Limited Exercise Capacity in Patients with Systemic Sclerosis: Identifying Contributing Factors with Cardiopulmonary Exercise Testing

Exercise pulmonary hypertension in patients with systemic sclerosis based on updated guidelines

Recent European guidelines have introduced the concept of exercise pulmonary hypertension (ex-PH). However, the clinical characteristics of ex-PH in systemic sclerosis (SSc) remains unknown. We aimed to investigate the characteristics of exercise pulmonary hypertension (ex-PH) in patients with systemic sclerosis (SSc), which are unknown. We retrospectively examined 77 patients with SSc who underwent symptom-limited exercise testing using a cycle ergometer with right heart catheterization at our hospital. Nineteen patients with postcapillary PH were excluded. Fifty-eight patients (median age, 63 years; 55 women) were divided into the overt-PH (n = 18, mean pulmonary arterial pressure [PAP] > 20 mmHg and pulmonary vascular resistance > 2 Wood units at rest), ex-PH (n = 19, mean PAP/cardiac output slope > 3), and non-PH (n = 21) groups. Exercise tolerance and echocardiography results were compared among the groups. Peak oxygen consumption was high in the non-PH group, intermediate in the ex-PH group, and low in the overt-PH group (14.5 vs. 13.0 vs. 12.5 mL/kg/min, p = 0.043), and the minute ventilation/peak carbon dioxide production slope was also intermediate in the ex-PH group (32.2 vs. 32.4 vs. 43.0, p = 0.003). The tricuspid annular plane systolic excursion/systolic PAP ratio decreased from non-PH to ex-PH to overt-PH (0.73 vs. 0.69 vs. 0.55 mm/mmHg, p = 0.018). In patients with SSc, exercise PH may represent an intermediate condition between not having PH and overt PH, according to the new guidelines.

Diffusing capacity of lungs for carbon monoxide associated with subclinical myocardial impairment in systemic sclerosis: A cardiac MR study

BACKGROUND

Systemic sclerosis (SSc) is characterised by microvascular and fibrotic lesions, which are located not only in skin but also in lungs and heart.

OBJECTIVE

This study aimed to investigate the association between lung function and myocardial T1 values using cardiac MR (CMR) imaging in patients with SSc without cardiovascular symptoms.

METHODS

The SSc patients and age- and sex-matched healthy subjects underwent CMR. The cardiac function and native T1 values of myocardium and lung function were measured. Spearman's rank correlations and linear regression analyses were performed to determine the association between lung function and myocardial T1.

RESULTS

Forty-five SSc patients (aged 47.7±13.2 years, 40 females) and 23 (aged 46.0±14.4 years, 20 females) healthy subjects were enrolled. SSc patients exhibited considerably higher native T1 values compared with healthy subjects (1305.9±49.8 ms vs 1272.6±37.6 ms, p=0.006). Linear regression analysis revealed that decrease of diffusing capacity of lungs for carbon monoxide (DLCO) in SSc patients was notably associated with myocardial native T1 value before (β -1.017; 95% CI -1.883 to -0.151; p=0.022) and after adjusting for confounding factors (β -1.108; 95% CI -2.053 to -0.164; p=0.023). Moderate-to-severe decrease of DLCO was found to be significantly associated with myocardial native T1 value (β 48.006; 95% CI 17.822 to 78.190; p=0.003) after adjusting for confounding factors.

CONCLUSION

DLCO inversely correlates with myocardial native T1 values in SSc patients, particularly moderate-to-severely decreased DLCO, suggesting that DLCO might be a potential indicator for subclinical myocardial impairment in SSc patients.

Autologous stem cell transplantation improves cardiopulmonary exercise testing outcomes in systemic sclerosis patients

OBJECTIVES

Autologous haematopoietic stem cell transplantation (AHSCT) is a disease-modifying treatment for patients with severe SSc. Here, we aimed at assessing cardiopulmonary function outcomes of SSc patients after AHSCT.

METHODS

Twenty-seven SSc adult patients treated with AHSCT were included in this retrospective study. Most had the diffuse cutaneous subset (93%) and pulmonary involvement (85%). Before and 12 months after AHSCT, patients underwent cardiopulmonary exercise testing, transthoracic echocardiography, pulmonary function test with diffusing capacity for carbon monoxide (DLCO), 6-min walk test (6MWT) and quality of life evaluations.

