Background We and others have previously demonstrated an increased risk of acute coronary syndrome (ACS) in patients with rheumatoid arthritis (RA) compared to the general population, already within a few years of RA diagnosis. With implementation of more intense therapeutic options and more intense treatment strategies in early RA, risk data from historical RA populations may no longer adequately reflect risks in contemporary patient cohorts.
Objectives To assess whether patients diagnosed with RA in recent years also are at increased risk of ACS even shortly after RA diagnosis.
Methods From the Swedish Rheumatology Quality Register, we assembled an incident RA-cohort consisting of patients diagnosed 1997 through 2012 within one year of symptom onset (n 13,128), and a general population comparator (n 113,990, matched 1:10 on year of birth, sex, and area of residency). Information on first time hospitalizations for ACS (ICD 10 codes I21 and I20.0) through 2012 was retrieved from the Swedish Patient register. Individuals with a history of ACS were excluded. Hazard Ratios (HR) were estimated using Cox models taking calendar period of RA diagnosis and RA duration into account. All models were adjusted for the matching factors, age and educational level.
Results Mean age at RA diagnosis was 57 years, 70% were women. The proportion of patients who initiated a DMARD therapy within the first year following diagnosis increased from 76% 1997-2001 to 89% (2002-2006) and 85% 2007-2012. Among those, the proportion who initiated MTX increased from 60% via 83% to 90%. Median (interquartile range) follow up was 5.3 (6.6) years in both RA patients and comparators. During the entire follow-up of 766,483 person years, 624 RA patients and 3,629 comparators were hospitalized with an incident first-time ACS, overall HR of 1.46 (95% confidence interval (CI) 1.34-1.59). Those diagnosed with RA 2007-2012 had similar HRs as patients diagnosed 1997-2001 (table). Patients diagnosed 2007-2012 had a 40% increased risk of ACS 1-<5 years after RA diagnosis, which was also true for patients diagnosed with RA 1997-2001.
Conclusions Despite intensified and improved treatment strategies in recent years, the short-term risk increase for ACS remains. Identification of and intervention against ACS risk factors should thus be part of early RA management.
Disclosure of Interest None declared