PRETHROMBOTIC STATE DUE TO HYPERCOAGULABILITY IN PATIENTS WITH PERMANENT TRANSVENOUS PACEMAKERS

Venous thrombosis is a relatively usual but serious complication of pe rmanent transvenous pacing. However, the pathogenesis has not been def ined. To clarify underlying abnormalities in the coagulation-fibrinoly sis system in patients with permanent transvenous pacemakers, we measu red serum levels of fibrinopeptide A (FPA), thrombin-antithrombin III complexes (TATs), plasmin-alpha(2) plasmin inhibitor complexes (PICs), D-dimer (D-D), beta-thromboglobulin (beta-TG), and platelet factor 4 (PF4) in 53 patients with permanent transvenous pacemakers and 10 cont rol subjects. The patients were divided into two groups, as follows, a ccording to the presence of mural thrombus documented along the pacing lead(s) by digital subtraction angiography and transesophageal echoca rdiography: Group Th (-), patients without venous route thrombus; and Group Th (+), patients with venous route thrombus. FPA and TAT levels increased significantly even in Group Th (-), and further increased in Group Th (+) compared with control subjects (FPA: 7.5 +/-4.9, 15.3 +/ -8.8 vs 3.0 +/-1.4 ng/mL, respectively,P<0.05; TAT: 2.9 +/-1.3, 4.8 +/ -2.3 vs 1.7 +/-0.6 ng/mL, respectively, P<0.05). There were no differe nces in levels of D-D, PIC, beta-TG, and PF4 among control subjects, G roup Th (-), and Group Th (+). These findings suggest that the hyperco agulable state appears in patients with permanent transvenous pacemake rs, even without apparent venous thrombosis. The patients with permane nt transvenous pacemakers are thought to be in the prethrombotic state even if they have no venous route thrombosis.