Submaximal Exercise Capacity in Juvenile Dermatomyositis after Longterm Disease: The Contribution of Muscle, Lung, and Heart Involvement

Cardiac evaluation of patients with juvenile dermatomyositis

BACKGROUND

The present study aims to evaluate possible cardiac involvement in juvenile dermatomyositis (JDM) patients by conventional methods and cardiac magnetic resonance imaging (MRI) along with a systematic review of the literature on cardiac features in JDM.

METHODS

The study group consisted of JDM patients who underwent cardiac MRI. We conducted a systematic review of the published literature involving JDM patients with cardiac involvement.

RESULTS

In the present study, although baseline cardiologic evaluations including electrocardiography and echocardiography were within normal limits, we showed late gadolinium enhancement on cardiac MRI in 3 of 11 JDM patients. In the literature review, we identified 25 articles related to cardiac involvement in JDM. However, none of them, except one case report, included cardiac MRI of JDM patients.

CONCLUSION

Cardiac abnormalities have been reported among the less frequent findings in patients with JDM. Cardiovascular complications during the long-term disease course are a leading cause of morbidity and mortality in these patients. Early detection of cardiac involvement by cardiac MRI in patients with JDM and aggressive treatment of them may improve the clinical course of these patients.

IMPACT

The myocardium in patients with JDM may be involved by inflammation. Myocardial involvement may be evaluated by using contrast-enhanced cardiac MRI. This is the first study evaluating cardiac involvement by cardiac MRI in JDM patients. MRI may show early cardiac involvement in patients whose baseline cardiologic evaluations are within normal limits. Early detection of cardiac involvement by cardiac MRI may improve the long-term prognosis of patients with JDM.

Feasibility of the wingate anaerobic exercise test as a clinical measure in patients with juvenile dermatomyositis

BACKGROUND

Core sets, while widely adopted for clinical assessment in juvenile dermatomyositis (JDM), have some drawbacks - they are time consuming, were developed primarily for research, and require an experienced multidisciplinary team. We propose the Wingate Anaerobic Test, a 30-s all out test performed on a cycle ergometer, as a potential alternative; it is valid and reliable in this patient population. We aimed to determine the feasibility of performing the Wingate test as part of a typical clinic visit, and to determine if it is correlated to current measures of disease activity.

METHODS

Patients 5-18 years of age, with JDM, were recruited from the JDM clinic at a large Canadian academic children's hospital. Participants underwent a standard clinic assessment, then completed a Wingate test at the end of the visit.

RESULTS

Twenty-six patients participated in the study, representing a recruitment rate of 81%; of those, 88% were able to complete the Wingate test. Patients liked the Wingate test and felt it should be included as a regular clinic test. Absolute peak power (watts) on the Wingate test was strongly correlated to the manual muscle test (MMT-8) and the timed squat test. Relative peak power (watts/kg) on the Wingate test was strongly correlated to the timed squat test and the Childhood Myositis Assessment Scale (CMAS). Exploratory principal components analysis revealed that Wingate relative average power explained almost 2/3 of the variance of the CMAS, MMT and timed squats combined.

CONCLUSION

The Wingate test is a feasible test for children with JDM and correlates well with standard clinical assessments. Given its brevity, it has the potential to replace more standard measures of physical function currently used in clinical assessments for children with JDM. Future work should focus on how best to operationalize Wingate testing in clinic without the use of dedicated personnel.

Cardiovascular Health in Pediatric Rheumatologic Diseases

Cardiovascular disease risk is evident during childhood for patients with juvenile systemic lupus erythematosus, juvenile dermatomyositis, and juvenile idiopathic arthritis. The American Heart Association defines cardiovascular health as a positive health construct reflecting the sum of protective factors against cardiovascular disease. Disease-related factors such as chronic inflammation and endothelial dysfunction increase cardiovascular disease risk directly and through bidirectional relationships with poor cardiovascular health factors. Pharmacologic and nonpharmacologic interventions to improve cardiovascular health and long-term cardiovascular outcomes in children with rheumatic disease are needed.

