Increased risk of acute myocardial infarction and mortality in patients with systemic lupus erythematosus: Two nationwide retrospective cohort studies

Background This study evaluated the risk of acute myocardial infarction (AMI) and mortality among patients with systemic lupus erythematosus (SLE) in two nationwide retrospective cohort studies.
Results During the follow-up period, there were 52 newly diagnosed AMI cases. The incidences of AMI for SLE cohort and non-SLE cohort were 2.10 and 0.49 per 1000 person-years, respectively, with an adjusted hazard ratio (HR) of 5.11 (95% confidence interval [CI] 2.63-9.92). For females, the adjusted HR of AMI associated with SLE was as high as 6.28 (95% CI 2.67-14.7). Further analyses in the nested cohort showed that SLE was significantly associated with post-AMI mortality (odds ratio, 2.60; 95% CI 1.09-6.19). Conclusion Patients with SLE had higher risk of AMI compared with non-SLE control, and this risk was more significant in females. In addition, SLE is an independent risk factor for post-AMI mortality.
Methods Using Taiwan's National Health Insurance Research Database, we conducted a retrospective cohort study and identified 1207 adults newly diagnosed with SLE in 2000-2004. Non-SLE cohort consisted of 9656 adults without SLE, frequency-matched for age and sex and randomly selected from the same data set. Events of AMI were considered as outcome during the follow-up period between 2000 and 2008. Another nested cohort study of 6900 patients with AMI receiving cardiac surgeries was conducted to analyze the impact of SLE on post-AMI mortality.