Thromboembolic events are associated with prolonged clot lysis time in patients with permanent atrial fibrillation.

INTRODUCTION: Atrial fibrillation (AF) is associated with a prothrombotic state.
OBJECTIVES: We evaluated associations of previous thromboembolic events with fibrinolytic parameters in patients with AF. PATIENTS AND METHODS: We studied 62 consecutive patients with permanent AF (27 men, 35 women, aged 46-89 years [median, 78 years]). Patients receiving warfarin or acenocoumarol on a long-term basis were eligible. We determined plasma fibrin clot lysis time (CLT), plasminogen activator inhibitor-1 (PAI-1) antigen, thrombin-activatable fibrinolysis inhibitor (TAFI) activity and antigen, plasminogen, α2-antiplasmin (α2AP), and soluble thrombomodulin (sTM).
RESULTS: There were 19 subjects (30.6%) with a history of thrombotic events (stroke in 11, myocardial infarction in 8, and pulmonary embolism in 3 patients). They had longer CLT (P = 0.0035 for patients with previous stroke and P = 0.001 for patients with any previous thrombotic event), together with higher PAI-1 (P = 0.025 and P = 0.016, respectively), TAFI activity (P = 0.002 and P = 0.011, respectively), sTM (P = 0.0023 and P = 0.012, respectively), and α2AP (P = 0.007 and P = 0.0006, respectively) than the remaining subjects. AF patients with previous stroke had also higher TAFI antigen than the remainder (P = 0.04). CLT (P = 0.024), PAI-1 (P = 0.022), TAFI activity (P = 0.048), and sTM (P = 0.032, all P for trend) increased with higher CHA2DS2-VASc scores. CLT was not associated with time from thrombotic event to enrollment. Patients taking oral anticoagulants (n = 46) had only slightly higher sTM levels (3.6 [2.9-6.3] vs. 2.9 [2.2-4.1] ng/ml, P = 0.049) than the remaining subjects.
CONCLUSIONS: Stroke or other thromboembolic event in AF patients is associated with impaired lysability of fibrin clots combined with elevated PAI-1, TAFI, sTM, and α2AP.