Risk for incident arterial or venous vascular events varies over the course of systemic lupus erythematosus.

OBJECTIVE: We describe the pattern of incidence of thrombovascular events after diagnosis of systemic lupus erythematosus (SLE) in a cohort of lupus patients.
METHODS: Descriptive study of prospectively collected data using incidence rates of thrombovascular events and 95% confidence intervals (CI) calculated for predetermined periods of observation. Kaplan-Meier survival curves were plotted to estimate thrombovascular event-free survival.
RESULTS: Among 426 individuals, person-years contributed were as follows: 399 persons and 4356.0 person-years for all events; 417 persons and 4691.9 person-years for arterial events; and 408 persons and 4846.6 person-years for venous events. The incidence of thrombovascular events was highest during the first year after SLE diagnosis (4.00, 95% CI 2.24-6.59) and after 20 years (ranging from 3.32, 95% CI 1.52-6.30, to 4.99, 95% CI 0.60-18.01), and was lowest between 1 and 5 years after SLE diagnosis (1.00, 95% CI 0.53-1.72). A similar pattern was observed for arterial events, while venous events showed a higher incidence rate only in the first 30 days after SLE diagnosis (12.06, 95% CI 3.29-30.87) and remained low afterwards. The probabilities of remaining event-free at 5, 10, and 15 years were as follows: 0.92, 0.85, and 0.78, respectively, for all thrombovascular events; 0.95, 0.88, and 0.82, respectively, for arterial events; and 0.98, 0.95, and 0.94, respectively, for venous events.
CONCLUSION: Thrombovascular events occur throughout the course of lupus, with the highest risk of arterial or venous events in the first year after diagnosis, and the pattern of occurrence varying thereafter.