Supplementary Material for: Increased risk of heart failure among patients with bullous pemphigoid: A nationwide cohort study

Background: Bullous pemphigoid (BP) and heart failure (HF) share similar mechanisms involving chronic inflammation. Nevertheless, the association of BP with HF has been unclear. This study aimed to investigate the association of BP with incident HF. Methods: We conducted a nationwide cohort study included adults aged ≥ 20 years from Taiwan’s National Health Insurance Research Database between 2011 and 2019. Adults with newly-diagnosed BP and matched controls were included. A Cox regression model considering stabilized inverse probability weighting was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident HF in association with BP. Stratified analyses according to age and sex were conducted. Multiple sensitivity analyses were also performed. Results: Among 39,835 subjects, 975 patients in the BP cohort and 2,311 patients in the non-BP cohort developed HF, with incidence rates of 46.1 and 16.9 per 1,000 person-years, respectively. Adults with BP had a significantly increased risk of incident HF (HR 2.63; 95% CI 2.44–2.83) compared to those without BP. The association remained significant in the age- and sex-stratified analyses. Multiple sensitivity analyses confirmed the robustness of our primary analyses. Conclusion: BP is associated with an increased risk for HF. Early detection of HF and cardiology consultation among patients with BP presenting relevant symptoms may be implicated in the current practice.