Vascular events in autoantibody-defined clusters of SLE: a 12-year prospective cohort study.

Abstract

We recently identified four SLE clusters based on 13 autoantibodies used in clinical practice. In this prospective cohort study, we investigate the incidence of major cardiovascular events (MACE) and venous thromboembolism (VTE) in SLE patients stratified by clusters. Clusters were compared with each other and to matched controls. Clusters were defined at baseline: cluster 1 dominated by anti-SSA/SSB, cluster 2 by anti-nucleosome/Sm/RNP/dsDNA, cluster 3 by aPL and cluster 4 negative for all 13 autoantibodies. SLE clinical data were collected at enrolment. Vascular outcomes were prospectively retrieved from the National Patient Register using ICD codes. Each patient was matched on birth/sex/residence to 10 controls from the Total Population Register. Subjects with previous vascular events were excluded. Hazard ratios (HRs) and 95% CIs from Cox proportional hazards models estimated the age-adjusted relative risks of incident vascular events. We included 461 SLE patients, mean follow-up 12.2 ± 5.6 years. Compared with reference clusters, cluster 3 (n = 154) had the highest relative risk for MACE (HR 1.91 (95% CI: 1.01-3.58)) and VTE (HR 2.69 (95% CI: 1.05-6.9)). Cluster 2 (n = 105) had high risk for heart failure and VTE, similar to cluster 3, despite younger age. The lowest incidence of vascular events was observed in cluster 4 (n = 61) in comparison to the other clusters. We observed differences regarding the incidence of MACE and VTE during 12 years of follow-up for four autoantibody-defined clusters. The highest incidences were seen in the aPL-dominated cluster, while the lowest were detected in the autoantibody-negative cluster.