Six-Minute Walk Test for the Evaluation of Pulmonary Disease Severity in Scleroderma Patients

Diagnostic Approach to Interstitial Lung Diseases Associated with Connective Tissue Diseases

Interstitial lung disorders are a group of respiratory diseases characterized by interstitial compartment infiltration, varying degrees of infiltration, and fibrosis, with or without small airway involvement. Although some are idiopathic (e.g., idiopathic pulmonary fibrosis, idiopathic interstitial pneumonias, and sarcoidosis), the great majority have an underlying etiology, such as systemic autoimmune rheumatic disease (SARD, also called Connective Tissue Diseases or CTD), inhalational exposure to organic matter, medications, and rarely, genetic disorders. This review focuses on diagnostic approaches in interstitial lung diseases associated with SARDs. To make an accurate diagnosis, a multidisciplinary, personalized approach is required, with input from various specialties, including pulmonary, rheumatology, radiology, and pathology, to reach a consensus. In a minority of patients, a definitive diagnosis cannot be established. Their clinical presentations and prognosis can be variable even within subsets of SARDs.

Validity and reliability of measurement of peripheral oxygen saturation during the 6-Minute Walk Test in patients with systemic sclerosis

Peripheral oxygen saturation (SpO2) using the fingers may have important limitations due to Raynaud's phenomenon and sclerodactyly in patients with systemic sclerosis (SSc). Sensors located at more central body positions may be more accurate as these as less prone to Raynaud attacks. To determine the validity and reliability of the SpO2 measured at the finger, forehead, and earlobe during the 6-Minute Walk Test (6MWT). Eighty two patients with SSc had an arterial line placed while performing the 6MWT. Peripheral oxygen saturation was simultaneously measured by finger, forehead, and earlobe sensors and compared to the arterial oxygen saturation (SaO2) measured before and after the 6MWT. 40 patients repeated the 6MWT one week later to determine re-test reliability. We used Bland-Altman plots to display the agreement between SpO2 and SaO2. The intraclass correlation coefficient for repeated measurement of minimum SpO2 was calculated. The mean difference between SpO2 and SaO2 after the 6MWT was - 3% (SD: ± 5), 0% (SD: ± 2), and 1% (SD: ± 2) for the finger, forehead, and earlobe, respectively. The minimum SpO2 measured at the finger demonstrated the poorest re-test reliability: The ICC (95% CI) showed good agreement using the ear and forehead probe (ICCear = 0.89 [95% CI 0.80; 0.94]; ICCforehead = 0.77 [95% CI 0.60; 0.87]), while a modest reliability was found using the finger probe (ICCfinger = 0.65 95% CI [0.43; 0.80]). SpO2 should be measured using either the earlobe or forehead during the 6MWT in patients with SSc. Clinical Trials.Gov (NCT04650659).

Comparison of physiological responses after incremental shuttle walking test and 6-minute walk test in patients with systemic sclerosis

BACKGROUND

The 6‑minute walk test (6MWT) is a commonly used to evaluate exercise capacity in patients with systemic sclerosis (SSc), but there was no study using the incremental shuttle walking test (ISWT) for assessing exercise capacity and comparing the patient's cardiorespiratory responses to these tests. The aim was to investigate the usability and determinants of the ISWT in patients with SSc and compare the physiological responses after the ISWT and 6MWT.

METHODS

A total of thirty four female patients with SSc were included. Dyspnea during daily activities and knee extensor muscle strength was assessed, skin fibrosis and disease severity were recorded, and 6MWT and ISWT were carried out for the exercise capacity measurement. Pulmonary function test results were recorded from the individuals' medical records for SSc with interstitial lung disease (SSc-ILD) patients.

RESULTS

The ISWT distance was significantly correlated with the 6MWT distance (p < 0.001). The 6MWT was correlated with age, modified Rodnan skin score, Medsger severity score, modified British Medical Research Council Questionnaire (mMRC) score, and knee extensor muscle strength (p < 0.05). The 6MWT was correlated with the forced expiratory volume in the first second (FEV1) (lt) and forced vital capacity (FVC) (lt) in patients with SSc-ILD (p < 0.05). The ISWT distance was correlated with age, modified Rodnan skin score, mMRC score, and knee extensor muscle strength (p < 0.05). Age, mMRC, and knee extensor muscle strength explained 33.8% of the variance in 6MWT distance, while age, mMRC, and knee extensor muscle strength explained 51.7% of the variance in the ISWT distance.

CONCLUSION

Because of the higher cardiopulmonary responses, and having a more standardized procedure, the ISWT may be preferable for investigating symptom-limited exercise capacity in patients with SSc. Age, dyspnea, and knee extensor muscle strength were the determinants of exercise capacity in patients with SSc.

Effects of cardiorespiratory rehabilitation program on submaximal exercise in patients with long-COVID-19 conditions: a systematic review of randomized controlled trials and recommendations for future studies

INTRODUCTION

Long-COVID-19 patients (LC19Ps) often experience cardiovascular and respiratory complications. Cardiorespiratory rehabilitation programs (CRRPs) have emerged as promising interventions to enhance exercise capacity in this population. This systematic review aimed to assess the impact of CRRPs on submaximal exercise performance, specifically the 6-minute walk test (6MWT) outcomes, in LC19Ps through an analysis of available randomized controlled trials (RCTs).

METHODS

A systematic search was conducted in PubMed/Medline and Scopus to identify relevant RCTs. Six RCTs meeting inclusion criteria were included in this review, investigating the effects of CRRPs on 6MWT outcomes in LC19Ps.

RESULTS

The findings from the included RCTs provide compelling evidence supporting the effectiveness of CRRPs in improving submaximal exercise performance in LC19Ps. These results underscore the potential of CRRPs to enhance submaximal exercise capacity and overall functional well-being in this population. However, future research is imperative to determine optimal CRRPs, including duration, intensity, and specific intervention components. Additionally, the long-term sustainability and durability of CRRP-induced improvements warrant further exploration. Future studies should prioritize patient-centric outcomes and address potential implementation barriers.

CONCLUSION

CRRPs show promise in ameliorating submaximal exercise performance among LC19Ps. Further research is needed to refine these programs and ensure their lasting impact on this patient group.

SYSTEMATIC REVIEW REGISTRATION

https://doi.org/10.17605/OSF.IO/HMN38. [Figure: see text].

Reference value for the 6-min walking distance in women with systemic sclerosis considering the impact of muscle strength

BACKGROUND

Early triage, the search for new therapies, and closer monitoring of patients with systemic sclerosis before their lung function irreversibly deteriorates are urgent concerns. Because it is an independent predictor of systemic sclerosis-related mortality, the 6-min walk test is a potentially useful tool to evaluate outcomes, along with pulmonary function and computed tomography. This study aimed to establish a reference value for the 6-min walking distance in women with diffuse cutaneous systemic sclerosis-associated interstitial lung disease that takes into account the effects of muscle and lung function.

