Baseline Echocardiography and Laboratory Findings in MIS-C and Associations with Clinical Illness Severity.

Children with COVID-associated multisystem inflammatory syndrome (MIS-C) may develop severe disease. We explored the association of admission echocardiographic and laboratory parameters with MIS-C disease severity. This retrospective, single center study of consecutive MIS-C patients (4/2020-12/2021) excluded those with preexisting cardiomyopathy, congenital heart disease, or prior cardiotoxic therapy. Our hypothesis was that worse admission echocardiographic and laboratory parameters were associated with more severe disease based on vasoactive medication use. Univariable and multivariable logistic regression models assessed the association between vasoactive medication use and baseline variables. Of 118 MIS-C patients, median age was 7.8 years (IQR 4.6, 11.8), 48% received vasoactive medication. Higher admission brain natriuretic peptide [OR 1.07 (95% CI 1.02,1.14), p = 0.019], C-reactive protein [OR 1.08 (1.03,1.14), p = 0.002], troponin [OR 1.05 (1.02,1.1), p = 0.015]; lower left ventricular ejection fraction [LVEF, OR 0.96 (0.92,1), p = 0.042], and worse left atrial reservoir strain [OR 0.96 (0.92,1), p = 0.04] were associated with vasoactive medication use. Only higher CRP [OR 1.07 (1.01, 1.11), p = 0.034] and lower LVEF [0.91 (0.84,0.98), p = 0.015] remained independently significant. Among those with normal admission LVEF (78%, 92/118), 43% received vasoactive medication and only higher BNP [OR 1.09 (1.02,1.19), p = 0.021 per 100 pg/mL] and higher CRP [OR 1.07 (1.02,1.14), p = 0.013] were associated with use of vasoactive medication. Nearly half of all children admitted for MIS-C subsequently received vasoactive medication, including those admitted with a normal LVEF. Similarly, admission strain parameters were not discriminatory. Laboratory markers of systemic inflammation and cardiac injury may better predict early MIS-C disease severity.

Left Atrial Strain in Multisystem Inflammatory Syndrome in Children and Associations with Systemic Inflammation and Cardiac Injury.

Multisystem inflammatory syndrome in children (MIS-C) commonly involves cardiac injury with both systolic and diastolic dysfunction. Left atrial strain (LAS) detects subclinical diastolic dysfunction in adults but is infrequently used in children. We evaluated LAS in MIS-C and the associations with systemic inflammation and cardiac injury. In this retrospective cohort study, LAS parameters [reservoir (LAS-r), conduit (LAS-cd), and contractile (LAS-ct)] obtained from admission echocardiograms of MIS-C patients were compared to healthy controls and between MIS-C patients with and without cardiac injury (BNP > 500 pg/ml or troponin-I > 0.04 ng/ml). Correlation and logistic regression analyses were performed to assess LAS associations with admission inflammatory and cardiac biomarkers. Reliability testing was performed. We identified 118 patients with MIS-C and 20 healthy controls. Median LAS parameters were reduced in MIS-C patients compared to controls (LAS-r: 31.8 vs. 43.1%, p < 0.001; LAS-cd: - 28.8 vs. - 34.5%, p = 0.006; LAS-ct: - 5.2 vs. - 9.3%, p < 0.001) and reduced in MIS-C patients with cardiac injury (n = 59) compared to no injury (n = 59) (LAS-r: 29.6 vs. 35.8%, p = 0.001; LAS-cd: - 26.5 vs. - 30.4%, p = 0.036; LAS-ct: - 4.6 vs. - 9.3%, p = 0.008). A discrete LAS-ct peak was absent in 65 (55%) MIS-C patients but present in all controls (p < 0.001). Procalcitonin correlated strongly with averaged E/e' (r = 0.55, p = 0.001). Moderate correlations were found for ESR and LAS-ct (r = - 0.41, p = 0.007) as well as BNP and LAS-r (r = - 0.39, p < 0.001) and LAS-ct (r = 0.31, p = 0.023). Troponin-I had only weak correlations. Intra-rater reliability was good for all LAS parameters, and inter-rater reliability was good to excellent for LAS-r, and fair for LAS-cd and LAS-ct. LAS analysis, particularly the absence of a LAS-ct peak, was reproducible and may be superior to conventional echocardiographic parameters for detecting diastolic dysfunction in MIS-C. No strain parameters on admission were independently associated with cardiac injury.