RESULTS

After AHSCT, the peak VO2 increased from 954 to 1029 ml/min (P = 0.02), the percentage of predicted peak VO2 increased from 48.9 to 53.5 m (P = 0.01), and the distance measured by the 6MWT increased from 445 to 502 m (P = 0.01), compared with baseline. Improvements in peak VO2 correlated positively with improvements in 6MWT distance, and negatively with a decrease in resting heart rate. At baseline, patients with DLCO >70% had higher peak VO2 values than those with DLCO <70% (P = 0.04), but after AHSCT all patients showed improved VO2 values, regardless of baseline DLCO levels. Increases in VO2 levels after AHSCT positively correlated with increases in the physical component scores of the Short Form-36 quality of life questionnaire (r = 0.70; P = 0.0003).

CONCLUSION

AHSCT improves the aerobic capacity of SSc patients probably reflecting combined increments in lungs, skeletal muscle and cardiac function.

Disease specific determinants of cardiopulmonary fitness in systemic sclerosis

OBJECTIVES

We aimed to quantify the burden of exercise intolerance in systemic sclerosis (SSc) and explore the disease features that contribute to impaired exercise capacity (measured as peak oxygen uptake, peak VO₂) to provide novel mechanistic insights into the causes of physical disability in SSc.

METHODS

Thirty-three SSc patients with no history of cardiac disease and no active myositis underwent cardiac and skeletal muscle MRI, transthoracic echocardiography, pulmonary function tests and cardiopulmonary exercise testing (CPET). CPET results were compared to an age-, sex-, and weight-matched controls with no overt cardiopulmonary disease. Native T1 and T2-mapping sequences were used to quantify diffuse fibroinflammatory myocardial disease and qualitative assessment of skeletal muscle oedema was performed. The associations between parameters of cardiorespiratory function and skeletal muscle abnormalities and peak VO₂ were evaluated with linear regression analysis.

RESULTS

Exercise capacity was markedly impaired in SSc and significantly reduced when compared to control subjects (percent predicted peak VO₂: 70% vs 98%, p < 0⋅01). Diffuse myocardial fibroinflammatory disease (p < 0⋅01) and skeletal muscle oedema (p = 0⋅01) were significantly associated with reduced exercise capacity. There was no association between impaired exercise capacity and left ventricular ejection fraction.

CONCLUSION

SSc is associated with marked functional impairment that is not explained by commonly used parameters of cardiac function such as left ventricular ejection fraction. Rather, only more sensitive measures of organ involvement are associated with impaired exercise tolerance. Our results show diffuse interstitial changes of the myocardium and skeletal muscle affect oxygen uptake and are important contributors to functional limitation in SSc.

Systemic sclerosis associated interstitial lung disease: a survey of current practices in France

Background

Interstitial lung disease (ILD) is the leading cause of mortality in systemic sclerosis (SSc).

Objective

We performed an overview of the diagnostic approaches, follow-up and treatment strategies used in France for the management of SSc-associated ILD (SSc-ILD).

Design Structured nationwide online surveyMethods

A structured nationwide online survey was submitted to participants via the French Medical Societies for Internal Medicine and Pneumology, and research groups on SSc-ILD from May 2018 to June 2020. The 79 multiple-choice and 9 open-ended questions covered the screening of ILD at baseline, monitoring of patients with established SSc-ILD and its management. Fourteen optional vignettes exploring different clinical phenotypes of SSc-ILD were submitted to evaluate therapeutic decisions.

Results

All of the 93 participants screened SSc patients for ILD at baseline with 83 (89%) participants relying on a systematic chest computed tomography (CT) scan. Pulmonary function tests (PFT) were prescribed by 87 (94%) participants at baseline and during follow-up. Treatment was started based on abnormal PFT (95%), chest CT scan characteristics (89%), worsening dyspnoea (72%) and drop in SpO₂ during 6-min walk tests (66%). First-line therapy was cyclophosphamide (CYC) (89%), mycophenolate mofetil (MMF) (83%) and prednisone (73%). Rituximab as second-line immunosuppressive therapy (41%) was preferred to antifibrotic agents (18%), and a median daily prednisone dose of 10 mg (interquartile range, 10-15) was prescribed by 73% participants. Extensive SSc-ILD with worsening PFT (95%), regardless of diffusing capacity for carbon monoxide values and skin extension, were more likely to be treated, and CYC was favoured over MMF (p < 0.01). Extensive SSc-ILD with disease duration of less than 5 years was also a criterium for treatment initiation.

