Validity and reliability of a wearable blood flow restriction training device for arterial occlusion pressure assessment

Purpose

The blood flow restriction (BFR) training is an effective approach to promoting muscle strength, muscle hypertrophy, and regulating the peripheral vascular system. It is recommended to use to the percentage of individual arterial occlusion pressure (AOP) to ensure safety and effectiveness. The gold standard method for assessing arterial occlusive disease is typically measured using Doppler ultrasound. However, its high cost and limited accessibility restrict its use in clinical and practical applications. A novel wearable BFR training device (Airbands) with automatic AOP assessment provides an alternative solution. This study aims to examine the reliability and validity of the wearable BFR training device.

Methods

Ninety-two participants (46 female and 46 male) were recruited for this study. Participants were positioned in the supine position with the wearable BFR training device placed on the proximal portion of the right thigh. AOP was measured automatically by the software program and manually by gradually increasing the pressure until the pulse was no longer detected by color Doppler ultrasound, respectively. Validity, inter-rater reliability, and test-retest reliability were assessed by intraclass correlation coefficients (ICC) and Bland-Altman analysis.

Results

The wearable BFR training device demonstrated good validity (ICC = 0.85, mean difference = 4.1 ± 13.8 mmHg [95% CI: -23.0 to 31.2]), excellent inter-rater reliability (ICC = 0.97, mean difference = -1.4 ± 6.7 mmHg [95% CI: -14.4 to 11.7]), and excellent test-retest reliability (ICC = 0.94, mean difference = 0.6 ± 8.6 mmHg [95% CI: -16.3 to 17.5]) for the assessment of AOP. These results were robust in both male and female subgroups.

Conclusion

The wearable BFR training device can be used as a valid and reliable tool to assess the AOP of the lower limb in the supine position during BFR training.

Effect of supervised exercise training on cardiovascular function in patients with intermittent claudication: a systematic review and meta-analysis of randomized controlled trials

This study aimed to determine the effect of supervised exercise training (SET) on cardiovascular function in patients with intermittent claudication (IC). A systematic search in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases was conducted. Primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), rate pressure product (RPP), cardiac output (CO), peak oxygen consumption (VO2peak), and heart rate variability (HRV). Secondary outcomes were maximum walking distance (MWD) and pain-free walking distance (PFWD). Outcomes were reported as weighted mean difference (WMD) between the SET group and the control group and synthesized by using the random-effects model. Seventeen RCTs with a total of 936 patients were included in this review. SET resulted in significant improvements of SBP (WMD =  - 7.40, 95% CI - 10.69 ~  - 4.11, p < 0.001, I2 = 15.2%), DBP (WMD =  - 1.92, 95% CI - 3.82 ~  - 0.02, p = 0.048, I2 = 0.0%), HR (WMD =  - 3.38, 95% CI - 6.30 ~  - 0.46, p = 0.023, I2 = 0.0%), RPP (WMD =  - 1072.82, 95% CI - 1977.05 ~  - 168.59, p = 0.020, I2 = 42.7%), and VO2peak with plantar flexion ergometer exercise (WMD = 5.57, 95% CI 1.66 ~ 9.49, p = 0.005, I2 = 62.4%), whereas CO and HRV remained statistically unaltered. SET also improved MWD (WMD = 139.04, 95% CI 48.64 ~ 229.44, p = 0.003, I2 = 79.3%) and PFWD (WMD = 40.02, 95% CI 23.85 ~ 56.18, p < 0.001, I2 = 0.0%). In conclusion, SET is effective in improving cardiovascular function in patients with IC, which was confirmed on outcomes of cardiovascular function associated with exercise ability. The findings hold out that the standard therapy of SET can improve not only walking distance but also cardiovascular function in patients with IC.

Effects of exercise training on heart rate variability in individuals with lower extremity arterial disease and claudication: A systematic review

PURPOSE

To perform a systematic review of studies assessing the effects of regular exercise on heart rate variability (HRV) in individuals with lower extremity arterial disease (LEAD) and symptoms of claudication.

METHODS

A systematic search in the electronic databases MEDLINE, Embase, and Scielo, was conducted and updated on January 21, 2023. Randomized clinical trials investigating patients with LEAD and IC, assessing ≥ 4 wk of exercise interventions, and reporting at least one HRV measure (e.g., time or frequency domains) at baseline and follow-up were included. Two reviewers independently screened studies for inclusion, performed data extraction, and quality assessment of included studies.