Echocardiographic image collection and evaluation in infants with CHD: lessons learned from the imaging core lab for the Residual Lesion Score study.

Many factors affect patient outcome after congenital heart surgery, including the complexity of the heart disease, pre-operative status, patient specific factors (prematurity, nutritional status and/or presence of comorbid conditions or genetic syndromes), and post-operative residual lesions. The Residual Lesion Score is a novel tool for assessing whether specific residual cardiac lesions after surgery have a measurable impact on outcome. The goal is to understand which residual lesions can be tolerated and which should be addressed prior to leaving the operating room. The Residual Lesion Score study is a large multicentre prospective study designed to evaluate the association of Residual Lesion Score to outcomes in infants undergoing surgery for CHD. This Pediatric Heart Network and National Heart, Lung, and Blood Institute-funded study prospectively enrolled 1,149 infants undergoing 5 different congenital cardiac surgical repairs at 17 surgical centres. Given the contribution of echocardiographic measurements in assigning the Residual Lesion Score, the Residual Lesion Score study made use of a centralised core lab in addition to site review of all data. The data collection plan was designed with the added goal of collecting image quality information in a way that would permit us to improve our understanding of the reproducibility, variability, and feasibility of the echocardiographic measurements being made. There were significant challenges along the way, including the coordination, de-identification, storage, and interpretation of very large quantities of imaging data. This necessitated the development of new infrastructure and technology, as well as use of novel statistical methods. The study was successfully completed, but the size and complexity of the population being studied and the data being extracted required more technologic and human resources than expected which impacted the length and cost of conducting the study. This paper outlines the process of designing and executing this complex protocol, some of the barriers to implementation and lessons to be considered in the design of future studies.

Associations of Home Monitoring Data to Interventional Catheterization for Infants with Recurrent Coarctation of the Aorta and Hypoplastic Left Heart Syndrome.

The post-Norwood interstage period for infants with hypoplastic left heart syndrome is a high-risk time with 10-20% of infants having a complication of recurrent coarctation of the aorta (RCoA). Many interstage programs utilize mobile applications allowing caregivers to submit home physiologic data and videos to the clinical team. This study aimed to investigate if caregiver-entered data resulted in earlier identification of patients requiring interventional catheterization for RCoA. Retrospective home monitoring data were extracted from five high-volume Children's High Acuity Monitoring Program®-affiliated centers (defined as contributing > 20 patients to the registry) between 2014 and 2021 after IRB approval. Demographics and caregiver-recorded data evaluated include weight, heart rate (HR), oxygen saturation (SpO2), video recordings, and 'red flag' concerns prior to interstage readmissions. 27% (44/161) of infants required interventional catheterization for RCoA. In the 7 days prior to readmission, associations with higher odds of RCoA included (mean bootstrap coefficient, [90% CI]) increased number of total recorded videos (1.65, [1.07-2.62]) and days of recorded video (1.62, [1.03-2.59]); increased number of total recorded weights (1.66, [1.09-2.70]) and days of weights (1.56, [1.02-2.44]); increasing mean SpO2 (1.55, [1.02-2.44]); and increased variation and range of HR (1.59, [1.04-2.51]) and (1.71, [1.10-2.80]), respectively. Interstage patients with RCoA had increased caregiver-entered home monitoring data including weight and video recordings, as well as changes in HR and SpO2trends. Identifying these items by home monitoring teams may be beneficial in clinical decision-making for evaluation of RCoA in this high-risk population.

Implications of Left Ventricular Dysfunction at Presentation for Infants with Coarctation of the Aorta.

