Electrocardiographic findings in systemic lupus erythematosus: Data from an international inception cohort

Objective: To estimate the early prevalence of various electrocardiographic (ECG) abnormalities in patients with SLE and to evaluate possible associations between repolarization changes (increased corrected QT, QTc, and QT dispersion, QTd) and clinical and laboratory variables, including the anti-Ro/SSA level and specificity (52 or 60KDa). Methods: We studied adult SLE patients from 19 centers participating in the Systemic Lupus International Collaborating Clinics (SLICC) Inception Registry. Demographics, disease activity (SLEDAI-2K), disease damage (SLICC/ACR DI), and laboratory data from the baseline or first follow-up visit were assessed. Multivariate logistic and linear regression models were used to asses for any cross-sectional associations between anti-Ro/SSA and ECG repolarization abnormalities. Results: For the 779 patients included, mean age (SD) was 35.6 years (13.8), 88.4% were women, and mean disease duration was 10.5 months (14.4). Mean SLEDAI-2K was 5.4 (5.6) and mean SLICC/ACR DI was 0.5 (1.0). ECG abnormalities were frequent and included non-specific ST-T changes (30.9%), possible left ventricular hypertrophy (5.4%) and supraventricular arrhythmias (1.3%). A QTc ≥ 440ms was found in 15.3%, while QTc ≥ 460ms was found in 5.3%. Mean (SD) QTd was 34.2ms (14.7) and QTd ≥ 40ms was frequent (38.1%). Neither the specificity, nor the level of anti-Ro/SSA was associated with QTc duration or QTd, although confidence intervals were wide. Total DI was significantly associated with a QTc interval exceeding 440 ms (OR 1.38 95% CI 1.06, 1.79). Conclusion: A substantial proportion of recent-onset SLE patients exhibit repolarization abnormalities although severe abnormalities were rare. © 2014 American College of Rheumatology.