Home-based exercise program for adolescents with juvenile dermatomyositis quarantined during COVID-19 pandemic: a mixed methods study

BACKGROUND

Exercise has been suggested to prevent deterioration of health-related quality of life (HRQL) and overall health in pediatric rheumatologic diseases during the COVID-19 pandemic. Herein we describe the effects of a 12-week, home-based, exercise program on overall health and quality of life among quarantined patients with juvenile dermatomyositis (JDM).

METHOD

This prospective, quasi-experimental, mixed methods (qualitative and quantitative) study was conducted between July and December 2020, during the most restricted period of COVID-19 pandemic in Brazil. The home-based exercise program consisted of a 12-week, three-times-a-week, aerobic and strengthening (bodyweight) training program. Qualitative data were systematically evaluated. Strengths and Difficulties Questionnaire (SDQ), Pediatric Quality of Life Inventory (PedsQOL) and Pittsburgh Sleep Quality Index (PSQI) evaluate symptoms of mental health disorder, HRQL, and quality of sleep.

FINDINGS

11 patients (out of 27) met the inclusion criteria (91% female; mean ± SD age: 13.5 ± 3.2 years). Adherence to the intervention was 72.6%. Barriers to exercise involved poor internet connectivity, excessive weekly sessions, and other commitments. Even though not statistically significant, Self-report SDQ subscales Total Difficulties Score, Emotional Problems Score, and PedsQOL School Functioning Score improved after intervention (- 2.4; 95%confidence interval [CI] -5.1; 0.2, p = 0.06; - 1.0; 95%CI -2.2; 0.2, p = 0.09 and; 11.7; 95%CI -2.5; 25.8, p = 0.09, respectively). Remaining SDQ subscales were not altered. Six themes emerged from patients' and parents' comments (qualitative results). Patients engaged in exercise reported other health-related benefits including increased motivation, concentration and strength.

INTERPRETATION

A home-based exercise program was associated with qualitative perceptions of improvements in overall health and HRQL by quarantined adolescents with JDM during COVID-19 pandemic. Lessons from this trial may help developing interventions focused on tackling physical inactivity in JDM.

Updates on Juvenile Dermatomyositis from the Last Decade: Classification to Outcomes

Juvenile dermatomyositis (JDM) is a heterogeneous disease with new classification criteria and updates in myositis-specific autoantibody and myositis-associated antibody groups. There are many validated assessment tools for assessing disease activity in JDM. Future studies will optimize these tools and improve feasibility in clinical and research contexts. Genetic and environmental risk factors, mechanisms of muscle pathology, role of interferon, vascular markers, and changes in immune cells provide insights to JDM pathogenesis. Outcomes have improved, but chronic disease, damage, and mortality highlight the need for better outcome predictors and treatments. Increased collaboration of stakeholders may help overcome research barriers and improve JDM treatment.

Identification and prediction of novel classes of long-term disease trajectories for patients with juvenile dermatomyositis using growth mixture models

Objectives

Uncertainty around clinical heterogeneity and outcomes for patients with JDM represents a major burden of disease and a challenge for clinical management. We sought to identify novel classes of patients having similar temporal patterns in disease activity and relate them to baseline clinical features.

Methods

Data were obtained for n = 519 patients, including baseline demographic and clinical features, baseline and follow-up records of physician’s global assessment of disease (PGA), and skin disease activity (modified DAS). Growth mixture models (GMMs) were fitted to identify classes of patients with similar trajectories of these variables. Baseline predictors of class membership were identified using Lasso regression.

Results

GMM analysis of PGA identified two classes of patients. Patients in class 1 (89%) tended to improve, while patients in class 2 (11%) had more persistent disease. Lasso regression identified abnormal respiration, lipodystrophy and time since diagnosis as baseline predictors of class 2 membership, with estimated odds ratios, controlling for the other two variables, of 1.91 for presence of abnormal respiration, 1.92 for lipodystrophy and 1.32 for time since diagnosis. GMM analysis of modified DAS identified three classes of patients. Patients in classes 1 (16%) and 2 (12%) had higher levels of modified DAS at diagnosis that improved or remained high, respectively. Patients in class 3 (72%) began with lower DAS levels that improved more quickly. Higher proportions of patients in PGA class 2 were in DAS class 2 (19%, compared with 16 and 10%).