Infants with aortic coarctation may present with left ventricular (LV) dysfunction which may complicate the postoperative course and lead to increased healthcare costs. We aimed to define the prevalence of moderate to severe left ventricular (LV) systolic dysfunction, evaluate time to recovery, and compare health care costs. Single-center retrospective cohort study at a tertiary care hospital was conducted. Infants < 6 months old at diagnosis with aortic coarctation were identified using surgical codes for coarctation repair between January 2010 and May 2018. Moderate to severe dysfunction was defined as ejection fraction (EF) < 40%. Of 160 infants studied, 18 (11%) had moderate to severe LV dysfunction at presentation. Compared to those with better LV function, infants with moderate to severe LV dysfunction were older at presentation (12 vs. 6 days, p = 0.004), had more postoperative cardiac intensive care unit (ICU) days (5 vs. 3, p < 0.001), and more ventilator days (3.5 vs. 1, p < 0.001). The median time to normal LV EF (≥ 55%) was 6 days postoperatively (range 1-230 days). Infants presenting with moderate to severe LV dysfunction had higher index hospitalization costs ($90,560 vs. $59,968, p = 0.02), but no difference in cost of medical follow-up for the first year following discharge ($3,078 vs. $2,568, p = 0.46). In the current era, > 10% of infants with coarctation present with moderate to severe LV dysfunction that typically recovers. Those with moderate to severe dysfunction had longer duration of mechanical ventilation and postoperative cardiac ICU stays, likely driving higher costs of index hospitalization.

Fetal Echocardiographic Z Score Pilot Project: Study Design and Impact of Gestational Age and Variable Type on Reproducibility of Measurements Within and Across Investigators.

BACKGROUND: Fetal echocardiography is widely available, but normative data are not robust. In this pilot study, the authors evaluated (1) the feasibility of prespecified measurements in a normal fetal echocardiogram to inform study design and (2) measurement variability to assign thresholds of clinical significance and guide analyses in larger fetal echocardiographic Z score initiatives. METHODS: Images from predefined gestational age groups (16-20, >20-24, >24-28, and >28-32 weeks) were retrospectively analyzed. Fetal echocardiography expert raters attended online group training and then independently analyzed 73 fetal studies (18 per age group) in a fully crossed design of 53 variables; each observer repeated measures for 12 fetuses. Kruskal-Wallis tests were used to compare measurements across centers and age groups. Coefficients of variation (CoVs) were calculated at the subject level for each measurement as the ratio of SD to mean. Intraclass correlation coefficients were used to show inter- and intrarater reliabilities. Cohen's d > 0.8 was used to define clinically important differences. Measurements were plotted against gestational age, biparietal diameter, and femur length. RESULTS: Expert raters completed each set of measurements in a mean of 23 ± 9 min/fetus. Missingness ranged from 0% to 29%. CoVs were similar across age groups for all variables (P < .05) except ductus arteriosus mean velocity and left ventricular ejection time, which were both higher at older gestational age. CoVs were >15% for right ventricular systolic and diastolic widths despite fair to good repeatability (intraclass correlation coefficient > 0.5); ductal velocities and two-dimensional measures, left ventricular short-axis dimensions, and isovolumic times all had high CoVs and high interobserver variability despite good to excellent intraobserver agreement (intraclass correlation coefficient > 0.6). CoVs did not improve when ratios (e.g., tricuspid/mitral annulus) were used instead of linear measurements. Overall, 27 variables had acceptable inter- and intraobserver repeatability, while 14 had excessive variability between readers despite good intraobserver agreement. CONCLUSIONS: There is considerable variability in fetal echocardiographic quantification in clinical practice that may affect the design of multicenter fetal echocardiographic Z score studies, and not all measurements may be feasible for standard normalization. As missingness was substantial, a prospective design will be needed. Data from this pilot study may aid in the calculation of sample sizes and inform thresholds for distinguishing clinically significant from statistically significant effects.

Left atrial strain in multisystem inflammatory syndrome in children (MIS-C) and associations with systemic inflammation and cardiac injury.