METHODS

This was a cross-sectional study in which 69 women with systemic sclerosis underwent the 6-min walk test, Health Assessment Questionnaire-Disability Index, pulmonary function, handgrip strength test, and quadriceps strength test.

FINDINGS

The mean 6-min walking distance was 447 ± 78 m, and 43.5% of the participants did not reach 80% of their predicted value. 6-min walking distance correlated positively with quadriceps strength (r = 0.418, P = 0.0004), forced vital capacity (r = 0.306, P = 0.011), pulmonary diffusion (r = 0.360, P = 0.002), maximum inspiratory pressure (r = 0.268, P = 0.029), and maximum expiratory pressure (r = 0.288, P = 0.019) and negatively with age (r = -0.378, P = 0.001), body mass index (r = -0.248, P = 0.039), and Health Assessment Questionnaire-Disability Index (r = -0.438, P = 0.0001). In the multiple linear regression analysis, quadriceps strength, body mass index, pulmonary diffusion, age, and maximum expiratory pressure explained 72% of the 6-min walking distance variability.

INTERPRETATION

Muscle function and, to a lesser extent, lung function are key contributors in determining the reference value for the 6-min walking distance in women with diffuse cutaneous systemic sclerosis-associated interstitial lung disease.

Evaluation of cardiac autonomic control during the 6-min walk test in women with systemic sclerosis

OBJECTIVE

To evaluate the association between sympathovagal balance and exercise performance, as measured by the 6-min walk test (6MWT), in women with systemic sclerosis (SSc) without cardiac involvement.

RESULTS

This was a cross-sectional study in which 69 women with SSc [median age 51 (40-63 years)] without cardiac involvement underwent the 6MWT. Throughout the 6MWT, heart rate variability (HRV) was assessed using dedicated software.

METHODS

The median 6-min walking distance (6MWD) was 451 (392-498) meters, and 29 (42%) participants did not achieve 80% of the predicted value for healthy adults. Desaturation during the 6MWT (SpO2 ≤ 4%) was observed in 10.1% of participants. Significant correlations were observed between the 6MWD and the following HRV parameters: number of successive normal-to-normal RR interval differences > 50 ms (rs=-0.397, P = 0.013), low-frequency range (rs=0.374, P = 0.023), high-frequency range (rs=-0.372, P = 0.023), and parasympathetic nervous system index (rs=-0.342, P = 0.045).

CONCLUSION

In women with SSc, there is an interrelationship of the 6MWD with both vagal withdrawal and sympathetic hyperactivation. This relationship between autonomic imbalance and worse exercise performance might increase cardiovascular risk, even in patients without apparent cardiac involvement. Control of the heart by the autonomic nervous system may be a potential target for treating patients with SSc.

Relationship of Exercise Capacity, Physical Function, and Frailty Measures With Clinical Outcomes and Healthcare Utilization in Lung Transplantation: A Scoping Review

Measures of exercise capacity, frailty, and physical function are commonly used in lung transplant candidates and recipients to evaluate their physical limitations and the effects of exercise training and to select candidates for transplantation. It is unclear how these measures are related to clinical outcomes and healthcare utilization before and after lung transplantation. The purpose of this scoping review was to describe how measures of exercise capacity, physical function, and frailty are related to pre- and posttransplant outcomes.

Lack of association between six-minute walk distance and pulmonary artery pressure in patients with systemic sclerosis and cardiopulmonary symptoms

The six-minute walk test (6MWT) is a non-invasive test used to assess cardiopulmonary performance. The aim of this study was to evaluate the performance of 6MWT in predicting pulmonary artery hypertension (PAH) and interstitial lung disease in patients with systemic sclerosis (SSc) and cardiopulmonary symptoms. Sixty-three patients with SSc who had dyspnea, cough, chest pain and syncope underwent 6MWT, high-resolution computed tomography (HRCT), spirometry, body plethysmography and single breath carbon monoxide diffusion measurement. There were no significant differences in mean 6MWD between patients with diffuse SSc compared with limited disease, patients with no parenchymal involvement compared with patients with parenchymal involvement <20% and≥20% in HRCT, and patients with PAP ≥25 mm Hg compared with patents with PAP <25 mm Hg. No significant relationship was found between 6MWD and age, mean PAP, forced expiratory volume, forced vital capacity and diffusing capacity of the lungs for carbon monoxide. The present study showed that in patients with SSc and cardiopulmonary symptoms, 6MVT does not help to predict PAH and parenchymal lung involvement.

The effects of oral treatment for systemic sclerosis related pulmonary arterial hypertension: A systematic review and meta-analysis

OBJECTIVES

The usage of oral therapies, endothelin receptor antagonists (ERAs), phosphodiesterase type-5 (PDE-5) inhibitors and prostaglandin analogs has resulted in improved outcomes in patients with pulmonary arterial hypertension related to systemic sclerosis (SSc-PAH). However, the optimal therapeutics have not been determined.

METHODS

A systematic searching in the databases of Medline (PubMed), Embase, the Cochrane Library (Central) and unpublished clinical trials (clinicaltrials.gov) was conducted to identify the clinical studies with oral treatment for SSc-PAH patients published before 1 June 2019. The data were extracted and the quality was assessed. The main outcomes are exercise capacity and hemodynamic parameters, which were synthesized and analyzed.

RESULTS

In total, 27 clinical trials were enrolled for further analysis. It was demonstrated that bosentan treatment, the widely used drug for PAH, might improve the exercise capacity and pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) in this clinical setting, although without significant difference. Meanwhile, the usage of prostaglandin analogs could improve the parameters mentioned above. Furthermore, combined therapy with ambrisentan and tadalafil significantly increased the treatment efficacy of key parameters in SSc-PAH patients compared with basic treatment.

CONCLUSION

This meta-analysis reveals that combination therapy might provide more benefits to exercise capacity and hemodynamic parameters in SSc-PAH patients. Still more RCTs are needed to provide more solid evidence.

Oxygen therapy in COPD and interstitial lung disease: navigating the knowns and unknowns

Domiciliary oxygen therapy is often prescribed for patients with hypoxaemia due to advanced lung disease, most commonly chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). Long-term oxygen therapy (LTOT) trials conducted in patients with COPD in the 1980s remain the basis for clinical decisions and guideline recommendations regarding LTOT for patients with non-COPD conditions as there is a lack of high-quality evidence concerning its use in the non-COPD population. There is also a lack of evidence for the use of ambulatory and nocturnal oxygen therapy in patients with isolated exertional and nocturnal hypoxaemia. These deficiencies pose significant challenges in patient care, with consequent discrepancies in guideline recommendations and clinical approaches. In recent years, new studies have been and are currently being conducted to fill the gaps in our understanding and use of domiciliary oxygen therapy for other indications, including ILD. This article provides a comparison of the epidemiology and significance of hypoxaemia in patients with COPD and ILD, with an up-to-date review of current evidence regarding the role of different types of domiciliary oxygen therapy in these conditions.

