Mortality related to cerebrovascular disease in systemic lupus erythematosus

Abstract

The objective of this study was to examine mortality rates related to cerebrovascular disease in systemic lupus erythematosus (SLE) compared to the general population. Our sample was a multisite Canadian SLE cohort (10 centres, n = 2688 patients). Deaths due to cerebrovascular disease were ascertained by vital statistics registry linkage using ICD diagnostic codes. Standardized mortality ratio (SMR, ratio of deaths observed to expected) estimates were calculated. The total SMR for death due to cerebrovascular disease was 2.0 (95% confidence interval [CI] 1.0, 3.7). When considering specific types of events, the category with the greatest increased risk was that of ill-defined cerebrovascular events (SMR 44.9, 95% CI 9.3, 131.3) and other cerebrovascular disease (SMR 8.4, 95% CI 2.3, 21.6). Deaths due to cerebral infarctions appeared to be less common than hemorrhages and other types of cerebrovascular events. Our data suggest an increase in mortality related to cerebrovascular disease in SLE patients compared to the general population. The large increase in illdefined cerebrovascular events may represent cases of cerebral vasculitis or other rare forms of nervous system disease; alternately, it may reflect diagnostic uncertainty regarding the etiology of some clinical presentations in SLE patients. The suggestion that more deaths are attributed to cerebral hemorrhage, as opposed to infarction, indicates that inherent or iatrogenic factors (eg, thrombocytopenia or anticoagulation) may be important. In view of the paucity of large-scale studies of mortality attributed to neuropsychiatric outcomes in SLE, our findings highlight the need for additional research in large SLE cohorts.