Longterm Blood Pressure Variability in Patients with Rheumatoid Arthritis and Its Effect on Cardiovascular Events and All-cause Mortality in RA: A Population-based Comparative Cohort Study

Objective. To examine longterm visit-to-visit blood pressure (BP) variability in patients with rheumatoid arthritis (RA) versus non-RA subjects and to assess its effect on cardiovascular (CV) events and mortality in RA. Methods. Clinic BP measures were collected in a population-based incident cohort of patients with RA (1987 American College of Rheumatology criteria met between January 1, 1995, and January 1, 2008) and non-RA subjects. BP variability was defined as within-subject SD in systolic and diastolic BP. Results. The study included 442 patients with RA (mean age 55.5 yrs, 70% females) and 424 non-RA subjects (mean age 55.7 yrs, 69% females). Patients with RA had higher visit-to-visit variability in systolic BP (13.8 +/- 4.7 mm Hg) than did non-RA subjects (13.0 +/- 5.2 mm Hg, p = 0.004). Systolic BP variability declined after the index date in RA (p < 0.001) but not in the non-RA cohort (p = 0.73), adjusting for age, sex, and calendar year of RA. During the mean followup of 7.1 years, 33 CV events and 57 deaths occurred in the RA cohort. Visit-to-visit systolic BP variability was associated with increased risk of CV events (HR per 1 mm Hg increase in BP variability 1.12, 95% CI 1.01-1.25). Diastolic BP variability was associated with all-cause mortality in RA (HR 1.14, 95% CI 1.03-1.27), adjusting for systolic and diastolic BP, body mass index, smoking, diabetes, dyslipidemia, and use of antihypertensives. Conclusion. Patients with RA had higher visit-to-visit systolic BP variability than did non-RA subjects. There was a significant decline in systolic BP variability after RA incidence. Higher visit-to-visit BP variability was associated with adverse CV outcomes and all-cause mortality in RA.