VPB0281 - The use of Apixaban for thromboprophylaxis and treatment in children with cardiac disease younger than 6 months of age

Sunday, July 10, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: Virtual

Presenting Author(s)

Paul Esteso, MD PhD

Instructor in Pediatric Cardiology
Boston Children's Hospital, Harvard University
Boston, Massachusetts, United States

Co-Author(s)

RK

Ryan Kobayashi

Attending in cardiology
Boston Children's Hospital
Boston, Massachusetts, United States
RW

Ryan Williams

Attending in cardiology
Mattel Children’s Hospital at UCLA
Los Angeles, California, United States
CV

Courtney Ventresco

Cardiac Pediatric Nurse Practitioner
Boston Children's Hospital
Boston, Massachusetts, United States
BH

Beth Hawkins

Cardiac Pediatric Nurse Practitioner
Boston Children's Hospital
Boston, Massachusetts, United States
MC

Maria Cetatoui

Research Coordinator
Boston Children's Hospital
Boston, Massachusetts, United States
JE

Jesse Esch

Pediatric Cardiologist
Boston Children's Hospital, Harvard University
Boston, Massachusetts, United States
CV

Christina J. VanderPluym

Assistant Professor and Pediatric Cardiologist
Children’s Hospital, Harvard University
Boston, Massachusetts, United States

Background: Antithrombosis for children with congenital heart disease (CHD) is complicated by developmental hemostasis, difficult administration and monitoring. The evaluation of novel anticoagulation strategies is critical. To our knowledge, we report the first use of Apixaban in this age group with commercially available dosing.

Aims: Evaluate safety (clinically relevant non-major (CRNM) or major bleeding; thrombotic events) and efficacy (thrombosis improvement and resolution) of Apixaban in children with CHD.

Methods: Retrospective single-center analysis of children < 6 months old with CHD treated with Apixaban.

Results: From 1/2020-12/2021, 24 children < 6 months received Apixaban, median age 4.7 months (0.4-5.9), median weight 5.2 kg (2.9-6.5), for 2815 total days (1-396). Single ventricle CHD accounted for 14/24. Eight required thromboprophylaxis, 16 treatment (8 arterial, 1 intracardiac, 10 venous; 4 multifocal). Over half (13) received concomitant aspirin. Smallest dose possible using 2.5 mg tablets was 0.625 mg BID (21/24 patients) with median dose of 0.15 mg/kg/dose, median peak level (Apixaban chromogenic anti-Xa assay, HE-Stago 2) of 205 ng/ml (66-396, n=21). Based on level and indication, 10 patients required 1.25 mg BID (0.22 mg/kg/dose). Those requiring 0.625 mg BID were smaller (4.65 vs 5.5 kg).
There was no major bleeding and 2 patients had CRNM bleeding (blood-streaked stools) prompting discontinuation of Apixaban. One received concurrent aspirin. Supratherapeutic level of >400 ng/ml at minimum dose in 1 patient, in the absence of any symptoms, prompted discontinuation as a precautionary measure. One patient was transitioned to daily dosing without difficulty in achieving goal peak and trough levels. Two patients died during the study period due to progression of their underlying disease, for reasons unrelated to anticoagulation. Apixaban was associated with thrombus improvement or resolution in 11/16 (69%) patients.

Conclusion(s): Apixaban administration with commercially available tablets was feasible in young children with low rate of bleeding events.