Primary Sjogren's Syndrome and the Risk of Acute Myocardial Infarction: A Nationwide Study

Background: Patients with autoimmune diseases have a high cardiovascular risk. However, few data are available on the risk of acute myocardial infarction (AMI) in patients diagnosed with primary Sjogren's syndrome (PSS). We conducted a large nationwide cohort study to investigate the possible association between PSS and the risk of AMI. Methods: Between the years 2000-2006, a total of 5205 patients with newly diagnosed PSS and no history of AMI were identified from the Registry of Catastrophic Illness, a sub-dataset of the National Health Insurance Research Database in Taiwan. The control group, which consisted of subjects without systemic autoimmune disease or previous AMI, was matched by the date of enrollment, age, gender, history of coronary artery disease, diabetes, hypertension, chronic kidney disease, and hyperlipidemia. The study endpoints were the occurrence of AMI. Results: Of the 5205 subjects with PSS and 5205 controls included in the study, 77 (35 PSS patients and 42 controls) developed AMI during the mean 3.7-year (interquartile range, 2.1-5.1 years) follow-up period. The incidence of AMI was similar in PSS patients and controls (1.91/1000 versus 2.25/1000 person-years). Multivariate analysis adjusted for baseline covariates demonstrated an insignificant association between PSS and AMI [adjusted hazard ratio, 0.86; 95% confidence interval (CI), 0.55-1.35; p = 0.506], suggesting that PSS does not increase the risk of AMI. Conclusions: PSS is not associated with a higher risk of subsequent AMI.