[Mitral Valve Replacement with the On-X Valve]

This is a 3-case report of mitral valve replacement (MVR) with an On-X mechanical valve followed up to 10 years. Case 1(64-year-old man) and case 2 (66-year-old woman) experienced traffic accident and traumatic event, respectively, in their chronic phase after MVR. Case 1 had multiple bone fractures of the bilateral lower limbs, which was followed by systemic infection and pyogenic spondylitis. He needed long-term antibiotics therapy for more than 4 years. Case 2 fell down at home and severely hit her head, which resulted in a traumatic subarachnoid hemorrhage. She was in a deep coma, and needed discontinuation of anticoagulation therapy for 4 weeks. Case1, 2, and 3(54-year-old man) are doing well in New York Heart Association functional class I without any valve-related thromboembolic or hemorrhagic events at 10, 9 and 8 years after MVR, respectively. On-X valve performance has also been found well maintained in all cases by echocardiography, even after traumatic accident or discontinuation of anticoagulation in Case 1 and 2. In this report, the On-X mechanical valve demonstrated good midterm result of its valve performance in the mitral position and its potential advantages in antithrombogenicity.