The incidence of cardiovascular events in Italian patients with systemic lupus erythematosus is lower than in North European and American cohorts: implication of disease-associated and traditional risk factors as emerged by a 16-year retrospective GIRRCS study

Previous study from our group has pointed out a lower number of cardiovascular (CV) events in Italian patients with systemic lupus erythematosus (SLE) than in North European and American ones. This study aims to assess the incidence of the first CV event in a large, multicenter, Italian cohort of patients with SLE and search for differences in disease and traditional risk factors among distinct cohorts. Clinical charts of SLE patients consecutively admitted to 5 Italian rheumatologic centers from November 1st 2000 to December 31st 2015 and free of CV events at baseline were retrospectively studied. CV cumulative incidence (ie, the proportion of patients who experienced a new CV event over the follow-up period) and CV incidence rate (ie, the number of events in the cohort divided by the total number of years at risk) were evaluated. The detected incidences were compared with those reported in SLE cohorts from other countries. The median duration of follow-up was 6 years (IQR=3-11). During the observational period, 37 (cumulative incidence=7.2%) patients had a first episode of CV event with an incidence rate of 10.1/1000 person-years. The CV cumulative incidence and incidence rate detected in our Italian cohort were lower than those from most North European and American cohorts, characterized by a high impact of traditional risk factors. Nevertheless, the cumulative incidence was similar to that reported in a Spanish cohort with a high frequency of traditional risk factors (geographic impact), while the incidence rate was only slightly higher than that in the Baltimore cohort, which is characterized by a strict follow-up of patients (medical impact). Our results confirmed that Italian lupus patients have a low incidence of CV events. Moreover, the geographic origin, traditional risk factors, and medical approach appear to have an impact on CV disease in SLE.