The 10m incremental shuttle walk test is a highly reliable field exercise test for patients referred to cardiac rehabilitation: a retest reliability study

Comparison of physiological responses after incremental shuttle walking test and 6-minute walk test in patients with systemic sclerosis

BACKGROUND

The 6‑minute walk test (6MWT) is a commonly used to evaluate exercise capacity in patients with systemic sclerosis (SSc), but there was no study using the incremental shuttle walking test (ISWT) for assessing exercise capacity and comparing the patient's cardiorespiratory responses to these tests. The aim was to investigate the usability and determinants of the ISWT in patients with SSc and compare the physiological responses after the ISWT and 6MWT.

METHODS

A total of thirty four female patients with SSc were included. Dyspnea during daily activities and knee extensor muscle strength was assessed, skin fibrosis and disease severity were recorded, and 6MWT and ISWT were carried out for the exercise capacity measurement. Pulmonary function test results were recorded from the individuals' medical records for SSc with interstitial lung disease (SSc-ILD) patients.

RESULTS

The ISWT distance was significantly correlated with the 6MWT distance (p < 0.001). The 6MWT was correlated with age, modified Rodnan skin score, Medsger severity score, modified British Medical Research Council Questionnaire (mMRC) score, and knee extensor muscle strength (p < 0.05). The 6MWT was correlated with the forced expiratory volume in the first second (FEV1) (lt) and forced vital capacity (FVC) (lt) in patients with SSc-ILD (p < 0.05). The ISWT distance was correlated with age, modified Rodnan skin score, mMRC score, and knee extensor muscle strength (p < 0.05). Age, mMRC, and knee extensor muscle strength explained 33.8% of the variance in 6MWT distance, while age, mMRC, and knee extensor muscle strength explained 51.7% of the variance in the ISWT distance.

CONCLUSION

Because of the higher cardiopulmonary responses, and having a more standardized procedure, the ISWT may be preferable for investigating symptom-limited exercise capacity in patients with SSc. Age, dyspnea, and knee extensor muscle strength were the determinants of exercise capacity in patients with SSc.

Barriers and Facilitators to Delivering Inpatient Cardiac Rehabilitation: A Scoping Review

Objective

The purpose of this scoping review was to summarize the literature on barriers and facilitators that influence the provision and uptake of inpatient cardiac rehabilitation (ICR).

Methods

A literature search was conducted using PsycINFO, MEDLINE, EMBASE, CINAHL and AgeLine. Studies were included if they were published in English after the year 2000 and focused on adults who were receiving some form of ICR (eg, exercise counselling and training, education for heart-healthy living). For studies meeting inclusion criteria, descriptive data on authors, year, study design, and intervention type were extracted.

Results

The literature search resulted in a total of 44,331 publications, of which 229 studies met inclusion criteria. ICR programs vary drastically and often focus on promoting physical exercises and patient education. Barriers and facilitators were categorized through patient, provider and system level factors. Individual characteristics and provider knowledge and efficacy were categorized as both barriers and facilitators to ICR delivery and uptake. Team functioning, lack of resources, program coordination, and inconsistencies in evaluation acted as key barriers to ICR delivery and uptake. Key facilitators that influence ICR implementation and engagement include accreditation and professional associations and patient and family-centred practices.

Conclusion

ICR programs can be highly effective at improving health outcomes for those living with CVDs. Our review identified several patient, provider, and system-level considerations that act as barriers and facilitators to ICR delivery and uptake. Future research should explore how to encourage health promotion knowledge amongst ICR staff and patients.

Relationships of Walking and non-Walking Physical Activities in Daily Life with Cognitive Function and Physical Characteristics in Male Patients with Mild Chronic Obstructive Pulmonary Disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is accompanied by dyspnea on exertion due to airflow limitation caused by bronchial stenosis, with afflicted patients being less physically active. Therefore, physical activity is important for disease management.

OBJECTIVES

This study aimed to examine the relationships of walking and non-walking physical activities with cognitive function or physical characteristics of patients with mild COPD in a community without respiratory rehabilitation.

DESIGN

Cross-sectional study.

DATA SOURCES AND METHODS

We included 40 male patients (mean age, 75.7 ± 6.7 years) with stable mild COPD. A three-axis accelerometer was used to evaluate walking and non-walking physical activities in daily life. Cognition, respiratory function, skeletal muscle mass, limb muscle strength, exercise capacity, and health-related quality of life were assessed.

