self-efficacy and physical activity on the relationship between frailty and health-related quality of life among community-dwelling adults with CVD.

METHODS AND RESULTS

This cross-sectional study included 489 Korean patients aged >20 years diagnosed with CVD. Data were collected through an online survey conducted in June, 2021. The mediation hypothesis was tested using a serial multiple mediation model and the bootstrapping method. Approximately 39.5% of patients in this study were in a frail state. Our main finding revealed that frailty had an indirect effect on health-related quality of life through all three different pathways: each single mediation of exercise self-efficacy and physical activity, and the serial multiple mediation of exercise self-efficacy and physical activity as the first and second mediators, respectively. The direct effect of frailty on the health-related quality of life was also significant.

CONCLUSION

Frail adults with CVD tended to have lower levels of self-efficacy, physical activity, and poor health-related quality of life. Thus, early identification of frailty and interventions targeting the promotion of self-efficacy and physical activity may improve health-related quality of life in adults with CVD. Longitudinal studies are necessary to further refine our findings across other samples and to address the limitations of the current study.

Frailty Syndrome in Older Adults with Cardiovascular Diseases-What Do We Know and What Requires Further Research?

Cardiovascular diseases (CVD) affect 60% of people over 60 years of age and are one of the main causes of death in the world. Diagnosed cardiovascular disease also triples the likelihood of Frailty syndrome (FS). FS has become increasingly relevant in cardiology and cardiac surgery and occurs in a significant number of patients with CVD, with prevalence ranging from 25% to 62%. Viewed in a multidimensional, biopsychosocial perspective, FS increases a patient's vulnerability, making them susceptible to several adverse clinical outcomes. Frailty syndrome also is a predictor of mortality in patients with CVD regardless of age, severity of disease, multi-morbidity, and disability. Frailty syndrome potentially can be prevented in patients with CVD and its early identification is important to avoid the development of disability, dependence on others and reduced quality of life. The aim of this paper is to show the relationship between FS and specific CVDs (coronary artery disease, hypertension, atrial fibrillation, heart failure) and cardiac procedures (device implantation, cardiac surgery, and transcatheter aortic valve implantation). Furthermore, we highlight those areas that require further research to fully understand the relationship between FS and CVD and to be able to minimize or prevent its adverse effects.

Physical performance status predicts mortality in aging patients undergoing pacemaker implantation

AIMS

To assess whether frailty or reduced physical performance status may have an impact on clinical outcomes after pacemaker implantation in aging patients.

METHODS

A prospective cohort of patients aged more than 70 years, admitted to the hospital for pacemaker implantation, was enrolled. Patients were evaluated with the Short Physical Performance Battery (SPPB) and Handgrip Strength Test at hospital discharge and at 1 year. Overall mortality was the primary study endpoint.

RESULTS

Out of the 119 patients, the majority (71%) of patients had reduced physical performance (defined by an SPPB score <10 points). After a median follow-up of 46 months, the mortality was 31% of the population. SPPB value at discharge predicted death even after adjusting for pertinent confounders (adjusted hazard ratio 0.91, 95% confidence interval (CI) 0.84-0.99, P = 0.02). Patients with a poorer SPPB score at discharge (SPPB 0-3) had also an increased risk of death or rehospitalization at 1 year compared with patients with highest SPPB score (odds ratio OR 4.05, 95% CI 1-16.6).

CONCLUSION

Reduced physical performance is associated with increased mortality in aging patients with bradyarrhythmia requiring pacemaker implantation. The identification of patients with poor SPPB may tailor specific interventions to improve physical performance and outcomes after pacemaker implantation.The trial was registered in clinicaltrial.gov with the identifier NCT02386124.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially life-saving treatments for a number of cardiac conditions, but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased healthcare costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, anti-bacterial envelopes, prolonged antibiotics post-implantation, and others. Guidance on whether to use novel device alternatives expected to be less prone to infections and novel oral anticoagulants is also limited, as are definitions on minimum quality requirements for centres and operators and volumes. Moreover, an international consensus document on management of CIED infections is lacking. The recognition of these issues, the dissemination of results from important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially life-saving treatments for a number of cardiac conditions, but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased healthcare costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, anti-bacterial envelopes, prolonged antibiotics post-implantation, and others. Guidance on whether to use novel device alternatives expected to be less prone to infections and novel oral anticoagulants is also limited, as are definitions on minimum quality requirements for centres and operators and volumes. Moreover, an international consensus document on management of CIED infections is lacking. The recognition of these issues, the dissemination of results from important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID), and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially lifesaving treatments for a number of cardiac conditions but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased health care costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well-recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, antibacterial envelopes, prolonged antibiotics post-implantation, and others. When compared with previous guidelines or consensus statements, the present consensus document gives guidance on the use of novel device alternatives, novel oral anticoagulants, antibacterial envelopes, prolonged antibiotics post-implantation, as well as definitions on minimum quality requirements for centres and operators and volumes. The recognition that an international consensus document focused on management of CIED infections is lacking, the dissemination of results from new important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a Novel 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

