The role of atherosclerosis in the acute coronary syndromes (ACS) that occur in patients with rheumatoid arthritis (RA) has not been quantified in detail. We undertook this study to determine the extent to which ACS are associated with carotid atherosclerosis in RA.
We prospectively ascertained ACS, defined as myocardial infarction, unstable angina, cardiac arrest, or death due to ischemic heart disease, in an RA cohort. We measured carotid atherosclerosis using high-resolution ultrasound. We used Cox proportional hazards models to estimate the association between ACS and atherosclerosis, adjusting for demographic features, cardiovascular (CV) risk factors, and RA manifestations.
We performed carotid ultrasound on 636 patients whom we followed up for 3,402 person-years. During this time, 84 patients experienced 121 new or recurrent ACS events, a rate of 3.5 ACS events per 100 patient-years (95% confidence interval [95% CI] 3.0–4.3). Among the 599 patients without a history of ACS, 66 incident ACS events occurred over 3,085 person-years, an incidence of 2.1 ACS events per 100 person-years (95% CI 1.7–2.7). The incidence of new ACS events per 100 patient-years was 1.1 (95% CI 0.6–1.7) among patients without plaque, 2.5 (95% CI 1.7–3.8) among patients with unilateral plaque, and 4.3 (95% CI 2.9–6.3) among patients with bilateral plaque. Covariates associated with incident ACS events independent of atherosclerosis included male sex, diabetes mellitus, and a cumulative glucocorticoid dose of ≥20 gm.
Atherosclerosis is strongly associated with ACS in RA. RA patients with carotid plaque, multiple CV risk factors (particularly diabetes mellitus or hypertension), many swollen joints, and a high cumulative dose of glucocorticoids, as well as RA patients who are men, are at high risk of ACS.