Walking tests during the exercise training: specific use for the cardiac rehabilitation

Effect of exercise on functional capacity and body weight for people with hypertension, type 2 diabetes, or cardiovascular disease: a systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Hypertension, type 2 diabetes, and cardiovascular disease affect the activities of daily living at varying degree. While the effects of aerobic exercise on functional capacity are well-documented, the extent of change for different types of exercise in these chronic conditions remains unexplored. Additionally, there is conflicting evidence regarding the role of exercise in reducing body weight.

METHODS

We conducted systematic review with meta-analysis and trial sequential analysis and searched various databases from inception to July 2020. We included randomised clinical trials adding any form of trialist defined exercise to usual care versus usual care in people with either hypertension, type 2 diabetes, and/or cardiovascular disease irrespective of setting, publication status, year, and language. The outcomes assessed were i) functional capacity assessed through different scales separately i.e., Maximal Oxygen Uptake (VO2max), 6-min walk test (6MWT), 10-m walk test (10MWT), and ii) body weight.

RESULTS

We included 950 studies out of which 444 trials randomising 20,098 participants reported on various functional outcomes (355 trials) and body weight (169 trials). The median follow-up was 3 months (Interquartile ranges (IQR): 2.25 to 6). Exercise added to the usual care, improved VO2max (Mean Difference (MD):2.72 ml/kg/min; 95% Confidence Interval (CI) 2.38 to 3.06; p < 0.01; I2 = 96%), 6MWT (MD: 42.5 m; 95%CI 34.95 to 50.06; p < 0.01; I2 = 96%), and 10MWT (MD: 0.06 m/s; 95%CI 0.03 to 0.10; p < 0.01; I2 = 93%). Dynamic aerobic and resistance exercise showed a consistent improvement across various functional outcomes, whereas body-mind therapies (MD: 3.23 ml/kg/min; 95%CI 1.97 to 4.49, p < 0.01) seemed especially beneficial for VO2max and inspiratory muscle training (MD: 59.32 m; 95%CI 33.84 to 84.80; p < 0.01) for 6MWT. Exercise yielded significant reduction in body weight for people with hypertension (MD: -1.45 kg; 95%CI -2.47 to -0.43; p < 0.01), and type 2 diabetes (MD: -1.53 kg; 95%CI -2.19 to -0.87; p < 0.01) but not for cardiovascular disease with most pronounced for combined exercise (MD: -1.73 kg; 95%CI -3.08 to -0.39; p < 0.05). The very low certainty of evidence warrants cautious interpretations of the results.

CONCLUSION

Exercise seemed to improve functional capacity for people with hypertension, type 2 diabetes, and/or cardiovascular disease but the effectiveness seems to vary with different forms of exercise. The potentially superior improvement in VO2max and 6MWT by body-mind therapies and inspiratory muscle training calls for further exploration. Additionally, prescribing exercise for the sole purpose of losing weight may be a potential strategy for people with hypertension and type 2 diabetes. The extent of improvement in functional capacity and body weight reduction differed with different exercise regimens hence personalised exercise prescriptions tailored to individual needs may be of importance. PROSPERO REGISTRATION: PROSPERO registration number: CRD42019142313.

Validity and reliability of automated treadmill six-minute walk test in patients entering exercise-based cardiac rehabilitation

Introduction: The six-minute walk test (6MWT) is a well-established tool for assessing submaximal functional capacity for cardiac patients, but space limitations challenge its implementation. Treadmill-based (TR) 6MWT is a promising alternative, but it requires patients to complete a familiarization test to adapt treadmill speed regulation. With the advancement of sensors, it is possible to automatically control speed for individual patients and thus overcome the space limitation or the speed control difficulty on the treadmill for each patient.Methods: This study investigated the validity and interchangeability of automated speed TR6MWT and standard hallway (HL) 6MWT. Eighteen patients were assessed at baseline of the 12-week cardiac rehabilitation program. Fourteen of them were assessed after rehabilitation. All patients performed three TR6MWTs and three HL6MWTs at baseline and one of each test after the program.Results: Patients well tolerated the TR6MWT. There was a strong correlation between both test methods (r = 0.79). However, patients performed significantly better in HL6MWT (514.8m ± 59.7m) than in TR6MWT (447.2 ± 79.1m) with 95% CI, 40.4-94.6m, p < 0.05. Both tests showed high test-retest reliability (intraclass correlation coefficient of 0.86). The TR6MWT showed a valuable comparison of the effect of the cardiac rehabilitation program (20% increase, effect size 1.1) even though it is not interchangeable with the HL6MWT.Conclusion: The automated speed TR6MWT appears to be an acceptable tool with adequate validity, reliability, and responsiveness for assessing functional capacity in patients utilizing cardiac rehabilitation programs.

Aerobic Exercise Prescription in Cardiac Rehabilitation Based on Heart Rate from Talk Test Stages and 6-Minute Walk Test

BACKGROUND

Although the Talk Test (TT) is a reliable and low-cost test, its use for aerobic exercise prescription is still limited.

OBJECTIVE

To analyze the heart rate (HR) in the stages of the TT and at the peak of the 6-minute walk test (6MWT) as a parameter to prescribe aerobic exercise compared with HR at the first and second ventilatory thresholds (VT1 and VT2) of cardiopulmonary exercise test (CPET).

METHODS

Individuals with cardiovascular disease attended three assessment days: 1) anamnesis and CPET; 2) 6MWT; and 3) TT. One-way repeated measures ANOVA or Friedman's test were used to compare HR at VT1 and VT2 with HR at TT stages: last positive (TT+), first equivocal (TT±), and negative (TT-), and at the peak of the 6MWT. Pearson's or Spearman's test assessed correlations between HR at VTs, TT stages, and 6MWT. Statistical significance was set at 5%.

RESULTS

The study included 22 cardiac patients (13 men, 61 ± 8 years). HR at VT1 was similar to HR at TT+ (p = 0.987) and TT± (p = 0.154), and moderately correlated with TT+ (r = 0.479, p = 0.024). HR at VT2 was similar to TT- (p = 0.383), with a strong correlation (r = 0.757, p < 0.001). HR at the peak of the 6MWT was significantly different from HR at TT+, TT±, and VT1 (p = 0.001, p = 0.005, and p < 0.001, respectively) but similar to TT- (p = 0.68).

CONCLUSIONS

HR at TT+ and TT- reflect HR at VT1 and VT2, respectively, differently from 6MWT, which was similar only to VT2. TT may be an objective test to assist aerobic exercise prescription in cardiac rehabilitation.

