부산대학교 도서관

The use of apixaban in the pediatric cardiac population is expanding. We describe our apixaban dosing and monitoring strategy in children and young adults awaiting heart transplantation and outcomes related to bleeding and thrombosis during wait-list and early post-transplant periods. Retrospective, single center analysis of all patients on apixaban awaiting cardiac transplantation. Weight based dosing was monitored with peak drug-specific anti-Xa chromogenic analysis (apixaban levels). Goal apixaban peak levels were extrapolated from adult studies and center experience (prophylaxis 80-150 ng/mL, VAD or treatment 100-300 ng/ml). Between 2/1/2020 and 10/10/2022, 17 patients, median age 11.1 years (0.8 to 24), weighing 45.4 kg (6.76-101.5) received apixaban (median dose 5 mg po BID (0.625-7.5)). Indication was prophylaxis (n=16) and treatment of thrombus (n=1). Four patients were on aspirin co-therapy. There were no clinically relevant non-major, or major bleeding or thrombotic events while awaiting transplant. Median time from last apixaban dose to arrival in OR was 23.2 hours (15.6-33.8), with median random apixaban level of 45.6 ng/ml (<23-81.5), 6.3 hours (0-19.3) prior to arrival in OR. There were no reports of increase in perioperative bleeding. One patient received recombinant Factor Xa (ANDEXXA) with protamine reversal, despite hemostasis and pre-operative apixaban level of 29 ng/ml. This patient developed acute graft failure requiring ECMO in the first 12 hours. Angiogram POD 4 showed multiple pulmonary emboli, with subsequent death. One Fontan patient with complex venous reconstruction developed intra-operative upper venous thrombosis, requiring catheterization for recanalization immediately post-transplant. This event was not felt attributable to apixaban. One patient managed on HM3 LVAD with Apixaban and ASA prophophylaxis developed a global neurologic injury in the peri-transplant period unrelated to bleeding or thrombosis and likely unrelated to apixaban. Careful use of apixaban can be safe and effective while awaiting heart transplant. Anti-Xa monitoring can assess drug clearance preoperatively. There was no appreciable increase in perioperative bleeding. We advise against empiric use of recombinant FXa in the absence of life threatening bleeding, as potential trigger of thrombosis. [ABSTRACT FROM AUTHOR]