Adult onset polymyositis/dermatomyositis: An analysis of clinical and laboratory features and survival in 76 patients with a review of the literature☆

The interplay between dysphagia, cancer, and mortality in idiopathic inflammatory myopathies (IIM) has not been carefully studied. The aim of this study was to investigate possible effect modification of cancer on the association between dysphagia and mortality in early IIM.

A multi-center cohort of 230 adult IIM patients with dysphagia assessment within 6 months of disease onset was assembled. Crude mortality rates in IIM patients exposed or not to dysphagia were estimated for the 5-year period following cohort entry. To explore possible effect modification of cancer on the association between dysphagia and mortality, adjusted Cox models stratified on cancer status were performed as well as an interaction model.

Mortality rates per 100 person-years for IIM patients exposed to dysphagia were 2.3 (95 %CI 1.0 to 4.5) in those without cancer compared to 33.3 (95 %CI 16.6 to 59.5) in those with cancer. In stratified Cox models, the main effect of dysphagia was HR 0.5 (95 %CI 0.2 to 1.5) in non-cancer and 3.1 (95 %CI 1.0 to 10.2) in cancer patients. In the interaction model, the combination of dysphagia and cancer yielded a HR of 6.4 (1.2 to 35.1).

In this IIM cohort, dysphagia in non-cancer patients was not associated with increased mortality, while it was in presence of cancer, supporting effect modification of cancer on the association between dysphagia and mortality. This suggests that IIM patients with and without cancer differ and separate analyses for the two groups should be conducted when the outcome of interest is mortality.

Cardiac involvement has been well recognized in patients with dermatomyositis (DM) and polymyositis (PM) with a variable frequency between 9 and 72%. However, clinically significant heart involvement in DM/PM is relatively infrequent and there have been rare reports of cardiac transplantation in DM. Our aims were to describe a case of severe cardiac involvement in DM requiring heart transplantation and review the literature of cardiac disease in DM and PM.

A patient with dermatomyositis who was referred to our institution with severe heart failure is described. Pathology of the patient's skeletal and cardiac muscle is reviewed. A MEDLINE database search of reports of cardiac involvement in DM and PM was also conducted.

A 36 year-old man with DM presented with severe heart failure to our institution for evaluation of heart transplantation. After a three month hospitalization he underwent successful cardiac transplantation. Pathological examination of his explant heart revealed a pattern of inflammation and damage similar to DM in skeletal muscle. The patient is currently doing well, 20 months post-transplant, and is maintained on tacrolimus, cellcept, rituximab, and low dose prednisone. To our knowledge, this is the first case report of heart transplantation in dermatomyositis in which the muscle pathology is similar in both heart and skeletal muscle.

Severe cardiac involvement requiring transplantation is rare in dermatomyositis but does occur and appears to be related to a similar inflammatory process as noted in the skeletal muscle.