Impact of Adding Early Bedside Cycling to Inpatient Cardiac Rehabilitation on Physical Function and Length of Stay after Heart Valve Surgery. A Randomized Controlled Trial

OBJECTIVE

To assess whether adding bedside cycling to inpatient cardiac rehabilitation (CR) early after heart valve surgery could lead to better physical function and shorter length of hospital stays.

DESIGN

This is a single-centered, randomized, controlled, parallel-group intervention study.

SETTINGS

This study was conducted at the National Heart Institute from December 2022 to June 2023.

PARTICIPANTS

Thirty-one heart valve surgery patients completed this study after being randomized into two groups: an intervention group (n1=16) and an active control group (n2=15). Eligibility criteria were heart valve surgery with median sternotomy, clinical stability, and age from 20 to 40.

INTERVENTIONS

the intervention group received early bedside cycling for the lower limbs, using a mini bike, in addition to an inpatient CR program, and the control group received the CR program alone.

MAIN OUTCOME MEASURE

The primary outcome was six-minute walk distance (6MWD). The secondary outcomes comprised forced vital capacity (FVC), Barthel Index (BI), the length of ICU stay, the total length of hospital stay, and the physical component summary (PCS) of the 12-item Short Form (SF-12) Health Survey.

RESULTS

Compared to the control group, the intervention group showed more improvements in 6MWD (p<0.001), BI score (p<0.001), and FVC (p=0.006) at hospital discharge, and shorter ICU stay (p=0.002) and total hospital stay (0.015). At 1-month follow-up, the intervention group showed a non-significantly better improvement in the PCS of the SF-12 compared to the control group (p=0.057).

CONCLUSION

Adding early bedside cycling to a usual inpatient CR program after heart valve surgery could induce significantly better short-term physical function as assessed by 6MWD and BI, higher pulmonary function as measured by FVC, and shorter lengths of ICU and total hospital stays than the usual CR program alone.

TRIAL REGISTRATION

ClinicalTrial.gov (NCT05893433).

Correlation Between Diaphragmatic Excursion and Exercise Tolerance Improvement Following Pulmonary Rehabilitation in Patients with Chronic Obstructive Pulmonary Disease-Obstructive Sleep Apnea Overlap Syndrome

Purpose

We assess the predictive value of diaphragm excursion (DE) in enhancing exercise tolerance following pulmonary rehabilitation (PR) among patients with COPD-OSA overlap syndrome.

Material and Methods

This prospective cohort study enrolled 63 patients diagnosed with COPD-OSA overlap syndrome who actively participated in a PR program from January 2021 to May 2023. Among these, 58 patients successfully completed the 20-week PR program, with exercise tolerance assessed through the measurement of six-minute walk distance (6MWD), and DE evaluated by ultrasonography. The responder to PR in terms of exercise ability was defined as a patient who showed an increase of >30m in 6MWD. The cutoff value for predicting PR response based on DE was determined using receiver operating characteristic (ROC) curves.

Results

Following the PR program, significant improvements were observed in mMRC, 6MWD, DE during deep breathing, and diaphragm thickness fraction (DTF). Of the participants, 33 patients (57%) were classified as responders, while 25 patients (43%) were considered non-responders. Baseline values of FEV1% predicted, 6MWD, DE during deep breathing, DTF, and PaO2 exhibited a significant elevation in responders as compared to non-responders. The changes of 6MWD were positively associated with the baseline values of DTF and DE during deep breathing, FEV1% predicted and PaO2, while negatively correlated with baseline value of mMRC. The predictive performance in terms of the area under the ROC curve for determining responder's DTF was found to be 0.769, accompanied by a sensitivity of 85% and specificity of 68%, using a cutoff value at 17.26%. Moreover, it was observed that DE during deep breathing could predict the area under the ROC curve for responders to be 0.753, with a sensitivity of 91% and specificity of 56% at a cutoff value of 3.61cm.

Conclusion

Diaphragm excursion serves as a valuable predictor for determining the enhancement of exercise tolerance following PR in patients with COPD-OSA overlap syndrome.

Trial Registration

ChiCTR1800020257, www.chictr.org.cn/index.aspx.

Predictive equation for six-minute walk test in Indian children, adolescents, and adults

Background

Post-COVID residual dysfunction has been observed in a majority of people, with reduction in cardiopulmonary endurance emerging as a primary symptom. The Six-Minute Walk Test is a simple, reliable, and valid test that is used routinely on people with chronic respiratory dysfunction. In the current COVID-19 pandemic situation, reference values and a predictive equation developed from a large sample across a large age group, from 6 to 75 years, will enable one to establish goals of treatment for post-COVID rehabilitation.