Despite the significance of hypoxaemia in patients with chronic lung diseases, an up-to-date review shows current evidence for clinical use of domiciliary oxygen therapy remains limitedhttp://bit.ly/33aW31n

Clinical and laboratory features of African-Brazilian patients with systemic sclerosis

OBJECTIVE

African-Brazilians comprise a group of blacks and "pardos." As racial differences can be associated with distinct presentations, we evaluated the clinical and serological associations of African-Brazilians with systemic sclerosis (SSc).

METHODS

Sera from 260 adult SSc patients (203 whites and 57 African-Brazilians) were evaluated. Patients with overlap syndromes were excluded. Clinical and demographic data were obtained from an electronic register database. Laboratory analysis included the following: anti-CENP-A/CENP-B, Scl70, RNA polymerase III, Ku, fibrillarin, Th/To, PM-Scl75, and PM-Scl100 by line immunoassay and anti-nuclear antibodies (ANA) by indirect immunofluorescence (IIF) on HEp-2 cells.

RESULTS

African-Brazilian SSc patients presented shorter disease duration (12.8 ± 6.5 vs. 15.9 ± 8.1 years, p = 0.009), higher frequency of nucleolar ANA pattern (28% vs. 13%, p = 0.008), and lower frequencies of centromeric ANA pattern (14% vs. 29%, p = 0.026) and CENP-B (18% vs. 34%, p = 0.017), as well as an association with severe interstitial lung disease (58% vs. 43%; p = 0.044). Further comparison of ethnic groups according to subsets revealed that diffuse SSc African-Brazilian patients presented higher frequency of pulmonary hypertension (p = 0.017), heart involvement (p = 0.037), nucleolar ANA pattern (p = 0.036), anti-fibrillarin antibodies (p = 0.037), and higher mortality (48% vs. 19%; p = 0.009). A different pattern was observed for the limited subset with solely a lower frequency of esophageal involvement (p = 0.050) and centromeric ANA pattern (p = 0.049). Survival analysis showed that African-Brazilians had a higher mortality, when adjusted for age, gender, and clinical subset (RR 2.06, CI 95% 1.10-3.83, p = 0.023).

CONCLUSION

African-Brazilians have distinct characteristics according to clinical subset and an overall more severe SSc than whites, similar to the blacks from other countries.Key Points • African-Brazilian SSc patients were associated with severe interstitial lung disease and nucleolar ANA pattern when compared to white SSc patients. • When disease subsets were considered, African-Brazilian patients with diffuse SSc presented association with pulmonary hypertension, heart involvement, nucleolar ANA pattern, and anti-fibrillarin antibodies. • White SSc patients were associated with centromeric ANA pattern. • Survival analysis at 5, 10, 15, and 20 years, adjusted for age, gender, and disease subset, was significantly worse in African-Brazilian SSc patients.

Observation of the curative effect of device-guided rehabilitation on respiratory function in stable patients with chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a serious lung disease for individuals in middle age and especially in old people. The study was aimed to observe the curative effect of device-guided rehabilitation on respiratory functions in stable COPD patients.

METHODS

Sixty-seven stable COPD patients were enrolled and assigned to the experiment group (n = 36) and the control group (n = 31). The conventional pulmonary rehabilitation treatments, including pursed lips breathing (PLB) and abdominal breathing training, were applied in the control group. Respiratory muscle training of the experiment group was performed using the respiratory endurance training device combined with traditional techniques. Both groups were assessed by 6-minute walk test (6MWT), COPD assessment test (CAT), body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index. Besides, the pulmonary function (FVC%, FEVl%) were measured at 6 months before and after treatment.

RESULTS

After treatment, the 6MWT, CAT, BODE index were significantly increased compared with pre-treatment in both groups (P < .01), but not FVC% and FEVl%. Compared with the control group, the combination therapy in the experiment group could significantly improve the 6MWT (P = .0094), CAT (P = .0071) and BODE index (P = .0064) as well as the changes of 6MWT (P < .01), CAT (P < .01), and BODE index (P < .01) before and after treatment.

CONCLUSIONS

The traditional respiratory training combined with device-guided pulmonary rehabilitation can improve the respiratory muscle function and athletic ability in stable COPD patients.

Determining progression of scleroderma-related interstitial lung disease

Interstitial lung disease occurs in the majority of patients with systemic sclerosis. Although interstitial lung disease is the number one cause of death in systemic sclerosis, interstitial lung disease progression rates vary considerably among patients with systemic sclerosis. Some patients with systemic sclerosis-associated interstitial lung disease have sub-clinical disease and may not derive benefit from immunosuppression, while others have a more aggressive interstitial lung disease phenotype. Reliable predictors of interstitial lung disease progression are lacking. The present review describes our current approach to monitoring systemic sclerosis-associated interstitial lung disease progression in clinical practice. To illustrate the marked heterogeneity that exists in interstitial lung disease progression rates in systemic sclerosis, this review presents the individual disease course of five unique patients with systemic sclerosis-associated interstitial lung disease who participated in the Scleroderma Lung Study II. These cases illustrate that treatment response rates vary in systemic sclerosis-associated interstitial lung disease and more research is needed to determine how to predict treatment response in systemic sclerosis-associated interstitial lung disease and to develop personalized treatment approaches for patients with this devastating disease.

Reproducibility and Utility of the 6-minute Walk Test in Systemic Sclerosis

OBJECTIVE

To assess the reproducibility and the utility of the 6-minute walk test (6MWT) in systemic sclerosis (SSc).

METHODS

All patients with SSc who underwent at least two 6MWT within a minimum 3-month interval plus simultaneous routine clinical, biological, and functional evaluations were consecutively enrolled in this observational study over 6 years. Following American Thoracic Society guidelines, each 6MWT was repeated twice to assess the 6-minute walk distance (6MWD) reproducibility, with the highest value being reported for subsequent analysis.

RESULTS

Among 56 (38 female) included patients aged 46 ± SD 12.7 years, with 17 ± 10 modified Rodnan skin score (mRSS) and 1 ± 0.8 Scleroderma Health Assessment Questionnaire (SHAQ) at first referral, 277 6MWT evaluations (5 ± 3.9 6MWT per patient) were performed over 23 ± 22.5 months followup. Meanwhile, 8 deaths (87.5% SSc-related) occurred. The mean 6MWD absolute value was 457 ± 117 m with a 4 ± 2.2 mean Borg dyspnea score. The 6MWD intraclass correlation coefficient was 0.996 (95% CI 0.995-0.999, p < 0.0001). In multivariate linear regression analysis, these factors were independently associated with a lower 6MWD: sex (R² = 0.47, p < 0.0001), mRSS (R² = 0.47, p = 0.008), tendon friction rub (R² = 0.47, p = 0.003), SHAQ (R² = 0.47, p = 0.02), muscle disability score (R² = 0.47, p = 0.03), DLCO% (R² = 0.47, p = 0.0008), and left ventricular ejection fraction (R² = 0.47, p = 0.006). The 6MWD at first referral was an independent predictor for the overall mortality (HR 0.99, 95% CI 0.988-0.999) and the SSc-related mortality (HR 0.99, 95% CI 0.988-0.999).

