Multidisciplinary-derived clinical score for accurate prediction of long-term mortality in fibrotic lung disease patients

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) stands out as one of the most aggressive forms of interstitial lung diseases (ILDs), currently without a definitive cure. Multidisciplinary discussion (MDD) is now considered a cornerstone in diagnosing and differentiating ILD subtypes. The Gender-Age-Physiology (GAP) score, developed to assess IPF prognosis based on sex, age, forced vital capacity, and diffusion capacity for carbon monoxide (DLCO), is limited in not considering dyspnea and functional impairment during the walking test. We proposed a MDD-based clinical score for mortality prediction among those patients.

METHODS

From December 2018 to December 2019, we enrolled ILD patients with IPF and non-IPF and followed-up them till December 2020. Based on DLCO, modified Medical Research Council (mMRC) Dyspnea Scale, and six-minute walking test (6MWT) distance, a functional score was developed for mortality prediction.

RESULTS

We enrolled 104 ILD patients, 12 (11.5%) died by the one-year follow-up. In receiver operating characteristic (ROC) curve analysis, DLCO (% predicted) was the most accurate variable predicting one-year mortality with an area under curve (AUC) of 0.88 (95% confidence interval [CI] = 0.80-0.94), followed by mMRC Dyspnea Score (AUC = 0.82 [95% CI = 0.73-0.89]), 6MWT distance (AUC = 0.80 [95% CI = 0.71-0.88]), and GAP score (AUC = 0.77 [95% CI = 0.67-0.84]). Only the GAP score (hazard ratio [HR] = 1.55, 95% CI = 1.03-2.34, p = 0.0.37) and functional score (HR = 3.45, 95% CI = 1.11-10.73, p = 0.032) were significantly associated with one-year mortality in multivariable analysis.

CONCLUSION

The clinical score composite of DLCO, mMRC Dyspnea Scale, and 6MWT distance could provide an accurate prediction for long-term mortality in ILD patients, laying out a helpful tool for managing and following these patients.

Kinematic parameters related to functional capacity, fatigue, and breathlessness during the 6-min walk test in older adults with heart failure with preserved ejection fraction

AIMS

This paper aims to assess kinematic parameters related to functional capacity, fatigue, and breathlessness during the 6-min walk test (6MWT) in patients with heart failure with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

A cross-sectional study was conducted in which adults 70 years or older with HFpEF were voluntarily recruited between April 2019 and March 2020. An inertial sensor was placed at the L3-L4 level and another on the sternum to assess kinematic parameters. The 6MWT was divided into two 3-min phases. Leg fatigue and breathlessness, assessed by the Borg scale, the heart rate (HR), and the oxygen saturation (SpO2), were measured at the beginning and the end of the 6MWT. The difference in kinematic parameters between the 6MWT two 3-min phases was also calculated. Bivariate Pearson correlations and subsequent multivariate linear regression analysis were performed. Seventy older adults with HFpEF (mean = 80.74 years old) were included. Kinematic parameters explained 81.00% of the functional capacity, 45.50% of the leg fatigue and 66.10% of the breathlessness variance. Moreover, kinematic parameters could explain 30.90% of the SpO2 variance at the end of the 6MWT. Kinematic parameters also explained 33.10% of the SpO2 difference between the beginning and end of 6MWT. Kinematic parameters explained neither the HR variance at the end of 6MWT nor the HR difference between the beginning and end.

CONCLUSION

Gait kinematics from L3-L4 and sternum explain a part of the variance in subjective outcomes, assessed by the Borg scale, and objective outcomes such as functional capacity and SpO2. The kinematic assessment allows clinicians to quantify fatigue and breathlessness through objective parameters related to the patient's functional capacity.

REGISTRATION

ClinicalTrials.gov NCT03909919.

Post-COVID-19 cardio-pulmonary manifestations after 1-year of SARS-CoV-2 infection among Indian population: A single centre, case-control study (OneCoV2 study)

BACKGROUND

The evolving challenge of persistent symptoms post-Coronavirus disease-2019 (COVID-19), particularly debilitating cardio-pulmonary manifestations, necessitates further exploration. Our study aimed to assess the cardio-pulmonary complications in patients a year after hospital discharge from severe COVID-19, contrasting these with findings from a non-COVID group.

METHODS

The OneCoV2 study, a prospective, case-control study, was conducted at a tertiary care teaching hospital in northern India. We enrolled 43 subjects, with a mean age of 25.57 ± 7.94 years (COVID group) and 27.30 ± 8.17 years (non-COVID group). Comprehensive tests included pulmonary function tests, cardiac function tests, 6-min walk tests, and laboratory investigations.

RESULTS

Significant differences were found in the pulmonary function [forced vital capacity (FVC) (p = 0.037), forced expiratory flow (FEF) 25-75 % (p = 0.013)], and cardiac function [left ventricular ejection fraction (LVEF) (p = 0.032), heart rate (HR) (p = 0.047)], along with the six-minute walk test results between the two groups. In the COVID group, Pearson's correlation showed a negative correlation between FVC and C-reactive protein (CRP) [r = -0.488, p = 0.007] and a positive correlation between the six-minute walk test [r = 0.431, p = 0.003] and HR [r = 0.503, p = 0.013].

CONCLUSIONS

Our data suggest that pulmonary abnormalities are prevalent in COVID patients even after 1-year of hospital discharge. Cardiac biomarkers also show an inclination towards the COVID group. While we found significant correlations involving some parameters like FVC, CRP, HR, and results from the six-minute walk test, we did not find any significant correlations with the other tested parameters in our study.

Influence of transcutaneous electrical nerve stimulation on the distance walked by older adults during the 6-min test of walking endurance

The purpose of our study was to compare the influence of two types of transcutaneous electrical nerve stimulation (TENS) on the performance of older adults on the 6-min test of walking endurance and on the ability to maintain balance during upright standing. Twenty-six healthy older adults (72 ± 5.4 yrs) performed tests of motor function while TENS was applied to the tibialis anterior and rectus femoris muscles of each leg. Linear mixed models were used to compare the influence of TENS on walking distance in a 6-min test of walking endurance and on sway-area rate in tests of standing balance. There was a significant decrease in the distances walked in each minute of the 6-min walk test for both the Continuous and Burst TENS modes compared with Baseline (p < 0.01 and p < 0.001, respectively). The influence of TENS on walking distance was associated with several significant effects on the mean and coefficient of variation for stride length and stride frequency between the first and last minute of the test and between the two TENS modes and the Baseline values. In contrast, there was no significant effect of TENS on sway-area rate in any balance test, which indicates that the supplementary sensory feedback compromised walking performance of older adults but not the ability to maintain balance during upright standing.

Exercise-induced desaturation during a six-minute walk test is associated with poor clinical outcomes in patients with pulmonary arterial hypertension

BACKGROUND

The six-minute walk test (6MWT) is an established exercise test for patients with pulmonary arterial hypertension (PAH), affording insight into both exercise intolerance and overall prognosis. Despite the widespread application of the 6MWT, the prognostic implications of exercise-induced desaturation (EID) during this test has been inadequately studied in PAH patients. Thus, we evaluated the occurrence of EID and its prognostic significance in PAH patients.

METHODS

We analyzed PAH patients in a single-center cohort from April 2016 to March 2021. EID was defined as a reduction in oxygen saturation exceeding 4% from the baseline or to below 90% at any point during the test.

RESULTS

We analyzed 20 PAH patients in this cohort, primarily consisting of 16 females with an average age of 48.4 ± 13.3 years. Among them, ten exhibited EID. Baseline characteristics, echocardiographic data and right heart catheterization data were similar between the two groups. However, total distance (354.3 ± 124.4 m vs. 485.4 ± 41.4 m, P = 0.019) and peak oxygen uptake (12.9 ± 3.2 mL/kg⋅min vs. 16.4 ± 3.6 mL/kg⋅min, P = 0.019) were significantly lower in the EID group. During the total follow-up duration of 51.9 ± 25.7 months, 17 patients had at least one adverse clinical event (2 deaths, 1 lung transplantation, and 13 hospital admissions). The presence of EID was associated with poor clinical outcome (hazard ratio = 6.099, 95% confidence interval = 1.783-20.869, P = 0.004).

CONCLUSIONS

During the 6MWT, EID was observed in a half of PAH patients and emerged as a significant prognostic marker for adverse clinical events.

Study the association between spirometry based functional grading and six minute walk distance in chronic respiratory disease patients at a rural tertiary care centre of India

Introduction

Six-min walk test (6MWT) is easy to use, the least expensive, and a quick measure of physical function and it reflects the capacity to perform our day-to-day activities hence quality of life can be assessed with 6MWT. This study was planned to assess the role of 6MWT in chronic respiratory disease patients and its association with spirometry-based functional grading at a rural tertiary care center of northern India.

Materials and Methods

This was a hospital-based cross-sectional study done between December 2019 and July 2021. In this study, 110 patients were included as per inclusion and exclusion criteria. 6MWT and spirometry were conducted as per the American Thoracic Society/European Research Society recommendation using Spiropalm 6MWT and the association between 6MWT and spirometry was assessed.

Results

A total of 110 chronic respiratory disease patients were included in the study. There were 69 (63%) males while 41 (37%) were females. Among study participants, chronic obstructive pulmonary disease patients were the most common 48 (43.6%) patients, followed by asthma 28 (25.5%), posttuberculosis sequelae patients 22 (20%), interstitial lung disease 9 (8.2%), and bronchiectasis 3 (2.7%) patients were found. There was a significant positive correlation of 6-min walk distance (6MWD) and % predicted 6MWD with spirometric parameters, forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and there was a significant positive correlation of 6MWD with FEV1% (predicted) also. 6MWD and % predicted 6MWD negatively correlated with FEV1/FVC and association between 6MWD and FEV1/FVC was not statistically significant and between % predicted 6MWD and FEV1/FVC, it was found statistically significant.

Conclusion

The 6MWD traveled by chronic respiratory disease patients was significantly lower than the predicted 6MWD and 6MWD correlated with spirometric variables well. Therefore, it can conclude that 6MWT is a useful alternative of spirometry in the management of chronic respiratory disease patients in resource-limited settings.

Persistent Endothelial Lung Damage and Impaired Diffusion Capacity in Long COVID

Since the beginning of the pandemic, both COVID-19-associated coagulopathy biomarkers and a plethora of endothelial biomarkers have been proposed and tested as prognostic tools of severity and mortality prediction. As the pandemic is gradually being controlled, attention is now focusing on the long-term sequelae of COVID-19. In the present study, we investigated the role of endothelial activation/dysfunction in long COVID syndrome. This observational study included 68 consecutive long COVID patients and a healthy age and sex-matched control group. In both groups, we measured 13 endothelial biomarkers. Moreover, in the long COVID patients, we evaluated fatigue and dyspnea severity, lung diffusion capacity (DLCO), and the 6-min walk (6MWT) test as measures of functional capacity. Our results showed that markers of endothelial activation/dysfunction were higher in long COVID patients, and that soluble intracellular adhesion molecule 1 (sICAM-1) and soluble vascular adhesion molecule 1 (sVCAM-1) negatively correlated with lung diffusion and functional capacity (sICAM-1 vs. DLCO, r = -0.306, p = 0.018; vs. 6MWT, r = -0.263, p = 0.044; and sVCAM-1 vs. DLCO, r= -0.346, p = 0.008; vs. 6MWT, r = -0.504, p < 0.0001). In conclusion, evaluating endothelial biomarkers alongside clinical tests might yield more specific insights into the pathophysiological mechanisms of long COVID manifestations.