RESULTS

Regarding daily exercise amount (metabolic equivalents × hours; Ex), 87.5% of the participants had walking activities of 0-2 Ex, while 67.5% had non-walking activities of 1-3 Ex. Walking activity was significantly correlated with cognitive function (P < .05), walking distance (P < .01), and health-related quality of life (P < .05), but not with muscle mass. However, non-walking activity was significantly correlated with the body mass index (P < .05), muscle mass (P < .05), and walking distance (P < .01), but not with cognitive function. Moreover, the relationship between non-walking activity and health-related quality of life was weaker than the corresponding relationship with walking activity.

CONCLUSION

In patients with mild COPD, walking and non-walking physical activities showed different relationships with cognitive function and physical characteristics. The findings suggest that self-management of such patients requires maintenance of both walking and non-walking activities in a balanced manner.

Walking distance in incremental shuttle walking test as a predictor of physical activity in patients diagnosed with low-risk chronic obstructive pulmonary disease

OBJECTIVES

Research on the determinants of physical activity in mildly symptomatic patients with chronic obstructive pulmonary disease is lacking. This study examined the predictors of physical activity in patients with low-risk chronic obstructive pulmonary disease.

METHODS

A total of 41 male patients with chronic obstructive pulmonary disease belonging to Group A of the Global Initiative for Chronic Obstructive Lung Disease were included. Regarding the objective index, the physical activity (number of steps/day and the amount of Ex (metabolic equivalent × hours)/day) of the participants was measured with a tri-axis accelerometer. In addition, regarding the evaluation index, respiratory function and dynamic lung hyperinflation were measured by a spirometer, skeletal muscle mass was measured using bioelectrical impedance analysis, skeletal muscle strength (grip and lower limb muscle strength) was measured using a dynamometer, exercise capacity was measured by the incremental shuttle walking test, and health-related quality of life was measured.

RESULTS

Significant correlations were found between the number of steps per day and age (ρ = -0.501, p < 0.01), forced vital capacity predictive values (ρ = 0.381, p < 0.05), dynamic lung hyperinflation (ρ = 0.454, p < 0.01), grip strength (ρ = 0.318, p < 0.05), and walking distance in incremental shuttle walking test (ρ = 0.779, p < 0.01), but not skeletal muscle mass, lower limb muscle strength, or health-related quality of life. A multiple-regression analysis with the number of steps per day as the dependent variable extracted only walking distance in incremental shuttle walking test, yielding a moderate single-regression equation (steps/day = -934.909 + 11.052 × walking distance in incremental shuttle walking test, adjusted R2 = 0.548, p < 0.001).

CONCLUSION

It was suggested that the amount of physical activity of patients with low-risk chronic obstructive pulmonary disease could be predicted by walking distance in incremental shuttle walking test.

Cross-Validation of Predictive Equation for Cardiorespiratory Fitness by Modified Shuttle Walk Test in Adults with Schizophrenia: A Secondary Analysis of the CORTEX-SP Study

Cardiorespiratory fitness (CRF) can be direct or estimated from different field tests. The Modified Shuttle Walk Test (MSWT) is suitable for all levels of function, allowing a peak response to be elicited. Therefore, we aimed (1) to validate the equation presented in the original study by Singh et al. for evaluating the relationship between MSWT with peak oxygen uptake (VO_2peak) in adults with schizophrenia (SZ), (2) to develop a new equation for the MSWT to predict VO_2peak, and (3) to validate the new equation. Participants (N = 144, 41.3 ± 10.2 years old) with SZ performed a direct measurement of VO_2peak through a cardiopulmonary exercise test and the MSWT. A new equation incorporating resting heart rate, body mass index, and distance from MSWT (R² = 0.617; adjusted R² = 0.60; p < 0.001) performs better than the Singh et al. equation (R² = 0.57; adjusted R² = 0.57; p < 0.001) to estimate VO_2peak for the studied population. The posteriori cross-validation method confirmed the model’s stability (R² = 0.617 vs. 0.626). The findings of the current study support the validity of the new regression equation incorporating resting heart rate, body mass index, and distance from MSWT to predict VO_2peak for assessment of CRF in people with SZ.

