Single and persistent elevation of C-reactive protein levels and the risk of atrial fibrillation in a general population: The Ansan-Ansung Cohort of the Korean Genome and Epidemiology Study.

Background: Inflammation has been reported to cause atrial fibrillation (AF). However, it remains unclear whether C-reactive protein (CRP) levels predict AF. We investigated whether there was an association between serum CRP levels and the development of AF.

Methods: A total of 10,030 subjects aged between 40 and 69 years were enrolled and followed biennially over a 12-year period in the Ansan-Ansung cohort study. Serum CRP levels were measured at baseline and high-sensitivity CRP (hsCRP) levels were measured at every revisit. AF was identified using 12-lead standard electrocardiography. Inverse probability of treatment weighting was applied to balance the confounders of AF development between groups.

Results: Serum CRP levels were higher in subjects with AF at baseline and those with new-onset AF than in those without AF. Cox-regression analysis showed that high CRP levels (>3 mg/L) and intermediate CRP levels (1-3 mg/L) at baseline were not associated with a higher risk of new-onset AF compared with low CRP levels (<1 mg/L) after adjustments for covariates. The weighted incidences of AF also did not differ according to the CRP levels. In contrast, persistent elevation of CRP or hsCRP levels (≥1 mg/L at all visits) was associated with a higher risk of AF compared with nonpersistent elevation of CRP or hsCRP levels after adjustment for covariates in both unweighted and weighted cohorts.

Conclusion: A high CRP level at a single measurement was not associated with the risk of AF, whereas persistently elevated CRP levels independently predicted the development of AF.