El Kuffash et al. [31] and Czernik et al. [32] also evaluated urinary proBNP as a simple and noninvasive PDA indicator, becoming higher in ventilated neonates nonresponders to treatment; according to Vettukattil [33] urinary NT-proBNP-to-creatinine ratio may be related to medical treatment response. This evidence concerns the gene NPPB and Patent ductus arteriosus.