CONCLUSION

We show strong reproducibility for the 6MWD and confirm the 6MWT utility to assess the overall prognosis of patients with SSc.

Exercise-based evaluations and interventions for pulmonary hypertension with connective tissue disorders

INTRODUCTION

Exercise intolerance is a common and often significant limitation in pulmonary arterial hypertension (PAH). This intolerance greatly affects the quality of life and function of the individual with PAH, irrespective of its etiology. In PAH associated with connective tissue disorders (PAH-CTD), exercise intolerance is further amplified by the presence of coexisting musculoskeletal manifestations of CTD. The evaluation of exercise capacity and prescription for exercise training therefore becomes a challenge to the clinician. Areas covered: This review highlights factors contributing to exercise intolerance in PAH-CTD, evaluation methods of exercise capacity and an overview on exercise training and a roadmap for future research. Expert commentary: Exercise intolerance is a complex interplay of cardiovascular, pulmonary, and musculoskeletal systems. Data from cardiopulmonary exercise tests have shown predictive abilities for both diagnosis and prognosis. In its absence, the 6-min walk test can be used to provide similar information thereby making the role of exercise testing an invaluable evaluation method in PAH-CTD. Exercise training data in PAH-CTD are still sparse, though, data from PAH studies suggest potential benefit. However, more research is required in this area of testing and training for greater understanding on exercise hemodynamic, phenotypes, and training benefits.

Clinical significance and usefulness of rehabilitation for systemic sclerosis

Systemic sclerosis is a multisystem connective tissue disorder characterized by excessive fibrosis of the skin and internal organs. Impairments in skin, the musculoskeletal system, and respiratory system require rehabilitation therapy because they may lead to disabilities and reduce the quality of life in daily activities. Rehabilitation for systemic sclerosis mainly comprises two distinct approaches that include local and global rehabilitation. Local rehabilitation is applied to maintain and/or improve hand and face functions, while global rehabilitation includes aerobic and resistance exercises. Although few high-quality randomized clinical trials have been conducted to date, previous studies indicated the effectiveness of rehabilitation therapy for decreasing local and systemic disabilities, resulting in improved quality of life. Rehabilitation for systemic sclerosis needs to be regularly and constantly performed at home as well as in hospitals. Physicians involved in the treatment of systemic sclerosis need to consider rehabilitation, and skilled physiotherapists and occupational therapists also play a crucial role in evaluating and treating systemic sclerosis patients.

Factors associated with the 6-minute walk distance in patients with systemic sclerosis

Background

There is an ongoing debate regarding the relevance of the 6-minute walking distance (6MWD) in systemic sclerosis (SSc) assessment, widely used as a usual test in these patients as well as an outcome measure in clinical trials. In this work, we aimed to assess the associations between the 6MWD and various disease parameters in patients with SSc.

Methods

Consecutive patients followed in our SSc National Reference Centre were included in this cross-sectional study if they fulfilled the 2013 American College of Rheumatology/European League Against Rheumatism criteria for SSc. Data were systematically collected during a comprehensive standardized evaluation that included a 6-minute walk test, clinical assessment, biological results, pulmonary function tests, transthoracic echocardiography, composite scores (European Scleroderma Study Group Activity Index, Medsger severity score, Health Assessment Questionnaire–Disability Index (HAQ-DI)) and treatments.

Associations of the 6MWD with various disease parameters were assessed by linear regression in univariate and multivariate analyses.

Results

The study population comprised 298 patients (females 81%; mean age 58.2 ± 13.3 years; limited cutaneous SSc 82%; interstitial lung disease (ILD) 42%; pulmonary arterial hypertension (PAH) 6%). The 6MWD was significantly and independently associated with gender, age, body mass index, baseline heart rate (HR), HR variation during the test, PAH, history of arterial thrombosis and C-reactive protein levels, as well as with the HAQ-DI score in a sensitivity analysis. Muscle involvement, joint involvement and ILD were not independently associated with the 6MWD.

Conclusions

During SSc, the 6MWD is independently associated with initial HR and HR variation; with PAH but not ILD, suggesting that pulmonary vasculopathy may have a greater impact than parenchymal involvement on functional limitation; and with global markers of disease activity and patient disability. These results give clinicians further insight into how to interpret the 6MWD in the context of SSc.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1489-4) contains supplementary material, which is available to authorized users.

Aerobic and resistance exercise in systemic sclerosis: State of the art

INTRODUCTION

Patients with systemic sclerosis (SSc) experience reduced exercise capacity and muscle strength compared with healthy subjects. There are also indications of reduced levels of physical activity.

OBJECTIVE

To present the current knowledge of physical exercise in SSc.

RESULTS

Most studies presently available [three case studies, one single subject experimental design, one study comparing patients with healthy controls, one quasi experimental design (pre-post), two clinical trials and two random controlled trials] have included small samples of patients, mostly composed of patients with and without pulmonary involvement. It seems that patients with SSc without pulmonary involvement are able to perform and benefit from aerobic exercises of at least moderate intensity. Exercise tolerance, aerobic capacity, walking distance, muscle strength and muscle function as well as health-related quality of life (HRQL) have been found to be improved after participation in programmes including aerobic exercise and aerobic exercise combined with resistance exercises. Improvements seem to be only partially retained at follow up. Patients with pulmonary involvement may also experience improved muscle strength, physical and aerobic capacity, as well as HRQL following exercise.

CONCLUSIONS

Patients with SSc without pulmonary involvement can be recommended to be as physically active as the general population. Patients with mild pulmonary involvement can be recommended to be physically active by engaging in exercises of moderate intensity and to participate in moderate-load resistance exercises. Health professionals should inform patients with SSc about the importance of physical activity and avoidance of a sedentary lifestyle.

Pulmonary Artery Dimensions as a Prognosticator of Transplant-Free Survival in Scleroderma Interstitial Lung Disease

BACKGROUND

Systemic sclerosis is a chronic debilitating autoimmune disease characterized by endothelial dysfunction and multi-organ fibrosis. Interstitial lung disease, a common manifestation of SSc, is termed scleroderma-related interstitial lung disease (SSc-ILD) and along with pulmonary hypertension contributes to a majority of deaths in SSc. SSc-ILD patients frequently develop pulmonary hypertension, which prognosticates a poorer outcome. We investigated pulmonary artery dimensions as an outcome predictor in patients with SSc-ILD.