Lower-limb Nonparametric Functional Muscle Network: Test-retest Reliability Analysis

Objective

Functional muscle network analysis has attracted a great deal of interest in recent years, promising high sensitivity to changes of intermuscular synchronicity, studied mostly for healthy subjects and recently for patients living with neurological conditions (e.g., those caused by stroke). Despite the promising results, the between- and within-session reliability of the functional muscle network measures are yet to be established. Here, for the first time, we question and evaluate the test-retest reliability of non-parametric lower-limb functional muscle networks for controlled and lightly-controlled tasks, i.e., sit-to-stand, and over-the-ground walking, respectively, in healthy subjects.

Method

Fifteen subjects (eight females) were included over two sessions on two different days. The muscle activity was recorded using 14 surface electromyography (sEMG) sensors. The intraclass correlation coefficient (ICC) of the within-session and between-session trials was quantified for the various network metrics, including degree and weighted clustering coefficient. In order to compare with common classical sEMG measures, the reliabilities of the root mean square (RMS) of sEMG and the median frequency (MDF) of sEMG were also calculated.

Results

The ICC analysis revealed superior between-session reliability for muscle networks, with statistically significant differences when compared to classic measures.

Conclusion and Significance

This paper proposed that the topographical metrics generated from functional muscle network can be reliably used for multi-session observations securing high reliability for quantifying the distribution of synergistic intermuscular synchronicities of both controlled and lightly controlled lower limb tasks. In addition, the low number of sessions required by the topographical network metrics to reach reliable measurements indicates the potential as biomarkers during rehabilitation.

Incremental shuttle walking test to assess functional capacity in cardiac rehabilitation: a narrative review

Background/Aims

Low functional capacity has been recognised to be the most important predictor of overall mortality compared to all other cardiovascular risk factors in patients with cardiovascular disease. Walk tests, such as the incremental shuttle walking test and the 6-Minute Walk Test, are used to assess functional capacity in patients, the effectiveness of a cardiac rehabilitation programme and the prognosis of cardiovascular diseases. The aim of this review was to provide a narrative review of the literature and identify the key features of the incremental shuttle walking test as a measure of functional capacity testing in cardiac rehabilitation patients.

Methods

The PubMed, MEDLINE, Elsevier and Google Scholar databases were searched for relevant scientific articles published up to March 2021 with no restriction on start day. The key words defined by researchers were ‘incremental shuttle walking test’, ‘exercise test’, ‘functional capacity’, ‘cardiovascular disease’, ‘cardiac rehabilitation’, ‘reliability’ ‘prediction; ‘walk tests’. A final set of 31 articles was included in this narrative review.

Results

Evidence-based findings suggest that the incremental shuttle walking test is a valid, reliable, sensitive, useful tool for detecting and predict cardiorespiratory capacity.

Conclusions

Clinicians can be confident that they can use the incremental shuttle walking test to monitor changes in functional capacity in patients with cardiovascular disease.

Agreement between heart rate at first ventilatory threshold on treadmill and at 6-min walk test in coronary artery disease patients on β-blockers treatment

The purpose of this study was to verify the accuracy of the agreement between heart rate at the first ventilatory threshold (HR_VT1) and heart rate at the end of the 6-min walk test (HR_6MWT) in coronary artery disease (CAD) patients on β-blockers treatment. This was a cross-sectional study with stable CAD patients, which performed a cardiopulmonary exercise test (CPET) on a treadmill and a 6-min walk test (6MWT) on nonconsecutive days. The accuracy of agreement between HR_VT1 and HR_6MWT was evaluated by Bland–Altman analysis and Lin’s concordance correlation coefficient (r_c), mean absolute percentage error (MAPE), and standard error of estimate (SEE). Seventeen stable CAD patients on β-blockers treatment (male, 64.7%; age, 61±10 years) were included in data analysis. The Bland–Altman analysis revealed a negative bias of −0.41±6.4 bpm (95% limits of agreements, −13 to 12.2 bpm) between HR_VT1 and HR_6MWT. There was acceptable agreement between HR_VT1 and HR_6MWT (r_c=0.84; 95% confidence interval, 0.63 to 0.93; study power analysis=0.79). The MAPE of the HR_6MWT was 5.1% and SEE was 6.6 bpm. The ratio HR_VT1/HR_peak and HR_6MWT/HR_peak from CPET were not significantly different (81%±5% vs. 81%±6%, P=0.85); respectively. There was a high correlation between HR_VT1 and HR_6MWT (r=0.85, P<0.0001). Finally, the results of the present study demonstrate that there was an acceptable agreement between HR_VT1 and HR_6MWT in CAD patients on β-blockers treatment and suggest that HR_6MWT may be useful to prescribe and control aerobic exercise intensity in cardiac rehabilitation programs.

Testing of a Self-administered 6-Minute Walk Test Using Technology: Usability, Reliability and Validity Study

BACKGROUND

The need to attend a medically supervised hospital- or clinic-based appointment is a well-recognized barrier to exercise participation. The development of reliable and accurate home-based functional tests has the potential to decrease the burden on the health care system while enabling support, information, and assessment.

OBJECTIVE

This study aims to explore the usability (ie, acceptability, satisfaction, accuracy, and practicality) of the EasyMeasure app to self-administer the 6-minute walk test (6MWT) in young, healthy adults and determine parallel form reliability and construct validity of conducting a self-administered 6MWT using technology.

METHODS

We used a usability study design. English-speaking, undergraduate university students who had access to an iPhone or iPad device running iOS 10 or later and self-reported ability to walk for 6 minutes were recruited for this study. Consenting participants were randomized to either a standard 6MWT group (ie, supervised without the use of the app) or a technology 6MWT group (ie, unsupervised with the app to mimic independent implementation of the test). All participants performed a maximal treadmill test. Participants in the 6MWT group completed the Unified Theory of Acceptance and Use of Technology (UTAUT) questionnaire and a satisfaction questionnaire after completing the assessment. Parallel form reliability of the 6MWT using technology was analyzed by comparing participant self-administered scores and assessor scores using Pearson correlation coefficients across and between trials. Construct validity was assessed by comparing participant 6MWT scores (both standard and using technology) with maximum treadmill test variables (peak oxygen uptake and ventilatory threshold [VT]).

RESULTS

In total, 20 university students consented to participate in the study. All but 2 participants (8/10, 80%) in the technology 6MWT group had deviations that prevented them from accurately conducting the 6MWT using the app, and none of the participants were able to successfully score the 6MWT. However, a significantly strong correlation was found (r=.834; P=.003) when comparing participants' scores for the 6MWT using technology with the assessors' scores. No significant correlations were found between maximal treadmill test peak oxygen uptake scores and 6MWT prediction equations using standard 6MWT scores (equation 1: r=0.119; P=.78; equation 2: r=0.095; P=.82; equation 3: r=0.119; P=.78); however, standard 6MWT scores were significantly correlated with VT values (r=0.810; P=.02). The calculated submaximal treadmill scores and assessor 6MWT scores using technology also demonstrated a significant correlation (r=0.661; P=.04).