Influence of transcutaneous electrical nerve stimulation on walking kinematics and standing balance of older adults who differ in walking speed

The purpose was to determine the impact of transcutaneous electrical nerve stimulation (TENS) on measures of walking kinematics and standing balance of healthy older adults who were stratified into two groups based on differences in the distance walked during the 6-min test of walking endurance. Regression models were developed to explain the variance in the 6-min distance and to assess the predictive power of balance metrics to categorize the 26 older adults (72 ± 5.4 yrs) as either slow or fast walkers. Walking kinematics were measured during 6- and 2-min walk tests that were performed with and without the concurrent application of TENS to the hip flexor and ankle dorsiflexor muscles. Participants walked briskly during the 6-min test and at a preferred pace during the 2-min test. The supplementary sensory stimulation provided by TENS did not alter the power of the models to explain the variance in the Baseline 6-min distance: Baseline, R² = 0.85; TENS, R² = 0.83. In contrast, TENS improved the explanatory power of the data obtained during the 2-min walk to account for the variance in the Baseline 6-min distance: no TENS, R² = 0.40; TENS, R² = 0.64. Logistic regression models based on force-plate and kinematic data obtained during the balance tasks were able to discriminate between the two groups with excellent certainty. The impact of TENS was greatest when older adults walked at a preferred speed but not when they walked at a brisk pace or performed tests of standing balance.

Effects of early mobilisation program on functional capacity, daily living activities, and N-terminal prohormone brain natriuretic peptide in patients hospitalised for acute heart failure. A randomised controlled trial

Background

Patients hospitalised for acute decompensated heart failure (ADHF) show reduced functional capacity, limited activities of daily living (ADL), and elevated N-terminal prohormone of brain natriuretic peptide (NT-proBNP). The management of these patients focuses mainly on medical therapy with little consideration for in-patient cardiac rehabilitation. There has been a growing interest in evaluating the efficacy of early mobilisation, as the core for in-hospital rehabilitation, in ADHF patients in the last decade; however, the randomised trials on this topic are few.

Objective

This randomised-controlled study, therefore, aimed to further test the hypothesis that early supervised mobilisation would have beneficial effects on functional capacity, ADL, and NT-proBNP in stabilised patients following ADHF.

Methods

This is a single-centered, randomised-controlled, parallel-group trial in which 30 patients hospitalised for ADHF were randomly assigned to two groups; the study group (age = 55 . 4 ± 5 . 46 years, n 1 = 15 ) and the control group (age = 55 . 73 ± 5 . 61 years, n 2 =15). Inclusion criteria were ADHF on top of chronic heart failure independent of etiology or ejection fraction, clinical/hemodynamic stability, age from 40 to 60 years old, and both genders. Exclusion criteria were cardiogenic shock, acute coronary ischemia, or significant arrhythmia. Both groups received the usual medical care, but only the study group received an early structured mobilisation protocol within 3 days of hospital admission till discharge. The outcome measures were the 6-min walk distance (6-MWD) and the rating of perceived exertion (RPE) determined from the 6-min walk test at discharge, the Barthel index (BI), NT-proBNP, and the length of hospital stays (LOS).

Results

The study group showed significantly greater improvements compared to the controls in the 6-MWD (252 . 28 ± 92 . 32 versus 106 . 35 ± 56 . 36 m, P < 0 . 001 ), the RPE (12 . 53 ± 0 . 91 versus 15 . 4 ± 1 . 63 , P < 0 . 001 ), and the LOS (10 . 42 ± 4 . 23 versus 16 . 85 ± 6 . 87 days, p = 0 . 009 ) at discharge. Also, the study group showed significant improvements in the BI compared to baseline [100 (100-100) versus 41.87 (35-55), p = 0 . 009 ] and the controls [100 (100-100) versus 92.5(85-95), p = 0 . 006 ]. The mean value of NT-proBNP showed a significant reduction only compared to baseline (786 . 28 ± 269 . 5 versus 1069 . 03 ± 528 . 87 pg/mL, p = 0 . 04 ) following the intervention. The absolute mean change (Δ ) of NT-proBNP showed an observed difference between groups in favor of the study group (i.e., Δ = ↓ 282 . 75 ± 494 . 13 pg/mL in the study group versus ↓ 26 . 42 ± 222 . 21 pg/mL in the control group, p = 0 . 077 ).

Conclusion

Early structured mobilisation under the supervision of a physiotherapist could be strongly suggested in combination with the usual medical care to help improve the functional capacity and daily living activities, reduce NT-proBNP levels, and shorten the hospital stay in stabilised patients following ADHF. Trial registration number: PACTR202202476383975.

estimated maximum oxygen consumption for predicting postoperative pulmonary complications in patients undergoing upper abdominal surgery: a prospective cohort study

OBJECTIVE

The present study aims to evaluate the predictive ability of estimated maximum oxygen consumption (e[Formula: see text]O_2max) and 6-min walk distance (6MWD) for postoperative pulmonary complications (PPCs) in adult surgical patients undergoing major upper abdominal surgery.

METHOD

This study was conducted by collecting data prospectively from a single center. The two predictive variables in the study were defined as 6MWD and e[Formula: see text]O_2max. Patients scheduled for elective major upper abdominal surgery from March 2019 to May 2021 were included. The 6MWD was measured for all patients before surgery. e[Formula: see text]O_2max was calculated using the regression model of Burr, which uses 6MWD, age, gender, weight, and resting heart rate (HR) to predict aerobic fitness. The patients were categorized into PPC and non-PPC group. The sensitivity, specificity, and optimum cutoff values for 6MWD and e[Formula: see text]O_2max were calculated to predict PPCs. The area under the receiver operating characteristic curve (AUC) of 6MWD or e[Formula: see text]O_2max was constructed and compared using the Z test. The primary outcome measure was the AUC of 6MWD and e[Formula: see text]O_2max in predicting PPCs. In addition, the net reclassification index (NRI) was calculated to assess ability of e[Formula: see text]O_2max compared with 6MWT in predicting PPCs.

RESULTS

A total of 308 patients were included 71/308 developed PPCs. Patients unable to complete the 6-min walk test (6MWT) due to contraindications or restrictions, or those taking beta-blockers, were excluded. The optimum cutoff point for 6MWD in predicting PPCs was 372.5 m with a sensitivity of 63.4% and specificity of 79.3%. The optimum cutoff point for e[Formula: see text]O_2max was 30.8 ml/kg/min with a sensitivity of 91.6% and specificity of 79.3%. The AUC for 6MWD in predicting PPCs was 0.758 (95% confidence interval (CI): 0.694-0.822), and the AUC for e[Formula: see text]O_2max was 0.912 (95%CI: 0.875-0.949). A significantly increased AUC was observed in e[Formula: see text]O_2max compared to 6MWD in predicting PPCs (P < 0.001, Z = 4.713). And compared with 6MWT, the NRI of e[Formula: see text]O_2max was 0.272 (95%CI: 0.130, 0.406).

CONCLUSION

The results suggested that e[Formula: see text]O_2max calculated from the 6MWT is a better predictor of PPCs than 6MWD in patients undergoing upper abdominal surgery and can be used as a tool to screen patients at risk of PPCs.

Associations between physical activity and cardiorespiratory fitness with vascular health phenotypes in older adults: a cross-sectional study

Objective: We investigated the associations between physical activity (PA) and cardiorespiratory fitness (CRF) with vascular health phenotypes in community-dwelling older adults. Methods: This cross-sectional study included 82 participants (66.8 ± 5.2 years; 81% females). Moderate-to-vigorous physical activity (MVPA) was assessed using accelerometers, and CRF was measured using the distance covered in the 6-min walk test (6MWT). The vascular health markers were as follows: i) arterial function measured as aortic pulse wave velocity (aPWV) estimated using an automatic blood pressure device; and ii) arterial structure measured as the common carotid intima-media thickness (cIMT). Using a combination of normal cIMT and aPWV values, four groups of vascular health phenotypes were created: normal aPWV and cIMT, abnormal aPWV only, abnormal cIMT only, and abnormal aPWV and cIMT. Multiple linear regression was used to estimate the beta coefficients (β) and their respective 95% confidence intervals (95% CI) adjusting for BMI, and medication for diabetes, lipid, and hypertension, sex, age, and blood pressure. Results: Participants with abnormal aPWV and normal cIMT (β = -53.76; 95% CI = -97.73--9.78 m; p = 0.017), and participants with both abnormal aPWV and cIMT (β = -71.89; 95% CI = -125.46--18.31 m; p = 0.009) covered less distance in the 6MWT, although adjusting for age, sex and blood pressure decreased the strength of the association with only groups of abnormal aPWV and cIMT covering a lower 6MWT distance compared to participants with both normal aPWV and cIMT (β = -55.68 95% CI = -111.95-0.59; p = 0.052). No associations were observed between MVPA and the vascular health phenotypes. Conslusion: In summary, poor CRF, but not MVPA, is associated with the unhealthiest vascular health phenotype (abnormal aPWV/cIMT) in older adults.

Predictors of the 6-min walk test in patients with ovarian cancer

PURPOSE

To identify the predictors of the 6-min walk test (6MWT) and investigate the relationship between 6MWT, performance status, functional mobility, fatigue, quality of life, neuropathy, physical activity level, and peripheral muscle strength in patients with ovarian cancer (OC).

METHODS

Twenty-four patients diagnosed with stage II-III ovarian cancer were included in the study. Patients were assessed using the following measurement methods: 6MWT for walking capacity, Eastern Cooperative Oncology Group Performance Scale (ECOG-PS) for performance status, an armband physical activity monitor for physical activity level, Checklist Individual Strength (CIS) for fatigue, Functional Cancer Treatment Evaluation with Quality of Life-Extreme (FACT-O) for quality of life, Functional Evaluation of Cancer Treatment/Gynecological Oncology-Neurotoxicity (FACT/GOG-NTX) for neuropathy, a hand-held dynamometer for peripheral muscle strength, and 30-s chair-stand test for functional mobility.

RESULTS

The mean 6MWT distance was 578.48 ± 115.33 meters. 6MWT distance correlated with ECOG-PS score (r = -0.438, p = 0.032), handgrip strength (r = 0.452, p= 0030), METs (r = 0.414, p = 0.044) 30s-CST (r= 0.417, p= 0.043), and neuropathy score (r = 0.417, p = 0.043) significantly. There was no relationship between 6MWT distance and other parameters (p> 0.05). Multiple linear regression analysis demonstrated that performance status was the sole predictor of 6MWT.