RESULTS

Data from 7 trials were included (i.e., 5 walking, 1 resistance, and 1 isometric handgrip training), totaling 327 patients (66% males; range: 61 - 68 yr; ankle brachial index: 0.4 - 0.7). Following exercise training, three studies investigating walking training reported an increase in parasympathetic modulation indices and/or a decrease in sympathetic modulation indices (n = 2) as well as an increase in non-linear indices (n = 1).

CONCLUSION

The current evidence is weak, and larger randomized controlled trials are needed to confirm the efficacy of exercise training in improving HRV. Additionally, the high divergence in the methodology of studies indicated the need for standard tools to improve the quality of HRV measurements in exercise trials. It is recommended to use standard procedures in future trials investigating HRV.

Long-Term Physical Activity Effectively Reduces the Consumption of Antihypertensive Drugs: A Randomized Controlled Trial

BACKGROUND

Although physical activity (PA) has been shown to enhance hypertension control, the impact of exercise on the potential decrease of the use of antihypertensive medications remains inadequately researched.

AIM

The aim was to assess the impact of a two-year PA on the medication requirements of individuals with hypertension.

METHODS

A clinical trial was conducted, involving 130 participants with essential hypertension who took at least one antihypertensive medication. Participants were randomly assigned to either a control group (CG n = 65) or an experimental group (EG n = 65) that underwent a 24-month supervised PA program based on a combination of aerobic and resistance training. The antihypertensive drug load for each participant was determined by adding the ratios of the prescribed daily dose (PDD) to the defined daily dose (DDD) for all antihypertensive medications taken by the participants. The outcome measures were evaluated at 0, 6, 12, 18, and 24 months.

RESULTS

A total of 76 participants completed the 24-month assessment, and RM-ANOVA revealed a significantly lower antihypertensive drug load in the EG compared to the CG at 18 (p < 0.017) and 24 months (p < 0.003).

CONCLUSION

A long-term PA program can decrease the antihypertensive drug load in older adults with essential hypertension. The trend of improvement regarding the EG drug load intake and the trend of CG drug load increase, although not significant over time, results in a significant difference between the groups at 18 months and an even greater difference at 24 months. This trend certifies the protective value of PA against the aging process and its related health risk factors.

Inequity in exercise-based interventions for adults with intermittent claudication due to peripheral arterial disease: a systematic review

PURPOSE

To determine the equity in access to trials of exercise interventions for adults with intermittent claudication due to peripheral arterial disease.

METHODS

Systematic electronic database searches of MEDLINE, Embase, CINAHL, Cochrane Central Register of Controlled Clinical Trials, PEDRO, Opengrey, ISRCTN and ClinincalTrials.gov for randomised controlled trials of exercise interventions for adults with intermittent claudication were conducted. Data extraction was informed by Cochrane's PROGRESS-Plus framework.

RESULTS

Searches identified 6412 records. Following the screening of 262 full texts, 49 trials including 3695 participants were included. All trials excluded potential participants on at least one equity factor. This comprised place of residence, language, sex, personal characteristics (e.g., age and disability), features of relationships (e.g., familial risk factors) and time-dependent factors, (e.g., time since revascularisation). Overall, 1839 of 7567 potential participants (24.3%) were excluded based on equity factors. Disability was the most frequently reported factor for exclusions.

CONCLUSION

Trialists endeavour to enrol a representative sample in exercise trials whilst preserving the safety profile of the intervention. This review highlights that these efforts can inadvertently lead to inequities in access as all trials excluded potential participants on at least one equity factor. Future exercise trials should optimise participation to maximise generalisability of findings. PROSPERO registration no. CRD42020189965.Implications for rehabilitationEquity factors influence health opportunities and outcomes.All trials of exercise for people with intermittent claudication excluded adults on at least one equity factor.Disability was the predominant factor for exclusions from trials.Trials should optimise participation to maximise generalisability of results as these findings are used to inform treatment and service design.

Cardiac Rehabilitation in Patients with Peripheral Artery Disease-A Literature Review in COVID-19 Era

Cardiac rehabilitation (CR) is an integral part of the management of various cardiovascular disease such as coronary artery disease (CAD), peripheral artery disease (PAD), or chronic heart failure (CHF), with proven morbidity and mortality benefits. This article aims to review and summarize the scientific literature related to cardiac rehabilitation programs for patients with PAD and how they were adapted during the COVID-19 pandemic. The implementation of CR programs has been problematic since the COVID-19 pandemic due to social distancing and work-related restrictions. One of the main challenges for physicians and health systems alike has been the management of PAD patients. COVID-19 predisposes to coagulation disorders that can lead to severe thrombotic events. Home-based walking exercises are more accessible and easier to accept than supervised exercise programs. Cycling or other forms of exercise are more entertaining or challenging alternatives to exercise therapy. Besides treadmill exercises, upper- and lower-extremity ergometry also has great functional benefits, especially regarding walking endurance. Supervised exercise therapy has a positive impact on both functional capacity and also on the quality of life of such patients. The most effective manner to acquire this seems to be by combining revascularization therapy and supervised exercise. Rehabilitation programs proved to be a mandatory part of the integrative approach in these cases, increasing quality of life, and decreasing stress levels, depression, and anxiety.