Conclusion

This overview of practices in diagnosis, follow-up and treatment of SSc-ILD in France describes real-life management of patients. It highlights heterogeneity in this management and gaps in current strategies that should be addressed to improve and harmonize clinical practices in SSc-ILD.

The Preventive Role of Physical Activity in Systemic Sclerosis: A Cross-Sectional Study on the Correlation with Clinical Parameters and Disease Progression

Although exercise is associated with improved health in many medical conditions, little is known about the possible influences of physical activity (PA) habits pre- and post- a diagnosis of systemic sclerosis (SSc) on disease activity and progression. This cross-sectional study assessed, for the first time, self-reported pre- and post-diagnostic PA levels with the aim to verify if changes in these levels were correlated with demographic/anthropometric data (e.g., weight, height, gender, age, BMI), disease duration, diagnostic/clinical parameters (e.g., skin involvement, pulmonary hemodynamic/echocardiographic data, disease activity) related to disease activity and progression, and quality of life in a population-based sample of patients with SSc. Adult participants (n = 34, age 56.6 ± 13.3 years) with SSc (limited cutaneous SSc, lcSSc, n = 20; diffuse cutaneous SSc, dcSSc, n = 9; sine scleroderma SSc, n = 5) were enrolled at the Division of Rheumatology and Clinical Immunology of the Humanitas Research Hospital. All medical data were recorded during periodic clinical visits by a rheumatologist. Moreover, all subjects included in this study completed extensive questionnaires to evaluate their health-related quality of life (HRQOL), and others related to health-related physical activity performed before (PRE) and after (POST) the diagnosis of disease. The linear regression analysis has shown that either a high Sport_index or Leisure_index in the PRE-diagnostic period was correlated with lower disease duration in dcSSc patients. Physical load during sport activity and leisure time accounted for ~61.1% and ~52.6% of the individual variation in disease duration, respectively. In lcSSc patients, a high PRE value related to physical load during sporting activities was correlated with a low pulmonary artery systolic pressure (sPAP) and the POST value of the Work_index was positively correlated with the left ventricular ejection fraction (LVEF), and negatively with creatine kinase levels (CK). Interestingly, the univariate analysis showed that Work_index accounts for ~29.4% of the variance in LVEF. Our analysis clearly reinforces the concept that high levels of physical load may play a role in primary prevention-delaying the onset of the disease in those subjects with a family history of SSc-as well as in secondary prevention, improving SSc management through a positive impact on different clinical parameters of the disease. However, it remains a priority to identify a customized physical load in order to minimize the possible negative effects of PA.

[Cardiopulmonary exercise testing in the management of systemic sclerosis]

Cardiopulmonary complications are the leading cause of mortality in patients with systemic sclerosis (SSc) requiring an early identification. The complexity of the overlapping aetiologies of dyspnoea in SSc often requires a global and comprehensive approach. Through its integrative approach of ventilatory, metabolic, cardiovascular, skeletal muscular and gas exchange findings, cardiopulmonary exercise testing (CPET) has been known to identify and sort competing mechanisms of exercise limitation in scleroderma patients presenting with dyspnoea. CPET may be used to screen for pulmonary arterial hypertension, suspect interstitial lung disease and guide therapeutic strategies including exercise rehabilitation. This review focuses on the clinical value of CPET in the decision-making processes for a more personalised diagnostic approach to SSc-related complications.

High prevalence of occult left ventricular diastolic dysfunction detected by exercise stress test in systemic sclerosis

Despite the poor prognosis of systemic sclerosis (SSc) due to the co-occurrence of left ventricular diastolic dysfunction (LVDD), presence of occult LVDD has not been sufficiently investigated. This retrospective study aimed to reveal the prevalence and determinants of occult LVDD in patients with SSc by exercise stress test. Forty-five SSc patients (age, 63 ± 13 years; men/women, 6/39) with normal pulmonary artery pressure and pulmonary artery wedge pressure (PAWP) at rest underwent a symptom-limited exercise test with right heart catheterization using a supine cycle ergometer; haemodynamic parameters at rest, leg raise and during exercise were evaluated. Occult LVDD defined PAWP ≥ 25 mmHg during exercise was seen in 13 patients (29%). Higher PAWP, lower pulmonary vascular resistance and diastolic pulmonary pressure gradient, larger left atrium at rest, and higher PAWP during leg raise (15 ± 4 vs 10 ± 4 mmHg in non-LVDD group, p < 0.001) were observed in the occult LVDD group. The area under the ROC curve for PAWP after leg raise was largest at 0.83 (95% CI: 0.70–0.95, p = 0.001). About one-third (29%) of SSc patients with normal haemodynamics at rest showed occult LVDD. A higher PAWP after leg raise could be useful for detecting occult LVDD.