Methods

Following institutional ethical clearance, we recruited 1369 participants for the study (685 females and 684 males). Participants were classified according to biological age into group 1 (6-12 years), group 2 (13-17 years), group 3 (18-40 years), group 4 (41-65 years), and group 5 (>65 years). Informed consent was sought and participants were screened using a health history questionnaire. Demographic features, namely, age, height, weight, and body mass index (BMI) were noted. The Six-Minute Walk Test was administered as per ATS guidelines. Clinical parameters, namely, pulse rate, respiratory rate, systolic blood pressure, diastolic blood pressure, and rate of perceived exertion were recorded.

Results

The Six-Minute Walk Test (6MWT) was significantly influenced by age and gender (r = 0.257, P = 0.00 and r = 0.501, P = 0.00, respectively). Walking distance was longest in 13-17-year-old males, whereas females demonstrated a linear decline after 12 years. In each age group, males walked a greater distance than females. Stepwise linear regression analysis was used to derive the following predictive equation: 6MWT = 491.93 - (2.148 × age) + (107.07 × gender) (females = 0, males = 1).

Conclusion

The study confirmed variability of the Six-Minute Walk Test, with age and gender being predominant predictors. Reference values, equations, and percentile charts generated from the study can be utilised to guide clinical decision-making while exercise prescription for patients with post COVID dysfunction.

Whole-Body Vibration or Aerobic Exercise in Patients with Bronchiectasis? A Randomized Controlled Study

Background and Objectives: The whole-body vibration (WBV) technique is an exercise training method. It has been reported to improve muscle strength, exercise capacity, and the quality of life. However, there is no study on the use of the WBV technique in bronchiectasis. The aim of the present study is to compare the effect of aerobic exercise with whole-body vibration on exercise capacity, respiratory function, dyspnea, and quality of life (QoL) in bronchiectasis patients. Materials and Methods: Clinically stable bronchiectasis patients aged 18−74 years participated in this study. A pulmonary function test, 6 minute walk test (6MWT), five times sit-to-stand test (FTSST), Modified Medical Research Council (mMRC) Scale, an, St. Georges Respiratory Questionnaire (SGRQ) were used in the evaluation. In total, 41 patients (WBV group: 20, aerobic group: 21) completed the study. The patients were treated for eight weeks. Results: When the two groups were compared after the treatment, there was a significant difference between the mMRC scores in favor of the WBV group (p < 0.05). When the results of the WBV group were examined before and after treatment, a significant difference was found between the 5SST and 6MWT (p < 0.05). When the aerobic group was compared before and after the treatment, it was observed that there was a significant difference in FVC, FVC%, 5SST, 6MWT, and SGRQ total score, and activity and impact scores, which are the sub-parameters (p < 0.05). Conclusions: Eight weeks of WBV exercise can lead to significant improvements in patients with bronchiectasis, exercise capacity, and dyspnea. Larger studies are needed to define the optimal intensity and duration of WBV, as well as to investigate its possible long-term effects.

Inspiratory Muscle Training Improves Aerobic Fitness in Active Children

Research on the effect of inspiratory muscle training (IMT) on exercise performance is inconsistent. IMT has not been applied to fit child athletes, who are more likely to develop inspiratory muscle fatigue, and, consequently, to benefit from IMT. Methods: Thirty children (mean age: 10.7 ± 1.2 years) were recruited and randomly assigned to a high-intensity (HG), a low-intensity (LG), or a control group (CG). For both training groups, a double-blind procedure was applied. In the HG, 80% of maximal inspiratory pressure (MIP) was used as the level of training intensity. The LG used 30% MIP. Training groups were trained at 6 breaths a set, 4 sets a day, totaling 24 breaths a day for 6 weeks. Exercise capacity outcomes include maximal and submaximal aerobic capacity, as measured as VO₂max and distance from six-minute walk test (6MWD). Results show improvement in MIP, VO₂max, and 6MWD only in the HG. MIP in the HG significantly increases from 108.7 (100.8-143.3) to 144.4 (130.0-175.6) cmH₂O. VO₂max in the HG increases from 43.0 (40.5-45) to 53.0 (46-63) mL·kg^-1·min^-1. The 6MWD increases from 792.0 (737.5-818.0) to 862.0 (798.5-953.5) m. Data are presented as median (interquartile range). No difference is found in the LG or CG. Conclusion: high-intensity IMT increases MIP, maximal, and submaximal exercise capacity in the HG, but no difference is found in the LG or CG. Therefore, high-intensity type of IMT improves aerobic fitness in fit children by appropriately applying inspiratory muscle strength training.

