The impact of non heparin-induced thrombocytopenia on the clinical outcomes for pediatric cardiac surgery patients who required veno-arterial extracorporeal membrane support (VA-ECMO) for failure to wean from cardiopulmonary bypass (CPB) is uncertain. This study aimed to investigate the relationship between thrombocytopenia and prognosis in these patients.

This retrospective study enrolled 96 pediatric patients (age < 18) who received VA-ECMO directly transitioned from CPB at Fuwai Hospital from January 2010 to June 2020. The association between relative decrease in platelet count (△PLT) post-ECMO 24 h and clinical outcomes was explored.

There were significant differences in Post-ECMO 24 h platelet counts, platelet count nadir, and duration of platelet decline between the survivors and non-survivors in CPB-ECMO groups. A positive correlation was found between △PLT post-ECMO 24 h and plasma-free hemoglobin (pFHb) (p = .014, r = 0.305), peak serum creatinine (p = .016, r = 0.299), peak AST (p = .014, r = 0.302), duration of platelet transfusion (p = .032, r = 0.270),The △PLT post-ECMO 24 h had predictive value on in-hospital mortality [(p < .001, AUROC = 0.781 (95% CI: 0.670–0.892)], massive bleeding (p = .001, AUROC 95% CI: 0.627–0.870), hemolysis (p = .046, AUROC 95% CI: 0.510–0.780), and nosocomial infection (p = .020, AUROC 95% CI: 0.536–0.801). Multivariate logistic regression showed that △PLT post-ECMO 24 h was associated with in-hospital mortality and hemolysis.

The relative early decrease in platelet count 24 h following transition to ECMO is associated with increased patient mortality, and is positively associated with adverse outcomes in pediatric cardiac surgery patients transferred from CPB to ECMO. Moreover, this decline rate can predict in-hospital survival, major bleeding, hemolysis, and hospital-acquired infections.