Evaluation of Myocarditis in Patients With Still Disease: Clinical Findings From the Multicenter International AIDA Network Still Disease Registry

Objective. We aimed to (1) evaluate the cardiac involvement, with a focus on myocarditis, in patients with Still disease included in the multicenter Autoinflammatory Disease Alliance (AIDA) Network Still disease registry; and (2) assess the predictive factors for myocarditis by deriving a clinical risk patient profile for this severe manifestation. Methods. A multicenter observational study was established, in which consecutive patients with Still disease in the AIDA Network Still disease registry were characterized by cardiac involvement. Cardiac involvement was defined according to the presence of pericarditis, tamponade, myocarditis, and/or aseptic endocarditis. Results. In total, 73 patients with Still disease and cardiac involvement were assessed (mean age 36.3 [SD 19.9] years; male sex, 42.5%), out of which 21.9% were children. The most common cardiac manifestation was pericarditis, occurring in 90.4% of patients; patients also presented with myocarditis (26%), and less frequently endocarditis (2.7%) and tamponade (1.4%). In comparing clinical features of patients with myocarditis to those without, significantly increased frequencies of skin rash and pleuritis, as well as higher systemic scores, were seen. Further, a higher mortality rate was shown in patients with myocarditis. In regression models, skin rash and the systemic score independently predicted the myocarditis. Conclusion. The characteristics of patients with Still disease and cardiac involvement were assessed in the AIDA Network. The most common feature was the pericarditis, but a more severe clinical picture was also reported in patients with myocarditis. The latter was associated with increased mortality rate and higher systemic score, identifying patients who should be carefully managed.