To determine whether systemic inflammation confers any additional risk for cardiovascular death among patients with rheumatoid arthritis (RA), after adjusting for traditional cardiovascular risk factors and comorbidities.
Using the population-based data resources of the Rochester Epidemiology Project, we assembled an incidence cohort of all Rochester, Minnesota residents ages >or=18 years who first fulfilled the American College of Rheumatology 1987 criteria for RA between January 1, 1955 and January 1, 1995. All subjects were followed up longitudinally through their complete (inpatient, outpatient) medical records, beginning at age 18 years and continuing until death, migration, or January 1, 2001. Detailed information on the occurrence of various cardiovascular risk factors (personal history of coronary heart disease [CHD], congestive heart failure, smoking, hypertension, dyslipidemia, body mass index [BMI], diabetes mellitus, menopausal status) as well as indicators of systemic inflammation and RA disease severity (rheumatoid factor [RF] seropositivity, erythrocyte sedimentation rate [ESR], joint swelling, radiographic changes, RA nodules, RA complications, RA treatments, disease duration) and comorbidities were collected on all subjects. Causes of death were ascertained from death certificates and medical records. Cox regression models were used to estimate the independent predictors of cardiovascular death.
This inception cohort comprised a total of 603 RA patients whose mean age was 58 years, of whom 73% were women. During a mean followup of 15 years, 354 patients died and cardiovascular disease was the primary cause of death in 176 patients. Personal history of CHD, smoking, hypertension, low BMI, and diabetes mellitus, as well as comorbidities, including peripheral vascular disease, cerebrovascular disease, chronic pulmonary disease, dementia, ulcers, malignancies, renal disease, liver disease, and history of alcoholism, were all significant risk factors for cardiovascular death (P < 0.01 for each). Multivariable Cox regression analyses, controlled for cardiovascular risk factors and comorbidities, revealed that the risk of cardiovascular death was significantly higher among RA patients with at least 3 ESR values of >or=60 mm/hour (hazard ratio [HR] 2.03, 95% confidence interval [95% CI] 1.45-2.83), RA vasculitis (HR 2.41, 95% CI 1.00-5.81), and RA lung disease (HR 2.32, 95% CI 1.11-4.84).
These results indicate that markers of systemic inflammation confer a statistically significant additional risk for cardiovascular death among patients with RA, even after controlling for traditional cardiovascular risk factors and comorbidities.