CONCLUSION

The walking capacity seems to be associated with performance status, peripheral muscle strength, level of physical activity, functional mobility, and severity of neuropathy in patients with ovarian cancer. Evaluating these may help clinicians to understand factors behind the decreased walking capacity.

Effects of incorporating dual task into repeated 6-min walk test on balance and walking functions in patients with subacute stroke: A randomized controlled trial

OBJECTIVE

To explore the effects of incorporating dual task into a repeated 6-min walk test (6MWT) on balance and walking functions in patients with subacute stroke.

METHODS

Twenty-eight subacute stroke survivors were randomized into experimental group (EG) and control group (CG). EG and CG participated in dual task during the repeated 6MWT and the repeated 6-min test, respectively, for twice a day, three times weekly over 4 weeks. Outcome assessments were measured pre- and post-test using the 10-m walk test (10MWT), timed up and go test (TUG), 6MWT, Berg balance scale (BBS), and the activities specific balance confidence scale (ABC).

RESULTS

In the between-group comparison, change values in the 6MWT and ABC values between pre- and post-test appeared to be significantly different (p < 0.05). In within-group comparisons, the 10MWT, 6MWT, TUG, and ABC scores showed significant differences between pre- and post-test values in two groups (p < 0.05).

CONCLUSION

Repeated 6MWT may be beneficial to enhance balance and walking functions in patients with subacute stroke, with more favorable effects when performing dual tasks.

Impaired Dynamic Response of Oxygen Saturation During the 6-min Walk Test Is Associated With Mortality in Chronic Fibrosing Interstitial Pneumonia

BACKGROUND

The 6-min walk test (6MWT) is a common assessment of exercise-induced hypoxemia and exercise capacity used in patients with chronic fibrosing interstitial pneumonia (CFIP). However, whether the dynamic changes in SpO2 and heart rate during the 6MWT are associated with mortality in patients with CFIP has been undefined.

METHODS

This retrospective study enrolled 63 subjects with mild to severe CFIP who underwent the 6MWT. Subjects with CFIP were divided into 2 groups according to disease severity: mild, diffusing capacity of the lungs for carbon monoxide percentage predicted (%DLCO) > 55% and %FVC > 75%; and severe, %DLCO ≤ 55% and/or %FVC ≤ 75%. This study aimed to evaluate dynamic changes in the 6MWT including 6-min walk distance, change in SpO2 (ΔSpO2 ), SpO2 reduction time, SpO2 recovery time, change in heart rate (Δ heart rate), heart rate acceleration time, slope of heart rate acceleration, heart rate recovery at 1 min of rest after the 6MWT (HR-recovery), and dyspnea on exertion that are reflected by static pulmonary function and are related to exacerbation of CFIP and mortality.

RESULTS

Compared with subjects with mild CFIP, subjects with severe CFIP had significantly larger ΔSpO2 and longer SpO 2 reduction time and recovery time. The slope of heart rate, heart rate immediately after the 6MWT, and HR-recovery were lower in subjects with severe CFIP than in those with mild CFIP. In multiple regression analysis, percent vital capacity was significantly associated with SpO2 reduction time, and %DLCO was significantly associated with ΔSpO2 and SpO2 recovery time. Subjects with ΔSpO2 of > 10% and SpO2 recovery time of > 79 s had a significantly higher risk for exacerbation and mortality.

CONCLUSIONS

Dynamic changes in SpO2 and heart rate during the 6MWT were associated with risk for exacerbation and mortality in subjects with CFIP. Impaired dynamic response of SpO2 could reflect likelihood of exacerbation and increased mortality in CFIP.

Fat infiltration in the thigh muscles is associated with symptomatic spinal stenosis and reduced physical functioning in adults with achondroplasia

BACKGROUND

Symptomatic spinal stenosis is a prevalent complication in adults with achondroplasia. Increased muscle fat infiltration (MFI) and reduced thigh muscle volumes have also been reported, but the pathophysiology is poorly understood. We explored whether the increased MFI and reduced thigh muscle volumes were associated with the presence of symptomatic spinal stenosis and physical functioning.

METHODS

MFI and thigh muscle volumes were assessed by MRI in 40 adults with achondroplasia, and compared to 80 average-statured controls, matched for BMI, gender, and age. In achondroplasia participants, the six-minute walk-test (6MWT), the 30-s sit-to-stand test (30sSTS), and a questionnaire (the IPAQ) assessed physical functioning.

RESULTS

Symptomatic spinal stenosis was present in 25 of the participants (the stenosis group), while 15 did not have stenosis (the non-stenosis group). In the stenosis group, 84% (21/25) had undergone at least one spinal decompression surgery. The stenosis group had significantly higher MFI than the non-stenosis group, with an age-, gender and BMI-adjusted difference in total MFI of 3.3 percentage points (pp) (95% confidence interval [CI] 0.04 to 6.3 pp; p = 0.03). Compared to matched controls, the mean age-adjusted difference was 3.3 pp (95% CI 1.7 to 4.9 pp; p < 0.01). The non-stenosis group had MFI similar to controls (age-adjusted difference - 0.9 pp, 95% CI - 3.4 to 1.8 pp; p = 0.51). MFI was strongly correlated with the 6MWT (r = - 0.81, - 0.83, and - 0.86; all p-values < 0.01), and moderately correlated with the 30sSTS (r = - 0.56, - 0.57, and - 0.59; all p-values < 0.01). There were no significant differences in muscle volumes or physical activity level between the stenosis group and the non-stenosis group.

CONCLUSION

Increased MFI in the thigh muscles was associated with the presence of symptomatic spinal stenosis, reduced functional walking capacity, and reduced lower limb muscle strength. The causality between spinal stenosis, accumulation of thigh MFI, and surgical outcomes need further study. We have demonstrated that MRI might serve as an objective muscle biomarker in future achondroplasia studies, in addition to functional outcome measures. The method could potentially aid in optimizing the timing of spinal decompression surgery and in planning of post-surgery rehabilitation.

Trajectories and Prognostic Significance of 6-Minute Walk Test Parameters in Fibrotic Interstitial Lung Disease: A Multicenter Study

BACKGROUND

Functional capacity, as measured by the 6-min walk test (6MWT), is often reduced in fibrotic interstitial lung disease (ILD). This study evaluated longitudinal changes and the prognostic significance of 6MWT parameters, and explored change in oxygenation status as a physiological criterion to define disease progression in patients with fibrotic ILD.

RESEARCH QUESTIONS

What are the trajectories and prognostic value of 6MWT parameters in patients with fibrotic ILD?

STUDY DESIGN AND METHODS

Using prospective registries in Australia and Canada, patients with idiopathic pulmonary fibrosis (IPF) and non-IPF fibrotic ILD were stratified by the presence of criteria for progressive pulmonary fibrosis (PPF). The cumulative incidence of exertional and resting hypoxemia and changes in 6-min walk distance (6MWD) and composite indices (distance-saturation product and distance-saturation-oxygen product) were determined, with prognostic significance evaluated at the time of meeting criteria for PPF. New-onset exertional or resting hypoxemia was evaluated as another potential criterion for PPF.

RESULTS

Patients with IPF/PPF (n = 126) and non-IPF/PPF (n = 227) had a similar cumulative incidence of exertional hypoxemia and annualized decline in 6MWD and composite indices, which varied across each PPF criterion. Patients with IPF/non-PPF (n = 231) and non-IPF/non-PPF (n = 531) had a significantly lower incidence of hypoxemia than those with IPF/PPF, with an annualized increase in 6MWD and composite indices in the non-IPF/non-PPF group. Exertional or resting hypoxemia at the time of meeting criteria for PPF was independently associated with reduced transplant-free survival in IPF and non-IPF, adjusting for patient demographics and lung function. Adding new-onset exertional or resting hypoxemia as a physiological criterion reduced the median time to development of PPF from 11.2 to 6.7 months in IPF and from 11.7 to 5.6 months in non-IPF in patients who eventually met both definitions (P < .001 for both).

INTERPRETATION

Patients with IPF/PPF and non-IPF/PPF have comparable deterioration in functional capacity. Oxygenation status provides prognostic information in PPF and may assist in defining disease progression in fibrotic ILD.

Efficacy and safety of long-term use of a positive expiratory pressure device in chronic obstructive pulmonary disease patients, a randomized controlled trial

BACKGROUND

Exercise intolerance is among the most common symptoms experienced by patients with chronic obstructive pulmonary disease (COPD), which is associated with lung dynamic hyperinflation (DH). There was evidence that positive expiratory pressure (PEP), which could be offered by less costly devices, could reduce DH. The purpose of this study was to evaluate the efficacy and safety of long-term domiciliary use of PEP device in subjects with COPD.

METHODS

A randomized controlled trial was conducted and 25 Pre-COPD or mild-to-very severe subjects with COPD were randomized to intervention group (PEP device, PEP = 5 cmH₂O, n = 13) and control group (Sham-PEP device, PEP = 0 cmH₂O, n = 12). PEP device was a spring-loaded resistor face mask. Subjects were treated 4 h per day for a total of 2 months. Six-minute walk test (6MWT), pulmonary function, the Modified British Medical Research Council score, and partial pressure of end-tidal carbon dioxide were evaluated at baseline and after two months.

RESULTS

The 6MWD (- 71.67 ± 8.70 m, P < 0.001), end-dyspnea (P = 0.002), and end-fatigue (P = 0.022) improved significantly in the intervention group when compared with the control group. All subjects in the intervention group reported that 4 h of daily use of the PEP device was well tolerated and accepted and there were no adverse events.

CONCLUSION

Regular daily use of PEP device is safe and may improve exercise capacity in subjects with COPD or pre-COPD. PEP device could be used as an add-on to pulmonary rehabilitation programs due to its efficacy, safety, and low cost.

TRIAL REGISTRATION

The study was prospectively registered on ClinicalTrials.gov (NCT04742114).

Continuous Monitoring of Pulse Oximetry During the 6-Minute Walk Test Improves Clinical Outcomes Prediction in COPD

BACKGROUND

Continuous monitoring of SpO2 throughout the 6-min walk test (6MWT) unveiled that some patients with respiratory diseases may present values across the test lower than SpO2 measured at the end of the test. Nevertheless, it remains unclear whether this approach improves the yield of walk-induced desaturation detection in predicting mortality and hospitalizations in patients with COPD.

METHODS

Four hundred twenty-one subjects (51% males) with mild-very severe COPD underwent a 6MWT with continuous measurement of SpO2 . Exercise desaturation was defined as a fall in SpO2 ≥ 4%. All-cause mortality was assessed up to 6 y of follow-up and the rate of hospitalizations in the year succeeding the 6MWT.