Background: Multisystem inflammatory syndrome in children (MIS-C) commonly involves cardiac injury with both systolic and diastolic dysfunction. Left atrial strain (LAS) detects subclinical diastolic dysfunction in adults but is infrequently used in children. We evaluated LAS in MIS-C and the associations with systemic inflammation and cardiac injury. Methods: In this retrospective cohort study, conventional parameters and LAS (reservoir [LAS-r], conduit [LAS-cd], and contractile [LAS-ct]) obtained from admission echocardiograms of MIS-C patients were compared to healthy controls and between MIS-C patients with and without cardiac injury (BNP >500 pg/ml or troponin-I >0.04 ng/ml). Correlation and logistic regression analyses were performed to assess LAS associations with admission inflammatory and cardiac biomarkers. Reliability testing was performed. Results: Median LAS components were reduced in MIS-C patients (n=118) compared to controls (n=20) (LAS-r: 31.8 vs. 43.1%, p<0.001; LAS-cd: -28.8 vs. -34.5%, p=0.006; LAS-ct: -5.2 vs. -9.3%, p<0.001) and reduced in MIS-C patients with cardiac injury (n=59) compared to no injury (n=59) (LAS-r: 29.6 vs. 35.8%, p=0.001; LAS-cd: -26.5 vs. -30.4%, p=0.036; LAS-ct: -4.6 vs. -9.3%, p=0.008). An LAS-ct peak was absent in 65 (55%) MIS-C patients but present in all controls (p<0.001). Procalcitonin had strong correlation with averaged E/e' (r=0.55, p=0.001); ESR had moderate correlation with LAS-ct (r=-0.41, p=0.007); BNP had moderate correlation with LAS-r (r=-0.39, p<0.001) and LAS-ct (r=0.31, p=0.023), and troponin-I had only weak correlations. No strain indices were independently associated with cardiac injury on regression analysis. Intra-rater reliability was good for all LAS components; and inter-rater reliability was good to excellent for LAS-r, and fair for LAS-cd and LAS-ct. Conclusions: LAS analysis, particularly the absence of a LAS-ct peak, was reproducible and may be superior to conventional echocardiographic parameters for detecting diastolic dysfunction in MIS-C. No strain parameters on admission were independently associated with cardiac injury.

Relation of Right Atrial Strain to Mortality in Infants With Single Right Ventricles.

We explored associations of surveillance testing in infants with single right ventricle (sRV) physiology with clinical outcomes. This prospective, single-center study included patients with sRV who had initial palliative surgery (September 2019 to December 2020). Echocardiograms and B-type naturetic peptide (BNP) obtained as a pair within 24 hours as part of clinical care were included. The primary outcome was death/heart transplant. Secondary outcomes included interstage duration of milrinone use, hospital length of stay, and no digoxin use. sRV functional assessment (subjective grade, fractional area change, tricuspid annular plane systolic excursion, global longitudinal strain, right atrial strain [RAS]) was performed offline. Associations between echocardiography, BNP, and clinical outcomes were determined. Of 26 subjects (47 encounters), 20 had hypoplastic left heart syndrome (77%). Median age at data collection was 50 days (interquartile range 26 to 90). In most encounters (73%), sRV function was subjectively normal. Median BNP was 332 pg/ml (interquartile range 160 to 1,085). A total of 5 patients (19%) met the primary outcome and had lower RAS (14.1 vs 21.3, p = 0.038), but all other parameters were similar to transplant-free survivors. RAS (16.1%, 0.83) had the highest area under curve, followed by global longitudinal strain (-14.4%, 0.77). Higher RAS was associated with fewer days on milrinone (coefficient -1.37, 95% confidence interval [CI] -2.54 to -0.20, p = 0.02) and higher odds of digoxin use (odds ratio 1.09, 95% CI 1.01 to 1.18, p = 0.047). Higher BNP was only associated with a lower odds of digoxin use (odds ratio 0.69, 95% CI 0.5 to 0.96, p = 0.03). In conclusion, RAS is a potentially important imaging marker in infants with sRV and merits further investigation in larger studies.

Short-Term Left Ventricular Reverse Remodeling after Transcatheter Aortic Valve Replacement in Children.

