A low platelet count is associated with treatment failure in preterm infants treated with ibuprofen for patent ductus arteriosus (PDA

Background: Recent studies have demonstrated that platelet count (PLTc) and function have an important role in promoting spontaneous closure of the PDA in animal models.Aimto evaluate whether response to ibuprofen in premature infants with PDA is influenced by PLTc. Methods: All infants with GA ≤ 28wks born in our unit between 1/1/2007 and 31/12/2009 were retrospectively studied. Exclusion criteria were: congenital malformations, death within 48 hrs and outborn. All infants had echocardiographic evaluation in 1st DoL. Patients with a hemodynamically significant PDA (HsPDA) were treated with a standard course of ibuprofen. GA, BW, antenatal steroids, gender, type of ventilatory support were analyzed along with PLTc before and after treatment. Associations with HsPDA and treatment response were assessed by univariate and multivariate analysis.Results: Data from 130 out of 162 newborns (GA 26.2w±1.5, BW 851.2±293g) were analysed. 117 patients showed a PDA at first evaluation. 88 newborns were treated with ibuprofen for HsPDA; after treatment 60 patients had a closed ductus (responders) while 28 were non-responders. A lower PLTc was observed in infants with HsPDA but difference was not statistically significant. Among treated infants, non-responders had a lower GA, were more likely mechanically ventilated and had a PLT significantly lower than responders (111.000/ μl vs. 184.000/μl, p=0,001). In the multivariate analysis only invasive ventilation and low PLTc were independent factors for treatment failure. Conclusion: A low PLTc increases the risk of treatment failure of PDA. Further studies are needed to evaluate the prognostic and therapeutic implications of this observation.