Associations between cardiac and pulmonary involvement in patients with juvenile dermatomyositis—a cross-sectional study

This study aimed at exploring the association between detectable cardiac and pulmonary involvement in long-term juvenile dermatomyositis (JDM) and to assess if patients with cardiac and pulmonary involvement differ with regard to clinical characteristics. 57 JDM patients were examined mean 17.3 (10.5) years after disease onset; this included clinical examination, myositis specific/associated autoantibodies (immunoblot), echocardiography, pulmonary function tests and high-resolution computed tomography. Cardiac involvement was defined as diastolic and/or systolic left ventricular dysfunction and pulmonary involvement as low diffusing capacity for carbon monoxide, low total lung capacity and/or high-resolution computed tomography abnormalities. Patients were stratified into the following four groups: (i) no organ involvement, (ii) pulmonary only, (iii) cardiac only, and (iv) co-existing pulmonary and cardiac involvement. Mean age was 25.7 (12.4) years and 37% were males. One patient had coronary artery disease, seven had a history of pericarditis, seven had hypertension and three had known interstitial lung disease prior to follow-up. There was no association between cardiac (10/57;18%) and pulmonary (41/57;72%) involvement (p = 0.83). After stratifying by organ involvement, 21% of patients had no organ involvement; 61% had pulmonary involvement only; 7% had cardiac involvement only and 11% had co-existing pulmonary or cardiac involvement. Patients with co-existing pulmonary or cardiac involvement had higher disease burden than the remaining patients. Patients with either cardiac or pulmonary involvement only, differed in clinical and autoantibody characteristics. We found no increased risk of developing concomitant cardiac/pulmonary involvement in JDM. Our results shed light upon possible different underlying mechanisms behind pulmonary and cardiac involvement in JDM.