Anticoagulation management and poor clinical outcomes in tamariki and rangatahi with rheumatic heart disease following mechanical valve replacement surgery in Counties Manukau

AIM: Rheumatic heart disease (RHD) causes significant cardiovascular morbidity and mortality, with persisting inequitably high rates in Māori and Pacific tamariki and rangatahi. Mechanical valve replacement surgery is required for people with severe RHD and requires lifetime anticoagulation. Contemporary data regarding anticoagulation management and outcomes for tamariki and rangatahi following mechanical valve replacement surgery for RHD are lacking. We aimed to describe patient characteristics, anticoagulation management practices and complications in a cohort of tamariki and rangatahi ≤25 years of age. METHODS: A retrospective observational study of patients aged ≤25 years with RHD and mechanical valves, living in Counties Manukau, South Auckland, 2016-2021, was conducted. RESULTS: A total of 53 patients were identified. The median age at time of first mechanical valve surgery was 15 years (range 4-23 years). Nineteen percent of the cohort were Māori and 81% were Pacific peoples. The median duration of anticoagulation was 4 years (range 0.5-18 years). The most common method of monitoring was via the community laboratory service and general practitioner. There were 38 individuals who had ≥1 anticoagulation-related hospitalisation. There were 80 anticoagulation-related hospitalisations: 52% were due to a subtherapeutic international normalised ratio (INR) without clinical complication; 15% had a supratherapeutic INR without clinical complication; 14% haemorrhage; 9% stroke; 6% other thromboembolic events; and 4% prosthetic valve thrombosis. Five deaths occurred between 2016 and 2021. CONCLUSION: The majority of the cohort had serious anticoagulation-related hospitalisation events, and 10% died. Urgent efforts are required to improve services for anticoagulation monitoring and management and clinical outcomes in young adults following mechanical valve surgery for RHD.