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 determined 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 demographics, CV risk factors, and RA manifestations.
We performed carotid ultrasound on 636 patients, whom we followed 3,402 person-years. During this time, 84 patients experienced 121 new or recurrent ACS, a rate of 3.5 ACS per 100 patient-years (95% CI 3.0, 4.3). Among the 599 patients without prior history of ACS, 66 incident ACS occurred over 3,085 person-years, an incidence of 2.1 ACS per 100 person-years (95% CI 1.7, 2.7). The incidence of new ACS per 100 patient-years among patients without plaque was 1.1 (0.6, 1.7); with unilateral plaque 2.5 (1.7, 3.8); and with bilateral plaque 4.3 (2.9, 6.3). Covariates associated with incident ACS independent of atherosclerosis included male sex, diabetes mellitus, and a cumulative glucocorticoid dose of ≥ 20 grams. In addition, hypertension and the number of swollen joints were associated with new or recurrent ACS.
Atherosclerosis is strongly associated with ACS in RA. Patients with carotid plaque, multiple CV risk factors, particularly diabetes or hypertension, many swollen joints, high cumulative dose of glucocorticoids or who are men, are at high risk of ACS.