Cardiopulmonary exercise testing in interstitial lung diseases and the value of ventilatory efficiency

Interstitial lung diseases (ILDs) are diverse parenchymal pulmonary disorders, primarily characterised by alveolar and interstitial inflammation and/or fibrosis, and sharing pathophysiological similarities. Thus, patients generally harbour common respiratory symptoms, lung function abnormalities and modified exercise adaptation. The most usual and disabling complaint is exertional dyspnoea, frequently responsible for premature exercise interruption. Cardiopulmonary exercise testing (CPET) is increasingly used for the clinical assessment of patients with ILD. This is because exercise performance or dyspnoea on exertion cannot reliably be predicted by resting pulmonary function tests. CPET, therefore, provides an accurate evaluation of functional capacity on an individual basis. CPET can unmask anomalies in the integrated functions of the respiratory, cardiovascular, metabolic, peripheral muscle and neurosensory systems in ILDs. CPET uniquely provides an evaluation of all above aspects and can help clinicians shape ILD patient management. Preliminary evidence suggests that CPET may also generate valuable prognostic information in ILDs and can be used to shed light on the presence of associated pulmonary hypertension. This review aims to provide comprehensive and updated evidence concerning the clinical utility of CPET in ILD patients, with particular focus on the physiological and clinical value of ventilatory efficiency (V˙_E/V˙_CO2 ).

Systemic vascular distensibility relates to exercise capacity in connective tissue disease

OBJECTIVE

Exercise intolerance is a common clinical manifestation of CTD. Frequently, CTD patients have associated cardio-pulmonary disease, including pulmonary hypertension or heart failure that impairs aerobic exercise capacity (pVO2). The contribution of the systemic micro-vasculature to reduced exercise capacity in CTD patients without cardiopulmonary disease has not been fully described. In this study, we sought to examine the role of systemic vascular distensibility, α in reducing exercise capacity (i.e. pVO2) in CTD patients.

METHODS

Systemic and pulmonary vascular distensibility, α (%/mmHg) was determined from multipoint systemic pressure-flow plots during invasive cardiopulmonary exercise testing with pulmonary and radial arterial catheters in place in 42 CTD patients without cardiopulmonary disease and compared with 24 age and gender matched normal controls.

RESULTS

During exercise, systemic vascular distensibility, α was reduced in CTD patients compared with controls (0.20 ± 0.12%/mmHg vs 0.30 ± 0.13%/mmHg, P =0.01). The reduced systemic vascular distensibility α, was associated with impaired stroke volume augmentation. On multivariate analysis, systemic vascular distensibility, α was associated with a decreased exercise capacity (pVO2) and decreased systemic oxygen extraction.

CONCLUSION

Systemic vascular distensibility, α is associated with impaired systemic oxygen extraction and decreased aerobic capacity in patients with CTD without cardiopulmonary disease.

Cardiopulmonary exercise testing and prognosis in patients with systemic sclerosis without baseline pulmonary hypertension: a prospective cohort study

Cardiopulmonary Exercise Testing (CPET) is a standardized, non-invasive procedure assessing pulmonary, cardiovascular, hematopoietic, and skeletal muscle functions during a symptom-limited test. Few studies have examined whether CPET is of prognostic value in Systemic Sclerosis (SSc), a disease characterized by highly increased cardiorespiratory morbidity and mortality. To examine the prognostic value of CPET in SSc patients without baseline pulmonary hypertension (PH). Sixty-two consecutive SSc patients underwent CPET, Pulmonary Function Tests (PFTs) and echocardiography at baseline. Four patients with Right Ventricular Systolic Pressure ≥ 40 mmHg, were excluded. Participants repeated PFTs approximately every 3 years. At the end of the follow-up period [median (IQR): 9.79 (2.78) years] patient vital status was recorded. Cox Regression analysis was used to identify predictors of deterioration of PFTs and 10-year survival. Median (IQR) age of 58 patients (90% women) at baseline was 54.0 (15.0) years, whereas 10-year survival was 88%. Baseline respiratory Oxygen uptake (VO₂max) predicted PFT deterioration, defined either as a decline in FVC ≥ 10% or a combined decline in FVC 5%-9% plus DLCO ≥ 15%, during follow-up, after correction for age, gender and smoking status (HR: 0.874, 95%CI: 0.779-0.979, p = 0.021). In addition, lower baseline VO₂max (HR = 0.861, 95%CI:0.739-1.003, p = 0.054) and DLCO (HR = 0.957, 95%CI: 0.910-1.006 p = 0.088), as well as male gender (HR = 5.68, 95%CI: 1.090-29.610 p = 0.039) and older age (HR = 1.069, 95%CI: 0.990-1.154, p = 0.086) were associated, after adjustment, with an increased risk for death. In the absence of baseline PH, CPET indices may predict pulmonary function deterioration and death in SSc patients during a nearly 10-year follow-up period.

