5047C-reactive protein and the risk of atrial fibrillation: KOGES 12 years' follow-up study

Objective: It is unclear whether systemic inflammation increases the risk of atrial fibrillation (AF) in the general population. We investigated whether there was an association between serum C-reactive protein (CRP) levels and the prevalence and incidence of AF. Methods: A total of 10,015 participants were enrolled in the Ansan-Ansung cohort study. Follow-up evaluations were performed biennially after a baseline evaluation. Serum CRP levels were measured at baseline and high-sensitivity CRP (hsCRP) levels were measured at every re-visit. AF was identified using 12-leads standard electrocardiography at baseline and re-visits. Results: The mean age of the participants was 52.3±8.9 years, and 4,752 (47.4%) were male. The prevalence of AF was 40 (0.4%) at baseline and the incidence of AF was 135 (1.35%) over a 12-year follow-up period (8.7 years/person). Serum CRP levels were higher in subjects with AF at baseline (1.7 [1.0–5.1], p=0.035) and those with new-onset AF (1.7 [0.8–3.0], p=0.036) than in those without AF overall (1.4, [0.7–2.5]). High CRP levels at baseline (>1 mg/L) were associated with new-onset AF (log rank p=0.036). The association between high CRP levels and new-onset AF was significant after adjustment for covariates until 9 years of follow-up (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1.05–2.94, p=0.031); however, the significance disappeared after 9 years (Figure panel A). Nevertheless, persistently high CRP and hsCRP levels versus persistently low CRP and hsCRP levels were significantly associated with a higher risk of AF (adjusted HR=2.55, 95% CI 1.26–5.14, p=0.009) throughout the follow-up period (Figure panel B).