METHODS

A retrospective chart review abstracting data from SSc-ILD patients evaluated at a large tertiary care center was performed. HRCT imaging was reviewed and pulmonary artery (PA) and ascending aorta (Ao) diameters were measured for calculation of the PA:Ao ratio. Additionally, demographics, vital signs, spirometric parameters, comorbidities, and mean pulmonary artery pressures were collected when available. Outcome analysis with lung transplant or death events within 4 years based on pulmonary artery size as well as PA:Ao ratio was performed.

RESULTS

70 SSc-ILD patients were identified. Mean pulmonary artery diameter and PA:Ao ratio was 31.17 and 1.07 mm, respectively. Patients with a pulmonary artery diameter ≥32 mm had higher risk of lung transplantation or death (p < 0.001) within 4 years. Patients with a PA:Ao ratio ≥1.1 also had higher risk of lung transplantation or death (p < 0.001) within 4 years. Unadjusted outcomes analyses also identified PA:Ao ratio ≥1.1 as an independent outcome predictor (hazard ratio 3.30, p < 0.001).

CONCLUSIONS/CLINICAL IMPLICATIONS

In SSc-ILD patients, a PA:Ao ratio ≥1.1 is associated with higher risk of lung transplant or death. These data suggest that PA:Ao dimension may be used for prognostication in SSc-ILD.

Pulmonary involvement in systemic sclerosis: A clinical profile

Background:

Systemic sclerosis is a generalized disorder of connective tissue affecting skin and internal organs. Lung involvement accounts for significant morbidity and is a leading cause of mortality in patients.

Objectives:

This study intends to study the frequency of occurrence of pulmonary involvement in progressive systemic sclerosis (PSS) and to describe the clinical and radiological picture of pulmonary involvement in PSS.

Materials and Methods:

This was a descriptive cross-sectional study. A detailed history, modified Rodnan score, clinical examination, routine investigation, antinuclear antibody, immuno biot, chest X-ray (CXR), pulmonary function test (PFT), and 6 min walk test (6MWT) were performed on all patients. High resolution computed tomography was done on those who consented.

Results:

Hundred subjects with PSS were included in the study; 90 were females and 10 were males. Common presenting complaints were skin thickening in 98% and Raynaud's phenomenon in 98%. Skin thickening of digits beyond metacarpo phalangeal was seen in 98%, face and neck in 92%, and hands in 92%. Chest wall thickening was seen in 40 subjects (40%). 90 (90%) of the studied subjects had pulmonary involvement, longer duration of disease was significantly associated with pulmonary involvement (P < 0.05). Dyspnea, cough, bilateral crepitations, CXR, Borg score, and Rodnan score was found to be significantly associated with severe pulmonary involvement (P < 0.05).

Conclusion:

The prevalence of pulmonary involvement in this cohort study was 90%. Almost 1/3^rd of patients, that is 29 (29%) were detected to have pulmonary involvement despite being asymptomatic for respiratory complaints, hence early screening and evaluation is recommended. PFT and 6MWT are noninvasive, cost-effective, and easily available screening tests which can be used in resource-limited settings.

[Epidemiological, clinical and evolutionary peculiarities of interstitial lung disease in systemic sclerosis]

Pulmonary involvement during systemic sclerosis (SS) is dominated by interstitial lung disease and arterial pulmonary hypertension. It is about a retrospective study analyzing 65 cases of SS over a period of 13 years. We compared cases with and without interstitial lung disease. The diagnosis of SS was retained according to American College of Rheumatology (ACR)/EULAR 2013 criteria. The diagnosis of interstitial lung disease was retained in TDM and EFR. Pulmonary hypertension is defined by a pulmonary arterial pression higher than 25 mmHg. The mean delay of diagnosis of interstitial lung disease and the diagnosis was of 48 months (extremes 0-78 months). The comparison between both groups according to average age of the patients, prevalence of pulmonary hypertension, frequency of Raynaud phenomenon and trophic disorders did not find any significant difference. Lung involvement was associated with an esophageal involvement in 71% of the cases (P=0.059). Antibodies anti-Scl 70 were noted more frequently in patient's with interstitial lung disease (79% of the cases, P=0.001). Patients were treated with colchicine and vitamin E. A corticotherapy had been indicated at a single patient. The evolution of SS was marked by the stabilisation of the restrictive syndrome in 71.8% of the cases and a worsening in 25% of the cases. Early and appropriate diagnosis of SS and screening of lung involvement are essential for a early care.

Determining the necessity for right heart catheterization in pulmonary hypertension associated with connective tissue diseases assessed by echocardiography

AIM

The prognosis of pulmonary hypertension (PH) in systemic sclerosis (SSC) and in systemic lupus erythematosus (SLE) is different. According to the guidelines, right heart catheterization (RHC) is necessary in pulmonary arterial hypertension (PAH) associated with connective tissue diseases (CTD). However, there is little supporting evidence. Therefore, we attempted to determine the necessity for RHC and the causes of differences in prognosis of PH by comparing SSC to SLE.

METHODS

The inclusion criteria were all patients with SSC or SLE with exertional dyspnea. Echocardiography and carotid Doppler ultrasound were performed.

RESULTS

Twenty-three patients with SSC and 23 with SLE participated in this study. There was no difference in the right ventricular systolic pressure (RVSP) between SSC and SLE (33.0 mmHg, range 25.3-41.7 mmHg vs. 32.4 mmHg, range 27.0-37.7 mmHg; P = 0.835). In multiple linear regression analysis, the ratio of peak tricuspid regurgitant velocity to right ventricular outflow tract time-velocity integral, which represents pulmonary vascular resistance (PVR), was correlated with RVSP in SSC (r(2) = 0.928, β = 0.362, P = 0.003), and the independent predictor of increased RVSP was the ratio of early diastolic transmitral filling velocity to early diastolic septal mitral annular velocity, which represents diastolic dysfunction in SLE (R(2) = 0.806, β = 0.803, P = 0.023).

CONCLUSIONS

PVR was an important cause of PH in SSC. Left ventricular dysfunction was an important cause of PH in SLE. Thus, these findings demonstrate the necessity for RHC and differences in prognosis of PH in CTD.

A prospective study of the 6 min walk test as a surrogate marker for haemodynamics in two independent cohorts of treatment-naïve systemic sclerosis-associated pulmonary arterial hypertension

OBJECTIVES

Despite the wide use of the 6 min walk distance (6MWD), no study has ever assessed its validity as a surrogate marker for haemodynamics and predictor of outcome in isolated pulmonary arterial hypertension associated with systemic sclerosis (SSc-PAH). We designed this work to address this issue.

