Increased Serum Uric Acid Levels Are Correlated with Decreased Left Atrial Appendage Peak Flow Velocity in Patients with Atrial Fibrillation

OBJECTIVE: We aimed to examine the relationship between serum uric acid levels and left atrial appendage (LAA) peak flow velocity, an indicator of the mechanical functions of the LAA, and atrial fibrillation (AF). SUBJECTS AND METHODS: Transesophageal echocardiography was performed before cardioversion in 153 patients with AF. The patients were categorized into 2 groups based on their LAA blood flow velocity. Group 1 included 87 patients with a low LAA flow velocity (<35 cm/s), and group 2 comprised 66 patients with a normal LAA flow velocity (≥35 cm/s). The χ(2) and Student's t tests were used to compare categorical and quantitative data between the groups. Linear regression analyses were performed to demonstrate the independent association between serum uric acid levels and LAA peak flow velocity. RESULTS: The LAA blood flow velocity was 24.62 ± 5.90 cm/s in group 1 and 49.28 ± 13.72 cm/s in group 2, respectively (p < 0.001). The serum uric acid levels were 6.88 ± 1.85 mg/dl in group 1 and 5.97 ± 1.51 mg/dl in group 2, and the difference was statistically significant (p = 0.001). There was a negative correlation between serum uric acid levels and LAA blood flow velocity (r = −0.216, p = 0.007). Multivariate regression analysis showed that serum uric acid levels, age and gender differences were significant predictors of the LAA peak flow velocity. CONCLUSIONS: High serum uric acid levels were associated with a low contractile function of the LAA and could provide additional prognostic information on future thromboembolic events in patients with AF.