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. 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. 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 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 3 control, and this risk was more significant in females. In addition, SLE is an independent risk factor for post-AMI mortality.