POS0580 TRENDS IN THE OCCURRENCE OF ISCHEMIC HEART DISEASE OVER TIME IN RHEUMATOID ARTHRITIS: A RETROSPECTIVE COHORT STUDY FROM NORWAY OF 1821 PATIENTS FROM 1972 TO 2014

Abstract

BackgroundPrevious studies have shown that rheumatoid arthritis is associated with a 1.5 to 2.0 times increased risk of acute myocardial infarction (AMI) and ischemic heart disease (IHD) compared with the general population [1,2]. RA treatment has improved vastly over the last two decades, due to the focus on early and aggressive treatment and the use of synthetic and biologic DMARDs. Several studies have documented higher rates of remission and better long-term outcomes in patients with early introduction of DMARDs [3]. This “window of opportunity” may also be a critical phase for intervention against the development of atherosclerosis in RA. There is little information about the occurrence of AMI and IHD in RA patients diagnosed after the introduction of modern RA treatment.ObjectivesTo evaluate trends of AMI and IHD in RA patients compared with the general population over time.MethodsWe performed a retrospective cohort study of 1821 RA patients diagnosed from 1972 to 2013. The total population of Hordaland, Norway was used as a comparison cohort. Information on AMI and IHD events was obtained from hospital patient administrative systems or cardiovascular registries during 1972-2014. Aggregated counts of AMI, IHD and population counts of the comparison cohort were used to calculate expected counts of AMI and IHD in the RA cohort per 5-year age group, sex and calendar year. We then used Poisson regression with expected counts as an offset to estimate standardized event ratios (SER) as a measure of excess events.ResultsThe difference in events (excess events) in RA patients compared with the general population declined on average 1.3% per year for AMI and 2.3% for IHD from 1972 to 2014. There was no significant excess AMI (SER 1.05, 95% CI 0.82–1.35) and IHD events (SER 1.02, 95% CI, 0.89–1.16) for RA patients diagnosed after 1998 compared with the general population.ConclusionRA patients have historically had an excess risk of IHD compared with the general population. Our study did not find excess AMI or IHD events in RA patients diagnosed after 1998. Our findings may reflect improved management of RA, CVD prevention or changes in the case-mix of RA patients over time.