Short-Term Impact of Iron Deficiency in Different Subsets of Patients with Precapillary Pulmonary Hypertension from an Eastern European Pulmonary Hypertension Referral Center

Background

Over the last few decades, interest in the role of iron status in pulmonary hypertension (PH) has grown considerably due to its potential impact on symptoms, exercise capacity (as assessed by the 6-minute walk distance [6MWD]), prognosis, and mortality. The aim of the present study was to identify iron deficiency (ID) prevalence in specific precapillary PH subgroups of Romanian patients and its short-term impact on 6MWD.

Patients and Methods

Complete datasets from 25 precapillary PH adults were examined and included in the analysis. Data were collected at baseline and after continuous follow-up of an average of 13.5 months. Enrolled patients were assigned to group 1 (pulmonary arterial hypertension) or subgroup 4.1 (chronic thromboembolic pulmonary hypertension), and individualized targeted therapy was prescribed. General characteristics, World Health Organization functional class, 6MWD, pulse oximetry, laboratory parameters, and echocardiographic and hemodynamic parameters were recorded. Ferritin values and transferrin saturation were used to assess ID.

Results

At baseline, 16 out of 25 patients were iron deficient. The univariate linear regression analysis did not show a statistically significant impact of ID on 6MWD (p=0.428). In multivariate regression analysis, possible predictors of 6MWD, including ID, were not statistically significant at baseline or after an average of 13.5 months follow-up (p=0.438, 0.361, respectively) and ID indicates a negative impact on 6MWD independent of applied corrections.

Conclusion

The results of this study demonstrate that 1.4.1 subgroup PAH patients have an increased prevalence of ID compared with other etiologies. ID has a negative impact on the functional status (assessed by 6MWD), in specific groups and subgroups of patients with precapillary PH, albeit not independently nor significant to other known predictors such as age, gender, oxygen saturation, and hemoglobin value. These data can be integrated with global research and are consistent with phenotypes of patients diagnosed with PH of different etiologies.

Study of the effect of Occlutech Atrial Flow Regulator on symptoms, hemodynamics, and echocardiographic parameters in advanced pulmonary arterial hypertension

Optimal sized balloon atrial septostomy improves hemodynamics in advanced pulmonary arterial hypertension. Occlutech Atrial Flow Regulator is designed to provide an atrial septal fenestration diameter titrated according to the age and right atrial pressures. This observational study analyzed symptoms, exercise distance, oxygen saturations, hemodynamics and echocardiographic parameters after Atrial Flow Regulator implantation in patients with syncope or right-heart failure. Patients with high-risk predictors of mortality during septostomy were scrutinized. Thirty-nine patients (9 children) with syncope (34/39) or right-heart failure (27/39) underwent Atrial Flow Regulator implantation without procedural complications. Six-minute walk distance increased from 310 ± 158.2 to 376.4 ± 182.6 m, none developed syncope. Oxygen saturations reduced from 96.4 ± 6.4% to 92 ± 4.9% at rest and further to 80.3 ± 5.9% on exercise. Right atrial pressures reduced from 9.4 ± 5 (2-27) mmHg to 6.9 ± 2.6 (1-12) mmHg, while cardiac index increased from 2.4 ± 0.8 (0.98-4.3) to 3 ± 1 (1.1-5.3) L/min/m² and systemic oxygen transport increased from 546.1 ± 157.9 (256.2-910.5) to 637.2 ± 191.1 (301.3-1020.2) ml/min. Echocardiographic improvement included significant reduction of pericardial effusion and inferior caval congestion at a median follow-up of 37 months. Overall survival improved except two early and one late deaths in high-risk patients. Five of seven patients with advanced disease and key hemodynamic predictors of mortality survived. Acute hemodynamic benefits in pulmonary arterial hypertension after Atrial Flow Regulator were improved cardiac output, systemic oxygen transport, and reduced right atrial pressures. Improvement of symptoms especially syncope, exercise duration, and right ventricular systolic function as well as device patency were sustained on mid-term follow-up. Implantation was safe in all including young children without procedural complications. Mortality was noted only in patients who had high-risk predictors and patients at advanced stage of the disease.

