Platelet Inhibition in Shunted Infants on Aspirin at Short and Midterm Follow-Up

• Published in: Pediatric cardiology Vol. 38; no. 2; pp. 401 - 409
• Main Authors: Truong, Dongngan T., Johnson, Joyce T., Bailly, David K., Clawson, Jason R., Sheng, Xiaoming, Burch, Phillip T., Witte, Madolin K., LuAnn Minich, L.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.02.2017; Springer
• Subjects: Aspirin; Aspirin - administration & dosage; Aspirin - adverse effects; Blood clot; Cardiac Surgery; Cardiac Surgical Procedures - adverse effects; Cardiology; Clopidogrel; Female; Follow-Up Studies; Heart Defects, Congenital - surgery; Hemorrhage - etiology; Humans; Infant; Infants; Linear Models; Male; Medicine; Medicine & Public Health; Original Article; Pilot Projects; Platelet Aggregation - drug effects; Platelet Aggregation Inhibitors - administration & dosage; Platelet Aggregation Inhibitors - adverse effects; Prospective Studies; Thrombelastography; Thrombosis; Thrombosis - epidemiology; Thrombosis - etiology; Thrombosis - prevention & control; Vascular Surgery; Coagulation/anticoagulation; Congenital heart disease; Blood
• ISSN: 0172-0643; 1432-1971; 1432-1971
• DOI: 10.1007/s00246-016-1529-x

There are few data to guide aspirin therapy to prevent shunt thrombosis in infants. We aimed to determine if aspirin administered at conventional dosing in shunted infants resulted in ≥50% arachidonic acid (AA) inhibition in short and midterm follow-up using thromboelastography with platelet mapping (TEG-PM) and to describe bleeding and thrombotic events during follow-up. We performed a prospective observational study of infants on aspirin following Norwood procedure, aortopulmonary shunt alone, or cavopulmonary shunt surgery. We obtained TEG-PM preoperatively, after the third dose of aspirin, at the first postoperative clinic visit, and 2–8 months after surgery. The primary outcome was the proportion of subjects with ≥50% AA inhibition on aspirin. All bleeding and thrombotic events were collected. Of 24 infants analyzed, 13% had ≥50% AA inhibition at all designated time points after aspirin initiation; 38% had ≥50% AA inhibition after the third aspirin dose of aspirin, 60% at the first postoperative clinic visit, and 26% 2–8 months after surgery. Bleeding events occurred in eight subjects, and two had a thrombotic event. Bleeding events were associated with greater AA inhibition just prior to starting aspirin ( p  = 0.02) and after the third dose of aspirin ( p  = 0.04), and greater ADP inhibition before surgery ( p  = 0.03). The majority of infants failed to consistently have ≥50% AA inhibition when checked longitudinally postoperatively. Preoperative TEG-PM may be useful in identifying infants at higher risk of bleeding events on aspirin in the early postoperative period. Further research is needed to guide antiplatelet therapy in this population.