| Optimal Anticoagulant Therapy
after Mechanical Valve Replacement Reviewed in Terms of Activity
of Coagulation and Fibrinolysis |
(Department of Cardiovascular Surgery, Hachioji
Medical Center, Tokyo Medical University, Hachioji, Japan and
Second Department of Surgery, Tokyo Medical University*, Tokyo,
Japan)
| Naoki Konagai |
Hiromi Yano |
Mitsunori Maeda |
| Tatsuhiko Kudo |
Shin Ishimaru* |
|
|
Patients with mechanical valve prosthesis
must receive long-term oral anticoagulant therapy, thus it is
important to set the optimal international normalized ratio of
prothrombin time (PT-INR) that effectively prevented thromboembolic
complications without excessive bleeding. In this study, anticoagulant
therapy was evaluated in terms of the activity of coagulation
and fibrinolysis in 137 patients after isolated mechanical valve
replacement. With a lower target range of 1.5 -2.0 for the PT-INR,
thrombin antithrombin III complex (TAT) increased to more than
3.0 ng/ml in 30 cases, and the activity of coagulation appeared
to increase due to insufficient anticoagulant therapy. After
the target range was raised to 2.0 -2.5 in all cases, the PT-INR
increased significantly from 1.63 to 2.25 (p<0.01)
and TAT decreased significantly from 7.58 to 2.81 ng/ml (p<0.01).
This showed that activity of coagulation and fibrinolysis was
suppressed by high intensity anticoagulation. It is necessary
to review the individual activity of coagulation and fibrinolysis
to determine the intensity of anticoagulation. We recommend 2.0
-2.5 as the target range for the PT-INR.
Jpn. J. Cardiovasc. Surg. 33: 9 -12 (2004) |
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