RESULTS

One hundred forty-nine subjects (35.4%) died during a mean (interquartile) follow-up of 55.5 (30.2-64.1) months. Desaturation was observed in 299/421 (71.0%). SpO2 along the test was < end SpO2 (88 [82-92]% vs 90 [84-93]%, P < .001). Desaturation detected only during (but not at the end of) the test was found in 81/421 (19.2%) participants. Multivariate Cox regression model adjusted for sex, body composition, FEV1, residual volume/total lung capacity ratio, walk distance, O2 supplementation during the test, and comorbidities retained the presence of desaturation either at the end (1.85 [95% CI 1.02-3.36]) or only along the test (2.08 [95% CI 1.09-4.01]) as significant predictors of mortality. The rate of hospitalizations was higher in those presenting with any kind of desaturation compared to those without exercise desaturation. Logistic regression analysis revealed that walking interruption and diffusing capacity of the lung for carbon monoxide predicted desaturation observed only during the test.

CONCLUSIONS

O2 desaturation missed by end-exercise SpO2 but exposed by measurements during the test was independently associated with all-cause mortality and hospitalizations in subjects with COPD.

Quantitative Interstitial Abnormality Progression and Outcomes in the Genetic Epidemiology of COPD and Pittsburgh Lung Screening Study Cohorts

BACKGROUND

The risk factors and clinical outcomes of quantitative interstitial abnormality progression over time have not been characterized.

RESEARCH QUESTIONS

What are the associations of quantitative interstitial abnormality progression with lung function, exercise capacity, and mortality? What are the demographic and genetic risk factors for quantitative interstitial abnormality progression?

STUDY DESIGN AND METHODS

Quantitative interstitial abnormality progression between visits 1 and 2 was assessed from 4,635 participants in the Genetic Epidemiology of COPD (COPDGene) cohort and 1,307 participants in the Pittsburgh Lung Screening Study (PLuSS) cohort. We used multivariable linear regression to determine the risk factors for progression and the longitudinal associations between progression and FVC and 6-min walk distance, and Cox regression models for the association with mortality.

RESULTS

Age at enrollment, female sex, current smoking status, and the MUC5B minor allele were associated with quantitative interstitial abnormality progression. Each percent annual increase in quantitative interstitial abnormalities was associated with annual declines in FVC (COPDGene: 8.5 mL/y; 95% CI, 4.7-12.4 mL/y; P < .001; PLuSS: 9.5 mL/y; 95% CI, 3.7-15.4 mL/y; P = .001) and 6-min walk distance, and increased mortality (COPDGene: hazard ratio, 1.69; 95% CI, 1.34-2.12; P < .001; PLuSS: hazard ratio, 1.28; 95% CI, 1.10-1.49; P = .001).

INTERPRETATION

The objective, longitudinal measurement of quantitative interstitial abnormalities may help identify people at greatest risk for adverse events and most likely to benefit from early intervention.

Factors associated with 6-min walk distance in severe asthma: A cross-sectional study

BACKGROUND AND OBJECTIVE

Exercise capacity is associated with health-related quality of life and symptom control in severe asthma. Thus, interventions targeting exercise capacity are likely to be beneficial. However, clinical and biological factors impacting exercise capacity in severe asthma are sparsely investigated. We aimed to describe the association of selected clinical and biological factors with 6-min walk distance (6MWD) in adults with severe asthma and investigate the impact of sex on these outcomes.

METHODS

A cross-sectional study in adults with severe asthma was conducted. Exercise capacity was measured by 6-min walk test, and association between 6MWD and predictors were evaluated using multiple linear regression.

RESULTS

A total of 137 patients (females, 85; median age, 59 years) were recruited. Overall, asthma control (-15.2 m, 95% CI -22.6 to -7.7; p = 0.0001) and BMI (-3.2 m, 95% CI -5.1 to -1.3; p = 0.001) were significantly associated with exercise capacity (adjusted variance, adj. R²  = 0.425). In females, 5-item Asthma Control Questionnaire (ACQ-5; p = 0.005) and BMI (p < 0.001) were significantly associated with 6MWD (adj. R²  = 0.423). In males, a 0.5-point increase in ACQ-5 was associated with a decrease in 6MWD by 10.2 m (95% CI -22.8 to 2.4; p = 0.11), but no clinical nor biological factors reached statistical significance (adj. R²  = 0.393).

CONCLUSION

Asthma symptoms and BMI were associated with exercise capacity in the overall population. Optimizing these factors may enhance the ability of patients to improve their exercise capacity and gain the associated positive health outcomes, but further studies are warranted.

Cardiac Effort to Compare Clinic and Remote 6-Minute Walk Testing in Pulmonary Arterial Hypertension

BACKGROUND

The SARS-CoV-2 pandemic has limited objective physiologic assessments. A standardized remote alternative is not currently available. "Cardiac effort" (CE), that is, the total number of heart beats divided by the 6-min walk test (6MWT) distance (beats/m), has improved reproducibility in the 6MWT and correlated with right ventricular function in pulmonary arterial hypertension.

RESEARCH QUESTION

Can a chest-based accelerometer estimate 6MWT distance remotely? Is remote cardiac effort more reproducible than 6MWT distance when compared with clinic assessment?

STUDY DESIGN AND METHODS

This was a single-center, prospective observational study, with institutional review board approval, completed between October 2020 and April 2021. Group 1 subjects with pulmonary arterial hypertension, receiving stable therapy for > 90 days, completed four to six total 6MWTs during a 2-week period to assess reproducibility. The first and last 6MWTs were performed in the clinic; two to four remote 6MWTs were completed at each participant's discretion. Masks were not worn. BioStamp nPoint sensors (MC10) were worn on the chest to measure heart rate and accelerometry. Two blinded readers counted laps, using accelerometry data obtained on the clinic or user-defined course. Averages of clinic variables and remote variables were used for Wilcoxon matched-pairs signed rank tests, Bland-Altman plots, or Spearman correlation coefficients.

RESULTS

Estimated 6MWT distance, using the MC10, correlated strongly with directly measured 6MWT distance (r = 0.99; P < .0001; in 20 subjects). Remote 6MWT distances were shorter than clinic 6MWT distances: 405 m (330-464 m) vs 389 m (312-430 m) (P = .002). There was no difference between in-clinic and remote CE: 1.75 beats/m (1.48-2.20 beats/m) vs 1.86 beats/m (1.57-2.14 beats/m) (P = .14).

INTERPRETATION

Remote 6MWT was feasible on a user-defined course; 6MWT distance was shorter than clinic distance. CE calculated by chest heart rate and accelerometer-estimated distance provides a reproducible remote assessment of exercise tolerance, comparable to the clinic-measured value.

Slower upper extremity function in older adults with hyperkyphosis negatively impacts the 6-min walk test

BACKGROUND

Approximately 30% to 40% of older adults have hyperkyphosis, defined as excessive curvature of the thoracic spine. Hyperkyphosis is associated with increased morbidity and mortality. This study aimed to determine whether hyperkyphosis (Cobb's angle) and upper extremity tasks were independently associated with the 6-min walk test (6MWT) in community-dwelling older adults with hyperkyphosis.

METHODS

In this cross-sectional study, we studied 71 women and 28 men aged 60-87 from the study of hyperkyphosis, exercise, and function trial (SHEAF) who had kyphosis, 3 timed upper extremity tasks and the 6MWT assessed at their baseline visit. We used standing lateral spine radiographs and a standardized protocol for thoracic kyphosis (T4-T12) to measure Cobb angle of kyphosis. In addition, 3 activity of daily living (ADL) extremity tests (putting on and removing a laboratory coat, picking up a penny from the floor, and lifting a 7-lb. book to a shelf) were used.

RESULTS

The mean ± SD age was 70.1 ± 6.1 years. The mean ± SD Cobb angle of kyphosis was 57.4 ± 12.5 degrees. On average ± SD, the participants walked 504.8 ± 84.2 m in 6 min and took 2.4 ± 2.2 prescription medications. The mean ± SD height was 164.7 ± 8.5 cm, weight was 68.7 ± 13.1 kg, and BMI was 25.2 ± 4.0 kg/m2. Multivariate regression revealed that age, height, upper extremity book lift task, and the number of prescribed medications were significant predictors of performance on the 6MWT (p < 0.05).

CONCLUSIONS

While kyphosis was not associated with the 6MWT, timed tests of upper extremity function indicated that upper body dynamics can affect walking performance. In addition, sociodemographic factors and the number of prescribed medications were significant contributing factors to the 6MWT in older adults with mild to moderate hyperkyphosis. These results illustrate multifactorial influences on physical performance and the need for an integrated and targeted approach in helping older hyperkyphotic adults maintain healthy physical functioning as they age.

Cardiorenal syndrome and the association with fitness: Data from a telerehabilitation randomized clinical trial

Aims

To investigate the associations of cardiorespiratory fitness with cardiac, vascular, renal and cardiorenal characteristics in chronic heart failure in a telerehabilitation randomized clinical trial. Secondly, to evaluate the associations of cardiorenal syndrome with the effects of exercise.

Methods and results

Sixty‐nine heart failure patients attended baseline examination, and 61 patients were randomly assigned 1:1 to 3‐month telerehabilitation or control. Data were collected at baseline and 3‐month post‐intervention, including echocardiography and vascular ultrasound, laboratory tests, exercise test with peak oxygen consumption (VO_2peak) measurement and 6‐min walk test (6MWT). Baseline VO_2peak and 6MWT distance was 0.85 mL*min⁻¹*kg⁻¹ lower and 20 m shorter per 10 mL/min/1.73m² lower estimated glomerular filtration rate (both P < 0.001). Heart failure patients with cardiorenal syndrome had 3.5 (1.1) mL*min⁻¹*kg⁻¹ lower VO_2peak and diastolic dysfunction grade 2–3, and elevated filling pressure was >50% more common compared with those without (all P < 0.05). At the 3‐month post‐intervention follow‐up, only the non‐CRS patients in the intervention group increased VO_2peak (0.73 (0.51) mL*min⁻¹*kg⁻¹), whereas VO_2peak in the CRS subpopulation of controls decreased (−1.34 (0.43) mL*min⁻¹*kg⁻¹). Cardiorenal syndrome was associated with a decrease in VO_2peak in CRS patients compared with non‐CRS patients, −0.91 (0.31) vs. 0.39 (0.35) mL*min⁻¹*kg⁻¹ respectively, P = 0.013.

Conclusions

Cardiorenal syndrome was negatively associated with VO_2peak and 6MWT distance in chronic HF, and the associations were stronger than for heart failure phenotypes and other characteristics. The effect of exercise was negatively associated with cardiorenal syndrome. Exercise seems to be as important in heart failure patients with cardiorenal syndrome, and future studies should include CRS patients to reveal the most beneficial type of exercise.

Responder analysis for improvement in 6-min walk test with ferric carboxymaltose in patients with heart failure with reduced ejection fraction and iron deficiency

AIM

Improving functional capacity is a key goal in heart failure (HF). This pooled analysis of FAIR-HF and CONFIRM-HF assessed the likelihood of improvement or deterioration in 6-min walk test (6MWT) among iron-deficient patients with chronic HF with reduced ejection fraction (HFrEF) receiving ferric carboxymaltose (FCM).