Cardiac Rehabilitation: A Bibliometric Review From 2001 to 2020

Cardiovascular disease (CVD) is a serious threat to global public health due to its high prevalence and disability rate. Meanwhile, cardiac rehabilitation (CR) has attracted increasing attention for its positive effects on the cardiovascular system. There is overwhelming evidence that CR for patients with CVD is effective in reducing cardiovascular morbidity and mortality. To learn more about the development of CR, 5,567 papers about CR and related research were retrieved in the Web of Science Core Collection from 2001 to 2020. Then, these publications were scientometrically analyzed based on CiteSpace in terms of spatiotemporal distribution, author distribution, subject categories, topic distribution, and references. The results can be elaborated from three aspects. Firstly, the number of annual publications related to CR has increased year by year in general over the past two decades. Secondly, a co-occurrence analysis of the output countries and authors shows that a few developed countries such as the United States, Canada, and the UK are the most active in carrying out CR and where regional academic communities represented by Sherry Grace and Ross Arena were formed. Thirdly, an analysis of the subject categories and topic distribution of the papers reveals that CR is a typical interdiscipline with a wide range of disciplines involved, including clinical medicine, basic medicine, public health management, and sports science. The research topics cover the participants and implementers, components, and the objectives and requirements of CR. The current research hotspots are the three core modalities of CR, namely patient education, exercise training and mental support, as well as mobile health (mHealth) dependent on computer science. In conclusion, this work has provided some useful information for acquiring knowledge about CR, including identifying potential collaborators for researchers interested in CR, and discovering research trends and hot topics in CR, which can offer some guidance for more extensive and in-depth CR-related studies in the future.

Home-based exercise in patients with refractory fatigue associated with primary biliary cholangitis: a protocol for the EXerCise Intervention in cholesTatic LivEr Disease (EXCITED) feasibility trial

INTRODUCTION

Fatigue is the most commonly reported symptom of the liver disease primary biliary cholangitis (PBC). It affects 40%-80% of patients, has no effective treatment and is associated with heightened mortality risk. The pathogenesis is unknown, but muscle bioenergetic abnormalities have been proposed to contribute. Directly observed exercise has been shown to attenuate symptoms in small groups; however, due to the rare nature of the disease, home-based interventions need to be evaluated for feasibility, safety and efficacy.

METHODS AND ANALYSIS

This is a phase 1/pilot, single-arm, open-label clinical trial evaluating a novel home-based exercise programme in patients with PBC with severe fatigue. Forty patients with moderate-severe fatigue (PBC40 fatigue domain score >33; other causes of fatigue excluded) will be selected using a convenience sampling method. A 12-week home-based exercise programme, consisting of individualised resistance, aerobic exercises and telephone health calls (first 6 weeks only), will be delivered. Measures of fatigue (PBC40 fatigue domain; fatigue impact scale), quality of life, sleep (Epworth Sleep Score), physical activity, anxiety and depression, aerobic exercise capacity (incremental shuttle walk test; Duke Activity Status Index) and functional capacity (short physical performance battery) will be assessed at baseline and at 6 and 12 weeks following the intervention.

ETHICS AND DISSEMINATION

The protocol is approved by the National Research Ethics Service Committee London (IRAS 253115). Recruitment commenced in April 2019 and ended in March 2020. Participant follow-up is due to finish by December 2020. Findings will be disseminated through peer-reviewed publication, conference presentation and social media.

TRIAL REGISTRATION NUMBER

NCT04265235.

ECG changes during ISWTs in adult patients commencing CR: a retrospective case note review

The incremental shuttle walk test (ISWT) is a valid, reliable submaximal exercise test used in the assessment of patients prior to cardiac rehabilitation (CR). Simultaneous electrocardiogram (ECG) measurements would provide important information on the safety of the test, and adequacy of subsequent cardiac risk stratification. Risk stratification is recommended to assess patients' suitability for cardiac rehabilitation. For example, ST-segment depression >2 mm from baseline during testing would place a person in a high-risk category. However, such ECG measurements are rarely undertaken in clinical practice. The aim of the study was to investigate the incidence of ECG changes during an ISWT, and report on the possible impact of these findings on subsequent cardiac risk stratification. A retrospective case note review was undertaken for the year 2017. Baseline clinical characteristics from eligible patients were gathered including those with ischaemic heart disease, heart failure, transplant and valve replacement, along with ECG measurements during the ISWT. The impact of ECG findings on cardiac risk stratification was calculated, based on risk stratification developed by the American Association of Cardiovascular and Pulmonary Rehabilitation. The safety of the ISWT was measured by the absence of major ECG changes. Data were gathered for 295 patients. Minor ECG changes were identified during the ISWT in 189 patients (64.1%), with no major changes. The presence of silent myocardial ischaemia (ST-segment depression) had an impact on cardiac risk stratification in 27 patients. There was a statistically significant positive association between ST-segment depression with cardiac risk stratification (p<0.001). In conclusion, the ISWT is safe in terms of ECG changes. The impact of ECG findings on cardiac risk stratification is significant and worthy of further consideration.