CONCLUSIONS

This study demonstrated significant usability concerns regarding the accuracy of a self-administered 6MWT using the EasyMeasure app. However, the strong and significant correlation between the 6MWT and VT values demonstrates the potential of the 6MWT to measure functional capacity for community-based exercise screening and patient monitoring.

The Future of Exercise-Based Cardiac Rehabilitation for Patients With Heart Failure

Cardiac rehabilitation (CR) is a comprehensive program that includes exercise training, titration of medical therapy, lifestyle modification, educational support, and psychosocial assessment. All these components are safe and beneficial resulting in significant improvements in quality of life, functional capacity, mortality, and hospital readmission. Current guidelines support its use in a broad spectrum of cardiac disease. This review focuses on exercise-based CR for heart failure (HF) patients in whom CR is a recommended treatment. Exercise should be prescribed according to a personalized approach, optimizing, and tailoring the rehabilitative program to the patient's characteristics. Specific CR programs are dedicated to older patients, those with HF and preserved ejection fraction, and recipients of cardiac implantable electronic devices or left ventricular assistance device. Telemedicine may increase CR participation and overcome some of the barriers that limit its utilization.

Temporal trends in 6-minute walking distance for older Japanese adults between 1998 and 2017

BACKGROUND

The 6-minute walking distance (6MWD) is an excellent measure of both functional endurance and health. The primary aim of this study was to estimate temporal trends in 6MWD for older Japanese adults between 1998 and 2017; the secondary aim was to estimate concurrent trends in body size (i.e., height and mass) and self-reported participation in exercise/sport.

METHODS

Adults aged 65-79 years were included. Annual nationally representative 6MWD data (n = 103,505) for the entire period were obtained from the Japanese Ministry of Education, Culture, Sports, Science and Technology. Temporal trends in means (and relative frequencies) were estimated at the gender-age level by best-fitting sample-weighted linear/polynomial regression models, with national trends estimated by a post-stratified population-weighting procedure. Temporal trends in distributional variability were estimated as the ratio of coefficients of variation.

RESULTS

Between 1998 and 2017 there was a steady, moderate improvement in mean 6MWD (absolute = 45 m (95% confidence interval (95%CI): 43-47); percent = 8.0% (95%CI: 7.6%-8.4%); effect size = 0.51 (95%CI: 0.48-0.54)). Gender- and age-related temporal differences in means were negligible. Variability in 6MWD declined substantially (ratio of coefficients of variation = 0.89, 95%CI: 0.87-0.92), with declines larger for women compared to men, and for 75-79-year-olds compared to 65-74-year-olds. Correspondingly, there were moderate and negligible increases in mean height and mass, respectively, and negligible increases in the percentage who participated in exercise/sport at least 3 days per week and at least 30 min per session.

CONCLUSION

There has been a steady, moderate improvement in mean 6MWD for older Japanese adults since 1998, which is suggestive of corresponding improvements in both functional endurance and health. The substantial decline in variability indicates that the temporal improvement in mean 6MWD was not uniform across the distribution. Trends in 6MWD are probably influenced by corresponding trends in body size and/or participation in exercise/sport.

Six-minute walk test protocol variations in low-resource settings - A scoping review

BACKGROUND

The 6-min walk test (6MWT) is a validated tool, of submaximal intensity, used to objectively measure functional exercise capacity. In 2002, the American Thoracic Society (ATS) developed guidelines on standardising the implementation of the 6MWT. Despite the relative ease of conducting the 6MWT as per these guidelines, adaptations are implemented.

OBJECTIVES

Identify (1) what 6MWT adaptations to the ATS guidelines have been described in low-resource settings (LRS), (2) the purpose of the adapted 6MWT and (3) the reported argumentation for making these adaptations in relation to the specific context.

METHODS

Five databases were searched from inception until February 2021. Studies that adapted and conducted the 6MWT in LRS were included. Data concerning the study source, participants, 6MWT: purpose, variations, outcome and rationale were extracted.

RESULTS

A total of 24 studies were included. The majority of studies (n = 18; 75%) were conducted in lower-middle income countries. The most common adaptation implemented was variation to course length. Eight studies provided a rationale for adapting the 6MWT. Space constraint was the most common reason for adaptation.

CONCLUSION

The most common reason (space constraints) for adapting the 6MWT in LRS was addressed through adaptations in course length and/or configuration. The results of this review suggest that the value of the ATS-guided 6MWT in LRS may need to be re-evaluated.

CLINICAL IMPLICATIONS

Using adapted forms of the 6MWT may lead to an underestimation of a patient's abilities, misinformed discharge and developing inappropriate exercise programmes. Additionally, diverting from ATS guidelines may affect the continuity of care.

Physical activities and surgical outcomes in elderly patients with acute type A aortic dissection

OBJECTIVE

Although elderly patients undergoing surgery for acute type A aortic dissection (ATAAD) is increasing, their physical activities are not fully understood. We report the physical activities and surgical outcomes in elderly patients who underwent ATAAD.

METHODS

From 2009 to 2019, 103 consecutive patients underwent surgery for ATAAD at our institution. Surgical outcomes along with pre- and postoperative physical activities in 52 elderly patients (≥70 years old) were compared with those in 51 younger patients (<70 years old). Postoperative walking difficulty was defined as taking ≥30 days to regain the ability to walk 200 m postoperatively or as the inability to walk at discharge.

RESULTS

It took longer for elderly patients to regain the ability to walk 100 or 200 m postoperatively. ROC analysis revealed the AUC of the duration for walking 200 m postoperatively as a prognostic indicator for late deaths was 0.878, with the highest accuracy at 30 days (sensitivity = 83.3%, specificity = 91.8%). Hospital mortality within 30 days was 3.8%, and 1-, 3-, and 5-years survival rates were 92%, 84.7%, 84.7%, respectively, for elderly patients, with no significant differences between groups. Cox proportional hazard analysis showed postoperative walking difficulty was an independent risk factor for late mortality in all cohorts (p = .017).

CONCLUSIONS

Elderly patients undergoing surgical ATAAD repair showed acceptable surgical outcomes. However, they were more likely to decrease their physical activities postoperatively. Postoperative difficulty in walking was an independent risk factor for the late mortality in patients with ATAAD.

