Uric acid elevation in atrial fibrillation.

INTRODUCTION: Uric acid is a cardiovascular risk marker associated with oxidative stress and inflammation. Recently, atrial fibrillation (AF) has been associated with inflammation and oxidative stress. We therefore investigated the association between AF and uric acid levels.
METHODS: Consecutive patients with AF and healthy control subjects were screened. Demographic, clinical, and echocardiographic characteristics were carefully recorded. In each participant, uric acid levels and conventional inflammatory markers were determined. The final study population consisted of 45 patients with paroxysmal AF, 41 patients with permanent AF, and 48 control subjects.
RESULTS: A significant variance in uric acid levels was evident between patients with paroxysmal AF (5.7 +/- 1.1 mg/dl), permanent AF (6.7 +/- 1.4 mg/dl), and control subjects (5.1 +/- 1.3 mg/dl) (p<0.001). After univariate analysis considering 2 groups (control, AF patients), the following variables were significantly associated with the presence of AF: age, hypertension, -blocker use, low left ventricular ejection fraction (LVEF), increased left atrial diameter, uric acid levels, and C-reactive protein (CRP) levels. After multivariate logistic regression analysis, only CRP was an independent predictor for AF (odds ratio, OR: 2.172). In a subgroup analysis, CRP (OR: 1.434) and LVEF (OR: 0.361) were independent predictors of paroxysmal AF, while CRP (OR: 3.048), uric acid (OR: 2.172), and LVEF (OR: 0.34) were predictors of permanent AF.
CONCLUSIONS: There is an association between increased levels of uric acid and permanent AF. Also, uric acid elevation may be related to the burden of AF. Undoubtedly, larger studies should further examine this potential association.