Novel dose-response analyses of treprostinil in pulmonary arterial hypertension and its effects on six-minute walk distance and hospitalizations

Treprostinil is a prostacyclin analogue approved for the treatment of pulmonary arterial hypertension. Apart from the inhaled formulation, there is neither a target dose nor a ceiling dose to guide clinicians using treprostinil; doses are individualized for each patient based upon tolerability and clinical improvement. Using combined data from the pivotal subcutaneous and oral treprostinil studies, we evaluated the effect of treprostinil dose on hospitalization and exercise capacity to better define the treprostinil dose–response relationship. Data from the pivotal subcutaneous and oral treprostinil studies were combined by converting oral doses to weight-based continuous doses (ng/kg/min) accounting for patient weight and bioavailability. Patients were divided into dose tertiles (lowest, middle, highest 33%) and retrospectively analyzed. Analysis 1 assessed the effect of dose on pulmonary arterial hypertension-related and all-cause hospitalizations. Analysis 2 evaluated the effects of dose on six-minute walk distance, Borg dyspnea score, and World Health Organization functional class. Results showed that, in Analysis 1, higher doses of treprostinil were associated with significantly longer times to first pulmonary arterial hypertension-related and all-cause hospitalization. In Analysis 2, there was a trend toward improvements in six-minute walk distance with higher doses. In patients with pulmonary arterial hypertension on systemic treprostinil therapy, higher doses were associated with significantly longer time to first pulmonary arterial hypertension-related and all-cause hospitalization. There was a trend toward improvements in six-minute walk distance. Collectively, these results underscore the importance of managing prostacyclin adverse events in order to achieve appropriate dose titration. Further studies are required to confirm these findings and to better characterize the dose–response relationship of treprostinil.

Effect of ferric-carboxy maltose on oxygen kinetics and functional status in heart failure patients with iron deficiency

There is a very high prevalence of iron deficiency anemia in patients with systolic heart failure. The present study is a prospective, parallel, 1:1 randomized controlled trial of intravenous ferric-carboxy maltose compared with standard of care in patients with heart failure. A total of 70 patients who presented to us with symptomatic chronic heart failure were included and randomly assigned to either groups (35 per group). Post 12 weeks, there were improvements noticed in peak VO₂, New York Heart Association functional classification, 6-min walk test distance covered and reduction in Minnesota Living with Heart Failure Questionnaire score in the ferric-carboxy maltose as compared with standard of care group. However, no improvement in ejection fraction was noticed.

Iron deficiency is commonly seen in patients with heart failure. This study was performed to observe the effect of intravenous iron therapy (ferric-carboxy maltose) in this population. The outcome showed significant benefit in symptoms and improvement in quality of life. These results are in concordance with other similar trials. Therefore, simple intravenous iron replacement along with other heart failure measures can make life easier for patients with heart failure.

Exercise Performance as a Predictor for Balance Impairment in COPD Patients

Background and objective: Six-minute walk test (6-MWT) is a widely used test for assessing exercise performance in chronic obstructive pulmonary (COPD). However, the association between reduced walking distance and balance impairment in COPD has not been directly investigated. Therefore, the aim of this study was to identify exercise performance as a predictor for balance impairment in COPD. Materials and Methods: The cross-sectional study was conducted at a single visit involving stable COPD patients in Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand from November 2015 to October 2017. The 6-MWT was measured for in all subjects. The prognostic confounding factors were also collected for all subjects. Balance test was measured using the Berg Balance Scale (BBS) and the Timed Up and Go (TUG) test. A cut-off score of BBS < 46 and/or the TUG ≥ 13.5 s was classified as balance impairment. Multivariable logistic regressions were performed to identify the six-minute walk distance (6-MWD) as a predictor for balance impairment in COPD. Results: Of the 176 COPD subjects assessed for eligibility, 118 COPD patients were enrolled including 86 males (72.9%) with a mean age of 73.5 ± 8.1 years. Thirty-three (28.0%) cases were classified with a balance impairment. The 6-MWD < 300 m was the predictor of balance impairment in COPD with an adjusted risk ratio of 10.10 (95%CI; 2.87, 35.61, p-value < 0.001). Conclusions: The 6-MWT is not only useful for evaluation of exercise performance, but also for prediction of balance impairment in patients with COPD. Our study suggests that the 6-MWD < 300 m is an important risk factor for balance impairment in COPD.

A 1-Month Physical Therapy-Based Outpatient Program for Adults Awaiting Lung Transplantation: A Retrospective Analysis of Exercise Capacity, Symptoms, and Quality of Life

Purpose

Rehabilitation can improve health outcomes in candidates for lung transplantation. The purpose of this study was to retrospectively evaluate the effect of a one-month physical therapy (PT)-based outpatient program on exercise capacity, symptoms, quality of life and examine predictors of functional outcome changes in adults awaiting lung transplantation.

