Time Trends in Acute Coronary Syndrome Hospitalizations and Outcomes in Patients With Systemic Lupus Erythematosus: A United States Inpatient Cohort Analysis

Abstract

Objective. Systemic lupus erythematosus (SLE) is an autoimmune disease linked to higher cardiovascular risks, such as acute coronary syndrome (ACS). Limited real-world data exist on ACS outcomes in patients with SLE. This study examines trends in ACS hospitalizations among patients with SLE (2006-2019) and compares outcomes and healthcare utilization between ACS patients with and without SLE. Methods. Using data from the US National Inpatient Sample from 2006 to 2019, ACS hospitalizations were classified by the presence or absence of SLE using International Classification of Diseases (ICD), 9th (ICD-9) and 10th revisions (ICD-10) codes. Hospitalization rates, mortality, length of stay, and charges were compared between the 2 groups. Chi-square and t tests assessed associations with SLE for categorical and continuous variables, respectively, with P < 0.05 as the significance threshold. Results. Of 17,318,554 ACS hospitalizations, 70,882 involved patients with SLE, who were more often < 50 years of age, female, Black, and had higher rates of antiphospholipid syndrome, chronic and endstage kidney disease, and prior thromboembolism. From 2006 to 2019, ACS hospitalization rates fell by 40% in patients with SLE—mainly from 2015 to 2019—and by 50% in patients without SLE. In-hospital mortality was similar (7% vs 6.9%, P = 0.52), though patients with SLE experienced longer hospital stays (6.22 vs 5.51 days, P < 0.001) and higher charges (US 79,909 vs 74,294, P < 0.001). Conclusion. SLE patients with ACS require higher healthcare utilization, with longer hospital stays and higher charges. Although ACS hospitalization rates declined for both groups, the decrease was greater in patients without SLE. These findings underscore the need for continuous targeted cardiovascular risk management strategies in patients with SLE to reduce morbidity and healthcare burden.