Physical Rehabilitation for Older Patients Hospitalized for Heart Failure.

BACKGROUND: Older patients who are hospitalized for acute decompensated heart failure have high rates of physical frailty, poor quality of life, delayed recovery, and frequent rehospitalizations. Interventions to address physical frailty in this population are not well established. METHODS: We conducted a multicenter, randomized, controlled trial to evaluate a transitional, tailored, progressive rehabilitation intervention that included four physical-function domains (strength, balance, mobility, and endurance). The intervention was initiated during, or early after, hospitalization for heart failure and was continued after discharge for 36 outpatient sessions. The primary outcome was the score on the Short Physical Performance Battery (total scores range from 0 to 12, with lower scores indicating more severe physical dysfunction) at 3 months. The secondary outcome was the 6-month rate of rehospitalization for any cause. RESULTS: A total of 349 patients underwent randomization; 175 were assigned to the rehabilitation intervention and 174 to usual care (control). At baseline, patients in each group had markedly impaired physical function, and 97% were frail or prefrail; the mean number of coexisting conditions was five in each group. Patient retention in the intervention group was 82%, and adherence to the intervention sessions was 67%. After adjustment for baseline Short Physical Performance Battery score and other baseline characteristics, the least-squares mean (±SE) score on the Short Physical Performance Battery at 3 months was 8.3±0.2 in the intervention group and 6.9±0.2 in the control group (mean between-group difference, 1.5; 95% confidence interval [CI], 0.9 to 2.0; P<0.001). At 6 months, the rates of rehospitalization for any cause were 1.18 in the intervention group and 1.28 in the control group (rate ratio, 0.93; 95% CI, 0.66 to 1.19). There were 21 deaths (15 from cardiovascular causes) in the intervention group and 16 deaths (8 from cardiovascular causes) in the control group. The rates of death from any cause were 0.13 and 0.10, respectively (rate ratio, 1.17; 95% CI, 0.61 to 2.27). CONCLUSIONS: In a diverse population of older patients who were hospitalized for acute decompensated heart failure, an early, transitional, tailored, progressive rehabilitation intervention that included multiple physical-function domains resulted in greater improvement in physical function than usual care. (Funded by the National Institutes of Health and others; REHAB-HF ClinicalTrials.gov number, NCT02196038.).

Physical activity and relationship to physical function, quality of life, and cognitive function in older patients with acute decompensated heart failure.

BACKGROUND: Volitional physical activity level is predictive of a variety of health outcomes, but has not been examined in patients recently hospitalized for acute decompensated HF (ADHF). METHODS: Ten to 14 days after index hospitalization for ADHF, 93 participants wore a wrist-mounted triaxial accelerometer (ActiGraph GT3X+) to objectively quantify sedentary behavior, light physical activity, and moderate-to-vigorous physical activity. Levels were compared to 2 groups of age-matched NHANES participants: healthy and chronic, stable HF. The relationship between physical activity levels and physical function [Short Physical Performance Battery (SPPB)], HF-specific quality-of-life (QOL) [Kansas City Cardiomyopathy Questionnaire (KCCQ)], and cognition [Montreal Cognitive Assessment (MOCA)] were examined. RESULTS: ADHF participants accumulated a median 1,008 (IQR 896, 1,109) minutes of sedentary time, 88 (57, 139) minutes of light physical activity, and 10 (6, 25) minutes of moderate-to-vigorous physical activity per day. Sedentary time, light physical activity, or moderate-to-vigorous activity did not differ by sex or EF subtype. ADHF participants spent only 9% of awake time nonsedentary, compared to 34% and 27% for healthy adults and adults with chronic, stable HF, respectively. Among ADHF participants, SPPB, KCCQ, and MOCA scores did not differ among quartiles of total physical activity. CONCLUSIONS: Older patients recently hospitalized for ADHF have very low levels of physical activity and high levels of sedentary time, both of which may be potential targets for interventions in this high-risk population. Physical activity level was not significantly associated with objectively measured physical function, QOL, or cognition, suggesting that this measure provides independent information regarding the patient experience of living with HF. TRIAL REGISTRATION: NCT02196038, https://clinicaltrials.gov/ct2/show/NCT02196038.

Methodological and Clinimetric Evaluation of Inspiratory Respiratory Muscle Ultrasound in the Critical Care Setting: A Systematic Review and Meta-Analysis.

