Improving walking speed reduces hospitalization costs in outpatients with cardiovascular disease. An analysis based on a multistrata non-parametric test

Change in Peak Oxygen Uptake Predicted by the Moderate 1-km Treadmill Walking Test After Walking Training in Outpatients With Cardiovascular Disease

PURPOSE

The purpose of this study was to determine the ability of the moderate 1-km treadmill walking test (1km-TWT) to predict changes in peak oxygen uptake (V˙O 2peak ) in patients with stable cardiovascular disease (CVD) during an exercise-based secondary prevention program.

METHODS

Sixty-four male outpatients with stable CVD (age 64 [41-85] yr) performed the 1km-TWT before and after an 8-wk walking training program. Patient V˙O 2peak was estimated using a sex-specific equation including age, body mass index, 1km-TWT performance time, and heart rate (V˙O 2peakEST ). Forty-one patients completed a maximal cardiopulmonary treadmill test (CPX) for direct V˙O 2peak determination (V˙O 2peakMEAS ). The training prescription consisted of moderate-to-high intensity supervised walking for 30-40 min/session, and an additional 2-4 times/wk of unsupervised home moderate walking sessions between 20-60 min at the end of the program. The walking intensity was based on the results of the 1km-TWT.

RESULTS

Patients participated in an average of 14 of the 16 supervised sessions. An overall significant improvement in V˙O 2peakMEAS and weekly recreational physical activity levels were observed. No differences were observed between V˙O 2peakMEAS and V˙O 2peakEST . Compared with CPX results, the 1km-TWT underestimated the V˙O 2peak increase after the exercise intervention (mean difference -0.3 mL/kg/min, P > .05).

CONCLUSIONS

The 1km-TWT provides a reasonably accurate and simple tool to predict changes in V˙O 2peak due to moderate walking training in male outpatients with CVD. These findings contribute to the growing body of evidence supporting the use of the 1km-TWT for exercise testing and training purposes in the context of cardiac rehabilitation/secondary prevention programs.

The value of walking: a systematic review on mobility and healthcare costs

BACKGROUND

The ability to walk is an important indicator of general health and mobility deficits have wide-ranging economic implications. We undertook a systematic review to elucidate the impact of walking parameters on health care costs.  METHODS: Publications reporting on associations between health care costs and walking parameters were identified by a systematic literature search in MEDLINE, Embase, and manual reference screening, following the PRISMA reporting guidelines. First, titles and abstracts were screened by two independent reviewers followed by a review of the full articles if they met the inclusion criteria. Costs were converted to US-Dollars with inflation adjustment for 2021. A narrative synthesis was performed.  RESULTS: Ten studies conducted between 2001 and 2021 fulfilled the inclusion criteria. Assessment of walking ability was carried out via patient reported outcomes, performance tests, or using wearable digital devices. Walking more than one hour per day, a faster walking speed and the ability to walk without impairments are associated with significant lower health care costs. A higher number of steps per day is associated with significant lower costs in two simulation studies, while in the study using a digital device, taking more than 10,000 steps per day is not significantly associated with lower direct costs. The heterogeneity of mobility assessments and of economic analyses both precluded a quantitative synthesis.

CONCLUSION

Cross-sectional and observational studies from this systematic review suggest a significant association of better walking performance with lower health care costs. Future health economic research and health technology assessments should use quantifiable mobility outcomes when evaluating new drugs or non-pharmacological interventions.

Pattern Changes in the Heart Rate Variability of Patients Undergoing Coronary Artery Bypass Grafting Surgery

Introduction

Coronary artery bypass grafting (CABG) with extracorporeal circulation is a key therapy for coronary artery disease (CAD). However, cardiovascular events and cardiac arrhythmias may still occur in these patients following surgery. Many studies have demonstrated a correlation between cardiac arrhythmias and heart rate variability (HRV). This study aimed to establish the temporal change pattern of HRV observed following CABG.

Methods

A prospective method was used to study 119 consecutive patients with stable CAD who were assessed using 24-hour Holter recordings 2 days before CABG and 1 week, 3 months, and 6 months after the surgery at Hanoi Heart Hospital from June 2016 to August 2018. Main results: All the time-domain and frequency-domain parameters of HRV decreased precipitately after CABG and were mostly recovered 3 months postoperatively. The percentage of decreased HRV before surgery was 28.6% and 51.8% after 7 days, 19.6% after 3 months, and 12.7% after 6 months. ASDNN and SDNN before and after surgery had the highest rates of change.

Conclusion

The early decrease in HRV observed 7 days after CABG may be related to the acute effects of the surgery. The recovery of HRV at 3 months after surgery, regardless of the preoperative state of the patients, implies that the autonomic nervous system (ANS) disorder may be improved at this time. At 6 months after surgery, the autonomic nervous injury was recovered in combination with improvement of reperfusion, resulting in improvement in almost all HRV indices compared with those indices preoperatively.