Echocardiographic study of juvenile dermatomyositis patients: new insights from speckle-tracking-derived strain.

OBJECTIVES: This study aimed to investigate subclinical left ventricle (LV) systolic dysfunction in juvenile dermatomyositis (JDM) using two-dimensional speckle-tracking echocardiography (2DST). Possible associations between LV deformation impairment and disease activity/cumulative damage were also evaluated.
METHODS: Thirty-five consecutive JDM patients without cardiac symptoms and 35 healthy volunteers were enrolled. Clinical data were collected from medical records, and echocardiograms were performed by a pediatric cardiologist, unaware of patients' conditions.
RESULTS: Patients and controls had similar age (12.6 ± 0.7 vs.12.5 ± 0.6; p = 0.97) and gender (11F:24M vs.11F:24M; p = 1.0). Median of JDM duration was 4.6 (0.04-17.6) years, and only 6/35 (17%) had active disease (disease activity score (DAS > 3)). Conventional echocardiogram revealed preserved LV ejection fraction (EF) (≥ 55%) in all individuals. In JDM, 2DST identified reduction of LV longitudinal [-22(-17.2 to -27.9) % vs. -23(-20.8 to -27.4) %; p = 0.028)] and circumferential -23.9 ± 2.8% vs. -26.7 ± 2.9%; p = 0.0002) strain. Lower longitudinal strain was associated with DAS >3 -19.9(-17.2 to -26.5)% vs. -22.1-18.9 to -27.9)%; p = 0.046], MDI extent > 0 [-19(-17.2 to -22.5)% vs. -22.1-19.2 to -27.9)%; p = 0.0008], MDI severity > 0 [-19(-17.2 to -22.1)% vs. -22.3(-20.3 to -27.9)%; p = 0.0001] and calcinosis[-20.6(-17.2 to -23)% vs. -22.3(-20.3 to -27.9)%; p = 0.03]. Lower circumferential strain was associated with MDI extent > 0 (-22.1 ± 3.87% vs. -24.4 ± 2.3%; p = 0.039), MDI severity > 0 (-21.7 ± 3% vs. 24.7 ± 2.3%; p = 0.004) and calcinosis (-22.5 ± 3.3% vs. -24.8 ± 2.1%; p = 0.02). There was a negative correlation between longitudinal strain and cumulative dose of prednisone (r = -0.44; p = 0.009) and methotrexate (r = -0.33; p = 0.0008).
CONCLUSIONS: LV 2DST detected early systolic myocardial compromise in asymptomatic pediatric JDM patients, with preserved EF. Longitudinal strain impairment was associated with disease activity and cumulative damage, whereas circumferential strain impairment was associated exclusively with cumulative damage. KEY POINTS: • Serious cardiac involvement is rare but has been associated with death in juvenile dermatomyositis. • Two-dimensional speckle tracking stands out for the identification of subclinical myocardial compromise in juvenile dermatomyositis. • Longitudinal strain impairment is associated with disease activity and cumulative damage, whereas circumferential strain impairment is associated exclusively with cumulative damage.