Methods

Participants (n=141) completed a 23-session exercise and educational program over one month. Outcomes included 6-minute walk distance (6MWD), San Diego Shortness of Breath Questionnaire (SOBQ), Center for Epidemiological Studies-Depression Scale (CESD), and Ferrans and Powers Quality of Life Index Pulmonary Version III (QOL).

Results

Participants were older (median age 63) with restrictive (59%) or obstructive (24%) disease. Moderate-to-large improvements in 6MWD were observed (69 m, p < 0.001, d = 0.72), independent of demographics, symptoms, and QOL. Lower initial 6MWD and lower oxygen utilization were associated with greater 6MWD improvements, with largest gains occurring in initial 6MWD < 305 m. Small-to-moderate improvements were observed on CESD (p < 0.001, d = 0.26) and in overall QOL (p < 0.001, d = 0.27), with a non-significant improvement observed on SOBQ (p = 0.248, d = 0.13).

Conclusions

Completion of a one-month PT-based outpatient rehabilitation program was associated with improved exercise capacity, depressive symptoms and QOL.

Pulmonary Rehabilitation in Patients with Chronic Lung Impairment from Pulmonary Tuberculosis

Setting

Our study was conducted at a tertiary care center for respiratory illnesses (Viswanathan Chest Hospital, Vallabhbhai Patel Chest Institute (VPCI), University of Delhi, Delhi, India). Patients were enrolled in the study from the outpatient clinic.

Objective

To assess the effects of pulmonary rehabilitation (PR) in patients with chronic lung impairment from previously treated tuberculosis (CLIPTB), on exercise capacity (six-minute walk distance), pulmonary function tests, quality of life and markers of systemic inflammation.

Design

Prospective cohort study including 29 patients who had finished anti-tubercular therapy and currently had symptoms of dyspnea with or without cough secondary to CLIPTB.

Result

Significant improvement in six-minute walk distance (488 meters at baseline vs 526 meters post PR intervention, p-value 0.033) and chronic respiratory questionnaire score (17.21 at baseline vs 18.96 post PR intervention, p-value 0.025) with pulmonary rehabilitation was noted. Pulmonary function tests, inflammatory markers and mid-thigh muscle mass trended towards improvement with pulmonary rehabilitation but were not statistically significant.

Conclusion

Our study shows that pulmonary rehabilitation is an effective intervention in post-tuberculosis patients and should be recommended.

Six-minute walk distance after coronary artery bypass grafting compared with medical therapy in ischaemic cardiomyopathy

Background

In patients with ischaemic left ventricular dysfunction, coronary artery bypass surgery (CABG) may decrease mortality, but it is not known whether CABG improves functional capacity.

Objective

To determine whether CABG compared with medical therapy alone (MED) increases 6 min walk distance in patients with ischaemic left ventricular dysfunction and coronary artery disease amenable to revascularisation.

Methods

The Surgical Treatment in Ischemic Heart disease trial randomised 1212 patients with ischaemic left ventricular dysfunction to CABG or MED. A 6 min walk distance test was performed both at baseline and at least one follow-up assessment at 4, 12, 24 and/or 36 months in 409 patients randomised to CABG and 466 to MED. Change in 6 min walk distance between baseline and follow-up were compared by treatment allocation.

Results

6 min walk distance at baseline for CABG was mean 340±117 m and for MED 339±118 m. Change in walk distance from baseline was similar for CABG and MED groups at 4 months (mean +38 vs +28 m), 12 months (+47 vs +36 m), 24 months (+31 vs +34 m) and 36 months (-7 vs +7 m), P>0.10 for all. Change in walk distance between CABG and MED groups over all assessments was also similar after adjusting for covariates and imputation for missing values (+8 m, 95% CI -7 to 23 m, P=0.29). Results were consistent for subgroups defined by angina, New York Heart Association class ≥3, left ventricular ejection fraction, baseline walk distance and geographic region.

Conclusion

In patients with ischaemic left ventricular dysfunction CABG compared with MED alone is known to reduce mortality but is unlikely to result in a clinically significant improvement in functional capacity.

Trial registration number

NCT00023595.

The Modified Borg Dyspnea Scale does not predict hospitalization in pulmonary arterial hypertension

Background

Breathlessness is the most common symptom reported by patients with pulmonary arterial hypertension (PAH). The Modified Borg Dyspnea Scale (MBS) is routinely obtained during the six-minute walk test in the assessment of PAH patients, but it is not known whether the MBS predicts clinical outcomes such as hospitalizations in PAH.