Walking Training Improves Ambulatory Blood Pressure Variability in Claudication

Fundamento:

O treinamento de caminhada (TC) melhora a capacidade de caminhar e reduz a pressão arterial (PA) clínica em pacientes com doença arterial periférica (DAP), mas seus efeitos na PA ambulatorial permanecem desconhecidos.

Objetivo:

Investigar o efeito de 12 semanas de TC na PA ambulatorial e sua variabilidade em pacientes com DAP.

Métodos:

Trinta e cinco pacientes do sexo masculino com DAP e sintomas de claudicação foram alocados aleatoriamente em dois grupos: controle (n = 16, 30 min de alongamento) e TC (n = 19, 15 séries de 2 minutos de caminhada na frequência cardíaca em que ocorreu limiar de dor intercalados por 2 minutos de repouso em pé). Antes e depois de 12 semanas, a PA ambulatorial de 24 horas foi avaliada. Os índices de variabilidade da PA ambulatorial avaliados em ambos os momentos incluíram o desvio-padrão de 24 horas (DP₂₄), o desvio-padrão ponderado de vigília e sono (DP_vs) e a variabilidade real média de 24 horas (VRM₂₄). Os dados foram analisados por ANOVAs mistas de dois fatores, considerando significativo P<0,05.

Resultados:

Após 12 semanas, nenhum dos grupos apresentou alterações na PA de 24 horas, vigília e sono. O TC diminuiu as variabilidades da PA sistólica e média (PA sistólica – 13,3 ± 2,8 vs 11,8 ± 2,3; 12,1 ± 2,84 vs 10,7 ± 2,5; e 9,4 ± 2,3 vs 8,8 ± 2,2 mmHg; PA média – 11,0 ± 1,7 vs 10,4 ± 1,9; 10,1 ± 1,6 vs 9,1 ± 1,7; e 8,0 ± 1,7 vs 7,2 ± 1,5 mmHg para DP₂₄, DPvs e VRM₂₄, respectivamente). Nenhum dos grupos apresentou mudanças significantesnos índices de variabilidade da PA diastólica após 12 semanas.

Conclusões:

O TC não altera os níveis ambulatoriais da PA, mas diminui a sua variabilidade em pacientes com DAP. Essa melhora pode ter um impacto favorável no risco cardiovascular de pacientes com DAP sintomática. (Arq Bras Cardiol. 2021; 116(5):898-905)

Supervised Resistance Training on Functional Capacity, Muscle Strength and Vascular Function in Peripheral Artery Disease: An Updated Systematic Review and Meta-Analysis

Supervised resistance training appears to be a promising alternative exercise modality to supervised walking in patients with peripheral artery disease (PAD). This meta-analysis examined the efficacy of supervised RT for improving walking capacity, and whether adaptations occur at the vascular and/or skeletal muscle level in PAD patients. We searched Medline, CINAHL, Scopus, and Cochrane Central Register of Controlled Trials databases for randomized controlled trials (RCTs) in PAD patients testing the effects of supervised RT for ≥4 wk. on walking capacity, vascular function, and muscle strength. Pooled effect estimates were calculated and evaluated using conventional meta-analytic procedures. Six RCTs compared supervised RT to standard care. Overall, supervised RT prolonged claudication onset distance during a 6-min walk test (6-MWT) (101.7 m (59.6, 143.8), p < 0.001) and improved total walking distance during graded treadmill walking (SMD: 0.67 (0.33, 1.01), p < 0.001) and the 6-MWT (49.4 m (3.1, 95.6), p = 0.04). Five RCTS compared supervised RT and supervised intermittent walking, where the differences in functional capacity between the two exercise modalities appear to depend on the intensity of the exercise program. The insufficient evidence on the effects of RT on vascular function and muscle strength permitted only limited exploration. We conclude that RT is effective in prolonging walking performance in PAD patients. Whether RT exerts its influence on functional capacity by promoting blood flow and/or enhancing skeletal muscle strength remains unclear.