METHODS

Treatment-naïve patients with SSc-PAH were prospectively included from two sources: the French PAH Network (a prospective epidemiological cohort) (n=83) and randomised clinical trials submitted for drug approval (Food and Drug Administration) (n=332). Correlations between absolute values of the 6MWD and haemodynamics at baseline, as well as between variations of 6MWD and haemodynamics during follow-up, were studied in both populations.

RESULTS

In the French cohort, baseline cardiac output (CO) (R(2)=0.19, p=0.001) and New York Heart Association class (R(2)=0.10, p<0.001) were significantly and independently correlated with baseline 6MWD in multivariate analysis. A significant, independent, but weaker, correlation with CO was also found in the Food and Drug Administration sample (R(2)=0.04, p<0.001). During follow-up, there was no association between the changes in 6MWD and haemodynamic parameters in patients under PAH-specific treatments.

CONCLUSIONS

In SSc-PAH, CO independently correlates with 6MWD at baseline, but accounts for a small amount of the variance of 6MWD in both study samples. This suggests that other non-haemodynamic factors could have an impact on the walk distance. Moreover, variations of 6MWD do not reflect changes in haemodynamics among treated patients. Our results suggest that 6MWD is not an accurate surrogate marker for haemodynamic severity, nor an appropriate outcome measure to assess changes in haemodynamics during follow-up in treated SSc-PAH.

Reliability, validity and responsiveness to change of the Saint George's Respiratory Questionnaire in early diffuse cutaneous systemic sclerosis

OBJECTIVE

Dyspnoea is a common, multifactorial source of functional impairment among patients with dcSSc. Our objective was to assess the reliability, construct validity and responsiveness to change of the Saint George's Respiratory Questionnaire (SGRQ) in patients with early dcSSc participating in a multicentre prospective study.

METHODS

At enrolment and 1 year, patients completed the SGRQ (a multi-item instrument with four scales: symptoms, activity, impact and total), a visual analogue scale (VAS) for breathing and the HAQ Disability Index (HAQ-DI) and underwent 6 min walk distance and pulmonary function tests, physician and patient global health assessments and high-resolution CT (HRCT). We assessed internal consistency reliability using Cronbach's α. For validity we examined the ability of the SGRQ to differentiate the presence vs absence of interstitial lung disease (ILD) on HRCT or restrictive lung disease and evaluated the 1 year responsiveness to change using pulmonary function tests and patient- and physician-reported anchors. Correlation coefficients of 0.24-0.36 were considered moderate and >0.37 was considered large.

RESULTS

A total of 177 patients were evaluated. Reliability was satisfactory for all SGRQ scales (0.70-0.93). All scales showed large correlations with the VAS for breathing and diffusing capacity of the lung for carbon monoxide in the overall cohort and in the subgroup with ILD. Three of the four scales in the overall cohort and the total scale in the ILD subgroup showed moderate to large correlation with the HAQ-DI and the predicted forced vital capacity (r = 0.33-0.44). Each scale discriminated between the presence and absence of ILD and restrictive lung disease (P ≤ 0.0001-0.03). At follow-up, all scales were responsive to change using different anchors.

CONCLUSION

The SGRQ has acceptable reliability, construct validity and responsiveness to change for use in a dcSSc population and differentiates between patients with and without ILD.

Relationship between quantitative radiographic assessments of interstitial lung disease and physiological and clinical features of systemic sclerosis

OBJECTIVES

Extent of systemic sclerosis (SSc)-related interstitial lung disease (ILD) assessed from thoracic high-resolution CT (HRCT) predicts disease course, mortality and treatment response. While quantitative HRCT analyses of extent of lung fibrosis (QLFib) or total interstitial lung disease (QILD) are more sensitive and reproducible than visual HRCT assessments of SSc-ILD, these analyses are not widely available. This study evaluates the relationship between clinical disease parameters and QLFib and QILD scores to identify potential surrogate measures of radiographic extent of ILD.

METHODS

Using baseline data from the Scleroderma Lung Study I (SLS I; N=158), multivariate regression analyses were performed using the best subset selection method to identify one to five variable models that best correlated with QLFib and QILD scores in both whole lung (WL) and the zone of maximal involvement (ZM). These models were subsequently validated using baseline data from SLS II (N=142). Bivariate analyses of the radiographic and clinical variables were also performed using pooled data. SLS I and II did not include patients with clinically significant pulmonary hypertension (PH).

RESULTS

Diffusing capacity for carbon monoxide (DLCO) was the single best predictor of both QLF and QILD in the WL and ZM in all of the best subset models. Adding other disease parameters to the models did not substantially improve model performance. Forced vital capacity (FVC) did not predict QLF or QILD scores in any of the models.

CONCLUSIONS

In the absence of PH, DLCO provides the best overall estimate of HRCT-measured lung disease in patients from two large SSc cohorts. FVC, although commonly used, may not be the best surrogate measure of extent of SSc-ILD at any point in time.

TRIAL REGISTRATION NUMBERS

SLS I: www.clinicaltrials.gov NCT 00000-4563; SLS II: www.clinicaltrials.gov NCT 00883129.

[Use of pulmonary function tests and biomarkers studies to diagnose and follow-up interstitial lung disease in systemic sclerosis]

Interstitial lung disease (ILD) is becoming one of the main causes of death of patients with systemic sclerosis (SSc). The prevalence of ILD associated with SSc (SSc-ILD) varies from 33% to 100% according to diagnostic methods. Clinical features such as dyspnea on exertion, dry cough, and chest pains are not specific and usually late-appearing, implying more specific tests in the diagnostic, prognosis, and follow-up of ILD in patients with SSc. High resolution thoracic CT scanner (HRCT) is more sensitive than chest X-ray in the detection of SSc-ILD. Pulmonary function tests (PFT) are non-invasive and periodically used to assess the impacts of SSc on respiratory function. Diagnostic values of bronchoalveolar lavage and histological examination on lung biopsy are controversial. However, these techniques are essential for studying cellular and molecular mechanisms underlying the pathophysiology of SSc-ILD. Several biomarkers such as surfactant-A (SP-A), -D (SP-D), mucin-like high molecular weight glycoprotein (KL-6), and chemokine CCL-18 have been implicated in SSc-PID. Serum levels of these proteins are correlated with the severity of SSc-ILD, as assessed by HRCT and/or PFT. Finally, alveolar concentration of exhaled nitric oxide can be used to screen SSc patients with high risk of deterioration of respiratory function, in whom immunosuppressant treatment could be useful in preventing the evolution to irreversible lung fibrosis.