Clinical utility of CorVue intrathoracic impedance alert with device-measured physical activity in predicting heart failure events

Cardiac implantable electronic devices (CIEDs) offer heart failure (HF) diagnostic information, including intrathoracic impedance (ITI) or physical activity (PA). However, few studies have evaluated the utility of these parameters measured by CIEDs with CorVue algorithm. The purpose of this study was to investigate the relationship between ITI alerts triggered by the CorVue algorithm and HF development. We also examined the association between device-measured PA and ITI alerts associated with HF development. We retrospectively studied consecutive patients with CIEDs equipped with CorVue algorithm, which were implanted between June 1, 2011 and August 31, 2019. These patients were divided into two groups: patients with decreased ITI followed by the ITI alerts (ITI alert group) and those without the alerts (non-ITI alert group). There were 35 and 14 patients in the ITI and non-ITI alert groups, respectively. A total of 96 ITI alerts were observed. ITI alerts associated with HF development were observed in 21% (20/96); whereas, ITI alerts not associated with HF development were observed in 79% (76/96). Accurate device-measured PA was confirmed in 76 ITI alerts, which consisted of 30 alerts with lower PA and 46 alerts without lower PA. ITI alerts associated with HF development were observed in 30% (9/30) of the alerts with lower PA, whereas observed only in 6.5% (3/46) of the alerts without lower PA. In conclusion, the CorVue ITI alerts indicated a high false-positive rate. However, device-measured PA may be useful to determine whether ITI alerts are associated with HF development or not, which was attributed to the high negative predictive value.

Feasibility of Frailty Assessment Integrated with Cardiac Implantable Electronic Device Clinic Follow-up: A Pilot Investigation

Background: The concept of frailty was originally created to explain why individuals of the same age have differing risk of disease, and it has since been found to be negatively associated with outcomes for a wide range of medical conditions, including cardiovascular disease and cardiac procedures. Although numerous risk scores and assessment tools have been proposed, opportunities for practical assessment of frailty remain limited. In this pilot study, we examine the feasibility of using routine follow-up of patients with cardiac implantable electronic devices (CIEDs) for assessment of frailty. Methods: From September 2017 through March 2018, 49 consecutive patients seen in CIED clinic were enrolled. Among the frailty assessments performed at the clinic visit included a 4-meter walk time, FRAIL scale calculation, Rockwood Frailty score assessment by another treating provider, mini-cog assessment, and analysis of daily activity measures on the CIED. Results: Among the three device manufacturers of patients' CIEDs, only Boston Scientific released analyzable activity time series data. On nine patients in whom daily activity data could be analyzed, there was no difference in mean daily activity (148.3 ± 31.9 vs. 100.1 ± 25.1 min/day, p = .27) between patients with and without an abnormal frailty or cognitive assessment, although interestingly, those with an abnormal assessment had a higher standard deviation of activity per day (52.6 ± 5.9 vs. 31.4 ± 4.7 min/day, p = .03). Conclusion: It is possible that a higher variation in daily activity over the course of a year could be a better indicator of frailty or cognitive impairment than average daily activity.

Ethical and Legal Implications of Remote Monitoring of Medical Devices

Policy Points Millions of life-sustaining implantable devices collect and relay massive amounts of digital health data, increasingly by using user-downloaded smartphone applications to facilitate data relay to clinicians via manufacturer servers. Our analysis of health privacy laws indicates that most US patients may have little access to their own digital health data in the United States under the Health Insurance Portability and Accountability Act Privacy Rule, whereas the EU General Data Protection Regulation and the California Consumer Privacy Act grant greater access to device-collected data. Our normative analysis argues for consistently granting patients access to the raw data collected by their implantable devices.

CONTEXT

Millions of life-sustaining implantable devices collect and relay massive amounts of digital health data, increasingly by using user-downloaded smartphone applications to facilitate data relay to clinicians via manufacturer servers. Whether patients have either legal or normative claims to data collected by these devices, particularly in the raw, granular format beyond that summarized in their medical records, remains incompletely explored.

