Background There is limited data on the risk of myocardial infarction (MI) and cerebrovascular accident (CVA) in patients with Sjögren's Syndrome (SjS).
Objectives To fill this knowledge gap we estimated the future risk of newly recorded MI and CVA events among incident cases, with SjS compared to controls from the general population using physician billing and hospitalization databases that cover the entire population of the province of British Columbia, Canada.
Methods Our data include all visits to health professionals and all hospital admissions from 1990 to 2010 and all dispensed medications from1995 to 2010 for all individuals. We conducted a retrospective matched cohort study among patients satisfying at least one of the following criteria: a) diagnosis of SjS (ICD-9-CM code 710.2, ICD-10-CM code M35.0) in adults on at least two visits within a two-year period between 1996 and 2010 by a non-rheumatologist physician; b) diagnosis of SjS on at least one visit by a rheumatologist or from hospitalization. Ten non-SLE controls matched by birth year, sex and calendar year of follow-up, were selected from the general population for each case. Outcomes: Incident MI and CVA events based on hospitalization or death certificate were recorded as an outcome. We estimated relative risks (RRs) comparing SjS with age-, sex- and entry time-matched comparison cohorts, adjusting for potential cardiovascular risk factors.
Results Among 1,176 (MI cohort) and 1,195 (CVA cohort) incident SjS cases, 28 developed a first time MI and 19 CVA events with an incident rate (IR) of 7.7 and 5.1 per 1000 person-years, respectively. Compared with the age, sex, and entry matched controls the RRs were 2.2 (95% CI 1.41-3.32) and 1.5 (0.9-2.4), respectively (see table) After adjusting for covariates the results remained similar for both MI and CVA. The risk of developing MI was highest within the first year following diagnosis of SjS, and persisted up to five years following the initial diagnosis.
Conclusions This is the first general population-based study investigating the risk of MI and CVA in SjS. We found a significantly increased risk of MI in patients with SjS, particularly in the first year following diagnosis, indicating that the acute inflammatory state in SjS, particularly at disease onset, is likely the main driver for this increased risk. We also found a trend towards an increased risk for CVA. Our results support increased monitoring for coronary artery disease in addition to management and modification of risk factors to reduce the risk of MI in patients with SjS.
Acknowledgements Research funded by an operating grant by the Canadian Arthritis Network/The Arthritis Society and the BC Lupus Society (Grant 10-SRP-IJD-01)
Disclosure of Interest None declared