Effects of three pulmonary ventilation regimes in patients undergoing coronary artery bypass graft surgery: a randomized clinical trial

The aim was to compare the effect of diaphragmatic breathing exercise (DBE), flow- (FIS) and volume-oriented incentive spirometry (VIS) on pulmonary function- (PFT), functional capacity-6-Minute Walk Test (6 MWT) and Functional Difficulties Questionnaire (FDQ) in subjects undergoing Coronary Artery Bypass Graft surgery (CABG). The purpose of incorporating pulmonary ventilator regimes is to improve ventilation and avoid post-operative pulmonary complications. CABG patients (n = 72) were allocated to FIS, VIS and DBE groups (n = 24 each) by block randomization. Preoperative and postoperative values for PFT were taken until day 7 for all three groups. On 7th postoperative day, 6 MWT and FDQ was analyzed using ANOVA and post-hoc analysis. PFT values were found to be decreased on postoperative day 1(Forced Vital Capacity (FVC) = FIS group-65%, VIS group-47%, DBE group-68%) compared to preoperative day (p < 0.001). PFT values for all 3 groups recovered until postoperative day 7 (FVC = FIS group-67%, VIS group-95%, DBE group-59%) but was found to reach the baseline in VIS group (p < 0.001). When compared between 3 groups, statistically significant improvement was observed in VIS group (p < 0.001) in 6 MWT and FDQ assessment. In conclusion, VIS was proven to be more beneficial in improving the pulmonary function (FVC), functional capacity and FDQ when compared to FIS and DBE.

Is the Short and Fast Step Test a safe and feasible tool for exploring anaerobic capacities of individuals with coronary heart disease in clinical practice?

BACKGROUND

While its importance in daily living, the anaerobic metabolism is not taken into account in clinical practice. The lack of validated functional performance tests for patients with chronic disabilities may explain this defect. In this context, the Short and Fast Step Test (SFST) was recently developed and validated in healthy volunteers.

AIM

The purpose of this study was to investigate the safety, feasibility and reliability of the SFST, a functional test exploring anaerobic metabolism in coronary patients during cardiac rehabilitation.

DESIGN

This study was a monocentric prospective study.

SETTINGS

This study took place in the rehabilitation center of the University Hospital Center of Dijon, France.

POPULATION

44 coronary patients, addressed for a first cardiac rehabilitation, were included in this protocol.

METHODS

All participants performed three SFST: T1 and T2 (including respiratory gas exchange) the first day of the program and T3 after 3 to 7 days. SFST consists of walking up and down a 17.5cm-high step as many times as possible in 1 minute. Safety was assessed by the percentage of patients who performed the SFST without reporting a fall, or muscular or cardiovascular events. Feasibility was evaluated by the percentage of patients who succeeded in doing the SFST. Reliability was assessed with the number of raised steps in same condition (T1-T3) and different conditions (T1-T2) using a 2-way intraclass correlation coefficient (ICC). Values were given with their 90% confidence interval [90%CI].

RESULTS

The safety was 95.2% [85.8;99.2] for T1, 88.1% [76.6;95.2] for T2 and 90.4% [79.5;96.7] for T3. 100% [93,1;100] of participants completed T1 and T2, 92.9% [82.6;98] T3. An ICC of 0.74 [0.60;0.84] was observed between T1 and T3 and of 0.87 [0.79;0.92] between T1 and T2.

CONCLUSIONS

This study demonstrates the good safety, feasibility and reliability of the SFST to assess anaerobic metabolism in coronary patients in a rehabilitation program.

CLINICAL REHABILITATION IMPACT

These results show that the SFST seems suitable for the evaluation of brief submaximal functional capacity in daily activities. It offers a real possibility to assess such capacity during the cardiac rehabilitation routine.

Six-minute walk test in cardiac rehabilitation

Six-minute walk test (6MWT) is a simple and safe tool for assessing exercise tolerance in  various  categories  of  patients.  Currently,  6MWT  is  used to assess the functional status of a patient and determine the strategy of increasing physical activity, primarily in patients with reduced exercise tolerance and contraindications for cardiopulmonary exercise  test. The basic requirements for the 6MWT are presented, taking into account the factors affecting its  informativeness  and  accuracy,  as  well  as the interpretation of results. The diagnostic and prognostic value of 6MWT in different categories of patients are discussed. The prospects for 6MWT use in cardiac rehabilitation for planning rehabilitation program, prescribing exercises,  determining  the  risk   of   complications,   and   evaluating the effectiveness  are  considered.  The  limitations  of  6MWT  and  ways to overcome it, as well as directions for further research are presented.

Validity of the Incremental Shuttle Walk Test to Assess Exercise Safety When Initiating Cardiac Rehabilitation in Low-Resource Settings

PURPOSE

To evaluate the validity of the Incremental Shuttle Walk Test (ISWT) for determining risk stratification in cardiac rehabilitation (CR).

METHODS

This is a cross-sectional study at a major CR center in a middle-income country. Clinically stable adult cardiac patients underwent an ISWT and an exercise test (ET), wore a pedometer for 7 d, and completed the Godin-Shepherd Leisure-Time Physical Activity Questionnaire. Metabolic equivalents of task (METs) achieved on the ISWT were calculated.

RESULTS

One hundred fifteen patients were evaluated. The mean ± standard deviation distance on the ISWT was 372.70 ± 128.52 m and METs were 5.03 ± 0.62. The correlation of ISWT distance with ET METs (7.57 ± 2.57), steps/d (4556.71 ± 3280.88), and self-reported exercise (13.08 ± 15.19) was rs = 0.61 (P < .001), rs = 0.37 (P < .001), and rs = 0.20 (P = .031), respectively. Distance on the ISWT accurately predicted METs from the ET (area under the receiver operating characteristic curve = 0.774). The ability to walk ≥410 m on the ISWT predicted, with a specificity of 81.5% and a sensitivity of 65.6%, a functional capacity of ≥7 METs on ET.

CONCLUSION

The ISWT is an alternative way to evaluate functional capacity in CR and can contribute to the process of identifying patients at low risk for a cardiac event during exercise at moderate intensity.

