C-reactive protein and left atrial appendage velocity are independent determinants of the risk of thrombogenesis in patients with atrial fibrillation

Background: The association between inflammatory status and thrombosis in patients with atrial fibrillation (AF) is unclear. We studied the correlation between inflammation and the risk of thrombogenesis in patients with AF and the relationship of inflammation with other factors associated with thrombotic risk. Methods: We studied 150 consecutive patients (69 men, age 65 +/- 12 years) with persistent non-valvular AF who had transesophageal echocardiography prior to cardioversion. Patients underwent also measurements of high-sensitivity C-reactive protein, fibrinogen, D-dimer, and hematocrit levels. Results: Patients were divided into two groups according to the presence (n=52) or absence (n=98) of dense spontaneous echo contrast (SEC) in left atrium or left atrial appendage. The two groups were similar for age, sex, and major clinical risk factors. Patients with dense SEC had significantly larger left atrium diameter (p=0.007), lower left atrial appendage mean velocity (p<0.0001), and higher levels of C-reactive protein (p=0.003), D-dimer (p=0.008), and fibrinogen (p=0.006). At multivariate analysis, only left atrial appendage velocity (odds ratio: 19.11; 95% confidence interval 4.2-80.9) and C-reactive protein (odds ratio: 3.41; 95% confidence interval 1.2-9.8) were significantly associated with thrombus and/or dense SEC. However, there was no relationship between C-reactive protein levels and left atrial appendage velocity (p=0.24, r=-0.09). Conclusions: Our results show that left atrial appendage velocity and C-reactive protein are independently associated with the risk of thromboembolism in AF. Thus, blood stasis and inflammation appear to constitute two major distinct components of thrombogenesis. (C) 2008 Elsevier Ireland Ltd. All rights reserved.