Use of low volume, high effort resistance training to manage blood pressure in hypertensive patients inside a public hospital: a proof of concept study

Physical exercise has been shown to have an important role in the prevention and treatment of arterial hypertension. However, the general exercise recommendations are time consuming, which might be detrimental to exercise adoption. Based on this, minimal doses of exercise have been suggested as an alternative approach and this report investigates the feasibility and effects of low volume and high effort resistance training for hypertensive patients in a hospital setting. This is a pilot non-randomized prospective study where 15 sedentary hypertensive patients (11 women and 4 men) performed 24 resistance training sessions over 12 weeks at a public hospital. The resistance training sessions consisted of two sets of four exercises, with a rest interval of two minutes between sets. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured 10 minutes before and 10 minutes after each training. No injuries or intercurrence were reported during the study. SBP decreased significantly when compared the first and last sessions, when the measures were performed at rest (152 ± 16 mmHg vs. 122 ± 9 mmHg vs, p<0.05), and after (137 ± 13 mmHg vs. 115 ± 5 mmHg, p<0.05) the resistance training session. Similarly, DBP also decreased significantly when the values from the last session were compared with the first session, when measured at rest (83 ± 14 mmHg vs 73 ± 9 mmHg, p<0.05). Low volume and high effort resistance training seems to be a feasible non-pharmacological strategy to help controlling blood pressure in hypertensive patients within a hospital.

Use of low volume, high effort resistance training to manage blood pressure in hypertensive patients inside a public hospital: a proof of concept study

Physical exercise has been shown to have an important role in the prevention and treatment of arterial hypertension. However, the general exercise recommendations are time consuming, which might be detrimental to exercise adoption. Based on this, minimal doses of exercise have been suggested as an alternative approach and this report investigates the feasibility and effects of low volume and high effort resistance training for hypertensive patients in a hospital setting. This is a pilot non-randomized prospective study where 15 sedentary hypertensive patients (11 women and 4 men) performed 24 resistance training sessions over 12 weeks at a public hospital. The resistance training sessions consisted of two sets of four exercises, with a rest interval of two minutes between sets. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured 10 minutes before and 10 minutes after each training. No injuries or intercurrence were reported during the study. SBP decreased significantly when compared the first and last sessions, when the measures were performed at rest (152 ± 16 mmHg vs. 122 ± 9 mmHg vs, p<0.05), and after (137 ± 13 mmHg vs. 115 ± 5 mmHg, p<0.05) the resistance training session. Similarly, DBP also decreased significantly when the values from the last session were compared with the first session, when measured at rest (83 ± 14 mmHg vs 73 ± 9 mmHg, p<0.05). Low volume and high effort resistance training seems to be a feasible non-pharmacological strategy to help controlling blood pressure in hypertensive patients within a hospital.

Cardiovascular Acute Effects of Traditional vs. Paired Set Resistance Training in Patients With Liver Cirrhosis

Purpose: This study compared the acute effects of two different resistance training methods on heart rate variability, blood pressure, and rating of perceived exertion in patients with liver cirrhosis. Methods: Ten patients with Child-Pugh A (seven women and three men) participated in two experimental sessions, in random order: The traditional set condition consisted of three sets of six exercises performed in a sequential manner, while the paired set condition consisted of alternating sets between two exercises (three pairs of exercises). Ten repetitions were performed for each set with 70% of a 10 repetition maximum load and with 2 min rest between sets. Blood pressure and heart rate variability were assessed pre-workout and for 60 min post-workout. The rating of perceived exertion was assessed at the end of the third set for each exercise. Results: Significant alterations in heart rate variability were observed when considering the lowest value obtained during recovery, in which the SDNN was reduced in both the traditional set and paired set conditions, as well as the root mean square of standard deviation for the traditional set condition (p < .05). Additionally, for the paired set condition, there was a significant reduction in the HFnu band and a significant increase in the LFnu band (p < .05). Effect size showed reductions in diastolic and mean blood pressure until 30 min in a small magnitude for traditional sets. Conclusion: Similar cardiovascular responses were observed between methods eliciting normal physiological responses within safe limits for patients with liver cirrhosis.