Conclusion

GMM analysis identified novel JDM phenotypes based on longitudinal PGA and modified DAS.

Long-term outcome in patients with juvenile dermatomyositis: A case series

BACKGROUND

Follow-up of juvenile dermatomyositis (JDM) patients has demonstrated the impact of the disease on several organs in the long term.

OBJECTIVE

As there is little information on the long-term outcome of JDM, we aimed to assess long-term outcomes in a series of JDM patients.

METHODS

After selection of JDM patients, a consultation with a dermatologist and a rheumatologist was held for each patient. Cutaneous, muscle, and disease damage was assessed using different validated scores including the abbreviated Cutaneous Assessment Tool (aCAT), 8-muscle Manual Muscle Testing (MMT8), Childhood Myositis Assessment Scale (CMAS), Myositis Damage Index (MDI), Childhood Health Assessment Questionnaire (CHAQ), and Health Assessment Questionnaire (HAQ). Long-term disease outcomes were recorded including growth and pubertal development, educational and vocational achievement, and development of comorbidities.

RESULTS

Seven patients were included in the study. After a mean follow-up of 14.9±8.8 years, the mean aCAT score was 0.57±1.4 and only one patient had a positive aCAT activity score. The mean aCAT damage score was 1.4±1.3 and five (71%) patients had a score of ≥1. Five (71.4%) patients had normal muscle strength with an MMT8 score of >72, and none had severe muscle weakness (MMT8 ≤32, and CMAS<35). The mean total extent of damage according to the MDI was ≥1 in five (71%) patients and mainly involved the skin. Two (29%) patients had mild disability according to the CHAQ/HAQ disability index. In terms of quality of life, no patient had a score of<40 (1 SD below the mean for healthy controls).

CONCLUSIONS

Based on validated cutaneous and musculoskeletal scores, our study demonstrated the good functional outcomes of JDM at long-term follow-up.

Myostatin and markers of bone metabolism in dermatomyositis

Background

In dermatomyostis (DM) patients, inflammation, reduced activity, and medication have a negative impact on the musculoskeletal system. Several endocrine factors are involved in muscle growth and bone turnover.

Objective: We aimed to investigate factors regulating myogenesis and bone metabolism and to evaluate possible associations between these endocrine factors, muscle strength, and functional tests in DM patients.

Methods

We conducted a cross-sectional study in 20 dermatomyositis patients. Serum levels of myostatin (MSTN), follistatin (FSTN), dickkopf 1 (Dkk1), sclerostin (SOST), periostin (PSTN), the receptor activator nuclear factor kB ligand (RANKL):osteoprotegerin (OPG) ratio and fibroblast growth factor 23 (FGF23) were determined. Physical function was evaluated by hand-held strength measurement, chair rising test, timed up and go test and the 3-min walking test.

Results

Serum MSTN and FGF23 levels (2.5 [1.9; 3.2] vs. 1.9 [1.6; 2.3] and 2.17 [1.45; 3.26] vs. 1.28 [0.79; 1.96], respectively; p <  0.05) were significantly higher in DM patients than in controls. Dkk1 was significantly lower (11.4 [6.9; 20.0] vs. 31.8 [14.3; 50.6], p <  0.01). Muscle strength and physical function tests correlated with each other (e.g. hip flexion – timed up and go test: r = − 0.748, p < 0.01).

Conclusion

In DM patients, biochemical musculo-skeletal markers are altered and physical function shows deficits. All these tests reflect independent of each other different deficits in long-term DM patients which is important for the assessment of DM patients as well as planning of therapeutic interventions in clinical routine.

The aerobic capacity in patients with antisynthetase syndrome and dermatomyositis

BACKGROUND

This study was aimed at evaluating the aerobic capacity of patients with antisynthetase syndrome (ASS) and dermatomyositis (DM) and analyzing possible relationships between aerobic capacity and disease status, cardiovascular diseases and their risk factors.

