Ventricular arrhythmia predicts poor outcome in polymyositis/dermatomyositis with myocardial involvement
Abstract Objective Myocardial involvement (MCI) is known to increase morbidity and mortality in polymyositis (PM) and dermatomyositis (DM). This study aims to investigate whether complicating with ventricular arrhythmia (VA) predicts poor outcomes in patients with PM/DM-related myocardial involvement (PM/DM-MCI). Methods We reviewed all PM/DM-MCI patients admitted in Peking Union Medical College Hospital from October 1997 to April 2019. VA and the other possible risk factors for the composite end point, including death from any cause and rehospitalization for cardiac causes, were analysed. Results A total of 75 PM/DM-MCI patients (44 PM and 31 DM) were enrolled, of which 27 (36%) met the composite end point during a median follow-up of 24 months. Independent prognostic factors for the composite end point includes VA (HR 4.215, 95% CI [1.737, 10.230]), NT-proBNP > 3415 pg/ml (HR 2.606, 95% CI [1.203, 5.646]), interstitial lung disease (HR 2.688, 95% CI [1.209, 5.978]), and anti-cardiac remodelling therapy (HR 0.302, 95% CI [0.115, 0.792]). The 3-year event-free survival rate of patients without VA was significantly higher than that of patients with VA (63.3% vs 40.7%, p = 0.034). Skin lesions (OR 0.163, 95% CI [0.051, 0.523]) and positive antimitochondrial antibody (OR 3.484, 95% CI [1.192, 10.183]) were independent predictors of VA. Conclusion VA provides prognostic insights for PM/DM-MCI patients and predicts poor outcome. Polymyositis and positive antimitochondrial antibody are closely associated with the presence of VA in PM/DM-MCI.