OBJECTIVE: Significant variations exist in the use of respiratory muscle ultrasound in intensive care with no society-level consensus on the optimal methodology. This systematic review aims to evaluate, synthesize, and compare the clinimetric properties of different image acquisition and analysis methodologies. DATA SOURCES: Systematic search of five databases up to November 24, 2021. STUDY SELECTION: Studies were included if they enrolled at least 50 adult ICU patients, reported respiratory muscle (diaphragm or intercostal) ultrasound measuring either echotexture, muscle thickness, thickening fraction, or excursion, and evaluated at least one clinimetric property. Two independent reviewers assessed titles, abstracts, and full text against eligibility. DATA EXTRACTION: Study demographics, ultrasound methodologies, and clinimetric data. DATA SYNTHESIS: Sixty studies, including 5,025 patients, were included with 39 studies contributing to meta-analyses. Most commonly measured was diaphragm thickness (DT) or diaphragm thickening fraction (DTF) using a linear transducer in B-mode, or diaphragm excursion (DE) using a curvilinear transducer in M-mode. There are significant variations in imaging methodology and acquisition across all studies. Inter- and intrarater measurement reliabilities were generally excellent, with the highest reliability reported for DT (ICC, 0.98; 95% CI, 0.94-0.99). Pooled data demonstrated acceptable to excellent accuracy for DT, DTF, and DE to predicting weaning outcome after 48 to 72 hours postextubation (DTF AUC, 0.79; 95% CI, 0.73-0.85). DT imaging was responsive to change over time. Only three eligible studies were available for intercostal muscles. Intercostal thickening fraction was shown to have excellent accuracy of predicting weaning outcome after 48-hour postextubation (AUC, 0.84; 95% CI, 0.78-0.91). CONCLUSIONS: Diaphragm muscle ultrasound is reliable, valid, and responsive in ICU patients, but significant variation exists in the imaging acquisition and analysis methodologies. Future work should focus on developing standardized protocols for ultrasound imaging and consider further research into the role of intercostal muscle imaging.

Skilled Nursing and Inpatient Rehabilitation Facility Use by Medicare Fee-for-Service Beneficiaries Discharged Home After a Stroke: Findings From the COMPASS Trial.

OBJECTIVES: To examine the effect of a comprehensive transitional care model on the use of skilled nursing facility (SNF) and inpatient rehabilitation facility (IRF) care in the 12 months after acute care discharge home following stroke; and to identify predictors of experiencing a SNF or IRF admission following discharge home after stroke. DESIGN: Cluster randomized pragmatic trial SETTING: Forty-one acute care hospitals in North Carolina. PARTICIPANTS: 2262 Medicare fee-for-service beneficiaries with transient ischemic attack or stroke discharged home. The sample was 80.3% White and 52.1% female, with a mean (SD) age of 74.9 (10.2) years and a mean ± SD National Institutes of Health stroke scale score of 2.3 (3.7). INTERVENTION: Comprehensive transitional care model (COMPASS-TC), which consisted of a 2-day follow-up phone call from the postacute care coordinator and 14-day in-person visit with the postacute care coordinator and advanced practice provider. MAIN OUTCOME MEASURES: Time to first SNF or IRF and SNF or IRF admission (yes/no) in the 12 months following discharge home. All analyses utilized multivariable mixed models including a hospital-specific random effect to account for the non-independence of measures within hospital. Intent to treat analyses using Cox proportional hazards regression assessed the effect of COMPASS-TC on time to SNF/IRF admission. Logistic regression was used to identify clinical and non-clinical predictors of SNF/IRF admission. RESULTS: Only 34% of patients in the intervention arm received COMPASS-TC per protocol. COMPASS-TC was not associated with a reduced hazard of a SNF/ IRF admission in the 12 months post-discharge (hazard ratio, 1.20, with a range of 0.95-1.52) compared to usual care. This estimate was robust to additional covariate adjustment (hazard ratio, 1.23) (0.93-1.64). Both clinical and non-clinical factors (ie, insurance, geography) were predictors of SNF/IRF use. CONCLUSIONS: COMPASS-TC was not consistently incorporated into real-world clinical practice. The use of a comprehensive transitional care model for patients discharged home after stroke was not associated with SNF or IRF admissions in a 12-month follow-up period. Non-clinical factors predictive of SNF/IRF use suggest potential issues with access to this type of care.

