The Association of Hydroxychloroquine Dosing with Adverse Cardiac Events in Patients with Systemic Lupus Erythematosus.

<bold>Objective: </bold>To determine if hydroxychloroquine (HCQ) dose is associated with adverse cardiac outcomes in patients with SLE.<bold>Methods: </bold>Patients with SLE on HCQ and with ≥1 echocardiogram followed at a tertiary care center in Bronx, NY between 2005-2021 were included. HCQ weight-based dose at HCQ start date was the main exposure of interest. The outcome was incident all-cause heart failure with reduced ejection fraction (HFrEF), life-threatening arrhythmia or cardiac death. We used Fine-Gray regression models with death as competing event to study the association of HCQ dose with the outcome. Due to a significant interaction between smoking and HCQ exposure, models were stratified by smoking status. Propensity score analysis was performed as secondary analysis.<bold>Results: </bold>Of 294 patients, 37 (13%) developed the outcome over a median (IQR) follow up time of 7.9 (4.2, 12.3) years. In non-smokers (n=226), multivariable analysis adjusted for age, body mass index, hypertension, chronic kidney disease, diabetes and thromboembolism showed that higher HCQ weight-based doses were not associated with an increased risk of the outcome, sHR 0.62 (0.41,0.92) p=0.02. Similarly, higher baseline HCQ doses were not associated with a higher risk of the outcome among smokers (n=68), sHR 0.85 (0.53, 1.34) per mg/kg, p=0.48. Propensity score analysis showed comparable results.<bold>Conclusion: </bold>Higher HCQ doses were not associated with an increased risk of HFrEF, life-threatening arrhythmia or cardiac death among patients with SLE and may decrease the risk among non-smokers. This article is protected by copyright. All rights reserved. [ABSTRACT FROM AUTHOR]