Effects of Isometric Handgrip Training in Patients With Peripheral Artery Disease: A Randomized Controlled Trial

Background Meta-analyses have shown that isometric handgrip training (IHT) can reduce brachial systolic and diastolic blood pressure (BP) by >6/4 mm Hg, respectively. However, whether IHT promotes these effects among patients with peripheral artery disease, who exhibit severe impairment in cardiovascular function, is currently unknown. This study aimed to evaluate the effects of IHT on the cardiovascular function of patients with peripheral artery disease. Methods and Results A randomized controlled trial with peripheral artery disease patients assigned to either the IHT or control group was conducted. The IHT group performed 3 sessions per week, for 8 weeks, of unilateral handgrip exercises, consisting of 4 sets of isometric contractions for 2 minutes at 30% of maximum voluntary contraction and a 4-minute interval between sets. The control group received a compression ball in order to minimize the placebo effects, representing sham training. The primary outcome was brachial BP. The secondary outcomes were central BP, arterial stiffness parameters, cardiac autonomic modulation, and vascular function. The IHT program reduced diastolic BP (75 [10] mm Hg preintervention versus 72 [11] mm Hg postintervention), with no change in the control group (74 [11] mm Hg preintervention versus 74 [11] mm Hg postintervention), with this between-group difference being significant (P=0.04). Flow-mediated dilation improved in the IHT group (6.0% [5.7] preintervention versus 9.7% [5.5] postintervention), with no change in the control group (7.6% [5.5] preintervention versus 7.4% [5.1] postintervention), with this between-group difference being significant (P=0.04). There was no change in other measured variables over the intervention period. Conclusions IHT reduced brachial diastolic BP and improved local vascular function in patients with peripheral artery disease. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02742220.

Cardiac Autonomic Modulation Is Associated with Arterial Stiffness in Patients with Symptomatic Peripheral Artery Disease

BACKGROUND

The objective of this study was to analyze the association between cardiac autonomic modulation and arterial stiffness in patients with peripheral artery disease (PAD).

METHODS

This cross-sectional study included one hundred fourteen patients with symptomatic PAD (67.5% men; 65 ± 7 years; body mass index: 26.8 ± 4.5 kg/m²). Heart rate variability (HRV) was measured within time (standard deviation of all RR intervals [beat to beat heart interval] [SDNN], root mean square of the successive differences between adjacent normal RR intervals [RMSSD], and the proportion of successive RR intervals that differed by more than 50 msec [pNN50]) and frequency (low frequency [LF] and high frequency [HF]) domains. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV). Crude and adjusted linear regression analyses examined the relationship between HRV and cfPWV.

RESULTS

Nonsignificant crude associations were identified among cfPWV and RMSSD (P = 0.181), SDNN (P = 0.105), pNN50 (P = 0.087), LF (P = 0.376), HF (P = 0.175), and LF/HF ratio (P = 0.426). After adjustments for age, sex, smoking, body mass index, ankle-brachial index, and use of beta-blockers, significant associations were identified among cfPWV and RMSSD (P = 0.037), SDNN (P = 0.049), and pNN50 (P = 0.049).

CONCLUSIONS

Cardiac autonomic modulation was significantly associated with arterial stiffness in patients with PAD after adjustment for confounding factors. This relationship may contribute to the enhanced cardiovascular disease risk for PAD patients and provides a target for strategies to improve patient clinical outcomes.

The Impact of Supervised Exercise Training on Traditional Cardiovascular Risk Factors in Patients With Intermittent Claudication: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with intermittent claudication (IC) are at increased risk of cardiovascular (CV) morbidity and mortality. Whereas extensive evidence supports the beneficial effects of supervised exercise training (SET) on walking capacity, little is known about the effect of SET on the CV risk profile of IC patients. Therefore, the aim was to evaluate the effects of SET on CV risk factors in IC patients by using meta-analysis techniques.

METHODS

A systematic search in the electronic databases MEDLINE, EMBASE, CINAHL, and CENTRAL was conducted from the earliest date available until October 2, 2018. Randomised and non-randomised controlled trials lasting ≥ four weeks and investigating the effect of SET on CV risk factors in IC patients were included. Traditional CV risk factors were studied as primary outcomes; pain free walking distance (PFWD) and maximum walking distance (MWD) were included as secondary outcomes. Data were pooled using random effects models with summary data reported as weighted means and 95% confidence interval (CIs).

RESULTS

Fifteen trials were included, involving 18 study groups (nine walking, four resistance, two aerobic training, and three combined groups), totalling 725 patients (mean age 66.3 years; mean ankle brachial index, 0.64). Exercise reduced systolic blood pressure (-5.8 mmHg; CI -9.89 to 1.67, p < .01) whereas all other CV risk factors (i.e., body weight, body mass index, diastolic blood pressure, and blood lipids) remained statistically unaltered. Exercise also improved PFWD (+132 m; CI 70-194, p < .001) and MWD (+183 m; CI 98-268, p < .001).

CONCLUSION

This meta-analysis supports the beneficial effects of SET on walking capacity. Little evidence for an improvement of the CV risk profile was found following exercise in patients with IC. However, given the scarcity of data, high quality RCTs that include an assessment of CV risk factors are urgently required to determine the effect of exercise therapy in the secondary prevention of CV disease of IC patients.