Getting evidence into clinical practice: protocol for evaluation of the implementation of a home-based cardiac rehabilitation programme for patients with heart failure

INTRODUCTION

Cardiac rehabilitation (CR) improves health-related quality of life and reduces hospital admissions. However, patients with heart failure (HF) often fail to attend centre-based CR programmes. Novel ways of delivering healthcare, such as home-based CR programmes, may improve uptake of CR. Rehabilitation EnAblement in CHronic Heart Failure (REACH-HF) is a new, effective and cost-effective home-based CR programme for people with HF. The aim of this prospective mixed-method implementation evaluation study is to assess the implementation of the REACH-HF CR programme in the UK National Health Service (NHS). The specific objectives are to (1) explore NHS staff perceptions of the barriers and facilitators to the implementation of REACH-HF, (2) assess the quality of delivery of the programme in real-life clinical settings, (3) consider the nature of any adaptation(s) made and how they might impact on intervention effectiveness and (4) compare real-world patient outcomes to those seen in a prior clinical trial.

METHODS AND ANALYSIS

REACH-HF will be rolled out in four NHS CR centres across the UK. Three healthcare professionals from each site will be trained to deliver the 12-week programme. In-depth qualitative interviews and focus groups will be conducted with approximately 24 NHS professionals involved in delivering or commissioning the programme. Consultations for 48 patients (12 per site) will be audio recorded and scored using an intervention fidelity checklist. Outcomes routinely recorded in the National Audit of Cardiac Rehabilitation will be analysed and compared with outcomes from a recent randomised controlled trial: the Minnesota Living with HF Questionnaire and exercise capacity (Incremental Shuttle Walk Test). Qualitative research findings will be mapped onto the Normalisation Process Theory framework and presented in the form of a narrative synthesis. Results of the study will inform national roll-out of REACH-HF.

ETHICS AND DISSEMINATION

The study (IRAS 261723) has received ethics approval from the South Central (Hampshire B) Research Ethics Committee (19/SC/0304). Written informed consent will be obtained from all health professionals and patients participating in the study. The research team will ensure that the study is conducted in accordance with the Declaration of Helsinki, the Data Protection Act 2018, General Data Protection Regulations and in accordance with the Research Governance Framework for Health and Social Care (2005). Findings will be published in scientific peer-reviewed journals and presented at local, national and international meetings to publicise and explain the research methods and findings to key audiences to facilitate the further uptake of the REACH-HF intervention.

TRIAL REGISTRATION

ISRCTN86234930.

Test-Retest Reliability for Physical Function Measures in Patients with Chronic Kidney Disease

BACKGROUND

It is important to determine relative and absolute reliability values in outcome measures that are used in clinical practice so as to discriminate between true changes following exercise interventions for patients with chronic kidney disease (CKD).

OBJECTIVE

The study aimed to assess test-retest reliability of the incremental shuttle walk test (ISWT), sit-to-stand transfers in 60 seconds (STS-60), timed up and go (TUAG), Duke's activity status index (DASI) and hospital anxiety and depression scale (HAD) in patients with CKD.

STUDY DESIGN

This study was a pragmatic non-randomised controlled trial.

METHODS

Forty people attended two study visits within a 16-day window involving the ISWT, STS-60, TUAG, DASI and HAD tests. Relative reliability was assessed using intraclass correlation coefficient (ICC) and absolute reliability using the standard error of measurement (SEM) and minimal detectable change (MDC).

RESULTS

Good test-retest reliability was found for the entire sample size across all outcome measures, with TUAG having the highest (ICC = 0.96) and HAD the lowest (ICC = 0.71). The MDC scores at 90% confidence interval (CI) were: 79.6 m for the ISWT, 2.9 seconds for the TUAG, 7.0 repetitions for the STS-60, 8.4 for the DASI, 3.8 for the anxiety HAD subscale and 4.4 for the depression HAD subscale.

