High acetylsalicylic acid dosing in infants after modified Blalock–Taussig shunt

Abstract

ObjectiveShunt-related adverse events are frequent in infants after modified Blalock–Taussig despite use of acetylsalicylic acid prophylaxis. A higher incidence of acetylsalicylic acid-resistance and sub-therapeutic acetylsalicylic acid levels has been reported in infants. We evaluated whether using high-dose acetylsalicylic acid can decrease shunt-related adverse events in infants after modified Blalock–Taussig.MethodsIn this single-centre retrospective cohort study, we included infants ⩽1-year-old who underwent modified Blalock–Taussig placement and received acetylsalicylic acid in the ICU. We defined acetylsalicylic acid treatment groups as standard dose (⩽7 mg/kg/day) and high dose (⩾8 mg/kg/day) based on the initiating dose.ResultsThere were 34 infants in each group. Both groups were similar in age, gender, cardiac defect type, ICU length of stay, and time interval to second stage or definitive repair. Shunt interventions (18 versus 32%, p=0.16), shunt thrombosis (14 versus 17%, p=0.74), and mortality (9 versus 12%, p=0.65) were not significantly different between groups. On multiple logistic regression analysis, single-ventricle morphology (odds ratio 5.2, 95% confidence interval of 1.2–23, p=0.03) and post-operative red blood cells transfusion ⩾24 hours [odds ratio 15, confidence interval of (3–71), p<0.01] were associated with shunt-related adverse events. High-dose acetylsalicylic acid treatment [odds ratio 2.6, confidence interval of (0.7–10), p=0.16] was not associated with decrease in these events.ConclusionsHigh-dose acetylsalicylic acid may not be sufficient in reducing shunt-related adverse events in infants after modified Blalock–Taussig. Post-operative red blood cells transfusion may be a modifiable risk factor for these events. A randomised trial is needed to determine appropriate acetylsalicylic acid dosing in infants with modified Blalock–Taussig.

A Narrative Review of Postoperative Anticoagulation Therapy for Congenital Cardiac Disease

“…Heparin-coated polytetrafluoroethylene shunts did not result in histopathologic differences compared to uncoated shunts, nor did their use eliminate the risk for shunt thrombosis ( 34 , 46 ). One single-center study of 68 patients compared “low” (<7 mg/kg/day) and “high” (≥8 mg/kg/day) empiric dosing of aspirin and found no difference in shunt thrombosis rates ( 47 ). One study reported shunt complications and interstage mortality when considering a variety of diagnoses, surgical interventions, and shunt types ( 48 ).…”

Impact of Reticulated Platelets on Platelet Reactivity in Neonates

“…31 In addition, other reports indicated that a pragmatic approach of higher dosages of aspirin (>7 mg/kg/day) may not be sufficient to reduce shunt-related adverse events in infants following modified Blalock-Taussig shunt replacement. 32 These studies suggest the need for platelet function testing and measurement of serum TXB 2 and urinary 11-dehydro-TXB 2 concentrations to determine the appropriate dosing for effective platelet inhibition.…”

Cangrelor PK/PD analysis in post‐operative neonatal cardiac patients at risk for thrombosis

“…7 Moreover, the effectiveness of aspirin, which is commonly used in this patient population once tolerating enteral feeds, remains controversial and is without definitive guidelines for administration. [8][9][10][11][12] Despite the plethora of US Food and Drug Administrationapproved antiplatelet medications for use in adults at high risk for cardiovascular events, neonatal application of these agents is limited because of a lack of information regarding dosing, safety profile, and potential efficacy. 13,14 Thus, many are used off-label with dire consequences as the prevention of thrombosis must be balanced with the risk of bleeding, which is a major concern following palliative surgery for complex CHD.…”

“…Unfortunately, the early institution of unfractionated heparin as parenteral thromboprophylaxis appears to be ineffective at preventing such events, which are initiated predominantly by platelet aggregation rather than activation of the coagulation system 7 . Moreover, the effectiveness of aspirin, which is commonly used in this patient population once tolerating enteral feeds, remains controversial and is without definitive guidelines for administration 8‐12 …”