An official European Respiratory Society/American Thoracic Society technical standard: field walking tests in chronic respiratory disease

Field walking tests are commonly employed to evaluate exercise capacity, assess prognosis and evaluate treatment response in chronic respiratory diseases. In recent years, there has been a wealth of new literature pertinent to the conduct of the 6-min walk test (6MWT), and a growing evidence base describing the incremental and endurance shuttle walk tests (ISWT and ESWT, respectively). The aim of this document is to describe the standard operating procedures for the 6MWT, ISWT and ESWT, which can be consistently employed by clinicians and researchers. The Technical Standard was developed by a multidisciplinary and international group of clinicians and researchers with expertise in the application of field walking tests. The procedures are underpinned by a concurrent systematic review of literature relevant to measurement properties and test conduct in adults with chronic respiratory disease. Current data confirm that the 6MWT, ISWT and ESWT are valid, reliable and responsive to change with some interventions. However, results are sensitive to small changes in methodology. It is important that two tests are conducted for the 6MWT and ISWT. This Technical Standard for field walking tests reflects current evidence regarding procedures that should be used to achieve robust results.

An official systematic review of the European Respiratory Society/American Thoracic Society: measurement properties of field walking tests in chronic respiratory disease

This systematic review examined the measurement properties of the 6-min walk test (6MWT), incremental shuttle walk test (ISWT) and endurance shuttle walk test (ESWT) in adults with chronic respiratory disease.

Studies that report the evaluation or use of the 6MWT, ISWT or ESWT were included. We searched electronic databases for studies published between January 2000 and September 2013.

The 6-min walking distance (6MWD) is a reliable measure (intra-class correlation coefficients ranged from 0.82 to 0.99 in seven studies). There is a learning effect, with greater distance walked on the second test (pooled mean improvement of 26 m in 13 studies). Reliability was similar for ISWT and ESWT, with a learning effect also evident for ISWT (pooled mean improvement of 20 m in six studies). The 6MWD correlates more strongly with peak work capacity (r=0.59–0.93) and physical activity (r=0.40–0.85) than with respiratory function (r=0.10–0.59). Methodological factors affecting 6MWD include track length, encouragement, supplemental oxygen and walking aids. Supplemental oxygen also affects ISWT and ESWT performance. Responsiveness was moderate to high for all tests, with greater responsiveness to interventions that included exercise training.

The findings of this review demonstrate that the 6MWT, ISWT and ESWT are robust tests of functional exercise capacity in adults with chronic respiratory disease.

Severity of systemic sclerosis-associated pulmonary arterial hypertension in African Americans

African Americans (AA) with systemic sclerosis (SSc) have a worse prognosis compared to Americans of European descent (EA). We conducted the current study to test the hypothesis that AA patients with SSc have more severe disease and poorer outcomes compared to EA patients when afflicted with pulmonary arterial hypertension (PAH). We studied 160 consecutive SSc patients with PAH diagnosed by right heart catheterization, comparing demographics, hemodynamics, and outcomes between AA and EA patients. The cohort included 29 AA and 131 EA patients with similar baseline characteristics except for increased prevalence of diffuse SSc in AA. AA patients had worse functional class (FC) (80% FC III-IV vs 53%; p = 0.02), higher brain natriuretic peptide (NT-pro-BNP) (5729 ± 9730 pg/mL vs 1892 ± 2417 pg/mL; p = 0.02), more depressed right ventricular function, a trend toward lower 6-minute walk distance (263 ± 111  m vs 333 ± 110  m; p = 0.07), and worse hemodynamics (cardiac index 1.95 ± 0.58 L/min/m vs 2.62 ± 0.80 L/min/m; pulmonary vascular resistance 10.3 ± 6.2 WU vs 7.6 ± 5.0 WU; p  < 0.05) compared with EA patients. Kaplan-Meier survival estimates for AA and EA patients, respectively, were 62% vs 73% at 2 years and 26% vs 44% at 5 years (p  > 0.05). In conclusion, AA patients with SSc-PAH are more likely to have diffuse SSc and to present with significantly more severe PAH compared with EA patients. AA patients also appear to have poorer survival, though larger studies are needed to investigate this association definitively.

Oxygen desaturation in healthy subjects undergoing the incremental shuttle walk test

OBJECTIVE

To determine the probability of oxygen desaturation in healthy individuals undergoing the incremental shuttle walk test (ISWT).

METHODS

We enrolled 83 healthy subjects: 55 males (including 1 smoker) and 28 females. We determined pre-ISWT FEV1, FEV6, HR and SpO2, as well as post-ISWT HR and SpO2.

RESULTS

Mean values overall were as follows: age, 35.05 ± 12.53 years; body mass index, 24.30 ± 3.47 kg/m2; resting HR, 75.12 ± 12.48 bpm; resting SpO2, 97.96 ± 1.02%; FEV1, 3.75 ± 0.81 L; FEV6, 4.45 ± 0.87 L; FEV1/FEV6 ratio, 0.83 ± 0.08 (no restriction or obstruction); incremental shuttle walk distance, 958.30 ± 146.32 m; post-ISWT HR, 162.41 ± 18.24 bpm; and post-ISWT SpO2, 96.27 ± 2.21%. In 11 subjects, post-ISWT SpO2 was higher than was pre-ISWT SpO2. In 17 subjects, there was a 4% decrease in SpO2 after the ISWT. There were no statistically significant differences between the groups with and without post-ISWT oxygen desaturation in terms of age, gender, FEV1, FEV6, FEV1/FEV6, pre-ISWT SpO2, incremental shuttle walk distance, HR, or percentage of maximal HR. In the individuals with post-ISWT oxygen desaturation, the body mass index was higher (p = 0.01) and post-ISWT SpO2 was lower (p = 0.0001).

CONCLUSIONS

Healthy individuals can present oxygen desaturation after the ISWT. Using the ISWT to predict subtle respiratory abnormalities can be misleading. In healthy subjects, oxygen desaturation is common after the ISWT, as it is during any intense physical activity.

Effect of capillaroscopic patterns on the pulse oximetry measurements in systemic sclerosis patients

Nailfold capillaroscopy is a simple method for determining microvascular damage in systemic sclerosis (SSc). The pulse oximeter is a noninvasive tool that is used to estimate a patient's arterial blood oxygen saturation. The aim of this study was to investigate the effect of capillaroscopic patterns on pulse oximetry measurements in SSc patients. The nailfolds from 2nd to 5th fingers in both hands were examined in all subjects by using capillaroscopy. Patients were categorized according to their capillaroscopy findings in 3 groups as having early, active or late patterns. Oxygen saturation (SpO2) measurements were performed from 2nd to 5th fingers in both hands with a finger probe. We studied 53 SSc patients (F/M: 48/5). According to capillaroscopy findings 18 patients were classified as having early pattern (34.0%), 19 active pattern (35.8%), and 15 late pattern (28.3%). Only 1 (1.9%) patient had normal capillaroscopy findings. SpO2 could not be measured in 47 (11.0%) fingers and in 20 (37.7%) SSc patients. There were 20 (37.7%) patients with a ≥4% difference between the minimum and maximum SpO2 measurements among fingers. There were no difference between the groups of SSc patients defined by capillaroscopy findings in terms of mean maximal SpO2 or mean minimal SpO2 measured from fingers (p NS, for all). Assessment of SpO2 values in patients with SSc is challenging. We did not detect any effect of capillaroscopic patterns on mean SpO2 values. On the other hand ≥4% difference between minimum and maximum SpO2 values measured from fingers of a patient may be considered as an indirect sign of microvascular damage. Assessment of the highest measured SpO2 values among the fingers of a patient may be more suitable in practice.