METHODS

The study was a cross-sectional, single-center study that assessed the aerobic capacity of 22 women (13 with DM and 9 with ASS) who were matched by age and body mass index to 17 healthy women (control group). The aerobic capacity (oxygen uptake [VO₂ peak], anaerobic threshold, respiratory compensation point and time-to-exhaustion) was evaluated using the cardiopulmonary treadmill test. Disease status was assessed using International Myositis Assessment & Clinical Studies Group (IMACS) set scores.

RESULTS

The patients had low IMACS parameters that showed low or absent disease activity. The distribution of cardiovascular diseases and their risk factors was similar between the patients and the control group (P >  0.05) at the time of the analysis. The patients with DM and the control group had similar aerobic capacity. However, the patients with ASS exhibited significantly reduced aerobic capacity (relative VO₂ peak, anaerobic threshold, respiratory compensation point and time to exhaustion) when compared to the control group. In addition, patients with ASS had a lower anaerobic threshold compared to the DM group. There were no significant relationships between the aerobic capacity and disease status, cardiovascular diseases and their risk factors.

CONCLUSION

In contrast to DM patients and healthy individuals, patients with stable ASS have significantly impaired aerobic capacity, which is unlikely to be totally explained by traditional cardiovascular diseases, their risk factors and disease status. Further studies are needed to corroborate our data and to clarify the cause of this reduced aerobic capacity in ASS.

Cardiorespiratory fitness in long-term juvenile dermatomyositis: a controlled, cross-sectional study of active/inactive disease

OBJECTIVES

To compare cardiorespiratory fitness (CRF) expressed as maximal oxygen uptake (VO2max) between patients with long-term JDM and controls and between patients with active and inactive disease, as well as to explore exercise limiting factors and associations between CRF and disease variables.

METHODS

JDM patients (n = 45) and age- and gender-matched controls (n = 45) performed a cardiopulmonary exercise test (CPET) on a treadmill until exhaustion. Physical activity was measured by accelerometers. Disease activity, damage and muscle strength/function were assessed by validated tools. Clinically inactive disease was defined according to PRINTO criteria.

RESULTS

The mean disease duration was 20.8 (s.d. 11.9) years and 29/45 (64%) patients had inactive disease. A low VO2max was found in 27% of patients vs 4% of controls (P = 0.006). The mean VO2max and maximal ventilation (VEmax) were lower in patients with active and inactive disease compared with controls. Patients with active disease also had lower maximal voluntary ventilation (MVV) compared with controls and lower VEmax and MVV compared with those with inactive disease. Patients with inactive disease had lower physical activity levels compared with controls. VO2max correlated negatively with disease damage in patients with inactive disease and positively with muscle strength/function in patients with active disease.

CONCLUSION

CRF was lower in JDM patients, both with active and inactive disease, compared with controls after a mean 20 years disease duration. Cardiopulmonary exercise test results suggested different limiting factors contributing to the reduced CRF according to disease activity, including deconditioning in inactive disease and reduced ventilatory capacity in active disease. Further research is needed to verify this.

Cardiovascular involvement in myositis

PURPOSE OF REVIEW

The purpose of this review is to provide an update on cardiovascular involvement in idiopathic inflammatory myopathy (IIM). Studies from the past 18 months are identified and reviewed. Finally, the clinical impact of these findings is discussed.

RECENT FINDINGS

Epidemiological studies have revealed an increased risk of myocardial infraction and venous thromboembolism (VTE) - including deep venous thrombosis and pulmonary embolism - in adults with polymyositis or dermatomyositis compared to the general population, even after adjustment for potential confounders. This increased risk applies particularly within the initial year of diagnosis. In addition, cross-sectional studies have shown subclinical cardiac involvement in IIM effecting both heart function and rhythm, and conduction abnormalities, which in part might be because of myocarditis. The International Consensus Group on cardiac magnetic resonance (CMR) imaging suggests that CMR should be considered as a potentially viable diagnostic tool to evaluate the possibility of silent myocardial inflammation in IIM with normal routine noninvasive evaluation.

SUMMARY

Updated literature on cardiovascular involvement in IIM has identified an increased risk for subclinical and clinical cardiovascular disease in these rare inflammatory muscle diseases.