Cognition, Physical Function, and Quality of Life in Older Patients With Acute Decompensated Heart Failure.

BACKGROUND: Older adults with acute decompensated heart failure have persistently poor clinical outcomes. Cognitive impairment (CI) may be a contributing factor. However, the prevalence of CI and the relationship of cognition with other patient-centered factors such a physical function and quality of life (QOL) that also may contribute to poor outcomes are incompletely understood. METHODS AND RESULTS: Older (≥60 years) hospitalized patients with acute decompensated heart failure were assessed for cognition (Montreal Cognitive Assessment [MoCA]), physical function (Short Physical Performance Battery [SPPB], 6-minute walk distance [6MWD]), and QOL (Kansas City Cardiomyopathy Questionnaire, Short Form-12). Among patients (N = 198, 72.1 ± 7.6 years), 78% screened positive for CI (MoCA of <26) despite rare medical record documentation (2%). Participants also had severely diminished physical function (SPPB 6.0 ± 2.5 units, 6MWD 186 ± 100 m) and QOL (scores of <50). MoCA positively related to SPPB (ß = 0.47, P < .001), 6MWD ß = 0.01, P = .006) and inversely related to Kansas City Cardiomyopathy Questionnaire Overall Score (ß = -0.05, P < .002) and Short Form-12 Physical Component Score (ß = -0.09, P = .006). MoCA was a small but significant predictor of the results on the SPPB, 6MWD, and Kansas City Cardiomyopathy Questionnaire. CONCLUSIONS: Among older hospitalized patients with acute decompensated heart failure, CI is highly prevalent, is underrecognized clinically, and is associated with severe physical dysfunction and poor QOL. Formal screening may reduce adverse events by identifying patients who may require more tailored care.

Movement Matters, and So Does Context: Lessons Learned From Multisite Implementation of the Movement Matters Activity Program for Stroke in the Comprehensive Postacute Stroke Services Study.

The purpose of this Special Communication is to discuss the rationale and design of the Movement Matters Activity Program for Stroke (MMAP) and explore implementation successes and challenges in home health and outpatient therapy practices across the stroke belt state of North Carolina. MMAP is an interventional component of the Comprehensive Postacute Stroke Services Study, a randomized multicenter pragmatic trial of stroke transitional care. MMAP was designed to maximize survivor health, recovery, and functional independence in the community and to promote evidence-based rehabilitative care. MMAP provided training, tools, and resources to enable rehabilitation providers to (1) prescribe physical activity and exercise according to evidence-based guidelines and programs, (2) match service setting and parameters with survivor function and benefit coverage, and (3) align treatment with quality metric reporting to demonstrate value-based care. MMAP implementation strategies were aligned with the Expert Recommendations for Implementing Change project, and MMAP site champion and facilitator survey feedback were thematically organized into the Consolidated Framework for Implementation Research domains. MMAP implementation was challenging, required modification and was affected by provider- and system-level factors. Program and study participation were limited and affected by practice priorities, productivity standards, and stroke patient volume. Sites with successful implementation appeared to have empowered MMAP champions in vertically integrated systems that embraced innovation. Findings from this broad evaluation can serve as a road map for the design and implementation of other comprehensive, complex interventions that aim to bridge the currently disconnected realms of acute care, postacute care, and community resources.

Novel approaches to metabolic assessment and structured exercise to promote recovery in ICU survivors.

PURPOSE OF REVIEW: Survivorship or addressing impaired quality of life (QoL) in ICU survivors has been named 'the defining challenge of critical care' for this century to address this challenge; in addition to optimal nutrition, we must learn to employ targeted metabolic/muscle assessment techniques and utilize structured, progressive ICU rehabilitative strategies. RECENT FINDINGS: Objective measurement tools such as ccardiopulmonary exercise testing (CPET) and muscle-specific ultrasound show great promise to assess/treat post-ICU physical dysfunction. CPET is showing that systemic mitochondrial dysfunction may underlie development and persistence of poor post-ICU functional recovery. Finally, recent data indicate that we are poor at delivering effective, early ICU rehabilitation and that there is limited benefit of currently employed later ICU rehabilitation on ICU-acquired weakness and QoL outcomes. SUMMARY: The combination of nutrition with effective, early rehabilitation is highly likely to be essential to optimize muscle mass/strength and physical function in ICU survivors. Currently, technologies such as muscle-specific ultrasound and CPET testing show great promise to guide ICU muscle/functional recovery. Further, we must evolve improved ICU-rehabilitation strategies, as current methods are not consistently improving outcomes. In conclusion, we must continue to look to other areas of medicine and to athletes if we hope to ultimately improve 'ICU Survivorship'.