Methods

We performed a retrospective study of World Health Organization (WHO) Group 1 PAH patients followed at our center. The dates of the first three MBS and hospitalizations that occurred within three months of a documented MBS were collected. Marginal Cox hazard regression modeling was used to assess for a relationship between MBS and all-cause as well as PAH-related hospitalization.

Results

A total of 50 patients were included; most (92%) were functional class III/IV, 44% and 65% were treatment-naïve prior to their first MBS and hospitalization, respectively. The first recorded MBS was inversely correlated with the first recorded six-minute walk distance (6MWD) (r = –0.41, P < 0.01) but did not track with WHO functional class (r = 0.07, P = 0.63). MBS did not predict all-cause (hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.76–1.08; P = 0.28) or PAH-related hospitalization (HR, 1.04; 95% CI, 0.89–1.23; P = 0.61), though there was a strong relationship between 6MWD and PAH-related hospitalization (P = 0.01). These findings persisted after multivariable adjustment.

Conclusions

Breathlessness as assessed by MBS does not predict all-cause or PAH-related hospitalization. Robust and validated patient-reported outcomes are needed in pulmonary vascular disease.

Post-operative delayed ambulation after thymectomy is associated withpre-operative six-minute walk distance

OBJECTIVE

Delayed post-operative ambulation is a risk of post-operative complications and increases overall healthcare costs. We investigated pre-operative and intraoperative variables associated with delayed ambulation in patients who underwent thymectomy.

METHODS

A total of 57 consecutive patients undergoing thymectomy were included in this study. Pre-operative functional exercise capacity was evaluated by six-minute walk distance. Ambulation was considered to be delayed if the patient could not walk the ward on post-operative day 1. Binary logistic regression analysis was performed to clarify the factors associated with delayed ambulation.

RESULTS

Pre-operative six-minute walk distance was the only significant variable that was associated with delayed ambulation. The area under the receiver operating characteristic curve for predicting delayed ambulation was 0.684 (95% confidential interval: 0.546-0.823, p = 0.017), and the optimal discriminatory pre-operative six-minute walk distance value was 498 m. Post-operative hospital stay was significantly longer in patients with low six-minute walk distance (<498 m) than those with high six-minute walk distance (≥498 m). In contrast, the presence of myasthenia gravis or adjuvant chemoradiotherapy was not associated with delayed ambulation.

CONCLUSIONS

Our results suggest that low pre-operative six-minute walk distance is associated with delayed post-operative ambulation and longer post-operative hospital stay in patients who underwent thymectomy. Implications for rehabilitation The predictors for delayed ambulation after thymectomy are not fully investigated. The presence of myasthenia gravis was not associated with delayed ambulation. Low pre-operative six-minute walk distance was associated with delayed ambulation.

Controlled Study of Correlation of Biomechanical Profile of Hemiparetic Patients with Distance Travelled in Six Minutes

The six-minute walking test (6MWT) is used to assess exercise tolerance that is associated with motor function of the lower limbs in hemiparetic patients. It is suggested that, for post-stroke subjects, performance in the 6MWT may be limited by biomechanical and cardiovascular factors. Our aim is to determine the correlation between the six-minute walk distance (6MWD) and the biomechanical profile of hemiparetic patients. During this cross-sectional controlled study, 10 hemiparetic patients with heart failure underwent 6MWT (ATS protocol). Tonus (Ashworth Scale) and goniometry of the lower limbs were measured. The average of 6MWD in two tests was 279±8 m. There was a negative correlation between the degree of spasticity for both the sural triceps (r=-0.57, P<0.05), quadriceps (r=-0.58, P<0.05) and the limitation in ankle dorsiflexion and the 6MWD (r=-0.76, P<0.05). Also, there was correlation between hip extension and ankle dorsiflexion limitations with 6MWD (r=0.66, P<0.05), (r=0.77, P<0.05). The negative correlation between the highest spasticity in paretic limb and the 6MWD and the correlation between the lower movement range of paretic hip and ankle suggest association with these factors and gait velocity in 6MWT. Loss percentage represents the percentage calculation between distance traveled and the distance predicted achieved by patients. In this study, the negative correlation between the percentage of loss of 6MWD and the limitation in the ankle dorsiflexion movement suggests that for a minor motion arch of the ankle, there is a higher percentage of walking distance loss foretold.