METHODS AND RESULTS

Data for 760 patients (FCM: n = 454; placebo: n = 306) were analysed. The proportions of patients receiving FCM or placebo who had ≥20, ≥30, and ≥40 m improvements or ≥10 m deterioration in 6MWT at 12 and 24 weeks were assessed. Patients receiving FCM experienced a mean (standard deviation) 31.1 (62.3) m improvement in 6MWT versus 0.1 (77.1) m improvement for placebo at week 12 (difference in mean changes 26.8 [16.6-37.0]). At week 12, the odds [95% confidence interval] of 6MWT improvements of ≥20 m (odds ratio 2.16 [1.57-2.96]; p < 0.0001), ≥30 m (2.00 [1.44-2.78]; p < 0.0001), and ≥40 m (2.29 [1.60-3.27]; p < 0.0001) were greater with FCM versus placebo, while the odds of a deterioration ≥10 m were reduced with FCM versus placebo (0.55 [0.38-0.80]; p = 0.0019). Among patients who experienced 6MWT improvements of ≥20, ≥30, or ≥40 m with FCM at week 12, more than 80% sustained this improvement at week 24.

CONCLUSION

Ferric carboxymaltose resulted in a significantly higher likelihood of improvement and a reduced likelihood of deterioration in 6MWT versus placebo among iron-deficient patients with HF. Of the patients experiencing clinically significant improvements at week 12, the majority sustained this improvement at week 24. These results are supportive of FCM to improve exercise capacity in HF.

The relationship between peak inspiratory flow and hand grip strength measurement in men with mild chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) decreases quality of life and muscular strength. Inspiratory flow is important for inhalants in the bronchi but is complicated to measure in routine practice. We hypothesized that hand grip strength (HGS) would correlate with inhalation rate in patients with mild COPD.

Methods

The COPD patients were recruited at the St. Marianna University School of Medicine, Yokohama Seibu Hospital, from 2015 to 2018. We measured peak inspiratory flow (PIF) through an In-Check flow meter attached with Diskus [PIF(D)] and Turbuhaler [PIF(T)] inhalers. The 6-min walking test (6MWT), and the fraction of exhaled nitric oxide (FENO), spirometry, HGS, or forced oscillation technique (FOT) parameters were measured.

Results

Forty-four subjects were enrolled. All were men, with a mean age (± SD) of 77.8 ± 9.36 years. Thirty-nine patients had mild COPD. PIF(D) was 110 (80, 140) L/min (median, interquartile range), PIF(T) was 80 (70, 90) L/min, and HGS was 28.7 (13.8, 43.6) kgf. PIF(D) and PIF(T) were significantly correlated (r = 0.443, p = 0.003). PIF(D) was significantly correlated with age (r = − 0.327, p = 0.030) and HGS (r = 0.326, p = 0.031). PIF(T) was significantly correlated with age (r = − 0.328, p = 0.030), FVC (r = 0.351, p = 0.019), 6MWT distance (r = 0.392, p = 0.011), and HGS (r = 0.328, p = 0.030).

Conclusion

HGS might be more useful for predicting PIF than other parameters. Also, elderly COPD patients need to be taught inhaled methods carefully.

The Correlation of Health-Related Quality of Life with Cystic Fibrosis Severity Markers in Chest CT Scan and 6-Minute Walk Test: A Cross-Sectional Study

OBJECTIVE

To investigate the correlation between severity of lung disease determined by chest computed tomography (CT) and 6-min walk test (6MWT) with health-related quality of life (HRQoL) score in cystic fibrosis (CF) patients.

METHODS

This cross-sectional study evaluated 76 CF patients referred to CF Clinic, aged 7-14 y. Subjects were asked to complete Pediatric quality of life (PedsQL4.0) forms, during their outpatient visits to determine their HRQoL score. Patients' lung disease severity was quantified by Bhalla score determined by the child's chest CT and their 6MWT. These three variables were then analyzed to determine whether there is correlation between HRQoL with severity of lung disease.

RESULTS

The mean distance of patients 6MWT score was 447.4 ± 81.4 m. There was a positive correlation between distance and HRQoL score in total, social, school and emotional function (p < 0.05). However, in physical function the correlation lacked significance (p = 0.07). Patients with a Bhalla score of less than 15 were older than patients with a Bhalla score of more than 15 (p < 0.001). Physical, emotional, social, school, and total function scores were significantly lower in patients with Bhalla score less than 15, compared to those with Bhalla score greater than 15 (p < 0.05).

CONCLUSIONS

The correlation among Bhalla score on CT scan, 6-min walk test, and HRQoL indicates that pulmonary disease has a clear impact on the quality of life of CF patients. HRQoL can be used in the care program of children with CF.

Evaluation of indices for predicting recovery of exercise tolerance in patients surviving allogenic hematopoietic stem cell transplantation

PURPOSE

Decline in physical function in the early stage after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a major challenge. Exercise tolerance tests, such as the 6-min walk test, are useful markers for predicting exercise tolerance and various other traits, including cardiometabolic risk and non-relapse mortality. This retrospective cohort study aimed to investigate and identify predictors of recovery of exercise tolerance in the early stage after allo-HSCT.

METHODS

Ninety-eight patients were classified into recovery and non-recovery groups according to the median 6-min walk distance (6MWD) at discharge.

RESULTS

Logistic regression analysis revealed that pre-post change in knee extensor strength (ΔKES) and hematopoietic cell transplantation comorbidity index were useful predictors of recovery of exercise tolerance at discharge and moderate predictors of 6MWD recovery in the early post-transplant period. Receiver operating characteristic analysis showed that pre-transplant ΔKES was an accurate predictor of 6MWD recovery in the early post-transplant period. The cutoff point for ΔKES calculated using the Youden index was - 1.17 Nm/kg.

CONCLUSIONS

The results of this study emphasize the importance of the need for programs designed to prevent muscle weakness in the early period after allo-HSCT. The results from markers of recovery of exercise tolerance are promising and can be used for patient education in rehabilitation programs after allo-HSCT.

Role of frailty on cardiac rehabilitation in hospitalized older patients

BACKGROUND

Cardiovascular diseases are the leading cause of mortality, morbidity, and disability in the world, especially in the older adults. A relevant proportion of patients admitted to Cardiac Rehabilitation (CR) may suffer from frailty, a complex geriatric syndrome with multifactorial aetiology.

AIMS

The hypothesis underlying the study is that frailty complicates the management of older patients undergoing CR. The main objective is, therefore, to determine the relationship between frailty and CR outcomes in hospitalized older adults.

METHODS

The participants have been recruited among patients aged ≥ 65 years admitted at the hospital for CR. A Comprehensive Geriatric Assessment (CGA)-based Frailty Index (FI) was created following a standard procedure. The outcome was measured as the ratio between 6-min walk test (6MWT) distance at the end of CR and normal predicted values for a healthy adult of same age and gender, according to reference equations.

RESULTS

The study population consisted of 559 elderly patients, 387 males (69.2%), with age of 72 (69-76) years. The most frequent diagnosis at admission was ischaemic heart disease (231, 41.5%) and overall 6MWT ratio was 0.62 ± 0.21. At the multivariable regression analysis, gender, diagnosis and FI were significantly and independently associated with 6MWT ratio (p ≤ 0.0001, p ≤ 0.001 and p ≤ 0.0001, respectively), while no significant association emerged for age.

CONCLUSION

FI resulted independently correlated to 6MWT ratio in a population of older patients undergoing in-hospital CR programs. Frailty is a multifactorial geriatric syndrome whose assessment is essential for prognostic evaluation of older patients, also in CR clinical setting.

Frequency and impact on clinical outcomes of sarcopenia in patients with idiopathic pulmonary fibrosis

Objectives

Sarcopenia is a syndrome characterized by reduced muscle mass and function. It is well-recognized as a complication in chronic diseases such as chronic obstructive pulmonary disease. However, little is known about sarcopenia in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to investigate the clinical characteristics of sarcopenia and the association between quality of life and sarcopenia in patients with IPF.

Methods

In this pilot cross-sectional study, 56 Japanese outpatients with IPF (49 men) were enrolled prospectively. Sarcopenia was diagnosed according to the criteria of the Asian Working Group for Sarcopenia 2019. Its associations with clinical parameters including age, pulmonary functions, physical performance, and patient-reported outcomes (PROs) were examined.

Results

The frequency of sarcopenia was 39.3% (n = 22) in this cohort. There were significant differences in St George’s Respiratory Questionnaire (p = .005), modified Medical Research Council score (p = .004), and Hospital and Anxiety Depression Scale depression score (p = .030) between the sarcopenic and non-sarcopenic groups. On multivariate regression analysis, 6-min walk distance (6MWD) was an independent factor associated with sarcopenia (odds ratio 1.241, 95% confidence interval 1.016–1.515, p = .034).

Conclusion

Sarcopenia was associated with PROs and physical performance in patients with IPF.

Cardiopulmonary Exercise Testing and Other Tests of Functional Capacity

Purpose of Review

Assessment of functional capacity is a cornerstone of preoperative risk assessment. While subjective clinician assessment of functional capacity is poorly predictive of postoperative outcomes, other objective functional assessment measures may provide more useful information.

Recent Findings

Cardiopulmonary exercise testing (CPET) is generally accepted as the gold standard for functional capacity assessment. However, CPET is resource-intensive and not universally available. Simpler objective tests of functional capacity such as the Duke Activity Status Index (DASI) and the 6-min walk test (6MWT) are cheap and efficient. In addition, they predict important postoperative outcomes including death, disability, and myocardial infarction.

Summary

Simple preoperative tests such as the DASI may be useful for routine preoperative assessment. CPET may be helpful to investigate further patients with functional status limitation, and to guide prehabilitation and perioperative shared decision-making in high-risk patients.

Functional outcomes following pelvic exenteration: results from a prospective cohort study

AIM

Postoperative functional outcomes following pelvic exenteration surgery for treatment of advanced or recurrent pelvic malignancies are poorly understood. The aim of this study was to determine the short-term functional outcomes following pelvic exenteration surgery using objective measures of physical function.

METHOD

Patients undergoing pelvic exenteration surgery between January 2017 and May 2020 were recruited at a single quaternary referral hospital in Sydney, Australia. The primary measures were the 6-min walk test (6MWT) and the five times sit to stand (5STS) test. Data were collected at baseline (preoperatively), 10 days postoperatively and at discharge from hospital, and were analysed according to tumour type, extent of exenteration, sacrectomy, length of hospital stay, major nerve resection and postoperative complications.

RESULTS

The cohort of patients that participated in functional assessments consisted of 135 patients, with a median age of 61 years. Pelvic exenteration patients had a reduced 6MWT distance preoperatively compared to the general population (P < 0.001). Following surgery, we observed a further decrease in 6MWT distance (P < 0.001) and an increase in time to complete 5STS (P < 0.001) at postoperative day 10 compared to baseline, with a slight improvement at discharge. There were no differences in 6MWT and 5STS outcomes between patients based on comparisons of surgical and oncological factors.

CONCLUSION

Pelvic exenteration patients are functionally impaired in the preoperative period compared to the general population. Surgery causes a further reduction in physical function in the short term; however, functional outcomes are not impacted by tumour type, extent of exenteration, sacrectomy or nerve resection.

