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

Carmel Maria Moore, Angela D’Amore, Suzanne Fustolo-Gunnink, Cara Hudson, Alice Newton, Beatriz Lopez Santamaria, Alison Deary, Renate Hodge, Valerie Hopkins, Ana Mora, Charlotte Llewelyn, Vidheya Venkatesh, Rizwan Khan, Karen Willoughby, Wes Onland, Karin Fijnvandraat, Helen V New, Paul Clarke, Enrico Lopriore, Timothy Watts, Simon Stanworth, Anna Curley, Moore, Carmel Maria, D'Amore, Angela, Fustolo-Gunnink, Suzanne, Hudson, Cara, Newton, Alice, Santamaria, Beatriz Lopez, Deary, Alison, Hodge, Renate, Hopkins, Valerie, Mora, Ana, Llewelyn, Charlotte, Venkatesh, Vidheya, Khan, Rizwan, Willoughby, Karen, Onland, Wes, Fijnvandraat, Karin, New, Helen V, Clarke, Paul, Lopriore, Enrico, Watts, Timothy, Stanworth, Simon, Curley, Anna, ,

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. 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. 43 level II/III/IV neonatal intensive care units (NICUs) across UK, Netherlands and Ireland. 660 infants born at less than 34 weeks' gestation with platelet counts less than 50×109/L. Infants were randomised to undergo a platelet transfusion at platelet count thresholds of 50×109/L (higher threshold group) or 25×109/L (lower threshold group). 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. 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). Infants randomised to a higher platelet transfusion threshold of 50×109/L compared with 25×109/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. ISRCTN87736839.