Pediatric Cardiology and Cardiac Surgery
Vol.26 No.1 2010 (49-53)

Yoshimasa Uno, Kiyozo Morita, Masahito Yamashiro, Gen Shinohara, and Koichi Muramatsu

Department of Cardiac Surgery, The Jikei University School of Medicine, Tokyo, Japan


Backgraound: There is still no consensus concerning the postoperative use and duration of warfarin as anticoagulation therapy for Fontan patients. The indication and timing for conversion to an antiplatelet agent are dependent on the surgeons or cardiologists in each hospital. We evaluate the changes of coagulability and fibrinolytic function after the surgery and try to use them as an indicator of anticoagulation therapy.
Methods: Plasma levels of thrombin antithrombin-3 complex (TAT) as the index of coagulability and α2-plasmin inhibitor-plasmin complex (PIC) as the index of fibrinolytic function were measured in 16 extracardiac Fontan patients (mean age at operation, 4.2 years). Intracardiac thrombus was also detected using primarily trans-thoracic echocardiography during the period of this study. Mean follow-up was 18.7 months (6 to 60 months) after the surgery.
Results: There were no late deaths or major complications. Both levels of TAT and PIC remained higher than normal within 6 months after surgery, even when taking warfarin. The levels began declining gradually and were almost normalized by 12 months. Confirming these results, we have converted warfarin to an anti-platelet agent for those cases. Even after its conversion, plasma levels have remained normal and no patient showed a thromboembolic event in echocardiography.
Conclusions: This study suggests that Fontan patients should receive warfarin as anticoagulation therapy for the first postoperative year, because of their activated status of coagulability. However, warfarin could be replaced by an anti-platelet agent for patients with normal results and no major complication up to 12 months after surgery.