Two-year outcomes following a randomised platelet transfusion trial in preterm infants

Objective Assess mortality and neurodevelopmental outcomes at 2 years of corrected age in children who participated in the PlaNeT-2/MATISSE (Platelets for Neonatal Transfusion - 2/Management of Thrombocytopenia in Special Subgroup) study, which reported that a higher platelet transfusion threshold was associated with significantly increased mortality or major bleeding compared to a lower one.Design Randomised clinical trial, enrolling from June 2011 to August 2017. Follow-up was complete by January 2020. Caregivers were not blinded; however, outcome assessors were blinded to treatment group.Setting 43 level II/III/IV neonatal intensive care units (NICUs) across UK, Netherlands and Ireland.Patients 660 infants born at less than 34 weeks' gestation with platelet counts less than 50x10(9)/L.Interventions Infants were randomised to undergo a platelet transfusion at platelet count thresholds of 50x10(9)/L (higher threshold group) or 25x10(9)/L (lower threshold group).Main outcomes measures Our prespecified long-term follow-up outcome was a composite of death or neurodevelopmental impairment (developmental delay, cerebral palsy, seizure disorder, profound hearing or vision loss) at 2 years of corrected age.Results Follow-up data were available for 601 of 653 (92%) eligible participants. Of the 296 infants assigned to the higher threshold group, 147 (50%) died or survived with neurodevelopmental impairment, as compared with 120 (39%) of 305 infants assigned to the lower threshold group (OR 1.54, 95% CI 1.09 to 2.17, p=0.017).Conclusions Infants randomised to a higher platelet transfusion threshold of 50x10(9)/L compared with 25x10(9)/L had a higher rate of death or significant neurodevelopmental impairment at a corrected age of 2 years. This further supports evidence of harm caused by high prophylactic platelet transfusion thresholds in preterm infants.

Automated summary

This study aims to assess mortality and neurodevelopmental outcomes in children participating in the PlaNeT-2/MATISSE study at 2 years of corrected age. The results show that a higher platelet transfusion threshold is associated with significantly increased mortality or major bleeding compared to a lower one. This further supports evidence of harm caused by high prophylactic platelet transfusion thresholds in preterm infants.