OC 15.3 - Real World use of Apixaban for the Prevention and Treatment of Thrombosis in Children with Cardiac and Complex Disease

Sunday, July 10, 2022

11:15 AM – 11:30 AM

Location: ExCel Center, ICC Capital Suite Room 14-16

Presentation Format: In-Person

Presenting Author(s)

Christina Vanderpluym, MD

Director of Cardiac Antithrombosis Program and Ventricular Assist Device Program Co-Director of the Stroke and Cerebrovascular Center
Boston Children's Hospital and Harvard School of Medicine
Boston, Massachusetts, United States

Co-Author(s)

Pe

Paul esteso

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

Amy Helllinger

Pharm D Cardiac Antithrombosis Management Program (CAMP)
Boston Children's Hospital
Boston, Massachusetts, United States
CV

Courtney Ventresco

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

Beth Hawkins

Nurse Practitioner
Boston Children's Hospital
Boston, Massachusetts, United States
SO

Sarah O'Brien

Nurse
Boston Children's Hospital
Boston, Massachusetts, United States
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
MC

Maria Cetatoui

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

Jesse Esch

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

Background: Direct oral anticoagulants (DAOCS) are ubiquitous for thromboprophylaxis and treatment in adults.

Aims: We present our experience of Apixaban use for prevention and treatment of thrombosis in children with congenital and acquired cardiac disease, using weight- and level-based dosing.

Methods: Retrospective single-center analysis of cardiac patients < 19 y treated with Apixaban (graduated/not enrolled/ineligible for any other DOAC trial). Patients were evaluated for safety (clinically relevant non-major (CRNM) or major bleeding; thrombotic events) and efficacy (thrombus improvement). Peak Apixaban levels were analyzed according to indication.

Results: Over three years (9/2018-9/2021) 220 children, median age 7 y (0.3-19), median weight 22.4 kg (4.8-160) received Apixaban, totaling 51,013 patient-days. 172 (78%) warranted thromboprophylaxis: 56 (25%) post cardiac surgery, 35 (16%) post catheterization, 22 (10%) failing Fontan, 15 (7%) heart failure, 17 (8%) Kawasaki/MIS-C and 11 (5%) other (including 2 ventricular assist devices). 48 required thrombosis treatment: 11 (5%) arterial, 19 (9%) venous, 15 (7%) intracardiac, and 3 pulmonary (1%). Peak levels (Apixaban chromogenic anti-Xa assay, HE-Stago2) were measured to be 158/220 ng/mL (72%), with median 166 ng/mL [23-474;n=125] among thromboprophylaxis and 153 ng/mL [30-450;n=33] among thrombosis treatment. Based on level and indication, dose adjustment resulted in lower repeat levels in thromboprophylaxis [median 123 ng/mL (23-450); n=36] and higher level in treatment [202 ng/mL (55-450); n=9].
There were 5 bleeding safety events (4 CRNM; 1 major, hemoptysis complicating empyema), all in the thromboprophylaxis group. Bleeding event rate was 3.6 per 100 patient-years of Apixaban. 16% of patients reported minor bleeding or minor adverse events (AEs), including 2 patients with leukopenia and 1 with transaminitis. Improvement in thrombosis was seen in 87% (n=33/38); 1 patient had thrombosis progression (pulmonary embolism requiring surgical revision of pulmonary artery graft).

Conclusion(s): Apixaban use was feasible and safe utilizing commercially available tablets dosed to weight and adjusted based on peak Apixaban levels.