Polymyositis/dermatomyositis is a potential risk factor for acute respiratory failure: a pulmonary heart disease

Background: Studies on the association between polymyositis/dermatomyositis (PM/DM) and acute respiratory failure (ARF) are considerably limited. We investigated whether ARF is associated with PM/DM using a nationwide cohort study. Methods: We identified 1,374 patients with newly diagnosed PM/DM and 13,740 comparison individuals without PM/DM (non-PM/DM) randomly selected from the general population; frequency matched by age, sex, and index year using the National Health Insurance Research Database; and followed up until the end of 2011 to measure the incidence of ARF. Cox proportional hazards regression analysis was used to measure the hazard ratio (HR) of ARF for the PM/DM cohort in comparison with the non-PM/DM cohort. Results: The adjusted HR of ARF was 5.05 for the PM/DM cohort compared with the non-PM/DM cohort after adjusting for sex, age, comorbidities, Charlson comorbidity index (CCI) score and medicine. The risk of ARF significantly increased irrespective of age, sex, comorbidities and medicine. Meanwhile, the PM/DM cohort with comorbidities, such as cardiac disease (hypertension), pulmonary disease (chronic obstructive pulmonary disease and pneumonia), and pulmonary vascular diseases had additive effects on the incident ARF. Conclusions: This study determined the cross-reaction of pulmonary heart disease in the PM/DM cohort with incident ARF even without comorbidities.