Time-Dependent Analysis of Risk of New-Onset Heart Failure Among Patients With Polymyositis and Dermatomyositis.

To determine the risk and time trends of hospitalized heart failure (HF) in individuals with newly diagnosed polymyositis (PM) and dermatomyositis (DM) at the general population level. We conducted a retrospective cohort study using a nationwide insurance database in Taiwan. Patients with incident PM/DM and without previous histories of HF were selected between 2000 and 2013. Unmatched and propensity score-matched cohorts were established separately. Multivariable Cox proportional hazard regression model was used to estimate adjusted hazard ratios (HRs) in the unmatched population. In the propensity-matched cohort, controls were selected and matched to the PM/DM group at a 1:1 ratio based on propensity scores, which accounted for confounding factors: sex, age, year of index date, comorbidities, and medication exposure. The cumulative HF incidence was estimated with Kaplan-Meier method. A stratified Cox model was used to calculate HR for HF events in the matched cohort. There were 2025 PM/DM patients and 196,109 controls in the unmatched cohort. Multivariable Cox regression model adjusted for age, sex, comorbidities, and medication use revealed a greater risk of hospitalized HF in the PM/DM than in the control groups (adjusted HR: 3.29, 95% confidence interval [CI]: 2.60-4.18). After propensity score matching, a total of 1997 pairs of PM/DM patients and controls were identified. The cumulative HF incidence at 3, 5, and 10 years in patients with PM/DM were 3.3%, 4.4%, and 7.4%, respectively. The absolute risk difference in the PM/DM group versus controls were 1.8% at 3 years, 2.1% at 5 years and 3.0% at 10 years. Compared with non-PM/DM individuals, PM/DM patients exhibited an augmented HF risk (HR: 2.06, 95% CI: 1.36-3.12]. The stratified analysis according to follow-up period revealed that the increased risk of HF persisted for up to 10 years after the PM/DM diagnosis. Our results indicated an increased risk of hospitalized HF in patients with PM/DM throughout the study period, supporting the need for increased vigilance and monitoring patients with PM/DM for this potential lethal complication.