THU0137 Rheumatoid arthritis as an emergency department risk factor for acute coronary syndrome
Authors: M. Bergström, J. Askling, A. Discacciati, M. Frick, T. Jernberg, R. Linder, L. Ljung, P. Svensson
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> In rheumatoid arthritis (RA), the risk of myocardial infarction (MI) is 1.5–2.0 times higher than for the general population. However, it is unknown whether RA is a risk factor also in high-risk populations, such as among patients subjected to a cardiac diagnostic work-up at the emergency department (ED). <h3>Objectives</h3> To study 1) whether RA is a risk factor for acute coronary syndrome (ACS) in a population-based sample of individuals seen in the ED, and 2) how any association with RA relates to the presence of chest pain. <h3>Methods</h3> A total of 96 220 patients (of whom 1 312 had RA) seen in the ED of the four hospitals in the larger Stockholm area, due to chest pain and/or tested for troponin T, were identified through records of ED visits and cross-referenced to other registers. The outcome measure was ACS, defined as a discharge diagnosis of MI, unstable angina requiring urgent revascularisation, or death within 30 days (for directly discharged only). The association between RA and the outcome was assessed using logistic regression. <h3>Results</h3> ACS was more common in patients with RA (4.7%) than in subjects without RA (3.3%) – but this difference was largely attributable to RA patients being older and, upon taking age and gender into account, not statistically significant (p=0.13). Overall and across all individuals with chest pain and/or a troponin T test taken, RA was not associated with ACS when adjusting for age, demographics and comorbidity, odds ratio (OR) 1.24, 95% confidence interval (CI): 0.95–1.61. In analyses restricted to patients presenting with chest pain (irrespective of troponin T test status, n=49 283), a significant association between RA and ACS was observed (adjusted OR 1.40 95% CI 1.01–1.96). <b>Figure 1 Odds ratios for myocardial infarction (MI) in rheumatoid arthritis (RA) patients compared with unexposed.</b> Patients with suspected MI in the emergency department (ED) grouped by presence of chest pain. Other chief complaints than chest pain labelled as atypical complaints. MI refers to combined outcome of MI or 30 day major cardiac event (MACE). * Model 1: adjusted for age, gender, hospital, year of ED visit. † Model 2: adjusted for age, gender, hospital, year of ED visit, smoking, estimated glomerular filtration rate (eGFR), hypertension, hyperlipidaemia, diabetes mellitus, obesity, atrial fibrillation, heart failure and previous cardiovascular disease. Previous cardiovascular disease meant having one of the following diagnoses: previous stroke or MI, angina pectoris or peripheral vascular disease. <h3>Conclusions</h3> Although RA was not an independent risk factor for ACS among all patients subjected to a cardiac diagnostic work-up in the ED, RA was an independent risk factor among patients presenting with chest pain as chief complaint, an association that was not readily explained by traditional cardiovascular risk factors. The combination of RA and chest pain should thus increase the suspicion of ACS. <h3>Disclosure of Interest</h3> None declared