Pulmonary arterial hypertension, a novelty in idiopathic inflammatory myopathies: insights and first experiences with vasoactive therapy

To characterise the different types of pulmonary hypertension (PH) among idiopathic inflammatory myopathy (IIM). A retrospective case series with assessment of PH by right heart catheterisation, extent of interstitial lung disease (ILD) and outcome of vasoactive therapy.The group of patients with IIM with PH (n=9) showed a median age at PH diagnosis of 62 years (IQR 48–71 years; eight women), seven diagnosed with polymyositis and two with dermatomyositis; median disease duration of 5.7 years and five patients with a positive anti-Jo1 antibody. We found one patient to be classified in PH WHO group 2 (left heart disease), five patients in WHO group 3 (lung disease) and three patients in WHO group 1 (pulmonary arterial hypertension (PAH)). During median observed follow-up of 24 months, mortality for the total group was 44%. Surprisingly, we found a relevant group (33%) of patients with IIM who suffered from non-ILD-PH, which reflects the presence of PAH phenotype. This result should lead to more awareness among treating physicians that complaints of dyspnoea among patient with IIM could be related to PAH and not only ILD. The role of vasoactive therapy remains to be defined in patients with IIM suffering from PAH or PH-ILD.