CONCLUSIONS

This study demonstrated good test-retest reliability for all outcome measures across the CKD trajectory but caution needs to be taken when interpreting the findings for each CKD sub-group separately. The MDC scores at 90% CI can support therapists in determining a true improvement in CKD patients' physical or mental performance.

Reliability, Validity, and Responsiveness of the Incremental Shuttle Walk Test in Patients With Interstitial Lung Disease

PURPOSE

To determine the reliability, validity, and responsiveness of the incremental shuttle walk test (ISWT) in patients with interstitial lung disease (ILD).

METHODS

This was a cross-sectional longitudinal study. Patients (n = 27, 10 males; mean age ± SD, 61 ± 9.8 y) with ILD of any etiology, who participated in an outpatient pulmonary rehabilitation (PR) program, were recruited. Reliability was determined by comparing the distance covered in meters between the ISWT-1 and the ISWT-2. Validity was assessed by correlating the distance covered in the ISWT-1, with the maximum oxygen consumption ((Equation is included in full-text article.)O2max) obtained through cardiopulmonary exercise testing and distance covered during the 6-min walk test (6MWT). Responsiveness was assessed by comparing the distance covered in the ISWT-3, undertaken after the completion of PR, to the ISWT-1.

RESULTS

The distance covered was equivalent between the ISWT-1 (216.7 ± 64.9 m) and the ISWT-2 (220.7 ± 67.3 m), with an excellent intraclass correlation coefficient (ICC2,1 = 0.91; 95% CI, 0.81-0.95). The standard error of measurement and minimal detectable change at the 95% CI (MDC95) values for the ISWT were 19.5 m and 53.9m, respectively. There were significant correlations between the distance covered on the ISWT and (Equation is included in full-text article.)O2max (r = 0.79, P < .0001) and the distance covered on the 6MWT (r = 0.76, P < .0001). Following PR, the change in the ISWT distance showed large effect size (ES = 0.85) and standardized response mean (SRM = 1.58).

CONCLUSIONS

The ISWT is a reliable, valid, and responsive measure of estimated functional capacity in patients with ILD.

Is Exercise Prescription in Cardiac Rehabilitation Influenced by Physical Capacity or Cardiac Intervention?

This study investigated the influence of cardiac intervention and physical capacity of individuals attending an Australian outpatient cardiac rehabilitation program on the initial exercise prescription. A total of 85 patients commencing outpatient cardiac rehabilitation at a major metropolitan hospital had their physical capacity assessed by an incremental shuttle walk test, and the initial aerobic exercise intensity and resistance training load prescribed were recorded. Physical capacity was lower in surgical patients than nonsurgical patients. While physical capacity was higher in younger compared with older surgical patients, there was no difference between younger and older nonsurgical patients. The initial exercise intensity did not differ between surgical and nonsurgical patients. This study highlights the importance of preprogram exercise testing to enable exercise prescription to be individualized according to actual physical capacity, rather than symptoms, comorbidities and age, in order to maximize the benefit of cardiac rehabilitation.

Interpreting Meaningful Change in the Distance Walked in the 10-Metre ISWT in Cardiac Rehabilitation

BACKGROUND

The interpretability of change in exercise test scores is an important measurement property. This study aimed to provide a framework for the interpretation of individual change scores of the 10metre incremental shuttle walk test (ISWT) in cardiac rehabilitation.

METHODS

In a quantitative pre-post design study, 52 patients who were referred to a hospital outpatient department for cardiac rehabilitation participated in this study. Participants completed two ISWTs prior to cardiac rehabilitation. Post cardiac rehabilitation, participants completed a global rating of change score and two ISWTs. Change scores were analysed for smallest detectable change (SDC) and minimum important change (MIC).

RESULTS

The SDC for an individual was 47 metres. The predicted MIC for participants to report an improvement ranged from 70 to 92 metres. The predicted MIC for participants who did not report a deterioration in the global rating of change (i.e., those who reported unchanged or improved) ranged from 16 to 42 metres.

CONCLUSIONS

The MIC for patients who report any improvement in physical fitness and functional capacity is 70 metres. These results suggest that over an 8-week program, patients would need to improve by at least seven shuttles to perceive an improvement in their physical fitness and functional capacity. Patients with small increases in the 10-metre ISWT distance may still report deterioration in their physical fitness and functional capacity.