Effect of a tailored home-based exercise program in patients with systemic sclerosis: A randomized controlled trial

OBJECTIVE

The aim was to evaluate the effect of a home-based exercise program on functional capacity, health-related quality of life (HRQoL), and disability, in patients with systemic sclerosis (SSc).

METHODS

A 6-month randomized controlled trial was conducted on SSc patients by comparing a home-based minimally supervised exercise program (exercise on a stationary cycle and strengthening of upper limbs; stretching of the hands) with usual care. At baseline and after 3 and 6 months, the patients underwent: 6 minutes walking test; hand mobility in scleroderma test; maximal exercise test on an ergocycle; strength measures (handgrip, quadriceps, and biceps). HRQoL (short-form 36 [SF-36]) and disability (health assessment questionnaire disability index [HAQ-DI]) were measured at the same time.

RESULTS

Forty-four patients participated in the study. Twenty-two were randomly assigned to the intervention group (IG, mean age 63.60 ± 10.40 years) and 22 to the control group (CG, 61.80 ± 14.40 years). At 6 months, the distance walked in 6 minutes increased by 46 m (baseline 486, 95% CI 458-513 m; 6 months 532, 95% CI 504-561 m) in IG, whereas it decreased by 5 m (baseline 464, 95% CI 431-497 m; 6 months 459, 95% CI 427-490 m) in CG with a significantly different temporal trend at the between-groups comparison (P < .001). An improvement was also observed for strength measures (handgrip, P = .003; quadriceps, P < .001; biceps, P < .001), for the SF-36 physical component score (P < .001) and for the HAQ-DI (P = .011).

CONCLUSIONS

This study indicates that in SSc patients, a minimally supervised home-based exercise program improves physical performance, quality of life, and disability in comparison with usual care.

Exercise capacity and clinical outcomes in adults followed in the Cooperative Study of Sickle Cell Disease (CSSCD)

OBJECTIVES

To determine the factors associated with exercise capacity in adults with sickle cell disease (SCD) and its relationship to hospitalizations and mortality.

METHODS

A total of 223 participants in the Cooperative Study of Sickle Cell Disease (CSSCD) (64% female, 70% hemoglobin SS/Sβ⁰ thalassemia, mean age 43.3 ± 7.5 years) underwent maximal exercise testing using a treadmill protocol with a mean duration of 11.6 ± 5.2 minutes.

RESULTS

Female sex (β = -3.34, 95% CI [-1.80, -4.88], P < 0.001), older age (β = -0.14, 95% CI [-0.24, -0.04], P = 0.005), higher body mass index (β = -0.23, 95% CI [-0.37, -0.10]; P = 0.001), and lower hemoglobin (β = 0.56, 95% CI [0.08, 1.04], P = 0.02) were independently associated with lower fitness, while there was a trend with abnormal pulmonary function testing (β = -1.42, 95% CI [-2.92, 0.07]; P = 0.06). Lower percent-predicted forced expiratory volume in 1 second (FEV₁ ) was independently associated with lower fitness (β = 0.08, 95% CI [0.03, 0.13], P = 0.001). Genotype and hospitalization rates for pain and acute chest syndrome (ACS) prior to testing were not associated with exercise capacity. Baseline exercise capacity predicted neither future pain or ACS nor survival in our cohort. Adults with SCD tolerated maximal exercise testing.

CONCLUSIONS

Prospective studies are needed to further evaluate the impact of regular exercise and improved fitness on clinical outcomes and mortality in SCD.