YM-60828 is an FXa inhibitor with antithrombotic properties. In the rat arteriovenous shunt model, YM-60828 does not prolong coagulation time but reduces the levels of thrombin-antithrombin III complex (TAT) in a dose-dependent manner. YM-60828 exhibits only anti- FXa activity and does not show anti-thrombin activity, indicating that its antithrombotic effect is independent of thrombin. Therefore, the antithrombotic effect of YM-60828 can be monitored by TAT.