Validity of the modified shuttle walk test to assess cardiorespiratory fitness after exercise intervention in overweight/obese adults with primary hypertension

The study aimed to assess whether the Modified Shuttle Walk Test (MSWT) can detect changes in cardiorespiratory fitness (CRF) in overweight/obese people with hypertension (HTN) after an exercise intervention evaluating the equation presented in the previous research by Jurio-Iriarte et al. Participants (N= 248) performed a peak cardiorespiratory exercise test (CPET) and MSWT before and after 16-weeks of different types of aerobic exercise intervention. The formula of Jurio-Iriarte et al. was used to predict peak oxygen uptake (V̇O_2peak). The correlation between measured and predicted V̇O_2peak was strong (r= 0.76, P< 0.001) with a standard error of estimate (SEE) of 4.9 mL·kg^-1·min^-1; SEE%= 17%. The intraclass correlation coefficient indicates a moderate level of association and agreement (ICC= 0.69; 95% CI 0.34-0.82; P< 0.001) between the measured and predicted V̇O_2peak. When analyzing obese participants alone (N= 128), MSWT equation was more accurate compared to the whole sample (ICC= 0.76; 95% CI 0.52-0.87). The relationship between the change of measured and predicted V̇O_2peak at follow-up was weak (r= 0.42, P< 0.001) with a 31% SEE, and a low level of association and agreement (ICC= 0.31; 95% CI 0.06-0.49; P< 0.001). In conclusion, although MSWT does not accurately predict CRF in people with HTN after exercise intervention and questions its validity, the new equation may have practical application to estimate V̇O_2peak for obese people with HTN when CPET is not available. Abbreviations: AC: Attention Control; BM: Body Mass; BP: Blood Pressure; CI: Confidence Interval; CRF: Cardiorespiratory Fitness; CPET: Cardiopulmonary Exercise Test; HTN: Primary Hypertension; HR: Heart Rate; HV-HIIT: High-Volume and High-Intensity Interval Training; ICC: Intraclass Correlation Coefficient; LV-HIIT: Low-Volume and High-Intensity Interval Training; MICT: Moderate-intensity continuous training; MSWT: Modified Shuttle Walk Test; SD: Standard Deviation; SEE: Standard Error of Estimate; V̇O_2peak: Peak Oxygen Uptake.

Effects of Different Exercise Training Programs on Cardiorespiratory Fitness in Overweight/Obese Adults With Hypertension: A Pilot Study

The goal of the study was to compare the effects of two supervised aerobic exercise programs (moderate-intensity continuous training [MICT] vs. high-intensity interval training [HIIT]) after 8-, 12-, and 16-week intervention periods on cardiorespiratory fitness (CRF) in overweight/obese adults diagnosed with hypertension. Participants ( N = 64) were divided into three intervention cohorts (control group [CG], MICT, and HIIT) and each of these, in turn, into three intervention length cohorts (8, 12, and 16 weeks). Supervised groups exercised twice a week. There were no statistical changes in postintervention periods in CG ( g < 0.1). CRF as assessed by peak oxygen uptake (mL kg^-1·min^-1) increased ( p < .001) in exercise groups (MICT, 3.8 ± 3.3, g = 0.6; HIIT, 4.2 ± 4.7, g = 0.7). The effect of exercise interventions compared with CG was substantial ( p < .02, g > .8) and mostly consequence of HIIT-related effects. The improvements on CRF occurred after 12 and 16 weeks in exercise interventions, rather than in the 8-week group or CG, where Hedges's g index indicated small effect. This study may suggest that both MICT and HIIT exert cardioprotector effects on hypertension in the overweight/obese population. However, short-term training duration (<12 weeks) does not seem to improve CRF, and HIIT intervention might generate higher aerobic capacity, which seems to grow as intervention lengthens.

Effects of combined high-intensity aerobic interval training program and Mediterranean diet recommendations after myocardial infarction (INTERFARCT Project): study protocol for a randomized controlled trial

BACKGROUND

Exercise therapy has long been used for rehabilitation purposes after myocardial infarction (MI) and the benefit of regular physical exercise is also well-established. High-intensity interval training (HIIT) has been proposed to be more effective than continuous exercise for improving exercise capacity and health-related adaptations to low-volume (LV) and HIIT are also known. Furthermore, the Mediterranean diet (Mediet) has been widely reported to be a model of healthy eating for its contribution to a favorable health status and a better quality of life, reducing overall mortality. This study will investigate the effects of different HIIT programs (high-volume [HV] vs LV) and Mediet recommendations in clinical condition, cardiorespiratory fitness, biomarkers, ventricular function, and perception of quality of life after MI, and compared to an attention control group that is recommended to Mediet and physical activity without supervision sessions.