BACKGROUND: There are no published data on left ventricular (LV) reverse remodeling after transcatheter aortic valve replacement (TAVR) in children. The aim of this study was to assess changes in LV echocardiographic parameters 6 months after TAVR in children. METHODS: This single-center, retrospective study included all 22 patients (age < 21 years) who underwent TAVR. The median age was 14.7 years (interquartile range, 13.3-15.9 years), median weight was 57 kg (interquartile range, 46.0-66.3 kg), and 59% of patients were male. Demographics, type and duration of aortic valve dysfunction, symptom and treatment data, and preprocedural and 6-month follow-up echocardiographic data (LV volume, mass, end-diastolic dimension, end-systolic dimension, ejection fraction [EF], sphericity, and longitudinal strain) were collected. Failure to reverse remodel at 6 months was defined as meeting at least two of the following: Z score ≥ 2 that was unchanged or increased from baseline for LV volume, mass, end-diastolic dimension, or end-systolic dimension; abnormally high sphericity index that was unchanged or increased; and abnormally low EF or longitudinal strain. Median, interquartile range, and range are reported for continuous variables, and pre- and post-TAVR data were compared using the Wilcoxon signed rank test. RESULTS: Eight patients (36%) had isolated aortic stenosis, four (18%) had isolated regurgitation, and 10 had (46%) mixed disease. Twelve (55%) had symptoms and 20 (91%) had prior surgical or catheter valve interventions. The primary complication was left bundle branch block, occurring in four children (18%). At 6 months, LV volume, mass, end-diastolic dimension, end-systolic dimension, and sphericity index improved. EF and strain were normal at baseline and at follow-up. Of three patients who failed to reverse remodel, two had left bundle branch block. Of three patients with persistent symptoms, one had failure of reverse remodeling. CONCLUSIONS: Most pediatric patients had evidence of reverse LV remodeling 6 months after TAVR, suggesting a possible alternative to surgical aortic valve replacement in this population. Functional parameters (EF and strain) were normal at baseline and follow-up. Future studies are needed to determine optimal timing of TAVR and to explore the association of postprocedural left bundle branch block on failed reverse remodeling and outcomes in this population.

A Comparison of Clinical Outcomes between Early Cervical Spine Stabilizer Training and Usual Care in Individuals following Anterior Cervical Discectomy and Fusion.

OBJECTIVES: Early physical therapy (PT) with specific stabilization training has been shown to benefit individuals after lumbar spinal surgery but has not been studied in patients after cervical spine surgery. The primary purpose of this study was to compare clinical outcomes between early cervical spine stabilizer (ECS) training and usual care (UC) in patients after anterior cervical discectomy and fusion (ACDF) surgery. The secondary purpose was to determine test-retest reliability of strength and endurance tests of cervical spinal stabilizers in this patient population. METHODS: Forty participants who were scheduled for ACDF surgery were randomized into either the ECS group or the UC group. After surgery, participants received their assigned group intervention during their hospital stay and continued their assigned intervention for 12 weeks. All participants had phone follow-ups twice during the first 6 weeks to address questions or problems. Clinical outcome measures including pain level using the Numeric Pain Rating Scale (NPRS), disability level using the Neck Disability Index (NDI), Craniocervical Flexor Strength (CCF-S), and Craniocervical Flexor Endurance (CCF-E) were collected three times: before surgery and 6 and 12 weeks after surgery. Test-retest reliability was assessed in the first 10 participants. RESULTS: There was no significant interaction between the groups over time for any of the outcome measures. However, all participants made significant improvements in all four outcome measures at 6 and 12 weeks post surgery. The results showed good-to-excellent test-retest reliability for the CCF-S and CCF-E tests. CONCLUSIONS: Both ECS training and UC resulted in the same amount of improvement at 6 and 12 weeks; therefore, both therapy approaches appear to have similar and positive effects on patients in their first 3 months of recovery after ACDF. Both the CCF-S and CCF-E tests can be used reliably to assess the strength and endurance of the cervical spinal stabilizers for patients after ACDF surgery. The study was registered with the ClinicalTrials.gov (NIH, U.S. National Library of Medicine, identifier # NCT01519115) Protocol Registration system.

Clinical measurements of cervical lordosis using flexirule and inclinometer methods in individuals with and without cervical spine dysfunction: A reliability and validity study.

OBJECTIVE: The purposes of this study were to determine the reliability and validity of two clinical measurements of cervical lordosis and to compare these measurements of individuals with cervical spine symptoms to those of asymptomatic individuals. METHODS: Fifty-seven participants were recruited for the study: 18 following cervical fusion, 20 with neck pain and no surgery, and 19 with no neck pain. Cervical lordosis was measured using a flexible ruler (flexirule) and a modified bubble inclinometer. Intertester and intratester reliability were calculated for both methods. Validity was assessed by correlating measurements taken using both methods to Cobb angles between C2 and C7 on lateral view radiography of the participants in the cervical fusion and the neck pain groups. RESULTS: Intraclass correlation coefficients (ICCs) revealed good intratester reliability for both methods. Intertester reliability was fair for the flexirule method but good for the inclinometer method. Pearson correlations with radiographic angles were poor for both methods. ANOVAs showed no significant difference in cervical lordosis measurements between asymptomatic and symptomatic groups. CONCLUSION: Although both the flexirule and inclinometer methods are reliable, neither method correlated with the Cobb angle on the radiography, suggesting these methods may measure different aspects of cervical spine alignment.

