High incidence of cardiovascular events in a rheumatoid arthritis cohort not explained by traditional cardiac risk factors

Objective. To compare the incidence of cardiovascular (CV) events in person s with rheumatoid arthritis (RA) with that in people from the general popul ation, adjusting for traditional CV risk factors. Methods. Two hundred thirty-six consecutive patients with RA were assessed for the 1-year occurrence of 1) CV-related hospitalizations, including myoc ardial infarction, stroke or other arterial occlusive events, or arterial r evascularization procedures, or 2) CV deaths. Both outcomes were ascertaine d by medical records or death certificates. For comparison, we used CV even ts that occurred during an 8-year period among participants in an epidemiol ogic study of atherosclerosis and CV disease who were ages 25-65 years at s tudy entry. We calculated the age- and sex-stratified incidence rate ratio (IRR) of CV events between the 2 cohorts and used Poisson regression to adj ust for age, sex, smoking status, diabetes mellitus, hypercholesterolemia, systolic blood pressure, and body mass index. Results. Of the 236 RA patients, 234 were observed for 252 patient-years, d uring which 15 CV events occurred. Of these, 7 incident events occurred dur ing the 204 patient-years contributed by patients ages 25-65 years, for an incidence of 3.43 per 100 patient-years. In the comparison cohort, 4,635 co mmunity-dwelling persons were followed up for 33,881 person-years, during w hich 200 new events occurred, for an incidence of 0.59 per 100 person-years . The age- and sex-adjusted IRR of incident CV events associated with RA wa s 3.96 (95% confidence interval [95% CI] 1.86-8.43). After adjusting for CV risk factors using Poisson regression, the IRR decreased slightly, to 3.17 (95% CI 1.33-6.36). Conclusion. The increased incidence of CV events in RA patients is independ ent of traditional CV risk factors. This suggests that additional mechanism s are responsible for CV disease in RA. Physicians who provide care to indi viduals with RA should be aware of their increased risk of CV events and im plement appropriate diagnostic and therapeutic measures.