Increased Heart Rate during Walk Test Predicts Chronic-Phase Worsening of Renal Function in Patients with Acute Myocardial Infarction and Normal Kidney Function

Chronic-phase worsening renal function (WRF) in patients with acute myocardial infarction (AMI) has been associated with poor prognosis. However, there is no consensus on either the method of prevention or the cause. The aim of this study was to determine factors predictive of chronic-phase WRF from the viewpoint of circulatory dynamics response to exercise during hospitalization of AMI patients without renal dysfunction on admission. We studied 186 consecutively AMI patients who underwent the 200-m walk test. Chronic-phase WRF was defined as a 20% decrease in estimated glomerular filtration rate (eGFR) from baseline to 8–10 months after AMI onset. Heart rate (HR) and systolic blood pressure recorded during the 200-m walk test were evaluated as circulatory dynamics responses. In total, 94 patients were enrolled. Multiple linear regression analysis showed that ΔHR (peak-rest) associated significantly with ΔeGFR (β = 0.427, p = 0.018). The receiver operating characteristic curve of ΔHR to predict chronic-phase WRF showed an area under the curve of 0.77, with a cut-off value of 22.0 bpm having a 95% sensitivity and 55% specificity. Among circulatory dynamics responses during exercise in the acute phase after AMI, ΔHR was an independent predictor of chronic-phase WRF.

Relationship between the Kihon Checklist and the clinical parameters in patients who participated in cardiac rehabilitation

AIM

The Kihon Checklist is a useful screening tool for assessing frailty in older individuals. However, the clinical significance of the Kihon Checklist in cardiac rehabilitation patients remains unclear. The present study aimed to evaluate the relationship between the Kihon Checklist and the clinical parameters in patients who participated in cardiac rehabilitation.

METHODS

We enrolled 845 consecutive patients (584 men, mean age 71 years) who participated in cardiac rehabilitation at Juntendo University Hospital, Tokyo, Japan, between November 2015 and October 2017. The patients were divided into non-frailty (n = 287), pre-frailty (n = 270) and frailty (n = 288) groups according to their Kihon Checklist scores. Cardiopulmonary exercise testing was carried out in 302 patients.

RESULTS

The frailty group was older and had a higher prevalence of history of heart failure than the non-frailty group, although left ventricular ejection fraction did not differ significantly between groups. Nutritional index, trunk and limb muscle mass, lean body weight, and grip strength were significantly lower in the frailty and pre-frailty groups than those in the non-frailty group. In the cardiopulmonary exercise test, a stepwise significant decrease in peak oxygen uptake was observed across the three groups (non-frailty 17.2 ± 3.6, pre-frailty 16.0 ± 3.4, frailty 14.4 ± 3.5 mL/kg/min, P < 0.01). Multivariate regression analyses showed that the Kihon Checklist score was significantly and independently associated with peak oxygen uptake (r = -0.34, P < 0.0001).

CONCLUSIONS

The Kihon Checklist, which was associated with frailty and exercise tolerance, could be used as a clinical assessment method for patients who participated in cardiac rehabilitation. Geriatr Gerontol Int 2019; 19: 287-292.

Six-minute walk test and incremental shuttle walk test in the evaluation of functional capacity in Chagas heart disease

Chagas heart disease (CHD) leads to a progressive functional impairment. Field tests, as the 6-min walk test (6MWT) and the incremental shuttle walk test (ISWT), may be inexpensive approaches in the evaluation of functional capacity of these patients. The present study was addressed to compare the 6MWT and the ISWT measures, and to determine the accuracy of these tests in the identification of functional impairment in patients with CHD. Thirty-five patients with CHD (47.1±8.2 years, NYHA I–III) were evaluated by echocardiography, cardiopulmonary exercise test (CPET), 6MWT, and ISWT. Correlations between the CPET (peak oxygen uptake [peak VO2] and the ratio between ventilation and the carbon dioxide production [VE/VCO2 slope]) and the field tests (walking distances) were also performed. The receiver operating characteristic (ROC) curve was selected to identify the best distances related to identify those patients with functional impairment. There was no difference between distances walked during the 6MWT and ISWT (P=0.694). The Bland-Altman analysis showed good agreement between the field tests. Both 6MWT and ISWT correlated with peak VO2 (r=0.577, P<0.001 and r=0.587, P<0.001, respectively) and ISWT correlated with VE/VCO2 slope (r=−0.339, P=0.003). The cutoff distances of 6MWT and ISWT to identify patients with peak VO2 less than 20 mL/kg/min were 520 m and 400 m, respectively, with no difference between the areas under ROC curves (P=0.276). Both the 6MWT and the ISWT demonstrated accuracy in identify functional impairment in patients with CHD, being useful tools for the risk stratification of these patients.

Donor site morbidity after vascularized fibula free flap: gait analysis during prolonged walk conditions

The aim of this study was to determine the effect of vascularized fibula free flap (VFFF) harvest on gait variables during the six-minute walk test (6MWT). Eleven patients who had undergone VFFF harvest and 11 healthy peers participated in this case-control study. The main evaluation consisted of the collection of gait variables using the GAITRite system during three periods of the 6MWT: beginning (0-1min), middle (2:30-3:30min), and end (5-6min). The 6MWT was significantly shorter in the VFFF group than in the reference group (-31%, P<0.001). Most gait variables differed significantly between the groups for each period (P-value range 0.04-0.0004), including toe in/out on the operated side (P-value range 0.005-0.01). The increase in toe in/out on the operated side suggests a functional modification caused by an imbalance of the agonist-antagonist muscles. On comparison of the different periods, gait velocity decreased between the beginning and middle periods and increased between the middle and end periods in both groups. However, a significantly lower velocity between the beginning and end periods was found only for the VFFF group (P=0.026), suggesting an alteration in physical management. In conclusion, these results suggest that VFFF harvesting could alter gait and joint integrity.

Protocol for a phase II, monocentre, double-blind, placebo-controlled, cross-over trial to assess efficacy of pyridostigmine in patients with spinal muscular atrophy types 2-4 (SPACE trial)

INTRODUCTION

Hereditary proximal spinal muscular atrophy (SMA) is caused by homozygous loss of function of the survival motor neuron 1 gene. The main characteristic of SMA is degeneration of alpha motor neurons in the anterior horn of the spinal cord, but recent studies in animal models and patients have shown additional anatomical abnormalities and dysfunction of the neuromuscular junction (NMJ). NMJ dysfunction could contribute to symptoms of weakness and fatigability in patients with SMA. We hypothesise that pyridostigmine, an acetylcholinesterase inhibitor that improves neuromuscular transmission, could improve NMJ function and thereby muscle strength and fatigability in patients with SMA.

METHODS AND ANALYSIS

We designed a monocentre, placebo-controlled, double-blind cross-over trial with pyridostigmine and placebo to investigate the effect and efficacy of pyridostigmine on muscle strength and fatigability in patients with genetically confirmed SMA. We aim to include 45 patients with SMA types 2-4, aged 12 years and older in the Netherlands. Participants receive 8 weeks of treatment with pyridostigmine and 8 weeks of treatment with placebo in a random order separated by a washout period of 1 week. Treatment allocation is double blinded. Treatment dose will gradually be increased from 2 mg/kg/day to the maximum dose of 6 mg/kg/day in four daily doses, in the first week of each treatment period. The primary outcome measures are a change in the Motor Function Measure and repeated nine-hole peg test before and after treatment. Secondary outcome measures are changes in recently developed endurance tests, that is, the endurance shuttle nine-hole peg test, the endurance shuttle box and block test and the endurance shuttle walk test, muscle strength, level of daily functioning, quality of and activity in life, perceived fatigue and fatigability, presence of decrement on repetitive nerve stimulation and adverse events.

