Background and Goal of Study:
Conflicting results exist regarding platelet (PL) count/function in infants with Cyanotic (Cyan) compared to Acyanotic (Acyan) heart disease.  We investigated this point and analysed the transfusion rate of PL concentrates in a homgeneous group of infants with these pathologies.
Materials and Methods:
This is a subanalysis of a prospective double-blinded randomised trial (NCT02567786) evaluating the effectiveness of a pump prime based on FFP vs Plasmalyte®  in infants weighing 7-15 kg and undergoing open-heart surgery. Blood was drawn for PL count and PL function evaluated by Point Of Care (POC) tests Multiplate® (ADP, ASPI, TRAP) and ROTEM® after the induction of anaesthesia (T1), at the end of cardiopulmonary bypass (T2) and at Paediatric Intensive Care Unit (PICU) arrival (T3). Transfusion was based on clinical bleeding and guided with POC tests.  A repeated measure ANOVA was performed to analyse the effect of time and group on PL count and function. A Student’s t-test and Fisher’exact were used to respectively compare continuous and categorical variables between both groups.
Results and Discussion:
After parental informed consent 30 children were included of whom 29 analysed. There was no significant difference between groups regarding POC tests and PL count. There was a statistically significant difference within groups for PL count, MCF EXTEM and ADP: p <0.001 T1 vs T2 and vs T3. This effect was much less observed for ASPI/TRAP. The transfusion of PL concentrates was similar between both groups.
Conclusion(s):
The results of this study show that PL number as well as PL function analysed by ROTEM® significantly deteriorate after CPB in infants with Cyan as well as Acyan heart disease without significant difference between groups. 
PL function test Multiplate® did not give additional information already available with PL count and ROTEM®. 
The transfusion of PL concentrate was not significantly different between both groups although children with Cyan heart disease showed statistically significant more blood loss up to 6 h postoperatively.

01 / Point-of-care assessment of platelet aggregation in infants and children with cyanotic and acyanotic heart disease undergoing open-heart surgery.