Association Between Disease Activity of Systemic Lupus Erythematosus and Resting Electrocardiogram Abnormalities

<b>Objective:</b> The association between the activity of SLE and abnormalities of ECG remains not well elucidated. We aimed to examine the relationship between the SLE Disease Activity Index 2000 (SLEDAI-2K) and abnormalities of ECG in a Chinese population. <b>Methods:</b> Data for this cross-sectional study were retrieved from an SLE database (2018-2023). According to the SLEDAI-2K, patients were categorized into inactive, mild activity, moderate activity, and severe activity groups. Weighted multivariable regression analyses and subgroup analyses were conducted to assess the independent relationship between the SLEDAI-2K and ECG abnormalities. Restricted cubic splines (RCSs) were employed to explore potential non-linear correlations. <b>Results:</b> A total of 317 SLE patients (282 women; mean age 30.0 [23.0; 43.0]) were included. The overall prevalence of ST segment changes and T wave abnormalities was 37.5%. Our findings indicated a linear relationship between the SLEDAI-2K and the risk of ST-T changes. We used interaction terms to assess heterogeneity among subgroups and discovered significant differences specifically related to female gender, age (≤25 years), combined autoimmune diseases, and infectious complications. This suggested that the positive association between the SLEDAI-2K and ST-T changes was influenced by participants' gender, age, presence of combined autoimmune diseases, and infectious complications. <b>Conclusions:</b> Higher SLEDAI-2K scores were associated with an increased incidence of ST-T changes in SLE patients. The SLEDAI-2K is anticipated to emerge as an effective index for identifying early heart involvement in this population.