Increased unrecognized coronary heart disease and sudden deaths in rheumatoid arthritis: a population-based cohort study

Abstract

Objective: To examine the risk of clinical coronary heart disease (CHD) in patients with rheumatoid arthritis (RA) compared with age- and sex-matched non-RA subjects, and to determine whether RA is a risk factor for CHD after accounting for traditional CHD risk factors.

Methods: We assembled a population-based incidence cohort of 603 Rochester, Minnesota residents ages >or=18 years who first fulfilled the American College of Rheumatology (ACR) 1987 criteria for RA between January 1, 1955 and January 1, 1995, and 603 age- and sex-matched non-RA subjects. All subjects were followed up through their complete inpatient and outpatient medical records, beginning at age 18 years until death, migration, or January 1, 2001. Data were collected on CHD events and traditional CHD risk factors (diabetes mellitus, hypertension, dyslipidemia, body mass index, smoking) using established diagnostic criteria. CHD events included hospitalized myocardial infarction (MI), unrecognized MI, coronary revascularization procedures, angina pectoris, and sudden CHD deaths. Conditional logistic regression and Cox regression models were used to estimate the risk of CHD associated with RA, both prior to and following RA diagnosis, after adjusting for CHD risk factors.

Results: During the 2-year period immediately prior to fulfillment of the ACR criteria, RA patients were significantly more likely to have been hospitalized for acute MI (odds ratio [OR] 3.17, 95% confidence interval [95% CI] 1.16-8.68) or to have experienced unrecognized MIs (OR 5.86, 95% CI 1.29-26.64), and less likely to have a history of angina pectoris (OR 0.58, 95% CI 0.34-0.99) compared with non-RA subjects. After the RA incidence date, RA patients were twice as likely to experience unrecognized MIs (hazard ratio [HR] 2.13, 95% CI 1.13-4.03) and sudden deaths (HR 1.94, 95% CI 1.06-3.55) and less likely to undergo coronary artery bypass grafting (HR 0.36, 95% CI 0.16-0.80) compared with non-RA subjects. Adjustment for the CHD risk factors did not substantially change the risk estimates.

Conclusion: Patients with RA have a significantly higher risk of CHD when compared with non-RA subjects. RA patients are less likely to report symptoms of angina and more likely to experience unrecognized MI and sudden cardiac death. The risk of CHD in RA patients precedes the ACR criteria-based diagnosis of RA, and the risk cannot be explained by an increased incidence of traditional CHD risk factors in RA patients.