ETHICS AND DISSEMINATION

The protocol is approved by the local medical ethical review committee at the University Medical Center Utrecht and by the national Central Committee on Research Involving Human Subjects. Findings will be shared with the academic and medical community, funding and patient organisations in order to contribute to optimisation of medical care and quality of life for patients with SMA.

TRIAL REGISTRATION NUMBER

NCT02941328.

SMARTphone and social media-based Cardiac Rehabilitation and Secondary Prevention (SMART-CR/SP) for patients with coronary heart disease in China: a randomised controlled trial protocol

INTRODUCTION

The burden of cardiovascular disease (CVD) is rapidly increasing in developing countries, however access to cardiac rehabilitation and secondary prevention (CR/SP) in these countries is limited. Alternative delivery models that are low-cost and easy to access are urgently needed to address this service gap. The objective of this study is to investigate whether a smartphone and social media-based (WeChat) home CR/SP programme can facilitate risk factor monitoring and modification to improve disease self-management and health outcomes in patients with coronary heart disease (CHD), after percutaneous coronary intervention (PCI) therapy.

METHODS AND ANALYSIS

We propose a single-blind, randomised controlled trial of 300 patients post-PCI with follow-up over 12 months. The intervention group will receive a smartphone-based and WeChat-based CR/SP programme providing education and support for risk factor monitoring and modification. SMART-CR/SP incorporates core components of modern CR/SP: physical activity tracking with interactive feedback and goal setting; education modules addressing CHD understanding and self-management; remote blood pressure monitoring and strategies to improve medication adherence. Furthermore, a dedicated data portal and a CR/SP coach will facilitate individualised supervision and counselling. The control group will receive usual care but no formal CR/SP programme. The primary outcome is change in exercise capacity measured by 6 minute walk test distance. Secondary outcomes include knowledge and awareness of CHD, risk factor status, medication adherence, psychological well-being and quality of life, major cardiovascular events, re-hospitalisations and all-cause mortality. To assess the feasibility and patients' acceptance of the intervention, a process evaluation will be performed at the conclusion of the study.

ETHICS AND DISSEMINATION

Ethics approval was granted by both the Human Research Ethics Committee of Fudan University Zhongshan Hospital (HREC B2016-058) and Curtin University Human Research Ethics Office (HRE2016-0120). Results will be disseminated via peer-reviewed publications and presentations at conferences.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR-INR-16009598; Pre-results.

Utility of Walk Tests in Evaluating Functional Status Among Participants in an Outpatient Cardiac Rehabilitation Program

PURPOSE

Although walk tests are frequently used in cardiac rehabilitation (CR), no prior study has evaluated the capacity of these measures to predict peak oxygen uptake during exercise testing ((Equation is included in full-text article.)O2peak). This study evaluated the interrelationship of objective measures of exercise performance (walk and exercise testing) among patients entering CR as well as a novel measure of functional status assessment for use in CR.

METHODS

Forty-nine patients (33 males) referred to an outpatient CR program were evaluated with objective measures of ambulatory functional status (peak oxygen uptake [(Equation is included in full-text article.)O2peak], 6-minute walk test [6MWT], and 60-ft walk test [60ftWT]).

RESULTS

All measures of functional status were moderately to highly intercorrelated (r values from 0.50 to 0.88; P values < .05). The relationship among measures differed by sex, but not by age or diagnosis. Among men, results were generally consistent with the full sample. Among women, the magnitude of correlations was generally lower and there was no relationship between (Equation is included in full-text article.)O2peak and other measures.

CONCLUSIONS

Measures of functional status, including (Equation is included in full-text article.)O2peak, 6MWT, and 60ftWT, were highly correlated among CR patients, suggesting the plausibility of using them interchangeably to fit the needs of the patient and testing environment. Among women, walk tests may not be appropriate substitutes for (Equation is included in full-text article.)O2peak. Because of the brevity of the 60ftWT, it may be particularly useful for measuring functional status in patients with greater symptoms and those with comorbidities limiting walking.

Number of raised steps: A tool to assess brief and intense effort involving anaerobic metabolism

BACKGROUND

Although the initial anaerobic component of exercise adaptation is unavoidable, no specific functional test is available for use in routine non-sporting practice to evaluate it.

OBJECTIVE

To assess the bioenergetic and biomechanical properties of the Short and Fast Step Test (SFST), which consists of walking up and down a step as many times as possible in 1minute and to analyse its ability to explore the initial anaerobic component of effort in comparison to a reference self-paced step test.

METHODS

Overall, 31 healthy subjects (19 women; mean [SD] age, 32.4 [10.2] years) completed a test-retest of a self-paced step test and the SFST, with pre- and post-test measurement of blood lactate concentration and continuous recording of VO₂ and modelling of excess post-exercise oxygen consumption (EPOC), near-infrared spectroscopy (NIRS) of the quadriceps and mechanical power (estimated by the number of steps climbed and 3-D motion analysis).

RESULTS

Both step tests were well tolerated. The reliability of the bioenergetics parameters, number of raised steps, mechanical power and NIRS tissue saturation index was good. Indirect mechanical power (estimated from number of steps) was correlated with direct power (computed from the centre of mass). Lactate accumulation was significantly increased during exercise with only the SFST (mean [SD] increase, 3.86 [3.26]mmolL^-1 from resting values, P<0.05). EPOC was higher with the SFST than the self-paced step test (P<0.05). Only the SFST showed significant correlations between number of steps climbed and EPOC (r=0.84; P<0.001) and decreased tissue saturation index (NIRS) and EPOC area (r=-0.39; P<0.05).

CONCLUSIONS

SFST is feasible, well tolerated, reliable and responsive to explore a brief exercise involving anaerobic metabolism at submaximal intensity. The number of steps taken in 1minute seems a suitable parameter for practical application.

Heart rate recovery of individuals undergoing cardiac rehabilitation after acute coronary syndrome

BACKGROUND

An efficient cardiac rehabilitation programme (CRP) can improve the functional ability of patients after acute coronary syndrome (ACS).

OBJECTIVE

To examine the effect of a CRP on parasympathetic reactivation and heart rate recovery (HRR) measured after a 6-min walk test (6MWT), and correlation with 6MWT distance and well-being after ACS.