Exercise capacity in relation to autoantibodies in systemic sclerosis patients

Autoantibodies have been detected in systemic sclerosis patients, and typical clinical features regarding organ involvement by each autoantibody have been reported. To reveal differences in exercise intolerance in patients with either anti-topoisomerase-I or anti-centromere antibodies, 53 systemic sclerosis patients were investigated retrospectively. A 6-min walking distance showed no significant differences (P = 0.090) between autoantibodies, while exercise-induced hypoxia during the 6-min walking test was significant in subjects with the anti-topoisomerase-I antibody (P = 0.033). The percent predicted of vital capacity, the diffusion capacity of the lung for carbon monoxide, and the modified Rodnan skin score were affected more in subjects with the anti-topoisomerase-I antibody than the anti-centromere antibody. The main parameter affecting the 6-min walking distance was the percent predicted of vital capacity for each autoantibody, and there was a significant positive relationship for all subjects (R² = 0.30, P < 0.0001). Exercise-induced hypoxia was also shown in the more affected subjects in the percent predicted of vital capacity and the diffusion capacity of the lung for carbon monoxide. Lung parameters were suggested to be more important factors determining exercise intolerance and induced hypoxia than detected autoantibodies.

Limitations to the 6-minute walk test in dermatomyositis with interstitial lung disease in comparison with idiopathic interstitial pneumonia

Although the relationship between muscle strength and exercise capacity has been demonstrated in dermatomyositis without lung dysfunction, little is known about the association between exercise capacity and interstitial lung disease in dermatomyositis. Eleven patients with dermatomyositis with interstitial lung disease without the manifestation of muscle weakness and 12 patients with idiopathic interstitial pneumonia underwent the 6-minute walk test (6MWT). PaO₂, creatine kinase, percentage predicted 6MWT distance (6MWD%), and SpO₂ at rest were similar between patients. Percentage predicted vital capacity, carbon monoxide diffusing capacity (DL_CO%), and SpO₂ after 6MWT were higher and exertional dyspnea was lower in patients with dermatomyositis than in patients with idiopathic interstitial pneumonia. SpO₂ after 6MWT was positively correlated with 6MWD% in patients with dermatomyositis, while DL_CO% and PaO₂ were positively correlated with 6MWD% in patients with idiopathic interstitial pneumonia. Lung dysfunction in dermatomyositis might not be a major limitation factor in exercise capacity.

Echo Doppler predictors of pulmonary artery hypertension in patients with systemic sclerosis

OBJECTIVES

Evaluate echocardiographic predictors of pulmonary artery hypertension (PAH) in a prospective cohort of patients with systemic sclerosis (SSc).

METHODS

38 patients with SSc who did not have PAH and significant left heart disease, with peak tricuspid regurgitant velocity (TRV) ≤ 2.8 m/sec and systolic pulmonary artery pressure (sPAP) < 40 mmHg on echo Doppler were enrolled. Patients underwent: clinical assessment, NT-proBNP, and DLco measurements. Echo Doppler evaluation included right ventricular (RV) dimensions, tricuspid annular plan systolic excursion, fractional area change, tricuspid DTI systolic velocity, Tei index, pulmonary flow acceleration time (AcT), ratio of TRV to RV outflow tract time-velocity integral (TVI) and a parameter of disturbed RV ejection (TRV/AcT). After a planned 12-month follow-up we evaluated the predictive value of these parameters for the development of PAH, as demonstrated by right heart catheterization (RHC). Criteria for RHC were TRV ≥ 3 m/sec or sPAP ≥ 40 mmHg.

RESULTS

Four patients developed PAH. Only TRV/TVI and TRV/AcT ratios significantly predicted PAH development (TRV/TVI ratio ≥ 0.16 [predefined and ROC confirmed]: OR 99, CI 95%: 4.865-2015, P = 0.004; TRV/AcT ratio ≥ 0.022 [predefined and ROC confirmed]: OR 12.68, CI 95% 1.163-379.3, P = 0.036). Both parameters showed a good diagnostic power (TRV/TVI ratio: ROC area 79%, sensitivity 75%, specificity 97% and diagnostic accuracy 94.74% for cutoff value of 0.16; TRV/AcT ratio: ROC area 75%, sensitivity 75%, specificity 71% and diagnostic accuracy 72% for cutoff value of 0.022).

CONCLUSIONS

This prospective study identified increased values of the two ratios TRV/TVI and TRV/AcT as predictors of PAH in SSc.

Pulmonary manifestations of scleroderma and mixed connective tissue disease

Pulmonary manifestations are common in connective tissue diseases, and are associated with significant morbidity and mortality in this patient population. Systemic sclerosis (SSc) and mixed connective tissue disease (MCTD) are clinical entities for which the detection of lung involvement is essential to improve patient care and outcomes. This article discusses the pathogenesis, clinical presentation, and evaluation of the patient with pulmonary disease related to SSc and MCTD, with an emphasis on interstitial lung disease and pulmonary hypertension.

Hypoxemia and arrhythmia during daily activities and six-minute walk test in fibrotic interstitial lung diseases

We performed 24-hr monitoring of pulse oximetric saturation (SpO(2)) with ECG and six-minute walk test (6MWT) in 19 patients with fibrotic interstitial lung diseases (ILD) to investigate; 1) The frequency and severity of hypoxemia and dysrhythmia during daily activities and 6MWT, 2) safety of 6MWT, and 3) the parameters of 6MWT which can replace 24-hr continuous monitoring of SpO(2) to predict hypoxemia during daily activities. All patients experienced waking hour hypoxemia, and eight of nineteen patients spent > 10% of waking hours in hypoxemic state. Most patients experienced frequent arrhythmia, mostly atrial premature contractions (APCs) and ventricular premature contractions (VPCs). There were significant correlation between the variables of 6MWT and hypoxemia during daily activities. All of the patients who desaturated below 80% before 300 meters spent more than 10% of waking hour in hypoxemia (P = 0.018). In contrast to waking hour hypoxemia, SpO(2) did not drop significantly during sleep except in the patients whose daytime resting SpO(2) was already low. In conclusion, patients with fibrotic ILD showed significant period of hypoxemia during daily activities and frequent VPCs and APCs. Six-minute walk test is a useful surrogate marker of waking hour hypoxemia and seems to be safe without continuous monitoring of SpO(2).