Role of anabolic testosterone agents and structured exercise to promote recovery in ICU survivors.

PURPOSE OF REVIEW: ICU survivors frequently suffer significant, prolonged physical disability. 'ICU Survivorship', or addressing quality-of-life impairments post-ICU care, is a defining challenge, and existing standards of care fail to successfully address these disabilities. We suggest addressing persistent catabolism by treatment with testosterone analogues combined with structured exercise is a promising novel intervention to improve 'ICU Survivorship'. RECENT FINDINGS: One explanation for lack of success in addressing post-ICU physical disability is most ICU patients exhibit severe testosterone deficiencies early in ICU that drives persistent catabolism despite rehabilitation efforts. Oxandrolone is an FDA-approved testosterone analogue for treating muscle weakness in ICU patients. A growing number of trials with this agent combined with structured exercise show clinical benefit, including improved physical function and safety in burns and other catabolic states. However, no trials of oxandrolone/testosterone and exercise in nonburn ICU populations have been conducted. SUMMARY: Critical illness leads to a catabolic state, including severe testosterone deficiency that persists throughout hospital stay, and results in persistent muscle weakness and physical dysfunction. The combination of an anabolic agent with adequate nutrition and structured exercise is likely essential to optimize muscle mass/strength and physical function in ICU survivors. Further research in ICU populations is needed.

Acute skeletal muscle wasting and dysfunction predict physical disability at hospital discharge in patients with critical illness.

BACKGROUND: Patients surviving critical illness develop muscle weakness and impairments in physical function; however, the relationship between early skeletal muscle alterations and physical function at hospital discharge remains unclear. The primary purpose of this study was to determine whether changes in muscle size, strength and power assessed in the intensive care unit (ICU) predict physical function at hospital discharge. METHODS: Study design is a single-center, prospective, observational study in patients admitted to the medicine or cardiothoracic ICU with diagnosis of sepsis or acute respiratory failure. Rectus femoris (RF) and tibialis anterior (TA) muscle ultrasound images were obtained day one of ICU admission, repeated serially and assessed for muscle cross-sectional area (CSA), layer thickness (mT) and echointensity (EI). Muscle strength, as measured by Medical Research Council-sum score, and muscle power (lower-extremity leg press) were assessed prior to ICU discharge. Physical function was assessed with performance on 5-times sit-to-stand (5STS) at hospital discharge. RESULTS: Forty-one patients with median age of 61 years (IQR 55-68), 56% male and sequential organ failure assessment score of 8.1 ± 4.8 were enrolled. RF muscle CSA decreased significantly a median percent change of 18.5% from day 1 to 7 (F = 26.6, p = 0.0253). RF EI increased at a mean percent change of 10.5 ± 21% in the first 7 days (F = 3.28, p = 0.081). At hospital discharge 25.7% of patients (9/35) met criteria for ICU-acquired weakness. Change in RF EI in first 7 days of ICU admission and muscle power measured prior to ICU were strong predictors of ICU-AW at hospital discharge (AUC = 0.912). Muscle power at ICU discharge, age and ICU length of stay were predictive of performance on 5STS at hospital discharge. CONCLUSION: ICU-assessed muscle alterations, specifically RF EI and muscle power, are predictors of diagnosis of ICU-AW and physical function assessed by 5x-STS at hospital discharge in patients surviving critical illness.

Implementation of a billable transitional care model for stroke patients: the COMPASS study.