Which field walking test should be used to assess functional exercise capacity in lung cancer? An observational study

BACKGROUND

There is emerging evidence regarding the efficacy of exercise training to improve exercise capacity for individuals with non-small cell lung cancer (NSCLC). Cardiopulmonary exercise testing (CPET) is the gold standard measure of exercise capacity; however this laboratory test has limitations for use in research and clinical practice. Alternative field walking tests are the six-minute walk test (6MWT), incremental-shuttle walk test (ISWT) and endurance-shuttle walk test (ESWT); however there is limited information about their clinimetric properties in NSCLC.

AIMS

In NSCLC to determine the 1) criterion validity of the 6MWT, ISWT and ESWT against CPET; 2) construct validity of the 6MWT, ISWT and ESWT against measures of function, strength, respiratory function and health-related quality of life (HRQoL); and 3) clinical applicability of the tests.

METHODS

Twenty participants (40 % male, mean ± SD age 66.1 ± 6.5 years) with stage I-IIIb NSCLC completed the 6MWT, ISWT, ESWT and CPET within six months of treatment. Testing order was randomised. Additional measures included Eastern Cooperative Oncology Group Performance-Status (ECOG-PS, function), respiratory function, hand-grip dynamometry and HRQoL. Correlations and regression analyses were used to assess relationships.

RESULTS

The ISWT demonstrated criterion validity with a moderate relationship between ISWT distance and CPET peak oxygen consumption (r = 0.61, p = 0.007). Relationships between CPET and six minute walk distance (6MWD) (r = 0.24, p = 0.329) or ESWT time (r = 0.02, p = 0.942) were poor. Moderate construct validity existed for the 6MWD and respiratory function (forced vital capacity % predicted r = 0.53, p = 0.019; forced expiratory volume in the first second % predicted r = 0.55, p = 0.015). There were no relationships between the walking tests and measures of function, strength or HRQoL. The ESWT had a ceiling effect with 18 % reaching maximum time. No floor effects were seen in the tests. The mean ± SD time required to perform the individual 6MWT, ISWT and ESWT was 12.8 ± 2.5, 14.7 ± 3.7 and 16.3 ± 5.0 min respectively; in comparison to CPET which was 51.2 ± 12.7 min. Only one assessor was required to perform all field walking tests and no adverse events occurred.

CONCLUSIONS

The ISWT is a promising measure of functional exercise capacity in lung cancer. Findings need to be confirmed in a larger sample prior to translation into practice.

Six-minute walk test in pulmonary arterial hypertension

Exercise intolerance is the main characteristic of pulmonary arterial hypertension (PAH). The six-minute walk test (6MWT) and cardiopulmonary exercise test are widely used in assessing exercise capacity of PAH patients. Six-minute walk distance (6MWD) has been specified as the main clinical outcome in PAH and has been used as the primary end-point in many studies conducted for new PAH treatments. Using 6MWD as the end-point in clinical studies has many advantages. 6MWT is an inexpensive, easily applicable, and repeatable standardized test that is well-tolerated by PAH patients. Moreover, it is a valid measure of symptomatic improvement. It is correlated with variables of maximal cardiopulmonary exercise test as a measure of submaximal exercise capacity and disease severity markers such as functional class and pulmonary hemodynamics. It is widely used in clinical practice together with other invasive and non-invasive disease markers in assessing disease progression and response to treatment. In addition, it has prognostic importance and is a good prognostic marker. On the other hand, there are limitations to the use of 6MWD as the primary end-point in PAH treatment. It has decreased sensitivity in individuals with less severe disease and high 6MWD at baseline and decreased adequacy in assessing the effects of treatment in patients who are still under PAH treatment. Despite the limitations, 6MWD plays a key role in the evaluation and management of PAH patients.

Pirfenidone treatment in idiopathic pulmonary fibrosis: A Saudi experience

BACKGROUND:

Recent trials involving pirfenidone suggest a beneficial effect in the treatment of idiopathic pulmonary fibrosis (IPF).

OBJECTIVE:

To report on the efficacy and safety of pirfenidone in the treatment of patients with IPF, at a tertiary care hospital in Saudi Arabia.

METHODS:

The study included 58 patients with IPF who were evaluated from March 2012 to March 2013. During the study period, 33 patients received pirfenidone, and the remaining patients (n = 25) served as a control group. Baseline clinical characteristics, physiological parameters and the results of a 36-Item Short Form Health Survey (SF-36) were compared between the groups. Furthermore, we compared changes in forced vital capacity (FVC), diffusion capacity of the lung for carbon monoxide (DLco), six-minute walk distance (6MWD) and SF-36 for both groups during follow-up. The last follow-up period ended in January 2014.