Detection of Walk Tests in Free-Living Activities Using a Wrist-Worn Device

Exercise testing to assess the response to physical rehabilitation or lifestyle interventions is administered in clinics thus at best can be repeated only few times a year. This study explores a novel approach to collecting information on functional performance through walk tests, e.g., a 6-min walk test (6MWT), unintentionally performed in free-living activities. Walk tests are detected in step data provided by a wrist-worn device. Only those events of minute-to-minute variation in walking cadence, which is equal or lower than the empirically determined maximal SD (e.g., 5-steps), are considered as walk test candidates. Out of detected walk tests within the non-overlapping sliding time interval (e.g., 1-week), the one with the largest number of steps is chosen as the most representative. This approach is studied on a cohort of 99 subjects, assigned to the groups of patients with cardiovascular disease (CVD) and healthy subjects below and over 40-years-old, who were asked to wear the device while maintaining their usual physical activity regimen. The total wear time was 8,864 subject-days after excluding the intervals of occasionally discontinued monitoring. About 82% (23/28) of patients with CVD and 88% (21/24) of healthy subjects over 40-years-old had at least a single 6MWT over the 1st month of monitoring. About 52% of patients with CVD (12/23) and 91% (19/21) of healthy subjects over 40-years-old exceeded 500 m. Patients with CVD, on average, walked 46 m shorter 6MWT distance (p = 0.04) compared to healthy subjects. Unintentional walk testing is feasible and could be valuable for repeated assessment of functional performance outside the clinical setting.

Experiences with pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension at multiple centers in Taiwan

BACKGROUND

Of the types of pulmonary hypertension, chronic thromboembolic pulmonary hypertension (CTEPH) may be cured through pulmonary endarterectomy (PEA). In this study, we investigated patient experiences with PEA for CTEPH treatment in Taiwan.

METHODS

We retrospectively reviewed the records of patients who underwent PEA in two medical centers between January 2005 and December 2019. We measured the following outcomes: in-hospital complications, improvements in cardiac function and exercise capacity, survival using Kaplan-Meier analysis after PEA.

RESULTS

Twenty-seven patients (female: 17) with a mean age of 52.6 years underwent PEA. Pre-operatively, most patients were New York Heart Association functional class (NYHA FC) III (n = 19) and IV (n = 7). The mean periods from the onset of symptoms to diagnosis and from diagnosis to operation were 22.6 and 22.3 months, respectively. After PEA, mean intubation time, and length of intensive care unit and hospital stay were 9, 11, and 20 days, respectively. Most patients' NYHA FCs improved to I (n = 15) and II (n = 10). The mean 6-min walk test (6MWT) result improved by 60.5%. The in-hospital mortality, mean follow-up period, and 5- and 10-year overall survival rates were 3.7%, 77.0 months, 96.3%, and 84.3%, respectively. Furthermore, 5- and 10-year disease-specific survival rates were both 96.3%.

CONCLUSION

When pre-operative and post-operative statuses were compared, we found a significant improvement in NYHA FC and 6MWT distance. Our study also found a lower in-hospital mortality rate compared to other published studies, except compared to the newer data provided by the University of California, San Diego group.

Baseline Functional Capacity and Transcatheter Mitral Valve Repair in Heart Failure With Secondary Mitral Regurgitation

OBJECTIVES

The aim of this study was to determine the prognostic utility of baseline functional status and its impact on the outcomes of transcatheter mitral valve repair (TMVr) in patients with heart failure (HF) with secondary mitral regurgitation (SMR).

BACKGROUND

The COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) trial demonstrated that TMVr with the MitraClip in patients with HF with moderate to severe or severe SMR improved health-related quality of life. The clinical utility of a baseline assessment of functional status for evaluating prognosis and identifying candidates likely to derive a robust benefit from TMVr has not been previously studied in patients with HF with SMR.

METHODS

The COAPT study was a multicenter, randomized, controlled, parallel-group, open-label trial of TMVr with the MitraClip plus guideline-directed medical therapy (GDMT) versus GDMT alone in patients with HF, left ventricular ejection fraction 20% to 50%, and moderate to severe or severe SMR. Baseline functional status was assessed by 6-min walk distance (6MWD).

RESULTS

Patients with 6MWD less than the median (240 m) were older, were more likely to be female, and had more comorbidities. After multivariate modeling, age (p = 0.005), baseline hemoglobin (p = 0.007), and New York Heart Association functional class III/IV symptoms (p < 0.0001) were independent clinical predictors of 6MWD. Patients with 6MWD <240 m versus ≥240 m had a higher unadjusted and adjusted rate of the 2-year composite of all-cause death or HF hospitalization (64.4% vs. 48.6%; adjusted hazard ratio: 1.53; 95% confidence interval: 1.19 to 1.98; p = 0.001). However, there was no interaction between baseline 6MWD and the relative effectiveness of TMVr plus GDMT versus GDMT alone with respect to the composite endpoint (p = 0.633).

CONCLUSIONS

Baseline assessment of functional capacity by 6MWD was a powerful discriminator of prognosis in patients with HF with SMR. TMVr with the MitraClip provided substantial improvements in clinical outcomes for this population irrespective of baseline functional capacity.

Associations of Cardiac Mechanics With Exercise Capacity: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Lower exercise capacity, as measured by 6-minute walk distance (6MWD), is associated with incident heart failure (HF). Among those without HF, the associations of measures of cardiac function with 6MWD are unclear, and may provide insight regarding the risk of incident HF.

OBJECTIVES

The purpose of this study was to understand the relationships between cardiac function and exercise capacity.

METHODS

This study evaluated the associations of cardiac mechanics with 6MWD in the sixth examination of the Multi-Ethnic Study of Atherosclerosis. Echocardiography (2-dimensional, Doppler, and speckle-tracking) was performed at rest and after passive leg raise to evaluate functional reserve after intravascular volume challenge.

RESULTS

Of 2,096 participants without HF (mean age 73 years, 48% men, 58% non-White), individuals with lower (worse) left atrial (LA) reservoir strain were older and had higher blood pressure. Lower resting LA reservoir strain (β coefficient per SD decrease: -5.0; 95% confidence interval [CI]: -8.8 to -1.3 m; p = 0.009), inability to augment LA reservoir strain after passive leg raise (β coefficient per SD decrease: -5.8; 95% CI: -9.1 to -2.5 m; p < 0.001), and lower right atrial reservoir strain (β coefficient per SD decrease: -4.4; 95% CI: -7.8 to -1.1 m; p = 0.01) were associated with shorter 6MWD. Worse left ventricular (LV) diastolic function was also associated with lower 6MWD. There were no independent associations of measures of LV systolic function (global longitudinal strain, circumferential strain, ejection fraction) with 6MWD.

CONCLUSIONS

Among individuals without HF, worse biatrial function, lack of LA functional reserve, and worse LV diastolic function were associated with reduced submaximal exercise capacity. Therapies aimed to improve these functional domains may increase exercise capacity and prevent HF.

Heart failure and promotion of physical activity before and after cardiac rehabilitation (HF-aPProACH): a study protocol

Aims

Lifestyle changes, such as increasing physical activity (PA), are a cornerstone of treatment of patients with chronic heart failure (HF). However, improving PA in HF patients is challenging, and low participation rates for cardiac rehabilitation (CR) as well as relapse to low PA levels after CR are major issues. We designed a randomized controlled trial to investigate if PA monitoring with motivational feedback before and after centre‐based CR in HF patients with reduced ejection fraction (HFrEF) will lead to a clinically meaningful increase in physical fitness.

Methods and results

A randomized controlled trial will be conducted in a sample of 180 HFrEF patients (New York Heart Association Class II/III) who are referred to 12‐week standard CR. Patients will be randomized (2:1) to (1) standard of care (SoC) plus wearing a PA monitoring device (Fitbit Charge 3) with personalized step goals, feedback and motivation or (2) SoC only. The intervention lasts ±7 months: 4–5 weeks before CR, 12 weeks during CR and 12 weeks after CR. Measurements will take place at three time points. The primary endpoint is the change in the distance in 6‐min walking test (6MWT) over the entire study period. Other endpoints include step count, grip strength, quality of life and all‐cause mortality or hospitalization.

Conclusions

HF‐aPProACH will provide novel information on the effectiveness of remote PA stimulation and feedback before, during and after standard CR using a commercially available device to improve physical fitness in HFrEF patients.

Inflammatory and oxidative biomarkers as determinants of functional capacity in patients with COPD assessed by 6-min walk test-derived outcomes

INTRODUCTION

Reduction in functional capacity is a negative clinical outcome of chronic obstructive pulmonary disease (COPD). Studies have shown association between inflammatory and oxidative stress biomarkers and functional capacity. However, it is unclear whether these biomarkers are associated with outcomes of functional capacity. Therefore, the aim of this study was to evaluate whether plasma biomarkers of inflammation and oxidative stress are predictors of the 6-min walking test (6MWT)-derived outcomes.

METHODS

Twenty COPD patients were assessed on three consecutive days with different clinical measures, including functional capacity, and blood sampling. Plasma concentrations of IL-6, IL-8, TNF-ɑ, IL-10 and soluble TNF-ɑ receptors (sTNFR1 and sTNFR2) were determined by immunoassays. Oxidative stress was evaluated by determining lipid peroxidation products based on the enzymatic activity of superoxide dismutase (SOD) and catalase, and total antioxidant capacity of plasma. Functional capacity was assessed considering the six-minute walking distance (6MWD) and the estimate of six-minute walking work (6MWW). The association between biomarkers (i.e. inflammation and oxidative stress) and functional exercise capacity was investigated through the Pearson's correlation coefficient. To identify the determinants of the 6MWT, multiple linear stepwise regression analyses were performed with adjustment for age, sex and GOLD classification.

RESULTS

Patients were predominantly male (65%), with mean age of 64 years and moderate airflow obstruction and impaired functional capacity. There were positive correlations between SOD activity and 6MWD (r = 0.520; p = 0.02) and 6MWW (r = 0.554; p = 0.01), as well as a negative correlation between sTNF-R1 and 6MWD (r = -0.437; p = 0.05). SOD was an independent determinant of the functional capacity, explaining 23% of the variability of 6MWD (p = 0.019) and 27% of the variability of 6MWW (p = 0.011). sTNF-R1 levels were associated with 6MWD and, together with SOD explained 40% of variability in 6MWD (p = 0.005).

CONCLUSION

SOD activity was an independent determinant of performance in the 6MWT, and together with sTNFR1 explained 40% of the variations in walking distance in COPD patients. SOD activity and sTNFR1 levels might be seen as potential biomarkers of the functional capacity in patients with COPD.

