Objectives: Thromboembolic complications account for significant morbidity after total cavopulmonary anastomosis. Prophylactic regimen includes antiplatelet medication with aspirin (acetylicsalicylic acid) in selected patients. The aim of this cross-sectional study was to evaluate the response to aspirin medication during long-term follow-up in children and adolescents after Fontan operation as in adult patients persisting platelet activation under Aspirin medication was found in 5 to 56% suggesting an increased risk for vascular events.
Methods and results: Twenty-seven consecutive patients (age range 2,3 to 26 years) who were taking aspirin (range 1,4 to 5 mg/kg/d) were seen on an outpatient basis having a mean follow-up of 7,8 years (SD 3.9 yeasr). Only in two patients the daily dose of aspirin was above 100mg.
As part of the routine follow-up platelet function was monitored using the platelet function analyzer (PFA-100). None of the patients included had had or was suspicious of a thromboembolic event or bleeding complication. With the PFA-100 the epinephrine closure time was prolonged in 16/27 patients (59,2%). There was no significant relation between closure time and aspirin dose per body weight or body surface area or age at examination.
Conclusion: Therapeutic monitoring of the individual efficacy of antiplatelet medication with the platelet function analyzer identifies a great variability in aspirin response in children and adolescents with the potential need for modification of the daily dose or initiating further detailed evaluation and change of the prophylactic regimen when aspirin resistance is suspected.