Low-dose aspirin as primary prophylaxis for cardiovascular events in systemic lupus erythematosus: a long-term retrospective cohort study.

Objectives: Cardiovascular (CV) morbidity and mortality are significantly greater in SLE patients than in the general population. ASA is known to be associated with a decrease in the incidence of CV events in high-risk patients from the general population, but its efficacy as primary prophylaxis in SLE patients has not yet been investigated.

Methods: The clinical charts of SLE patients consecutively admitted to a tertiary centre who, at admission, satisfied 1992 ACR and/or 2012 SLICC classification criteria for SLE and had not experienced any CV event, were reviewed. The occurrence of any CV event was recorded at each visit. ASA was prescribed to all patients at first visit. The rate and reasons for ASA discontinuation were also recorded at each visit.

Results: One hundred and sixty-seven consecutive SLE patients were enrolled and followed up for a median of 8 years (range 1-14 years). Among them, 146 regularly took the medication (ASA-treated patients) and 21 refused to take or discontinued it (non-ASA-treated patients). Five CV events occurred in the 146 ASA-treated patients (4.2 per 1000 person-years) and four in the 21 non-ASA-treated patients (30 per 1000 person-years; P = 0.0007). The CV event-free rate was higher in ASA-treated than in non-ASA-treated patients (log-rank test χ(2) = 15.74; P = 0.0001). No relevant side-effect related to ASA was recorded.

Conclusion: Low-dose ASA is a safe treatment and may be beneficial in the primary prophylaxis of CV events in SLE patients. Controlled, prospective studies are needed to provide a better definition of its role in these patients.