Activity Monitoring in Heart Failure Patients With Cardiac Resynchronization Therapy

Abstract

xercise intolerance is a hallmark of heart failure (HF) and is predictive of all-cause mortality and hospitalizations. 1,2 Discouraging a sedentary lifestyle and promoting physical activity have both been shown to improve functional capacity, quality of life, and clinical outcome. 3,4 Cardiac resynchronization therapy (CRT) restores the cardiac electro-mechanical synchrony, leading to improved pumping function in HF patients with ventricular conduction disturbances. Consequently, CRT is able to increase functional capacity, exercise tolerance, 5,6 and aerobic capacity, 7 to delay the onset of anaerobic metabolism, 5 and to decrease the sympathetic drive of the heart. 8 All these effects have been reported mainly in CRT patients with sinus rhythm (SR) within a few months after device implantation. 5,6 Long-term exercise data in HF patients treated with CRT are limited. Furthermore, etiology-, rhythm-, diabetes-, and age-related differences in the improvement in functionCirculation Journal Vol.71, December 2007 al capacity after CRT have not yet been fully evaluated.The 6-min walking test is frequently used to assess submaximal exercise capacity in HF patients treated with CRT. 5,9 However, the distance walked is influenced by several factors, including patient motivation, coaching, anatomical limitations, and physical training. Furthermore, in HF patients variability in the distance walked between 2 subsequent tests is frequently observed. 10 In contrast, symptom-limited exercise testing, eventually combined with an assessment of oxygen consumption, is influenced by familiarity with the test and may not reflect the patient's spontaneous daily physical activity, plus its routine determination is costly and time-consuming.Recent technological advances have made device-based monitoring of physical activity possible using data collected through the device's sensors. 11 Short-term, continuous, device-based monitoring of physical activity has proven to be feasible, although in a limited number of patients to date. 12 Because each device uses proprietary technology and analysis algorithms, the results obtained with 1 device may not be entirely applicable to other devices. Finally, whether this monitoring remains of value over the long term and in different subgroups of HF patients is unknown. It has been shown that the Activity Log Index (ALI), which quantifies body movement based on data derived from accelerometers built into the device, reliably tracks changes in the daily, spontaneous physical activity of patients with advanced HF. In addition, the ALI is well correlated with the distance walked within 6 min. 11 The aim of this study was to prospectively investigate the validity of long-term device-based monitoring of physical activity in advanced HF patients treated with CRT. Further- Activity Monitoring in Heart Failure Patients With Cardiac Resynchronization TherapyMihoko Kawabata, MD, PhD ‡, *; Cecilia Fantoni, MD* , **; Francois Regoli, MD*; Santi Raffa, MD*; Francesca Pastori, MD*; Simona Fratini, MD, Ph...

Measuring Physical Activity With Implanted Cardiac Devices: A Systematic Review

“…As expected, D‐PA was lowest immediately after device implantation and increased substantially over the next 90 days . After 90 days, some studies showed that activity levels remained stable, whereas other studies described a continued increase in D‐PA for up to 6 months after implantation . Interpretation of these findings is complicated by the variation in how and when baseline activity was determined.…”

“…D‐PA data are increasingly being used to understand patterns of activity engagement after ICD implantation; however, investigators have varied in the approach taken to calculate the baseline level of D‐PA, making it difficult to compare findings across studies. In some studies, baseline is defined as average activity over a period of several days, 1 to 2 weeks after CIED implantation, to account for procedural recovery time; in other studies, baseline is defined as average activity over 7 to 30 days, 1 to 2 months after implantation . Despite this variation in approach, D‐PA at baseline is consistently low across studies (<3 hours of total activity per day), regardless of device manufacturer or sample characteristics .…”

Accelerometer-Measured Daily Activity in Heart Failure With Preserved Ejection Fraction

“…Prior studies of accelerometer assessed activity in HF have been largely restricted to patients with HF and reduced EF (HFrEF) but have demonstrated correlations between variously quantitated accelerometer data and NYHA (14), 6MWD(12, 14), peak oxygen consumption (14, 15), estimated (Seattle Heart Failure Model) or observed mortality risks(16, 17), non-HF specific QOL questionnaires(18), therapeutic response to cardiac resynchronization(19, 20) and changes in clinical status(17, 21). Our findings document that accelerometer assessed activity is similarly associated with HF functional measures in HFpEF.…”

Nitrate’s Effect on Activity Tolerance in Heart Failure With Preserved Ejection Fraction Trial

“…Studies have also shown increases in accelerometer-assessed activity after cardiac resynchronization therapy, confirming its ability to reflect therapeutic response 41, 46, 47 . Validity, analytical issues, and compliance with externally worn accelerometer devices have been addressed in clinical trials for patients with COPD, among whom age and activity level are likely comparable to elderly patients with HFpEF 48–51 .…”