Abstract 1940: Coagulation Activity is Increased in the Left Atrium of Patients with Paroxysmal Atrial Fibrillation
Background: Measurements of plasma markers which reflect thrombin activity (thrombin-antithrombin III complex; TAT), active fibrinolysis (plasmin-alpha 2-plasmin inhibitor complex; PIC), and platelet activity (platelet factor 4; PF4) are useful in identifying patients with various cardiovascular disorders at high risk of thromboembolism. In this study, we investigated the hemostatic status of the left atrium in patients with paroxysmal atrial fibrillation (pAF).
Methods: Patients with pAF (n=10) and chronic AF (cAF) (n=10), and control subjects without AF (n=10) were enrolled in this study. TAT, PIC, and PF4 levels were determined in specimens of blood obtained from the left atrium of AF patients who were undergoing catheter ablation. The blood specimens were also obtained from the left ventricle of control subjects.
Results: Levels of PIC and PF4 did not differ significantly among 3 groups, whereas TAT levels in the left atrium of pAF and cAF patients were significantly higher than those in the left ventricle of control subjects (pAF: 29±19ng/ml, cAF: 28±19ng/ml, control: 3.1±3.0ng/ml, p<0.01).
Conclusion: We demonstrated for the first time that coagulation system is activated in the left atrium of pAF patients as well as cAF patients. This result suggests that even in a non-paroxysmal period, pAF patients are at high risk of thromboembolism, and anticoagulation therapy is indicated in those patients.