The effect of 15 weeks of exercise on balance, leg strength, and reduction in falls in 40 women aged 65 to 89 years.

OBJECTIVE: Risk of falling increases as people age, and decreased leg strength and poor balance have been implicated as contributors. Our aims were to:1) assess the efficacy of a fall-prevention exercise program on balance and leg strength in women aged 65 to 89 years and 2) conduct a 1-year follow-up to determine the effect of exercise on fall rates. METHODS: Forty women were classified by falling history and fear of falling and assigned to exercise and control groups using stratified randomization. We used the Berg Balance Scale, Get-up and Go, Functional Reach, and Wall-Sit Tests to evaluate changes in balance and leg strength before and after a supervised 15-week exercise program (31-hr sessions/week). We conducted 1-year follow-up telephone interviews and compared the number of falls reported by exercise and control groups.The study used a 2 x 2 (exercise/control by pretest/post-test) factorial design with the testing times being a repeated factor, so we used analysis of variance (ANOVA) to evaluate differences between the 2 groups across testing times. Power analysis computed a priori with STPLAN software (Version 4.2) showed that a sample size of 40 was necessary to determine statistical differences in balance and leg strength. RESULTS: Exercise subjects showed significant improvement on 5 of 14 items (5.2%, p < or = 05 to 34.4%, p < or = .01) in the Berg Balance Scale and on the total score (6.8%, p < or = .05). Leg strength increased significantly (p < or = .05) on post-test as measured by the Wall-Sit Test. Control subjects reported 6 falls and exercise subjects no falls during the follow-up year, but this difference was not significant using Fischer's exact test (p=.106). CONCLUSION: The exercise program resulted in increased balance and leg strength, but did not result in a significant difference in falls during the follow-up period. Further research with a larger and possibly older sample is needed to more adequately investigate this question. Health care providers who work with older women should provide exercise programs in which balance and leg strength are emphasized.

Short-term outcomes of sport- and recreation-related concussion in patients admitted to a pediatric trauma service.

The outcomes of patients admitted to the hospital following a sport-related concussion are largely unknown. Medical records of patients admitted to the pediatric trauma service between 2008 and 2011 after sustaining a sport-related concussion were reviewed. In all, 59 participants were in the high-velocity activities group, and 21 in the field or court sport group. Abnormal CT scans were found in 14 patients in the high-velocity group and 2 in the field or court sport group. The majority of participants in the field or court sport group were football players, all of whom had normal CT scans. Headache was predictive of an abnormal CT scan. Among the patients, 56% clinically improved and were discharged the following day. Patients with field or court sport-related concussion admitted to a pediatric trauma service appear to be at low risk for clinically significant intracranial pathology and do well in the acute setting.

A randomized trial comparing 2 types of in-home rehabilitation for chronic obstructive pulmonary disease: a pilot study.

BACKGROUND: Pulmonary rehabilitation has been shown to be effective for improving quality of life and function in patients with chronic obstructive pulmonary disease (COPD) but has not been studied extensively in homebound patients. Furthermore, little is known about the effectiveness of specific types of home-based interventions. PURPOSE: The purpose of this study was to examine the effectiveness of in-home rehabilitation programs for individuals with COPD considered homebound according to Medicare definition and to compare outcomes of 2 different rehabilitation interventions. METHODS: Patients were randomly assigned to 2 home-based interventions including aerobic conditioning (group A) or functional strength training (group B), which were conducted over 8 weeks. In addition, all patients received COPD self-management education. Outcome measures were collected after completion of the intervention and after 16 weeks and included the Chronic Respiratory Questionnaire (CRQ), Geriatric Depression Scale, and 2-minute walk test. RESULTS: Of 41 patients enrolled, 24 completed the 8-week intervention. On average, all CRQ quality-of-life domains improved in both groups, with the largest improvements in the CRQ-dyspnea domain. Overall, at 16 weeks, 80% of group A and 71% of group B patients had clinically significant improvements in the CRQ-dyspnea domain. Furthermore, depression scores improved in both groups. Only group A had a clinically significant improvement in walking distance. CONCLUSION: The results of this pilot study suggest that both forms of home-based rehabilitation may improve disease-specific quality of life in homebound patients with COPD.