METHODS

Using pacemakers and implantable cardioverter-defibrillators (ICDs) as a clinical model, we outline the clinical ecosystem of data collection, relay, retrieval, and documentation. We consider the legal implications of US and European privacy regulations for patient access to either summary or raw device data. Lastly, we evaluate ethical arguments for or against providing patients access to data beyond the summaries presented in medical records.

FINDINGS

Our analysis of applicable health privacy laws indicates that US patients may have little access to their raw data collected and held by device manufacturers in the United States under the Health Insurance Portability and Accountability Act Privacy Rule, whereas the EU General Data Protection Regulation (GDPR) grants greater access to device-collected data when the processing of personal data falls under the GDPR's territorial scope. The California Consumer Privacy Act, the "little sister" of the GDPR, also grants greater rights to California residents. By contrast, our normative analysis argues for consistently granting patients access to the raw data collected by their implantable devices. Smartphone applications are increasingly involved in the collection, relay, retrieval, and documentation of these data. Therefore, we argue that smartphone user agreements are an emerging but potentially underutilized opportunity for clarifying both legal and ethical claims for device-derived data.

CONCLUSIONS

Current health privacy legislation incompletely supports patients' normative claims for access to digital health data.

Dose-response association of implantable device-measured physical activity with long-term cardiac death and all-cause mortality in patients at high risk of sudden cardiac death: a cohort study

Background

Cardiovascular implantable electronic devices (CIEDs) with physical activity (PA) recording function can continuously and automatically collect patients’ long-term PA data. The dose-response association of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRTD)-measured PA with cardiovascular outcomes in patients at high risk of sudden cardiac death (SCD) was investigated.

Methods

In total, 822 patients fulfilling the inclusion criteria were included and divided into three groups according to baseline PA tertiles: tertile 1 (< 8.04%, n = 274), tertile 2 (8.04–13.24%, n = 274), and tertile 3 (> 13.24%, n = 274). The primary endpoint was cardiac death, the secondary endpoint was all-cause mortality.

Results

During a mean follow-up of 59.7 ± 22.4 months, cardiac death (18.6% vs 8.8% vs 5.5%, tertiles 1–3, P < 0.001) and all-cause mortality (39.4% vs 20.4% vs 9.9%, tertiles 1–3, P < 0.001) events decreased according to PA tertiles. Compared with patients younger than 60 years old, older patients had a lower average PA level (9.6% vs 12.8%, P < 0.001) but higher rates of cardiac death (13.2% vs 8.1%, P = 0.024) and all-cause mortality (28.4% vs 16.7%, P < 0.001) events. Adjusted multivariate Cox regression analyses showed that a higher tertile of PA was associated with a lower risk of cardiac death (hazard ratio (HR) 0.41, 95% confidence interval (CI): 0.25–0.68, tertile 2 vs tertile 1; HR 0.28, 95% CI: 0.15–0.51, tertile 3 vs tertile 1, P_trend < 0.001). Similar results were observed for all-cause mortality. The dose-response curve showed an inverse non-linear pattern, and a significant reduction in endpoint risk was observed at the low-moderate PA level. The HR for cardiac death was reduced by half with 12.32% PA (177 min), and the HR for all-cause mortality was reduced by half with 11.92% PA (172 min). Subgroup analysis results indicated that older adults could benefit from PA and the range for achieving optimal benefits might be lower.

Conclusions

PA monitoring may aid in long-term management of patients at high risk of SCD. More PA will generate better survival benefits, but even low-moderate PA is already good especially for older adults, which is relatively easy to achieve.

Impact of COVID-19 Pandemic on Physical Activity in Patients With Implantable Cardioverter-Defibrillators

The strict lockdown strategy prompted by the Italian government, to hamper severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) spreading, reduced opportunities to perform physical activity. This study quantified an abrupt and statistically significant reduction by 25% of physical activity in patients with implantable defibrillators, during the forced 40-d in-home confinement.

The coronavirus disease-2019 (COVID-19) pandemic has been spreading rapidly worldwide since late January 2020. The strict lockdown strategy prompted by the Italian government, to hamper severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) spreading, has reduced the possibility of performing either outdoor or gym physical activity (PA). This study investigated and quantified the reduction of PA in patients with automatic implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden death.

