Anticoagulant therapy in children with prosthetic valves

The purpose of this study was to evaluate the effectiveness and complications of several types of anticoagulant therapy in children with prosthetic valves. During a 7-year period ending April 1985, 130 children aged 1 to 19 years underwent left-sided valve replacement. Operative mortality was 3%, 5%, and 9%, respectively, for aortic, mitral, and aortic and mitral valve replacement. Among the 123 survivors, 32 (26%) had had aortic, 71 (58%) had had mitral, and 20 (16%) had had aortic and mitral valve replacement. Follow-up ranged from 2 months to 8.2 years, a total of 544 patient-years. The survivors were divided into three groups based on anticoagulant treatment: warfarin sodium, aspirin plus dipyridamole, and no anticoagulants. Among the patients who had aortic valve replacement, thromboembolic complications developed in 2.5% ( 2.5 / 100 patient-years) of the aspirin plus dipyridamole group and 5% of the group given no anticoagulants. Only the warfarin group (4%) experienced bleeding complications. Among the patients having mitral valve replacement, thromboembolic complications developed in 4% of the warfarin group, 3% of the aspirin plus dipyridamole group, and 11% of the no anticoagulant group. In addition, 2% of patients in the warfarin group experienced severe bleeding. Two fatal cerebrovascular accidents occurred, both in the aspirin plus dipyridamole group. Patients who received a mitral heterograft were not prescribed any anticoagulant medications, and no thromboembolic complications developed. Among patients having doable-valve replacement, complications developed in 5% of the warfarin group and 27% of the group given no anticoagulants. Based on these data, aspirin plus dipyridamole appears adequate for patients having aortic valve replacement, whereas warfarin is required in patients having double-valve replacement. Patients having mitral valve replacement with heterografts require no anticoagulation, but those with mechanical valves may need warfarin anticoagulation. There are not adequate data to evaluate the safety and efficacy of the combined use of warfarin and a platelet-inhibiting drug in children.