Hemostatic effects of 1 mg daily warfarin on post CABG patients

Although coronary bypass graft surgery has increased the survival and quali ty of life of many individuals, patients remain at risk of restenosis and t hrombotic occlusion of the coronary arteries and bypass grafts. In the scre ening period for participation in the multicenter Post Coronary Artery Bypa ss Graft (Post CABG) trial, the effects of 1 mg daily warfarin were evaluat ed using paired patient samples collected prior to and after at least 21 da ys of treatment. In stable patients (n = 40; 39 males 1 female; 51-74 years old) who previously had undergone coronary artery revascularization (1-10 years), no alterations in prothrombin time, international normalized ratio (INR), prothrombin fragment 1.2, or the hemostatic risk factors factor VII antigen and coagulant activity, von Willebrand's factor, fibrinogen, tPA, o r PAI-1 were associated with the 1 mg daily warfarin treatment. The observa tions reported here supported the Post CABG Studies Steering Committee deci sion to treat patients with 1-4 mg warfarin daily adjusted to achieve INRs not to exceed 2.0 consistent with low-intensity therapy.