Baseline and decline in device-derived activity level predict risk of death and heart failure in patients with an ICD for primary prevention

BACKGROUND

Implanted defibrillators are capable of recording activity data based on company-specific proprietary algorithms. This study aimed to determine the prognostic significance of baseline and decline in device-derived activity level across different device companies in the real world.

METHODS

We performed a retrospective cohort study of patients (n = 280) who underwent a defibrillator implantation (Boston, Medtronic, St. Jude, and Biotronik) for primary prevention at the University of Michigan from 2014 to 2016. Graphical data obtained from device interrogations were retrospectively converted to numerical data. The activity level averaged over a month from a week postimplantation was used as baseline. Subsequent weekly average activity levels (SALs) were standardized to this baseline. SAL below 59.4% was used as a threshold to group patients. All-cause mortality and death/heart failure were the primary end-points of this study.

RESULTS

Fifty-six patients died in this study. On average, they experienced a 50% decline in SAL prior to death. Patients (n = 129) who dropped their SAL below threshold were more likely to be older, male, diabetic, and have more symptomatic heart failure. They also had a significantly increased risk of heart failure/death (hazard ratio [HR] 3.6, 95% confidence interval [95% CI] 2.3-5.8, P < .0001) or death (HR 4.2, 95% CI 2.2-7.7, P < .0001) compared to those who had sustained activity levels. Lower baseline activity level was also associated with significantly increased risk of heart failure/death and death.

CONCLUSION

Significant decline in device-derived activity level and low baseline activity level are associated with increased mortality and heart failure in patients with an ICD for primary prevention.

Pacemaker detected active minutes are superior to pedometer-based step counts in measuring the response to physical activity counseling in sedentary older adults

BACKGROUND

In patients with permanent pacemakers (PPM), physical activity (PA) can be monitored using embedded accelerometers to measure pacemaker detected active hours (PDAH), a strong predictor of mortality. We examined the impact of a PA Counseling (PAC) intervention on increasing activity as measured by PDAH and daily step counts.

METHODS

Thirteen patients (average age 80 ± 6 years, 84.6% women) with implanted Medtronic PPMs with a ≤ 2 PDAH daily average were included in this study. Patients were randomized to Usual Care (UC, N = 6) or a Physical Activity Counseling Intervention (PACI, N = 7) groups. Step count and PDAH data were obtained at baseline, following a 12-week intervention, then 12 weeks after intervention completion. Data were analyzed using independent t-tests, Pearson's r, chi-square, and general linear models for repeated measures.

RESULTS

PDAH significantly differed by time point for all subject combined (P = 0.01) but not by study group. Subjects with baseline gait speeds of > 0.8 m/sec were responsible for the increases in PDAH observed. Step counts did not differ over time in the entire cohort or by study group. Step count and PDAH significantly correlated at baseline (r = 0.60, P = 0.03). This correlation disappeared by week 12.

CONCLUSION(S)

PDAH can be used to monitor PA and PA interventions and may be superior to hip-worn pedometers in detecting activity. A significant increase in PA, regardless of treatment group, suggests that patient awareness of the ability to monitor PA through a PPM increases PA in these patients, particularly in patients with gait speeds of < 0.8 m/sec.

TRIAL REGISTRATION

ClincalTrials.gov NCT03052829. Date of Registration: 2/14/2017.

The Relationship between Frailty Syndrome and Concerns about an Implantable Cardioverter Defibrillator

Frailty syndrome may cause cognitive decline and increased sensitivity to stressors. This can result in an increased incidence of anxiety and depression, and thus, concerns about life with an implantable cardioverter defibrillator (ICD). The aim of the study was to assess the impact of frailty syndrome on the increase in the number of device-related concerns after the implantation of an ICD. Material and methods: The study sample was a group of 103 consecutive patients (85 M; aged 71.6 ± 8.2) with an implanted ICD. The ICD Concerns Questionnaire (ICDC) was used to analyze their concerns about life with an ICD, and the Tilburg Frailty Indicator scale (TFI) was used to diagnose frailty. Results: In the group of patients with an ICD implanted, 73% had recognized frailty (83.3% women, 74.1% men); the average point value was 6.55 ± 2.67. The total ICDC questionnaire score for the patients with an implanted cardioverter defibrillator was 34.06 ± 18.15. Patients with frailty syndrome had statistically (p = 0.039) higher scores (36.14 ± 17.08) compared to robust patients (27.56 ± 20.13). In the logistic regression analysis, the presence of frailty was strongly associated with the total questionnaire score (OR = 1.0265, p = 0.00426), the severity of the concerns (OR = 1.0417, p = 0.00451), and device-specific concerns (OR = 1.0982, p = 0.00424). Conclusion: Frailty syndrome occurs in about 80% of patients after ICD implantation. The presence of frailty syndrome was strongly associated with concerns about an implantable cardioverter defibrillator.