The 6-Minute Walk Test and Anthropometric Characteristics as Assessment Tools in Patients with Obstructive Sleep Apnea Syndrome. A Preliminary Report during the Pandemic

Patients with obstructive sleep apnea syndrome (OSAS) exhibit low cardio-fitness impact, attributed to fragmented sleep architecture and associated pathophysiological sequelae. The purpose of our study was to investigate fitness indicators during 6-min walk test (6MWT) and oxidative stress markers in apnea-hypopnea index (AHI) in OSAS patients stratified by severity. A total of 37 newly diagnosed patients, comorbidity-free, were divided into two groups: (Moderate OSAS (n = 12), defined as ≥ 15 AHI < 30 events per hour; Age: 50.7 ± 7.2 years, BMI: 32.5 ± 4.0 kg/m2 vs. Severe OSAS (n = 25), defined as AHΙ ≥ 30 events per hour; Age: 46.3 ± 10.4 years, BMI: 33.3 ± 7.9 kg/m2). Measurements included demographics, anthropometric characteristics, body composition, blood sampling for reactive oxygen metabolites' levels (d-ROM) and plasma antioxidant capacity (PAT), and followed by a 6MWT. AHI was significantly associated with d-ROMs levels, chest circumference in maximal inhalation and exhalation (Δchest), neck circumference, as well as 6MWT-derived indices. In conclusion, our study determines bidirectional interrelationships between OSAS severity and anthropometrics, body composition, and fitness metrics. These findings indicate that the impact of OSAS should be evaluated well beyond polysomnography-derived parameters.

Prognostic value of 6-min walk stress echocardiography in patients with interstitial lung disease

BACKGROUND

The 6-min walk test (6MWT) provides prognostic information for patients with interstitial lung disease (ILD). Parameter determined by Doppler echocardiography after the 6MWT (6 MW stress echocardiography) is shown to be a predictor of future development of pulmonary hypertension in patients with connective tissue disease. However, the clinical utility of 6 MW stress echocardiography in predicting cardiopulmonary events in patients with ILD remains unknown. We examined whether parameters determined by 6 MW stress echocardiography independent predictors of adverse events in patients with ILD.

METHODS

Echocardiographic examinations were performed in 68 consecutively enrolled patients with ILD (age, 65 ± 10 years, 65% men). A pressure gradient of tricuspid regurgitation (TRPG) and pulmonary vascular resistance (PVRecho) calculated using the following formula [PVRecho = (peak velocity of TR × 10/time-velocity integral of right ventricular outflow (RVOT-VTI)) + 0.16] were measured at baseline and at post 6MWT. Data for parameters of pulmonary functional tests and for 6MWT were collected.

RESULTS

During a mean follow-up period of 22 ± 12 months, 22 patients experienced cardiopulmonary events. In univariate analysis, %VC, TRPG, PVRecho, TRPG post 6MWT, and PVRecho post 6MWT were significantly associated with cardiopulmonary events. Multivariate analysis using the Cox proportional hazards model indicated that %VC [hazard ratio (HR): 0.97, p = 0.009] and PVRecho post 6MWT (HR: 1.77, p = 0.004) were independent predictors of cardiopulmonary events in patients with ILD.

CONCLUSIONS

In addition to parameters of pulmonary function tests, increased PVRecho post 6MWT is a significant predictor of cardiopulmonary events in patients with ILD. A 6 MW stress echocardiography is useful in assessing the risk of adverse events in patients with ILD.

Validation of a breath-holding test as a screening test for exercise-induced hypoxemia in chronic respiratory diseases

The detection of exercise-induced hypoxemia is important for evaluating disease status in patients with chronic respiratory diseases. The 6-min walk test (6MWT) is useful for detecting exercise-induced hypoxemia. This pilot study aimed to validate the breath-holding test (BHT) as a screening for exercise-induced hypoxemia and compare its utility with that of the 6MWT in patients with chronic respiratory diseases. Fifty-nine patients with chronic respiratory diseases underwent BHTs lasting 10, 15, and 20 s. Percutaneous oxygen saturation (SpO₂), pulse rate, and severity of dyspnoea were measured. The participants also underwent a 6MWT, a pulmonary function test, and analysis of arterial blood gas at rest. Multivariate linear regression analysis was performed to identify significant predictors of desaturation in the 6MWT. The minimum SpO₂ during the BHT (all durations) and 6MWT were significantly correlated. Receiver operating characteristic analysis revealed the optimal cut-off for predicting SpO₂ < 90% during the 6MWT as a minimum SpO₂ ≤ 94% during the 15-s BHT. Perceived dyspnoea and maximum pulse rate were significantly lower during the 15-s BHT than during the 6MWT. In the multivariate linear regression analysis, the minimum SpO₂ during the 15-s BHT (β, 0.565, p < 0.001) and %DLco (β, 0.255, p < 0.028) were independent predictors of desaturation in the 6MWT. The minimum SpO₂ during the 15-s BHT may be a useful measure for screening for exercise-induced hypoxemia in patients with chronic respiratory diseases. The BHT is easier to perform, more readily available, and better tolerated than the 6MWT.

Correlation of 4-meter gait speed with clinical indicators of chronic obstructive pulmonary disease

BACKGROUND

Measuring daily physical activity and exercise capacity is recommended in the routine care of patients with chronic obstructive pulmonary disease (COPD). The 4-m gait speed (4mGS) is simple and effective in stratifying patients according to exercise performance, dyspnea, health status, and prognosis. We assessed the reliability of the 4mGS as a clinical marker by examining its association with established clinical indicators among hospitalized patients with COPD.

METHODS

This retrospective study included 78 patients hospitalized with COPD (mean age: 76.3 ± 0.9 years; males, n = 69) between January 2016 and June 2018 who were assessed using the 4mGS and divided into slow (<0.8 m/s) and normal (≥0.8 m/s) 4mGS groups. Clinical characteristics were compared, including death during the observation period, time to first exacerbation, and long-term oxygen therapy requirement.

RESULTS

There were strong relationships between 4mGS performance, the 6-min walk test (R = 0.70; p < 0.0001), and the modified Medical Research Council dyspnea scale (R = 0.68; p < 0.0001) among the 78 patients. The slow 4mGS group had a higher frequency of death during the observation period (p = 0.0095) and a greater requirement for long-term oxygen therapy (p = 0.0063). The 4mGS correlated with inspiratory capacity (IC) and IC/total lung capacity ratios, which are respiratory failure indicators.

CONCLUSIONS

The 4mGS is a simple and easy method of assessing the physical condition as well as estimating the prognosis of patients with COPD, and may serve as a useful marker in home medical treatment or clinical settings.

Acute exacerbation in interstitial lung disease

BACKGROUND:

Information regarding acute exacerbation (AE) in patients with interstitial lung disease (ILD) is limited.

OBJECTIVES:

The objective of the study was to elucidate the clinical features and outcome of AE among ILD patients.

METHODS:

We retrospectively analyzed the data of 667 consecutive ILD (nonidiopathic pulmonary fibrosis [IPF] ILD, n = 463; IPF, n = 204) patients. ILD patients meeting the 2016 definition of AE-IPF were identified. Information analyzed included pulmonary function tests, 6-min walk tests, and right heart catheterization data, among others. Cox regression models were used to identify independent predictors of survival.

RESULTS:

AE was identified in non-IPF ILD (n = 113) and IPF (n = 74). Compared with AE-IPF patients, non-IPF ILD patients with AE were of younger age, predominantly women, and primarily nonsmokers (all, P < 0.0001). The estimated survival probabilities at 1, 3, and 5 years were 88%, 75%, and 70%, respectively, in the ILD without AE group; 80%, 57%, and 50%, respectively, in the non-IPF ILD with AE group; and 53%, 38%, and 28%, respectively, in the AE-IPF group (P < 0.0001 by log-rank analysis). Age, body mass index, IPF diagnosis, AE, diffusion capacity of the lung for carbon monoxide <35% predicted, 6-min walk distance <300 meters, and cardiac index were independent predictors of survival in the ILD cohort.

CONCLUSIONS:

Non-IPF ILD patients with AE have distinct clinical features compared to AE-IPF patients. Importantly, AE is one of many independent risk factors associated with worsened outcomes regardless of the underlying ILD type.

Concurrence of 1- and 3-Min Sit-to-Stand Tests with the 6-Min Walk Test in Idiopathic Pulmonary Fibrosis

BACKGROUND

In idiopathic pulmonary fibrosis (IPF), some physiological parameters measured during a 6-min walk test (6-MWT) impart reliable prognostic information. Sit-to-stand tests (STSTs) are field exercise tests that are easier to implement than the 6-MWT in daily practice.

OBJECTIVES

The aims of the study were to test the reproducibility and compare 2 STSTs (the 1-min STST [1-STST] and the semi-paced 3-min chair rise test [3-CRT]) in IPF, and to determine if selected physiological parameters (speed of displacement and changes in pulse oxygen saturation [SpO2]) are interchangeable between the STSTs and the 6-MWT.

METHODS

Thirty-three patients with stable IPF were studied in 3 French expert centers. To test reproducibility, intra-class correlations (ICCs) of parameters measured during tests performed 7-14 days apart were calculated. To test interchangeability, the agreement and correlation of physiological responses measured during STSTs and during 6-MWT were studied.

RESULTS

Vertical displacements and changes in SpO2 during both STSTs were reproducible, with ICCs ranging from 0.78 [0.63-0.87] to 0.95 [0.92-0.97]. Vertical displacements during 1-STST and 3-CRT were correlated with 6-MWT distance (correlation coefficients (r) of 0.72 and 0.77, respectively; p < 0.001). Similarly, correlations were found between changes in SpO2 measured during the 2 STSTs and the 6-MWT, with coefficients ranging from 0.73 to 0.91 (p < 0.001). Distance walked and SpO2 during 6-MWT were well estimated from vertical displacement and SpO2 during the 2 STSTs, respectively.

CONCLUSION

The correlations found between the 2 STSTs and the 6-MWT suggest that STSTs may be of interest to assess displacement and exercise-induced changes in SpO2 in IPF patients.

Direct and indirect evidence of efficacy and safety of rapid exercise tests for exertional desaturation in Covid-19: a rapid systematic review

BACKGROUND

Even when resting pulse oximetry is normal in the patient with acute Covid-19, hypoxia can manifest on exertion. We summarise the literature on the performance of different rapid tests for exertional desaturation and draw on this evidence base to provide guidance in the context of acute Covid-19.

MAIN RESEARCH QUESTIONS

1. What exercise tests have been used to assess exertional hypoxia at home or in an ambulatory setting in the context of Covid-19 and to what extent have they been validated? 2. What exercise tests have been used to assess exertional hypoxia in other lung conditions, to what extent have they been validated and what is the applicability of these studies to acute Covid-19?

METHOD

AMED, CINAHL, EMBASE MEDLINE, Cochrane and PubMed using LitCovid, Scholar and Google databases were searched to September 2020. Studies where participants had Covid-19 or another lung disease and underwent any form of exercise test which was compared to a reference standard were eligible. Risk of bias was assessed using QUADAS 2. A protocol for the review was published on the Medrxiv database.

