Efficacy and Safety of Very Low-Dose Self-Management of Oral Anticoagulation in Patients With Mechanical Heart Valve Replacement

Background. Self-management improves oral anticoagulation control. Here we provide data of a preplanned interim analysis of very low-dose early self-controlled anticoagulation. Methods. In a prospective, randomized, multicenter trial, 1,137 patients performed low-dose international normalized ratio (INR) self-management with a target INR range of 1.8. to 2.8 for aortic valve replacement recipients and 2.5 to 3.5 for mitral or double valve replacement recipients for the first six postoperative months. Thereafter, 379 patients continued to achieve the aforementioned INR target range (LOW group), whereas the INR target value was set at 2.0 (range, 1.6 to 2.1) for the remaining patients with aortic valve replacement and 2.3 (range, 2.0 to 2.5) for the remaining patients with mitral valve or double valve replacement. One half of this latter group had to check their INR values once a week (VL1 group) the other half twice a week (VL2 group). Patients were followed up for 24 months. Results. Beyond study month six, the incidence of thromboembolic events that required hospital admission was 0.58%, 0.0%, and 0.58% in the LOW, VL1, and VL2 groups, respectively (p = 0.368). The incidence of bleeding events per patient-year was 1.16%, 1.07%, and 0.58% in the LOW, VL1, and VL2 groups, respectively (p = 0.665). Mortality rate did not differ among study groups. Conclusions. Data demonstrate the efficacy and safety of very low-dose INR self-management. (Ann Thorac Surg 2010;90:1487-94) (C) 2010 by The Society of Thoracic Surgeons