Sex-Based Differences in Presentation, Treatment, and Complications Among Older Adults Hospitalized for Acute Myocardial Infarction: The SILVER-AMI Study

BACKGROUND

Studies of sex-based differences in older adults with acute myocardial infarction (AMI) have yielded mixed results. We, therefore, sought to evaluate sex-based differences in presentation characteristics, treatments, functional impairments, and in-hospital complications in a large, well-characterized population of older adults (≥75 years) hospitalized with AMI.

METHODS AND RESULTS

We analyzed data from participants enrolled in SILVER-AMI (Comprehensive Evaluation of Risk Factors in Older Patients With Acute Myocardial Infarction)-a prospective observational study consisting of 3041 older patients (44% women) hospitalized for AMI. Participants were stratified by AMI subtype (ST-segment-elevation myocardial infarction [STEMI] and non-STEMI [NSTEMI]) and subsequently evaluated for sex-based differences in clinical presentation, functional impairments, management, and in-hospital complications. Among the study sample, women were slightly older than men (NSTEMI: 82.1 versus 81.3, P<0.001; STEMI: 82.2 versus 80.6, P<0.001) and had lower rates of prior coronary disease. Women in the NSTEMI subgroup presented less frequently with chest pain as their primary symptom. Age-associated functional impairments at baseline were more common in women in both AMI subgroups (cognitive impairment, NSTEMI: 20.6% versus 14.3%, P<0.001; STEMI: 20.6% versus 12.4%, P=0.001; activities of daily living disability, NSTEMI: 19.7% versus 11.4%, P<0.001; STEMI: 14.8% versus 6.4%, P<0.001; impaired functional mobility, NSTEMI: 44.5% versus 30.7%, P<0.001; STEMI: 39.4% versus 22.0%, P<0.001). Women with AMI had lower rates of obstructive coronary disease (NSTEMI: P<0.001; STEMI: P=0.02), driven by lower rates of 3-vessel or left main disease than men (STEMI: 38.8% versus 58.7%; STEMI: 24.3% versus 32.1%), and underwent revascularization less commonly (NSTEMI: 55.6% versus 63.6%, P<0.001; STEMI: 87.3% versus 93.3%, P=0.01). Rates of bleeding were higher among women with STEMI (26.2% versus 15.6%, P<0.001) but not NSTEMI (17.8% versus 15.7%, P=0.21). Women had a higher frequency of bleeding following percutaneous coronary intervention with both NSTEMI (11.0% versus 7.8%, P=0.04) and STEMI (22.6% versus 14.8%, P=0.02).

CONCLUSIONS

Among older adults hospitalized with AMI, women had a higher prevalence of age-related functional impairments and, among the STEMI subgroup, a higher incidence of overall bleeding events, which was driven by higher rates of nonmajor bleeding events and bleeding following percutaneous coronary intervention. These differences may have important implications for in-hospital and posthospitalization needs.

Device-measured physical activity data for classification of patients with ventricular arrhythmia events: A pilot investigation

Low levels of physical activity are associated with increased mortality risk, especially in cardiac patients, but most studies are based on self-report. Cardiac implantable electronic devices (CIEDs) offer an opportunity to collect data for longer periods of time. However, there is limited agreement on the best approaches for quantification of activity measures due to the time series nature of the data. We examined physical activity time series data from 235 subjects with CIEDs and at least 365 days of uninterrupted measures. Summary statistics for raw daily physical activity (minutes/day), including statistical moments (e.g., mean, standard deviation, skewness, kurtosis), time series regression coefficients, frequency domain components, and forecasted predicted values, were calculated for each individual, and used to predict occurrence of ventricular tachycardia (VT) events as recorded by the device. In unsupervised analyses using principal component analysis, we found that while certain features tended to cluster near each other, most provided a reasonable spread across activity space without a large degree of redundancy. In supervised analyses, we found several features that were associated with the outcome (P < 0.05) in univariable and multivariable approaches, but few were consistent across models. Using a machine-learning approach in which the data was split into training and testing sets, and models ranging in complexity from simple univariable logistic regression to ensemble decision trees were fit, there was no improvement in classification of risk over naïve methods for any approach. Although standard approaches identified summary features of physical activity data that were correlated with risk of VT, machine-learning approaches found that none of these features provided an improvement in classification. Future studies are needed to explore and validate methods for feature extraction and machine learning in classification of VT risk based on device-measured activity.

