RESUMO
BACKGROUND: The aim of this study is to evaluate whether there is an association between the platelet mass and patent ductus arteriosus (PDA) closure in premature newborns. METHODS: Preterm infants (gestational age ≤33 weeks) with hemodynamically significant PDA (group 1, n = 178) and a control group of preterm infants without PDA (group 2, n = 211) were retrospectively evaluated between August 1, 2013 and July 30, 2015 in the neonatal intensive care unit (NICU). Platelet counts and platelet indices including mean platelet volume (MPV), and platelet mass (platelet count x mean platelet volume) in the first 24 hours of life, demographic findings and morbidities were recorded. RESULTS: No differences were observed in demographic findings between the study groups in terms of birth weight, gestational age, gender and maternal risk factors. The mean platelet count in the first postnatal hemogram in group 1 and group 2 were 189.43 ± 72.14 (X103 /mm3) and 206.86 ± 70.11(X103/mm3), respectively (P < 0.05). The MPV were similar in both groups (P > 0.05). Platelet mass values were 1443.70 ± 572.40 fL/nL in Group 1 and 1669.49 ± 1200.42 fL/nL in group 2. There was a statistically significant difference in platelet mass values between the two groups (P = 0.011). Multivariable analysis including presence of thrombocytopenia, MPV and platelet mass showed that hemodynamically significant PDA was not independently associated with platelet count <150 000 (OR = 1.001, 95% CI 0.980-1.023; P = 0.921), MPV (OR = 0.967, 95% CI 0.587-1.596; P = 0.897) or platelet mass (OR = 0.999, 95% CI 0.997-1.002; P = 0.681). The optimal cut-off value of platelet mass for patients with PDA was ≤1530.8 fL/nL (area under the curve [AUC]: 0.580), with sensitivity of 58% and specificity of 56.2% (P = 0.008). CONCLUSION: Our data suggest that platelet count, MPV, and platelet mass do not contribute to closure of PDA in premature newborns.