METHODS

Eleven normoweight patients after ACS (BMI<25kg/m²; 10 males; mean [SD] age 61 [9] years) underwent an 8-week CRP. Before (pre-) and at weeks 4 (W4) and 8 (W8) during the CRP, they performed a 6MWT on a treadmill, followed by 10-min of seated passive recovery, with HRR and HR variability (HRV) recordings. HRR was measured at 1, 3, 5 and 10min after the 6MWT (HRR1, HRR3, HRR5, HRR10), then modelized by a mono-exponential function. Time-domain (square root of the mean of the sum of the squares of differences between adjacent normal R-R intervals [RMSSD]) and frequency-domain (with high- and low-frequency band powers) were used to analyse HRV. Participants completed a mental and physical well-being questionnaire at pre- and W8. Exhaustion after tests was assessed by the Borg scale. Pearson correlation was used to assess correlations.

RESULTS

HRR3, HRR5 and HRR10 increased by 37%, 36% and 28%, respectively, between pre- and W8 (P<0.05), and were positively correlated with change in 6MWT distance (r=0.58, 0.66 and 0.76; P<0.05). Percentage change in HRR3 was positively correlated with change in well-being (r=0.70; P=0.01). Parasympathic reactivation (RMSSD) was improved only during the first 30sec of recovery (P=0.04).

CONCLUSION

Among patients undergoing a CRP after ACS, increased HRR after a 6MWT, especially at 3min, was positively correlated with 6MWT distance and improved well-being. HRR raw data seem more sensitive than post-exercise HRV analysis for monitoring functional and autonomic improvement after ACS.

Fixed-distance walk tests at comfortable and fast speed: Potential tools for the functional assessment of coronary patients?

OBJECTIVES

There is ambiguity concerning the walk tests available for functional assessment of coronary patients, particularly for the walking speed. This study explores the psychometric properties of two walking tests, based on fixed-distance tests, at comfortable and fast velocity, in stabilized patients at the end of a cardiac rehabilitation program.

METHODS

At a three-day interval 58 coronary patients (mean age of 64.85±6.03 years, 50 men) performed three walk tests, the first two at a comfortable speed in a random order (6-minute walk test - 6MWT - and 400-metre comfortable walk test - 400mCWT) and the third at a brisk speed (200-metre fast walk test - 200mFWT). A modified Bruce treadmill test was associated at the end of the second phase. Monitored main parameters were: heart rate, walking velocity, VO₂.

RESULTS

Tolerance to the 3 tests was satisfactory. The reliability of the main parameters was good (intraclass correlation coefficient>0.8). The VO₂ concerning 6MWT and 400mCWT were not significantly different (P=0.33) and were lower to the first ventilatory threshold determined by the stress test (P<0.001): 16.2±3.0 vs. 16.5±2.6 vs. 20.7±5.1mL·min^-1·kg^-1 respectively. The VO₂ of the 200mFWT (20.2±3.7) was not different from the first ventilatory threshold.

CONCLUSIONS

400mCWT and 200mFWT are feasible, well-tolerated and reliable. They explore two levels of effort intensity (lower and not different to the first ventilatory threshold respectively). 400mCWT is a possible alternative to 6MWT. Associated with 200mFWT it should allow a better measurement of physical capacities and better customization of exercise training.

The Functional Exercise Capacity Is Associated With Global Functioning in People With Bipolar Disorder

The aim of the current study was to determine whether the Global Assessment of Functioning (GAF) score is associated with the functional exercise capacity among in- and outpatients with bipolar disorder. Sixty-five (36♀) persons with bipolar disorder performed a 6-minute walk test (6MWT) and were assessed with the GAF, Quick Inventory of Depressive Symptomatology Self Report (QIDS), and the International Physical Activity Questionnaire (IPAQ). The mean GAF-score was 55.0 ± 15.0, whereas the mean distance achieved on the 6MWT was 615.6 ± 118.6 m. There was a positive association between the GAF score and 6MWT score (r = 0.60, p < 0.001). A backward regression analysis demonstrated that an inpatient status, illness duration (16.1 ± 10.7 years), and the QIDS score (7.7 ± 5.7) explained 72.4% of the GAF-score variance. The GAF, QIDS score, and age explained 74.1% of the 6MWT-score variance. Our results indicate that a bidirectional relationship is evident between the exercise capacity and global functioning among people with bipolar disorder.

Comparison of two- and six-minute walk tests in detecting oxygen desaturation in patients with severe chronic obstructive pulmonary disease - A randomized crossover trial

The two-minute walk test (2MWT) is less well validated than the well-known six-minute walk test (6MWT) as a field walking test in patients with chronic obstructive pulmonary disease (COPD). The primary objective of this study was to compare the accuracy of the 2MWT to the 6MWT in detecting exercise-induced oxygen desaturation in patients with severe COPD. Twenty-six patients with COPD (age: 61 ± 10 years, forced expired volume in one second: 37 ± 10%) that were normoxemic at rest performed a 2MWT and a 6MWT under normal ambient conditions on two consecutive days in random order. Oxygen saturation, total walking distance, heart rate, breathing frequency, dyspnea, and leg fatigue were evaluated. Average walking distances were 150 m (95% confidence interval (95% CI): 134-165 m) and 397 m (95% CI: 347-447 m) for the 2MWT and 6MWT, respectively (r = 0.80, p < 0.0001). The difference in minimum oxygen saturation during the 2MWT (83%, 95% CI: 81-86%) and 6MWT (mean 82%, 95% CI: 80-84%) was not statistically different and the data strongly correlated between the groups (r = 0.81, p < 0.0001). Other measurements from the 6MWT, including heart rate, breathing rate, and levels of perceived exertion were also comparable in 2MWT. The 2MWT showed comparable validity in detecting exercise-induced oxygen desaturation in patients with severe COPD compared to the 6MWT.

Improvement of Pulmonary Functions Following Septoplasty: How Are Lower Airways Affected?

Objectives

Nasal septal deviation is a frequent cause of increased nasal airway resistance. A narrow nasal airway would result in a decreased airflow into the lungs. The aim of the present study was to evaluate the alterations of the pulmonary functions following septoplasty using spirometry and 6 minutes walking test (6mWT). And reveal the correlation of symptom score improvement with nasal obstruction symptom score (NOSE) and sino-nasal outcome test (SNOT22) questionnaires following surgery.

Methods

Thirty patients with obvious nasal septal deviations were enrolled in the study. All patients had a detailed otorhinolaryngologic examination, filled NOSE/SNOT22 questionnaires, performed spirometry and 6mWT preoperatively. One month after surgery, NOSE/SNOT22 questionnaires filled by subjects and spirometry with 6mWT were performed again, and the results were compared.

