Risk factors for thrombotic events in Korean patients with systemic lupus erythematosus

Thrombotic events (TE), including deep vein thrombosis, stroke, and myocardial infarction, occur in 30–40% of patients with systemic lupus erythematosus (SLE) resulting in substantial morbidity and mortality. We explored the risk factors for TE in SLE patients. We analyzed data obtained during a prospective cohort based on the KORean lupus NETwork (KORNET) registry, and enrolled 259 SLE patients with clinical data available at the onset of SLE. TE was defined as the presence of arterial or venous thrombosis. Multivariate Cox-proportional hazards analysis was performed to investigate risk factors for TE. During a mean follow-up of 103.3 months (SD 53.4), 27 patients (10.4%) had a TE. In multivariate analysis, hypertension (hazard ratio [HR] 7.805, 95% confidence interval [CI]: 1.929–31.581; P = 0.004), anti-phospholipid syndrome (APS) (HR 12.600, 95% CI: 4.305–36.292; P < 0.001), mean daily prednisolone > 5 mg/day (HR 3.666, 95% CI: 1.318–10.197; P = 0.013), and SLICC/ACR Damage Index (SDI) score (HR 1.992, 95% CI: 1.465–2.709; P < 0.001) were significantly associated with the development of TE in SLE patients. Instead, use of an ACEi or ARB (HR 0.159, 95% CI: 0.043–0.594; P = 0.006) was a protective factor against TE development in these patients. In conclusion, hypertension, higher mean daily dose of prednisolone, diagnosis of APS, and higher SDI were risk factors for TE in patients with SLE. On the other hand, the use of an ACEi or ARB was associated with a reduced risk of TE.