Abstract
To screen for risk of embolism, we investigated the association between the presence of left atrial (LA) thrombus by transesophageal echocardiography (TEE) and blood coagulation tests, including thrombin-anti-thrombin III complex (TAT), plasminogen activator inhibitor 1 (PAI-1), plasmin-α2-plasmin inhibitor complex (PIC), D-dimer, tissue plasminogen activator (tPA), free tPA, tPA·PAI-1 complex, prothrombin fragment 1+2 and fibrin degradation product E (FDP-E) in 40 patients with atrial fibrillation (Af) (13 males, 27 females, mean age 76±8yrs). Blood coagulation tests were performed in 21 control subjects with sinus rhythm (12 males, 9 females, mean age 75±4yrs). LA thrombi were detected in the appendage of 8 patients and in the atrium of 6 patients. Severe atherosclerotic plaque with thrombi in the thoracic aorta were detected in 6 patients without LA thrombi. FDP-E, D-dimer and PIC increased significantly in patients with LA thrombi or aortic plaque in comparison with controls with sinus rhythm. In patients with Af, 25 of them (group A) has more than 4 abnormal coagulation values out of 9 tests and 15 of them (group B) had abnormalities in less than 3 tests. LA thrombi or aortic plaque were detected in 18 patients in group A and 2 patients in group B (72% vs 13%, p<0.01). In 4 of 6 patients with large LA thrombi, the thrombi were resolved after administration of warfarin. Before administration of warfarin, tPA, PA-1 and tPA·PA-1 complex levels were higher in the two patients whose thrombi did not resolve. Thus, the combination of blood coagulation tests and TEE may be useful in early screening for risk of embolism in aged patients with Af and in predicting the effect of warfarin therapy on LA thrombi.