RESULTS

Of 47 relevant papers, 15 were empirical studies, of which 11 described an attempt to validate one or more exercise desaturation tests in lung diseases other than Covid-19. In all but one of these, methodological quality was poor or impossible to fully assess. None had been designed as a formal validation study (most used simple tests of correlation). Only one validation study (comparing a 1-min sit-to-stand test [1MSTST] with reference to the 6-min walk test [6MWT] in 107 patients with interstitial lung disease) contained sufficient raw data for us to calculate the sensitivity (88%), specificity (81%) and positive and negative predictive value (79% and 89% respectively) of the 1MSTST. The other 4 empirical studies included two predictive studies on patients with Covid-19, and two on HIV-positive patients with suspected pneumocystis pneumonia. We found no studies on the 40-step walk test (a less demanding test that is widely used in clinical practice to assess Covid-19 patients). Heterogeneity of study design precluded meta-analysis.

DISCUSSION

Exertional desaturation tests have not yet been validated in patients with (or suspected of having) Covid-19. A stronger evidence base exists for the diagnostic accuracy of the 1MSTST in chronic long-term pulmonary disease; the relative intensity of this test may raise safety concerns in remote consultations or unstable patients. The less strenuous 40-step walk test should be urgently evaluated.

Reliability of Smartphone Pulse Oximetry in Subjects at Risk for Hypoxemia

BACKGROUND

Pulse oximeters are used to measure [Formula: see text] and pulse rate. These devices are either standalone machines or integrated into physiologic monitoring systems. Some smartphones now have pulse oximetry capabilities. Because it is possible that some patients might utilize this technology, we sought to assess the accuracy and usability of smartphone pulse oximeters.

METHODS

This was a prospective, observational study that involved noninvasive measurements of [Formula: see text] and heart rate with 3 devices: Masimo Radical-7, Kenek Edge with the Apple iPhone 6S, and the Samsung S8 smartphone. Ambulatory adult patients visiting our institution's pulmonary function lab for a 6-min walk test were eligible to participate in the study. Pretest and posttest results for each subject were obtained simultaneously using all 3 devices. All results were analyzed with the Spearman rho correlation test, and Bland-Altman plots were used to assess the agreement of measures between the devices.

RESULTS

Forty-seven subjects were enrolled in the study, with pulmonary hypertension (30%) and COPD (23%) being the 2 major diagnoses. The mean ± SD difference between the Masimo and Apple devices for pretest [Formula: see text] was 2.3 ± 2.4%, and the difference for posttest [Formula: see text] was 2.1 ± 3.9%. The mean difference between the Masimo and Samsung devices for pretest [Formula: see text] was 3.2 ± 2.8%, and the difference for posttest [Formula: see text] was 2.4 ± 3.5%. The number of subjects who were unable to obtain [Formula: see text] was higher with the Samsung device than with the Apple device in both pretest (14 of 47 vs 3 of 47) and posttest (17 of 47 vs 5 of 47). In contrast, the Masimo device was able to measure [Formula: see text] in all subjects.

CONCLUSIONS

Smartphone pulse oximeters were unreliable compared to a hospital pulse oximeter. Further research is needed with evolving technology to better understand smartphone pulse oximetry. (ClinicalTrials.gov registration NCT03534271.).

Kinematic evaluation of patients with chronic obstructive pulmonary disease during the 6-min walk test

BACKGROUND

A better understanding of gait kinematics during the 6-min walk test (6MWT) may facilitate the development of rehabilitation strategies for patients with chronic obstructive pulmonary disease (COPD).

AIM

To evaluate gait kinematics during the 6MWT in patients with COPD.

METHOD

Thirty-six patients with COPD and 19 healthy controls underwent a full-body kinematic analysis during the 6MWT. Data were collected using a system with four infrared cameras to capture the movement of a spherical marker covered with retroreflective tape attached to a helmet worn during the test.

RESULTS

The walking distances measured by the assessor and by kinematics analysis were lower in the group of patients (P = 0.036 and P = 0.013, respectively). Moreover, the walking distances measured by kinematics analysis were greater than those measured by the assessor for both groups (P < 0.001). In the kinematics analysis of the complete test, the mean and maximum speeds were higher for the controls than for the patients (P = 0.007 and P = 0.044, respectively). In the half-turn analysis, acceleration, speed, and deceleration peaks (maximal absolute values) were lower for the patients than for the controls (P = 0.002, P = 0.012 and P = 0.006, respectively).

CONCLUSIONS

Patients with COPD show worse functional capacity due to lower gait speed and acceleration-deceleration peaks after turnings as compared to healthy individuals during the 6MWT. Assessors can accurately predict the 6MWD measured by kinematics, though they underestimate this distance.

Noninvasive Predictors of Functional Capacity in Patients with Pulmonary Hypertension due to Congenital Heart Disease: A Pilot Echocardiography Single-Center Study

Background

Pulmonary hypertension (PH) with congenital heart disease (CHD) affects the functional capacity (FC), quality of life, and survival. However, the importance of different echocardiographic parameters and their correlation with FC is unclear.

Methods and Results

A custom-made sheet for 34 consecutive patients with PH due to CHD was made to include patient's demographic data, underlying cardiac disorder, and FC by 6-min walk test (6MWT). The patients were subdivided into Group 1 with 6MWT < 330 m and Group 2 with 6MWT > 330 m. A cutoff value of 330 m was selected because it reflected the survival and outcome of patients in many studies before. Left ventricle global radial strain, baseline saturation, and saturation after 6MWT showed a significant strong positive correlation with 6MWT (r = 0.755, 0.714, and 0.721, P = 0.001, 0.000, and 0.000, respectively). Multiple regression analysis using a multivariate model showed that the mean pulmonary artery pressure (MPAP) and baseline saturation are the most independent predictors of the FC (P = 0.028 and 0.049, respectively), with a cutoff point for MPAP > 30 mmHg (area under the curve [AUC]: 0.85) with a sensitivity and specificity of 69.23% and 95.24%, respectively, and cutoff point for saturation < 94% (AUC: 0.852) with a sensitivity and specificity of 92.31% and 76.19%, respectively.

Conclusion

The MPAP and the baseline oxygen saturation were the most independent predictors of impaired FC. They can be used for risk stratification and as surrogate predictors of outcome in this group of patients.

Preoperative Improvement in Physical Function by Comprehensive Rehabilitation Leads to Decreased Postoperative Complications in Gastrointestinal Cancer Patients

Objectives:

The aim of this study was to investigate how baseline laboratory data and changes in physical function due to preoperative rehabilitation training in gastrointestinal cancer (GIC) patients can influence the frequency of postoperative complications (PCs).

Methods:

We enrolled 45 patients who were scheduled for elective surgery for GIC (27 men and 18 women, mean age 63.6±9.5 years). All patients underwent a medical examination and received general instruction from a rehabilitation physician and exercise instruction from a physical therapist from 7 to 34 days before the surgery. PCs were graded using the Clavien-Dindo classification based on the medical records 1 month postoperatively. We measured the grip strength and the isometric knee extension torque and conducted the 6-min walk test (6MWT) at baseline and just before surgery. The surgical duration, blood loss, and blood transfusion data were collected. Baseline laboratory information, including C-reactive protein levels, serum albumin levels, platelet count, white blood cell count, and the estimated glomerular filtration rate, was recorded.

Results:

The frequency of PCs was negatively correlated to the change in the 6MWT (β=−0.36) and positively correlated to the surgical duration (β=0.41). Baseline albumin was positively correlated to the change in the 6MWT distance (β=0.35). This model demonstrated an acceptable fit to the data (goodness of fit index=0.980, comparative fit index=1.000, root mean square error of approximation=0.000).

Conclusions:

The improvement of gait ability achieved with preoperative rehabilitation training in patients undergoing elective GIC surgery led to decreased PCs.

Idiopathic pulmonary fibrosis patients with severe physiologic impairment: characteristics and outcomes

RESEARCH QUESTION

There is no widely accepted grading system for IPF disease severity, although physiologic impairment based on pulmonary function testing is frequently employed. We sought to describe clinical and functional characteristics as well as outcomes of patients with severe physiologic impairment.

PATIENTS AND METHODS

IPF patients with severe physiologic impairment defined by FVC ≤ 50% and/or DLco ≤ 30% predicted evaluated in the Inova Advanced Lung Disease Program between 2011 and 2019 were included. Demographic, physiologic, functional treatment and outcome data were collated.

RESULTS

There were 531 patients with IPF evaluated of whom 242 (46%) had severe physiologic impairment. Mean age was 72 ± 8 years; baseline FVC was 53 ± 17% and DL_CO 28 ± 9% of predicted. The mean 6 min walks test (6MWT) distance was 304 ± 121 m with 59% of the patients requiring supplemental oxygen ([Formula: see text] group). There was a poor correlation between the 6MWT distance and both FVC% and DLco%. Patients in the 6MWT_RA group had a better transplant-free survival than the [Formula: see text] group (p = 0.002). Patients managed before October 2014 and not receiving antifibrotic therapy had worse outcomes with reduced transplant-free survival compared with patients presenting after this date who did receive antifibrotic therapy (n = 113) (log rank p < 0.0001).

CONCLUSION

IPF patients often present with severe physiologic impairment which may be poorly correlated with their functional status. Assessment of IPF disease severity should not be based on physiologic impairment alone, but should also encompass functional status as well as need for supplemental oxygen. Antifibrotic therapy in patients with severe physiologic impairment is associated with improved outcomes.

Differential Physical and Mental Benefits of Physiotherapy Program Among Patients With Schizophrenia and Healthy Controls Suggesting Different Physical Characteristics and Needs

In contrast to several other severe illnesses marked by inflammation and autoimmunity that now have potent and efficient treatments and even cures, schizophrenia (SCZ) is a disease still associated with poor outcome, incapacity, and social burden. Even after decades of research on the brain and behavior, this illness is still associated with profound effects on both mental health and physical health, with recent studies showing that treatment is more efficient when associating drugs with psychological and physical treatments. Most of the studies measured the effects of physical intervention compared with usual care and demonstrated a positive effect as an add-on treatment. What remains unclear is the different effects of the same intervention in normal subjects in a sample of patients with the illness. The study aimed to evaluate the effects of physical intervention over motor functional capacity and mental health in patients with SCZ compared with healthy controls (HC). The outcomes were (a) functional capacity [by 6-min walk test (6MWT)], (b) body flexibility index (Wells' bench), (c) disease severity [by Brief Psychiatric Rating Scale (BPRS)], (d) quality of life [by 36-Item Short Form (SF-36) questionnaire], and (e) physical activity [Simple Physical Activity Questionnaire (SIMPAQ)]. The intervention was associated with significant decrease of body mass index (BMI), blood pressure, disease severity, and improvement in daily life activities. Unexpectedly, it was observed that schizophrenics, compared with matched HC, were at a lower level of performance in the beginning, remained below HC over the studied time despite similar physical intervention, and had different changes. The intervention had lower effects over physical capacity and better effects over quality of life and disease severity. The results confirm previous studies comparing patients receiving physical intervention but suggest that they may receive different types of intervention, suited for their different baseline fitness, motivation, and capacity to engage in physical effort over sustained time. Additionally, they point to extended time of intervention of multidisciplinary treatment (physical and psychological-cognitive techniques) to improve outcomes in SCZ.