Toward Smart Footwear to Track Frailty Phenotypes-Using Propulsion Performance to Determine Frailty

Frailty assessment is dependent on the availability of trained personnel and it is currently limited to clinic and supervised setting. The growing aging population has made it necessary to find phenotypes of frailty that can be measured in an unsupervised setting for translational application in continuous, remote, and in-place monitoring during daily living activity, such as walking. We analyzed gait performance of 161 older adults using a shin-worn inertial sensor to investigate the feasibility of developing a foot-worn sensor to assess frailty. Sensor-derived gait parameters were extracted and modeled to distinguish different frailty stages, including non-frail, pre-frail, and frail, as determined by Fried Criteria. An artificial neural network model was implemented to evaluate the accuracy of an algorithm using a proposed set of gait parameters in predicting frailty stages. Changes in discriminating power was compared between sensor data extracted from the left and right shin sensor. The aim was to investigate the feasibility of developing a foot-worn sensor to assess frailty. The results yielded a highly accurate model in predicting frailty stages, irrespective of sensor location. The independent predictors of frailty stages were propulsion duration and acceleration, heel-off and toe-off speed, mid stance and mid swing speed, and speed norm. The proposed model enables discriminating different frailty stages with area under curve ranging between 83.2–95.8%. Furthermore, results from the neural network suggest the potential of developing a single-shin worn sensor that would be ideal for unsupervised application and footwear integration for continuous monitoring during walking.

Measuring Physical Activity With Implanted Cardiac Devices: A Systematic Review

Background

Physical activity is predictive of cardiovascular outcomes in patients with cardiovascular implantable electronic devices, yet it is not regularly assessed in routine care. Current‐generation cardiovascular implantable electronic devices, however, continuously monitor patient activity through a built‐in accelerometer, which provides new opportunities to remotely assess patient activity, detect changes in clinical status, and incorporate these data in risk stratification models. This review critically examines the literature on device‐measured physical activity (D‐PA), with a focus on identifying methodological issues that may affect interpretation of study results.

Methods and Results

We conducted a systematic review of D‐PA studies published from January 1 1995 to December 30 2017, identifying 29 studies meeting inclusion criteria, 5 of which were validation reports. Few technical details about D‐PA sensors are reported, and procedures for analyzing and interpreting D‐PA data are heterogeneous. Trends in D‐PA over time and associations with clinical outcomes were reported by 22 studies, and in 7 studies, D‐PA was combined with other device parameters in risk stratification models, demonstrating modest‐to‐good sensitivity in predicting acute heart failure decompensation, hospitalization, and mortality.

Conclusions

Current evidence suggests that D‐PA may be useful for assessing physical activity and predicting clinical outcomes in patients with cardiovascular implantable electronic devices when combined with other device parameters. Future work must address challenges related to D‐PA data measurement, interpretation, and generalizability to support expanded clinical applications of this technology.

Training with an Electric Exercise Bike versus a Conventional Exercise Bike during Hemodialysis for Patients with End-stage Renal Disease: A Randomized Clinical Trial

Objective

Hemodialysis (HD) patients have lower fitness levels than healthy subjects because of various structural, metabolic, and functional abnormalities secondary to uremic changes in skeletal muscles. Aerobic and resistance exercises are beneficial in improving not only physical function, including maximal oxygen uptake and muscle strength, but also anthropometrics, nutritional status, and hematologic indices. The use of electric ergometers that place light loads on patients has been implemented at many dialysis facilities in Japan. However, reports comparing the effects on body function of electric and variable-load ergometers are few. This study aimed to compare electric ergometers and variable-load ergometers in terms of exercise outcomes in HD patients.

Methods

A total of 15 ambulatory HD patients were randomly divided into two groups: the variable-load ergometer group (n=8) and the electric ergometer group (n=7). HD patients exercised at a level based on their physical function three times a week for 12 weeks.

Results

After the 12-week intervention period, only the variable-load ergometer group experienced significant increases in lower extremity muscle strength and exercise tolerance.

Conclusion

This study confirmed that conventional aerobic training and electric bike exercise during HD were efficacious and safe without causing sudden hypotension or any other side effects. However, exercise using a variable-load ergometer may be more effective than exercise using an electric bike in improving the physical function of HD patients. Exercise using a variable-load ergometer elicited specific whole-body and local effects.