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.

背景：大疱性类天疱疮（Bullous pemphigoid, BP）与心力衰竭（heart failure, HF）具有涉及慢性炎症的相似发病机制。然而，BP与HF之间的关联尚不明确。本研究旨在探讨BP与新发HF的关联。

方法：我们利用台湾全民健康保险研究数据库（Taiwan’s National Health Insurance Research Database），于2011年至2019年间对年龄≥20岁的成人开展了一项全国性队列研究。纳入新诊断为BP的成人患者及匹配的对照人群。采用考虑稳定逆概率加权的Cox回归模型，估算BP与新发HF关联的风险比（hazard ratios, HRs）及95%置信区间（confidence intervals, CIs）。此外，还进行了按年龄和性别分层的分析，以及多项敏感性分析。

结果：在39,835名研究对象中，BP队列的975例患者及非BP队列的2,311例患者发生HF，其发病率分别为每1000人年46.1例和16.9例。与非BP成人相比，BP成人的新发HF风险显著升高（HR 2.63；95% CI 2.44–2.83）。在按年龄和性别分层的分析中，该关联仍具有显著性。多项敏感性分析证实了主要分析结果的稳健性。

结论：BP与HF风险升高相关。对于出现相关症状的BP患者，早期检测HF并进行心内科会诊或可纳入当前临床实践。