METHODS/DESIGN

In this randomized controlled trial, cardiorespiratory fitness, anthropometry, central and peripheral cardiovascular variables, biochemical and nutritional condition, and quality of life will be assessed before and after 16 weeks of intervention in 177 participants diagnosed with MI type 1. All participants will be randomly (1:1:1) assigned to the attention control group or two exercise groups (Mediet recommendations plus supervised aerobic exercise two days/week: (1) HV (40 min) HIIT group and (2) LV (20 min) HIIT group.

DISCUSSION

This study will be the first clinical trial comparing the effects of two different volumes of HIIT programs with Mediet recommendations for people after MI. The results of this study will provide good evidence for physical rehabilitation in this population.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02876952 . Registered on 24 August 2016.

Is the 10 m incremental shuttle walk test a useful test of exercise capacity for patients referred to cardiac rehabilitation?

BACKGROUND

Field exercise tests are a feasible alternative to the symptom-limited exercise test for measuring exercise capacity in patients attending cardiac rehabilitation.

AIMS

To evaluate the criterion validity of the 10 m incremental shuttle walk test (ISWT) as a useful tool for measurement of exercise capacity for patients eligible for cardiac rehabilitation.

METHODS

Fifteen patients eligible for cardiac rehabilitation completed a treadmill symptom-limited exercise test and two ISWTs with the order of testing randomised. Associations between the symptom-limited exercise test and the ISWT were explored and the ability of the ISWT to predict symptom-limited exercise test duration estimated.

RESULTS

There was a moderate to high association ( r² ⩾0.72) between ISWT duration and distance, and symptom-limited exercise test duration; and a moderate association between ISWT peak heart rate and end of test oxygen saturation and these outcomes on the symptom-limited exercise test (0.47⩽ r² ⩽0.67). However, prediction of symptom-limited exercise test duration based on the ISWT produced wide 95% confidence intervals, for example, ranging from 9.1 to 16.3 minutes for an individual who completes the ISWT. Order of testing did not affect the results and the association between the ISWT and symptom-limited exercise test was similar for both the first (ISWT 1) and second test (ISWT 2) ISWT.

CONCLUSIONS

The results provide support for the ISWT as a convenient field test of exercise capacity in a cardiac rehabilitation population, but not as a surrogate to predict symptom-limited exercise test duration for individuals. A single ISWT may provide as good an estimate of exercise capacity as repeating the test.

Recumbent Stepper Submaximal Test response is reliable in adults with and without stroke

PURPOSE

The purpose of the present study was to determine the reliability of the exercise response (predicted peak VO2) using the total body recumbent stepper (TBRS) submaximal exercise test in: 1) healthy adults 20-70 years of age and 2) adults participating in inpatient stroke rehabilitation. We hypothesized that the predicted peak VO2 (Visit 1) would have an excellent relationship (r > 0.80) to predicted peak VO2 (Visit 2). We also wanted to test whether the exercise response at Visit 1 and Visit 2 would be significantly different.

METHODS

Healthy adults were recruited from the Kansas City metro area. Stroke participants were recruited during their inpatient rehabilitation stay. Eligible participants completed 2 TBRS submaximal exercise tests between 24 hours and 5 days at similar times of day.

RESULTS

A total of 70 participants completed the study. Healthy adults (n = 50) were 36 M, 38.1 ± 10.1 years and stroke participants (n = 20) were 15 M, 62.5 ± 11.8 years of age. The exercise response was reliable for healthy adults (r = 0.980, p<0.01) and stroke participants (r = 0.987, p<0.01) between Visit 1 and Visit 2. Repeated Measures ANOVA showed a significant difference in predicted values between the two visits for healthy adults (47.2 ± 8.4 vs 47.7 ± 8.5 mL∙kg-1∙min-1; p = 0.04) but not for stroke participants (25.0 ± 9.9 vs 25.3 ± 11.4 mL∙kg-1∙min-1; p = 0.65).

CONCLUSION

These results suggest that the exercise response is reliable using the TBRS submaximal exercise test in this cohort of healthy adults and stroke participants.