Oral anticoagulant therapy interruption in children: A single centre experience

The use of anticoagulant therapy in paediatrics is common, with vitamin K antagonists remaining the most commonly prescribed therapy. There is a weak evidence base behind many of the recommendations for anticoagulant therapy in paediatric patients. One of the areas requiring further research is the management of anticoagulant therapy interruption. Interruption to anticoagulation is the period surrounding a planned invasive procedure whereby long term anticoagulation is ceased, and recommenced post procedure. The word bridging refers to the use of low molecular weight heparin or unfractionated heparin to anticoagulate during the period of sub therapeutic INR. To date institutional protocols for bridging anticoagulation are based on adult guidelines. However, there are currently no studies validating the extrapolation of these guidelines to paediatrics. This study seeks to review the clinical outcomes associated with current bridging practices employed at a tertiary metropolitan children's hospital.

The patient population was selected from the warfarin management registry of a Clinical Haematology service of a major metropolitan children's hospital. The admission history of these patients was queried to identify admissions where anticoagulation interruption would typically be required. Namely, these were dental extraction, cerebral or cardiac angiography, or cardiac catheterization. Data relating to demographics, anticoagulant therapy interruption plan, and clinical outcomes were recorded.

A total of 61 admissions for children aged between 1 year and 17 years and 11 months were analysed for this study. Congenital heart disease (CHD) was the primary underlying disease for which long-term oral anticoagulation with warfarin was indicated. Children with Moyamoya in this cohort were treated more consistently compared to the other disease groups. There were no instances of major bleeding (n=0) or thrombotic events (n=0).

This study describes the current practices and outcomes associated with anticoagulant therapy interruption at one institution thereby filling an evidence gap in the paediatric anticoagulant management. It achieved this by analysing the largest and most representative cohort to date. This project is a stepping stone from which future studies of safety and efficacy of paediatric anticoagulation interruption management can be developed.