BACKGROUND: The COMprehensive Post-Acute Stroke Services (COMPASS) pragmatic trial compared the effectiveness of comprehensive transitional care (COMPASS-TC) versus usual care among stroke and transient ischemic attack (TIA) patients discharged home from North Carolina hospitals. We evaluated implementation of COMPASS-TC in 20 hospitals randomized to the intervention using the RE-AIM framework. METHODS: We evaluated hospital-level Adoption of COMPASS-TC; patient Reach (meeting transitional care management requirements of timely telephone and face-to-face follow-up); Implementation using hospital quality measures (concurrent enrollment, two-day telephone follow-up, 14-day clinic visit scheduling); and hospital-level sustainability (Maintenance). Effectiveness compared 90-day physical function (Stroke Impact Scale-16), between patients receiving COMPASS-TC versus not. Associations between hospital and patient characteristics with Implementation and Reach measures were estimated with mixed logistic regression models. RESULTS: Adoption: Of 95 eligible hospitals, 41 (43%) participated in the trial. Of the 20 hospitals randomized to the intervention, 19 (95%) initiated COMPASS-TC. Reach: A total of 24% (656/2751) of patients enrolled received a billable TC intervention, ranging from 6 to 66% across hospitals. IMPLEMENTATION: Of eligible patients enrolled, 75.9% received two-day calls (or two attempts) and 77.5% were scheduled/offered clinic visits. Most completed visits (78% of 975) occurred within 14 days. Effectiveness: Physical function was better among patients who attended a 14-day visit versus those who did not (adjusted mean difference: 3.84, 95% CI 1.42-6.27, p = 0.002). Maintenance: Of the 19 adopting hospitals, 14 (74%) sustained COMPASS-TC. CONCLUSIONS: COMPASS-TC implementation varied widely. The greatest challenge was reaching patients because of system difficulties maintaining consistent delivery of follow-up visits and patient preferences to pursue alternate post-acute care. Receiving COMPASS-TC was associated with better functional status. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT02588664. Registered 28 October 2015.

Effects of Structured Exercise Interventions for Older Adults Hospitalized With Acute Medical Illness: A Systematic Review.

This review examined effects of structured exercise (aerobic walking, with or without complementary modes of exercise) on cardiorespiratory measures, mobility, functional status, healthcare utilization, and quality of life in older adults (≥60 years) hospitalized for acute medical illness. Inclusion required exercise protocol, at least one patient-level or utilization outcome, and at least one physical assessment point during hospitalization or within 1 month of intervention. MEDLINE, Embase, and CINAHL databases were searched for studies published from 2000 to March 2015. Qualitative synthesis of 12 articles, reporting on 11 randomized controlled trials (RCTs) and quasi-experimental trials described a heterogeneous set of exercise programs and reported mixed results across outcome categories. Methodological quality was independently assessed by two reviewers using the Cochrane Collaboration Risk of Bias tool. Larger, well-designed RCTs are needed, incorporating measurement of premorbid function, randomization with intention-to-treat analysis, examination of a targeted intervention with predefined intensity, and reported adherence and attrition.

Rehabilitation Therapy in Older Acute Heart Failure Patients (REHAB-HF) trial: Design and rationale.

BACKGROUND: Acute decompensated heart failure (ADHF) is a leading cause of hospitalization in older persons in the United States. Reduced physical function and frailty are major determinants of adverse outcomes in older patients with hospitalized ADHF. However, these are not addressed by current heart failure (HF) management strategies and there has been little study of exercise training in older, frail HF patients with recent ADHF. HYPOTHESIS: Targeting physical frailty with a multi-domain structured physical rehabilitation intervention will improve physical function and reduce adverse outcomes among older patients experiencing a HF hospitalization. STUDY DESIGN: REHAB-HF is a multi-center clinical trial in which 360 patients ≥60 years hospitalized with ADHF will be randomized either to a novel 12-week multi-domain physical rehabilitation intervention or to attention control. The goal of the intervention is to improve balance, mobility, strength and endurance utilizing reproducible, targeted exercises administered by a multi-disciplinary team with specific milestones for progression. The primary study aim is to assess the efficacy of the REHAB-HF intervention on physical function measured by total Short Physical Performance Battery score. The secondary outcome is 6-month all-cause rehospitalization. Additional outcome measures include quality of life and costs. CONCLUSIONS: REHAB-HF is the first randomized trial of a physical function intervention in older patients with hospitalized ADHF designed to determine if addressing deficits in balance, mobility, strength and endurance improves physical function and reduces rehospitalizations. It will address key evidence gaps concerning the role of physical rehabilitation in the care of older patients, those with ADHF, frailty, and multiple comorbidities.