Results

The mean total walking distance was 702.3±68.2 m preoperatively, and it improved to 753.2±72.6 m postoperatively (P<0.001). Total tour count increased from 11 (range, 10.8 to 12.0) to 12 (range, 11 to 13.3), and the difference was found statistically significant (P<0.001). When the preoperative and postoperative mean 6mWT results were compared, diastolic blood pressure increased from 70 to 80 mmHg (P=0.031), heart rate increased from 83.5±13.2 to 90.1±12.5 bpm (P=0.017), dyspnea rate decreased from 1 to 0 (P=0.002), and fatigue scores reduced from 2 to 1 (P=0.003). Evaluation on spirometry findings revealed that FIF_50% (maximum inspiratory flow at 50% of forced vital capacity [FVC]) scores and peak expiratory flow (PEF) values improved significantly after surgery. Septoplasty improves the nasal breathing pattern. While reducing FEF_50% (maximum expiratory flow at 50% of FVC)/FIF_50%, it increases PEF and FIF_50% values. In addition, as shown by 6mWT, exercise capacity improves following surgery. Postoperative NOSE and SNOT22 scores reduced markedly compared to preoperative values (P<0.001).

Conclusion

These findings suggest that nasal septal surgery has a positive effect on pulmonary functions, and this can be an important clue for the relationship of lung disorders and nasal obstruction.

Could the two-minute step test be an alternative to the six-minute walk test for patients with systolic heart failure?

BACKGROUND

The consequence of exercise intolerance for patients with heart failure is the difficulty climbing stairs. The two-minute step test is a test that reflects the activity of climbing stairs.

DESIGN

The aim of the study design is to evaluate the applicability of the two-minute step test in an assessment of exercise tolerance in patients with heart failure and the association between the six-minute walk test and the two-minute step test.

METHODS

Participants in this study were 168 men with systolic heart failure (New York Heart Association (NYHA) class I-IV). In the study we used the two-minute step test, the six-minute walk test, the cardiopulmonary exercise test and isometric dynamometer armchair.

RESULTS

Patients who performed more steps during the two-minute step test covered a longer distance during the six-minute walk test (r = 0.45). The quadriceps strength was correlated with the two-minute step test and the six-minute walk test (r = 0.61 and r = 0.48). The greater number of steps performed during the two-minute step test was associated with higher values of peak oxygen consumption (r = 0.33), ventilatory response to exercise slope (r = -0.17) and longer time of exercise during the cardiopulmonary exercise test (r = 0.34). Fatigue and leg fatigue were greater after the two-minute step test than the six-minute walk test whereas dyspnoea and blood pressure responses were similar.

CONCLUSION

The two-minute step test is well tolerated by patients with heart failure and may thus be considered as an alternative for the six-minute walk test.

Are cardiovascular and metabolic responses to field walking tests interchangeable and obesity-dependent?

PURPOSE

To investigate if cardiovascular and metabolic responses to the six-minute walk test (6MWT) and incremental shuttle walking test (ISWT) are in agreement with cardiopulmonary exercise testing (CPX) and determine if both submaximal tests are interchangeable in obese and eutrophic individuals.

METHOD

Observational and cross-sectional study included 51 obese women (ObG) and 21 controls (CG) (20-45 years old). Subjects underwent clinical evaluation, CPX, the 6MWT and ISWT. We applied Bland-Altman plots to assess agreement between walking tests and CPX. Correlation analysis assessed relationships between key variables.

RESULTS

There was an agreement between CPX and both the 6MWT [oxygen uptake (VO2 mL kg(-1) min(-1)) = 6.9 (CI: 5.7-8.1), and heart rate (bpm) = 37.0 (CI: 33.3-40.7)] and ISWT [VO2 (mL kg(-1) min(-1)) = 6.1 (CI: 4.9-7.3), and heart rate (bpm) = 36.2 (CI: 32.1-40.3)]. We found similar cardiovascular and metabolic responses to both tests in the ObG but not in the CG. Strong correlations were demonstrated between 6MWT and ISWT variables: VO2 ( r = 0.70); dyspnoea (r = 0.80); and leg fatigue (r = 0.70).

CONCLUSIONS

6MWT and ISWT may both hold interchangeable clinical value when contrasted with CPX in obese women and may be a viable alternative in the clinical setting when resources and staffing are limited. Implications for Rehabilitation Obesity is a worldwide epidemic, with high prevalence in women, and it is associated to impaired cardiorespiratory fitness and functional capacity as well as high mortality risk. Assessing oxygen uptake by means of cardiopulmonary exercise testing is the gold standard method for evaluating and stratifying cardiorespiratory fitness, however it is not ever applied due to costs and staffing. Walking field tests may be a cost-effective approach that provides valuable information regarding the functional capacity in agreement to metabolic and cardiovascular responses of cardiopulmonary exercise testing.

Value of preoperative 6-minute walk test for predicting postoperative pulmonary complications

OBJECTIVES

The objective of this study was to determine the performance of preoperative 6-minute walk test (6MWT) for predicting postoperative pulmonary complications (PPC) in high risk patients undergoing elective surgery under general anesthesia.

METHODS

A prospective cohort study was conducted in patients scheduled to undergo elective thoracic or nonthoracic surgery and indicated for preoperative pulmonary evaluation in Songklanagarind Hospital, Songkhla, Thailand. Preoperative spirometry, 6MWT were done and 30-day PPC were recorded. The multiple regression analysis and receiver operating characteristic (ROC) curves were used to analyze the variables and to compare the performance of 6MWT and spirometry tests.

RESULTS

A total of 78 participants were recruited into the study. 6MWT was done completely in all cases without any complications. Among these tests, 14 cases (17.9%) had contraindications to spirometry and two cases were unable to achieve the criteria for acceptable efforts. PPC developed in 17 cases (21%) with a high mortality (17.7%). A multiple regression analysis showed elderly, poor general health status, smoking history, low level of the mean value of forced expiratory volume in 1 second (FEV1) % predicted (by spirometry) and shorter 6-minute walk distance (6MWD) were the independent factors associated with PPC. Patients developing PPC had a significantly lower preoperative 6MWD compared with patients without PPC (256.0 ± 48.0 versus 440.0 ± 117.1 meters, p < 0.001). 6MWD of ⩽325 meters was a threshold for predicting PPC with 77% sensitivity and 100% specificity, and had a good predictive value for PPC similar to that for the FEV1 %.

CONCLUSIONS

Preoperative 6MWT is a very useful alternative test for predicting PPC in high risk patients scheduled to undergo surgery under GA.