Coagulation activity is increased in the left atria of patients with paroxysmal atrial fibrillation during the non-paroxysmal period. Comparison with chronic atrial fibrillation.

Background: Evaluation of plasma markers of thrombin activity (thrombin-antithrombin III complex: TAT), active fibrinolysis (plasmin-alpha 2-plasmin inhibitor complex: PIC), and platelet activity (platelet factor 4: PF4) is useful for identifying patients with various cardiovascular disorders who are at high risk of thromboembolism. In this study, these markers were investigated in the left atria (LA) of patients with paroxysmal atrial fibrillation (pAF) in the non-paroxysmal period.

Methods And Results: Patients with pAF (n=10) and chronic AF (cAF) (n=10) were enrolled. TAT, PIC, and PF4 levels were determined in blood samples obtained from the LA of AF patients before radiofrequency catheter ablation. TAT levels were high in both pAF and cAF patients. PF4 levels were slightly elevated in both groups, but there was no significant difference between the groups. On the other hand, PIC levels in both groups were almost within normal limits, again with no significant difference between groups.

Conclusions: Coagulation activity is elevated in the LA of patients with pAF, even in the non-paroxysmal period, so these patients are at high risk of thromboembolism and anticoagulant therapy is indicated.