RESULTS:

There were no significant differences in baseline clinical characteristics between the groups. Furthermore, we found no differences in FVC, DLco and SF-36 during follow-up (median, 12 months). However, patients receiving pirfenidone treatment were less likely to experience reductions in 6MWD compared with the control group (13% vs. 52%, respectively; P = 0.001). Although adverse events were more frequently reported by the pirfenidone group compared with the control group (85 vs. 56%, respectively; P = 0.015), these patients did not require discontinuation of treatment.

CONCLUSION:

Pirfenidone treatment preserves functional capacity, as reflected by the 6MWD. Adverse events associated with pirfenidone treatment were generally well tolerated by the patients.

Application of a new parameter in the 6-minute walk test for manifold analysis of exercise capacity in patients with COPD

BACKGROUND

New parameters in the 6-minute walk test (6 MWT) are required for comprehensive analysis of exercise capacity in patients with chronic obstructive pulmonary disease (COPD). The aim of the present study was to apply a novel index, the desaturation distance ratio (DDR), to clinical research on COPD as an estimate of exercise capacity and to examine whether DDR is a potential parameter for manifold analysis of exercise capacity in patients with COPD.

METHODS

A total of 41 patients with COPD (median age [interquartile range] =75 [68-79] years; and body mass index [BMI] =22.3 [19.4-23.8] kg/m(2)) participated in the study. The 6 MWT was performed along with anthropometric measurements and a pulmonary function test. The "desaturation area" was measured as the total area above the curve created using peripheral oxygen saturation (SpO2) values observed at each minute during the 6 MWT. Then the DDR was calculated as the ratio of the desaturation area to the 6-minute walk distance (6 MWD).

RESULTS

The 6 MWD was 370 (328-445) m, and the decline in SpO2 values (ΔSpO2) was -5.0% (-8.0% to -1.5%). The DDR correlated modestly with baseline pulmonary function in patients with COPD (forced expiratory volume in 1 second [% of predicted value]: r=-0.658, P<0.001; and diffusing capacity of the lung for carbon monoxide [DL(CO)]: r=-0.470, P=0.002), comparable with the findings of the 6 MWD. The DDR correlated well with ΔSpO2 (r=-0.656, P<0.001) and with the increase in subjective sense of dyspnea during the 6 MWT, as assessed by Borg scale scores (ΔBorg) (r=0.486, P=0.001), in contrast with the 6 MWD, which was not significantly correlated with ΔSpO2 and ΔBorg scale scores.

CONCLUSION

The DDR is more informative for manifold analysis of exercise capacity associated with oxygen desaturation and subsequent sense of dyspnea by exercise in patients with COPD.

Measuring unsupported arm lifts as an outcome in pulmonary rehabilitation of chronic obstructive pulmonary disease patients

Pulmonary rehabilitation includes upper and lower extremity exercise training. While validated tests such as the six-minute walk distance (6MWD) and shuttle walk tests are available to evaluate the effectiveness of lower extremity training, the optimal method of evaluating the effectiveness of upper extremity training has not been determined. This study evaluates the potential utility of unsupported arm lifts (UALs) testing as an outcome measurement for pulmonary rehabilitation. Records of chronic obstructive pulmonary disease (COPD) patients who underwent outpatient pulmonary rehabilitation at our institution were reviewed. Outcomes assessed before and immediately after the intervention included 6MWD, the self-administered Chronic Respiratory Questionnaire (CRQ-SA), and UALs. For the latter, the patient repeatedly raises a wooden dowel from thigh to arm level, with the number of repetitions per minute used as the outcome. Changes in variables from pre- to post-pulmonary rehabilitation were analyzed using paired t test. Pearson correlation coefficients were used to evaluate associations. Of the 241 patients, 51% were male. Mean age was 69 ± 9 years, body mass index was 28 ± 7 kg/m(2), and forced expiratory volume in 1 second was 50 ± 20 percent-predicted. All studied variables increased significantly post-pulmonary rehabilitation: the 6MWD by 45 ± 50 m (effect size 0.49), the CRQ-SA total score by 0.84 ± 0.86 units (effect size 0.89), and UAL by 12 ± 13 lifts/minute (effect size 0.75; p < 0.0001 for all). As a measure of upper extremity exercise capacity, UAL appears to be responsive to the comprehensive pulmonary rehabilitation intervention. Using effect sizes, the degree of improvement appears to be between that of 6MWD and CRQ-SA. UAL may be a useful outcome assessment for pulmonary rehabilitation in COPD patients.