VPB0285 - Pediatric Thromboprophylaxis of Large Coronary Artery Aneurysm using Rivaroxaban

Background: Giant or large coronary artery aneurysms (CAA) are a rare occurrence in the pediatric population, most often secondary to Kawasaki disease. Anticoagulation therapy is recommended for prevention of thromboembolic events with either warfarin or low molecular weight heparin (LMWH). There are no currently published reports on the use of a direct oral anticoagulant (DOAC) in the pediatric population for this indication.

Aims: Describe the anticoagulation management of a pediatric patient with large coronary artery aneurysm secondary to Kawasaki disease using rivaroxaban, a DOAC.

Methods: Chart review of an 8-year-old male diagnosed with a persistently dilated right coronary artery aneurysm secondary to Kawasaki disease at age 4 years.

Results: A large to giant aneurysm (6-8mm) in the distal right coronary artery was noted one month following Kawasaki diagnosis. Patient was initially treated with high dose aspirin therapy with reduction to low dose aspirin and addition of low molecular weight heparin (LWMH) at the time of imaging findings. Therapy was complicated by multiple bleeding events, in the form of calf hematomas, prompting a switch from LMWH to warfarin. Due to labile INR levels on warfarin therapy, he was transitioned to rivaroxaban therapy (5 mg twice daily per weight-based dosing used in a phase III randomized controlled trial in children) two years following initial diagnosis of CAA. CAA has remained stable for greater than one year on dual anticoagulation with rivaroxaban and low dose aspirin without any thrombotic event or bleeding complication.

Conclusion(s): The use of rivaroxaban as an alternative to tradition vitamin K antagonist or LMWH appears to be safe and effective in the prevention of thrombosis in a pediatric patient with large to giant CAA.