Novel use of cangrelor in pediatrics: A pilot cohort study demonstrating use in ventricular assist devices

Gaseous Nitric Oxide-Cangrelor Combination to Prevent Clots in Extracorporeal Life Support System

INTRODUCTION

The objective of this study was to investigate the potential synergistic utility of a combination of gaseous nitric oxide (gNO)-intravenous Cangrelor as an effective pharmacological option for the prevention of thrombosis in an animal model of extracorporeal life support (ECLS) circuits.

METHODS

10 newborn lambs were placed on ECLS. 5 of them were administered a combination of gNO and intravenous Cangrelor. The remaining 5 were not administered any anticoagulant. The primary end point was duration of ECLS without clot formation. The secondary outcome measure was the absolute maximum transmembrane pressure gradient.

RESULTS

The mean duration of ECLS were 168 min (standard deviation 224.98 min) in the control group and 402 min (standard deviation 287.5 min) in the experimental group (P = 0.17). The peak trans-oxygenator pressure difference was 43 mm Hg (standard deviation 23 mm Hg) in the control group and 62 mm Hg (standard deviation 71 mm Hg) in the experimental group(P = 0.64). Two animals in the experimental group were supported up to 12 h without clot formation. Clot formation in the experimental group occurred after placement of the cannulae but prior to initiation of ECLS flows after cannulation.

CONCLUSIONS

A combination of gNO and Cangrelor is prevents clot formation in an experimental animal model when administered through a clean clot-free circuit. However, the combination s ineffective when there are pre-existing clots in the circuit. A bolus of anticoagulation prior to cannulation is needed prior to testing this combination in future studies with a larger sample size.

Platelet function in neonates and children

Platelets are major regulators of haemostasis and coagulation. The primary role of platelets in coagulation is to form a stable clot and stop bleeding. Studies of platelet phenotype and function in neonates and children have been restricted by the large volumes required for many common platelet function tests such as platelet aggregometry. Developmental changes in platelets have not been as well described as developmental changes in plasma coagulation proteins, and overall, platelet phenotype and function in neonates and children has been understudied when compared to adults. Recent developments in more sensitive platelet function testing methods requiring smaller blood volumes such as flow cytometry has enabled recent studies to further investigate platelet phenotype and function in neonates and children. In this review we will provide an overview of recent advances from the past five years in platelets in the context of developmental haemostasis, as well as the role of platelets in neonatal paediatric disease.

Cangrelor Dosing and Monitoring for Prevention of Acute Systemic-to-Pulmonary Artery Shunt Thrombosis in Neonates

OBJECTIVE

Systemic-to-pulmonary artery shunts are amongst the most common palliative procedures performed in neonates with congenital heart defects. These procedures require immediate postoperative thromboprophylaxis to prevent life-threatening shunt thrombosis. The novel use of intravenous P2Y12 platelet receptor antagonists has led to a need for dosing recommendations and monitoring. This study aims to determine cangrelor dosing in neonates through laboratory assessment of P2Y12 receptor reactivity and adverse events.

METHODS

Observational retrospective cohort study on the use of cangrelor for thromboprophylaxis in the immediate postoperative period of neonates undergoing placement of systemic-to-pulmonary artery shunts in a tertiary children's hospital from March 2020 to March 2021.

RESULTS

Ten neonates receiving cangrelor post systemic-to-pulmonary artery shunt placement were included in the study. Median age and weight were 4 days (IQR, 2.75–5.25) and 3.49 kg (IQR, 3.1–3.75), respectively. Five (50%) patients received a 3.5-mm shunt, while the remaining patients received a 4-mm shunt. For thrombin inhibition, 5 (50%) patients received heparin and 5 (50%) received bivalirudin. Median cangrelor dose was 0.1 mcg/kg/min (IQR, 0.1–0.1). Median achieved P2Y12 reaction units (PRU) at this cangrelor dose was 127.5 (IQR, 72.5–173.75). No shunt thrombosis occurred in these patients; however, there was 1 minor hemorrhagic event.

CONCLUSIONS

Our study suggests that a cangrelor dose of 0.1 mcg/kg/min is associated with therapeutic PRU and prevents shunt thrombosis in neonates post systemic-to-pulmonary artery shunt, with minimal hemorrhagic complications.