The Comprehensive Post-Acute Stroke Services (COMPASS) study: design and methods for a cluster-randomized pragmatic trial.

BACKGROUND: Patients discharged home after stroke face significant challenges managing residual neurological deficits, secondary prevention, and pre-existing chronic conditions. Post-discharge care is often fragmented leading to increased healthcare costs, readmissions, and sub-optimal utilization of rehabilitation and community services. The COMprehensive Post-Acute Stroke Services (COMPASS) Study is an ongoing cluster-randomized pragmatic trial to assess the effectiveness of a comprehensive, evidence-based, post-acute care model on patient-centered outcomes. METHODS: Forty-one hospitals in North Carolina were randomized (as 40 units) to either implement the COMPASS care model or continue their usual care. The recruitment goal is 6000 patients (3000 per arm). Hospital staff ascertain and enroll patients discharged home with a clinical diagnosis of stroke or transient ischemic attack. Patients discharged from intervention hospitals receive 2-day telephone follow-up; a comprehensive clinic visit within 2 weeks that includes a neurological evaluation, assessments of social and functional determinants of health, and an individualized COMPASS Care Plan™ integrated with a community-specific resource database; and additional follow-up calls at 30 and 60 days post-stroke discharge. This model is consistent with the Centers for Medicare and Medicaid Services transitional care management services provided by physicians or advanced practice providers with support from a nurse to conduct patient assessments and coordinate follow-up services. Patients discharged from usual care hospitals represent the control group and receive the standard of care in place at that hospital. Patient-centered outcomes are collected from telephone surveys administered at 90 days. The primary endpoint is patient-reported functional status as measured by the Stroke Impact Scale 16. Secondary outcomes are: caregiver strain, all-cause readmissions, mortality, healthcare utilization, and medication adherence. The study engages patients, caregivers, and other stakeholders (including policymakers, advocacy groups, payers, and local community coalitions) to advise and support the design, implementation, and sustainability of the COMPASS care model. DISCUSSION: Given the high societal and economic burden of stroke, identifying a care model to improve recovery, independence, and quality of life is critical for stroke survivors and their caregivers. The pragmatic trial design provides a real-world assessment of the COMPASS care model effectiveness and will facilitate rapid implementation into clinical practice if successful. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02588664 ; October 23, 2015.

Promoting Older Adult Physical Activity Throughout Care Transitions Using an Interprofessional Approach.

The nurse practitioner plays a key role in monitoring and improving physical activity and function of older adults. Physical activity is an essential component of care management for all older adults, even those who are frail with multimorbidities. All physical activity, no matter how small, has the potential to impact functional independence and quality of life. Partnering with the older adult and caregivers along with interprofessional providers, such as a physical therapist or occupational therapist and community-based resources, facilitates the development of successful goals and plans and the implementation of activities to promote physical activity across the continuum of care.

Surfactant protein A modulates induction of regulatory T cells via TGF-ß.

TCR signaling plays a critical role in regulatory T cell (Treg) development. However, the mechanism for tissue-specific induction of Tregs in the periphery remains unclear. We observed that surfactant protein A (SP-A)-deficient mice have impaired expression of Foxp3 and fewer CD25(+)Foxp3(+) Tregs after ex vivo stimulation and after stimulation with LPS in vivo. The addition of exogenous SP-A completely reversed this phenotype. Although SP-A is known to inhibit T cell proliferation under certain activation conditions, both IL-2 levels as well as active TGF-ß levels increase on extended culture with exogenous SP-A, providing a key mechanism for the maintenance and induction of Tregs. In addition, kinetic suppression assays demonstrate that SP-A enhances the frequency of functional Foxp3(+) Tregs in responder T cell populations in a TGF-ß-dependent manner. In mice treated with LPS in vivo, Tregs increased ∼160% in wild-type mice compared with only a 50% increase in LPS-treated SP-A(-/-) mice 8 d after exposure. Taken together, these findings support the hypothesis that SP-A affects T cell immune function by the induction of Tregs during activation.

Surfactant protein A integrates activation signal strength to differentially modulate T cell proliferation.

