Gene-based anticoagulation regimens for an infant after mitral-valve replacement: A case report

RATIONALE: Heart-valve replacement is one of the main surgical methods for various heart-valve diseases. Warfarin is the only oral anticoagulant used for thrombosis prevention after heart-valve replacement. However, warfarin has a narrow therapeutic window, large differences in efficacy between individuals, and can be affected by drugs, food and disease status. PATIENT CONCERNS: We used the Hamberg model to develop an anticoagulation regimen for a 10-month-old Chinese male after mitral-valve replacement. DIAGNOSES: Echocardiography revealed mitral malformation with severe regurgitation, patent foramen ovale, thickening of the left ventricular wall, enlargement of the left atrium, and the overall systolic function of the left ventricle was lower than normal. INTERVENTIONS: First, the patient was treated with Mitral valvuloplasty plus temporary implantation of a pacing wire. Since this was inadequate, he underwent mitral-valve replacement. Then, we used the Hamberg model to develop an anticoagulation regimen. OUTCOMES: After discharge from hospital, the pharmacist provided anticoagulation management for this pediatric patient using an “Online Anticoagulation Clinic” (OAC). Point-of-care testing could be employed by the boy's mother at home to obtain the International Normalized Ratio. His time to response was 89.6% during the 6 months after hospital discharge, and adverse reactions such as bleeding or thrombosis did not occur. LESSONS: This is the first time the Hamberg model has been employed to design anticoagulation therapy for an Asian infant. His anticoagulation therapy may be managed using the OAC.