Echocardiographic prediction of patent ductus arteriosus in need of therapeutic intervention

Aim: To evaluate the efficacy of various echocardiographic markers in predicting a patent ductus arteriosus (PDA) in need of treatment. Methods: Forty-five preterm infants with a mean (SD) gestational age of 27.7 (1.9) weeks underwent echocardiography at a postnatal age of 24 +/- 6 and 72 +/- 6 h. Four echocardiographic markers were studied: ductus diameter, ductal flow Doppler curves, the left atrial to aortic root (LA/Ao) ratio and Doppler pixels representing ductal shunting. Results: Twenty-eight infants had a PDA with a detectable left-to-right shunt. Of these, 12 (43%) were treated for a shunt through the PDA. Ductal diameter was the most accurate echocardiographic marker when it came to predicting a significant shunt, with a sensitivity of 89%, a specificity of 70%, a positive likelihood ratio of 2.97 and a negative likelihood ratio of 0.16 at the age of 72 h. The efficacy of the method at 72 h of age was 84%. The corresponding efficacy of the pulsatile Doppler curve was 72%, percentage of green colour pixels 63% and the LA/Ao ratio 53%. Conclusion: Ductus diameter appears to be the most important variable in determining the need for therapeutic intervention for PDA in preterm infants