Pulmonary surfactant lipoproteins lower the surface tension at the alveolar-airway interface of the lung and participate in host defense. Previous studies reported that surfactant protein A (SP-A) inhibits lymphocyte proliferation. We hypothesized that SP-A-mediated modulation of T cell activation depends upon the strength, duration, and type of lymphocyte activating signals. Modulation of T cell signal strength imparted by different activating agents ex vivo and in vivo in different mouse models and in vitro with human T cells shows a strong correlation between strength of signal (SoS) and functional effects of SP-A interactions. T cell proliferation is enhanced in the presence of SP-A at low SoS imparted by exogenous mitogens, specific Abs, APCs, or in homeostatic proliferation. Proliferation is inhibited at higher SoS imparted by different doses of the same T cell mitogens or indirect stimuli such as LPS. Importantly, reconstitution with exogenous SP-A into the lungs of SP-A(-/-) mice stimulated with a strong signal also resulted in suppression of T cell proliferation while elevating baseline proliferation in unstimulated T cells. These signal strength and SP-A-dependent effects are mediated by changes in intracellular Ca(2+) levels over time, involving extrinsic Ca(2+)-activated channels late during activation. These effects are intrinsic to the global T cell population and are manifested in vivo in naive as well as memory phenotype T cells. Thus, SP-A appears to integrate signal thresholds to control T cell proliferation.

Novel role for surfactant protein A in gastrointestinal graft-versus-host disease.

Graft-versus-host disease (GVHD) is a severe and frequent complication of allogeneic bone marrow transplantation (BMT) that involves the gastrointestinal (GI) tract and lungs. The pathobiology of GVHD is complex and involves immune cell recognition of host Ags as foreign. We hypothesize a central role for the collectin surfactant protein A (SP-A) in regulating the development of GVHD after allogeneic BMT. C57BL/6 (H2b; WT) and SP-A-deficient mice on a C57BL/6 background (H2b; SP-A(-/-)) mice underwent allogeneic or syngeneic BMT with cells from either C3HeB/FeJ (H2k; SP-A-deficient recipient mice that have undergone an allogeneic BMT [SP-A(-/-)alloBMT] or SP-A-sufficient recipient mice that have undergone an allogeneic BMT) or C57BL/6 (H2b; SP-A-deficient recipient mice that have undergone a syngeneic BMT or SP-A-sufficient recipient mice that have undergone a syngeneic BMT) mice. Five weeks post-BMT, mice were necropsied, and lung and GI tissue were analyzed. SP-A(-/-) alloBMT or SP-A-sufficient recipient mice that have undergone an allogeneic BMT had no significant differences in lung pathology; however, SP-A(-/-)alloBMT mice developed marked features of GI GVHD, including decreased body weight, increased tissue inflammation, and lymphocytic infiltration. SP-A(-/-)alloBMT mice also had increased colon expression of IL-1ß, IL-6, TNF-α, and IFN-γ and as well as increased Th17 cells and diminished regulatory T cells. Our results demonstrate the first evidence, to our knowledge, of a critical role for SP-A in modulating GI GVHD. In these studies, we demonstrate that mice deficient in SP-A that have undergone an allogeneic BMT have a greater incidence of GI GVHD that is associated with increased Th17 cells and decreased regulatory T cells. The results of these studies demonstrate that SP-A protects against the development of GI GVHD and establishes a role for SP-A in regulating the immune response in the GI tract.

Using Multiphase Optimization Strategy and Human-Centered Design to Create an Integrated Model of Palliative Care Skills in Home-Based Physical Therapy for Advanced Heart Failure.

Background: Many older adults with advanced heart failure receive home health rehabilitation after hospitalization. Yet, integration of palliative care skills into rehabilitation is limited. Objective: Describe using the Multiphase Optimization Strategy (MOST) framework with human-centered design principles to engage clinical partners in the Preparation phase of palliative physical therapy intervention development. Design: We convened a home-based physical therapy advisory team (four clinicians, three clinical leaders) to identify physical therapist needs and preferences for incorporating palliative care skills in rehabilitation and design an intervention prototype. Results: Between 2022 and 2023, we held five advisory team meetings. Initial feedback on palliative care skill preferences and training needs directly informed refinement of our conceptual model and skills in the intervention prototype. Later feedback focused on reviewing and revising intervention content, delivery strategy, and training considerations. Conclusion: Incorporating human-centered design principles within the MOST provided a useful framework to partner with clinical colleagues in intervention design.