Can early echocardiographic findings predict patent ductus arteriosus?

BACKGROUND

Prophylactic treatment with prostaglandin synthetase inhibitors (PSI) is potentially harmful. Moreover, long-term benefits of prophylactic use of indomethacin or ibuprofen are not proven. Early treatment of a high-risk population is alternative to the routine prophylactic use of PSI, but it remains unclear which newborn is at greatest risk for patent ductus arteriosus (PDA).

OBJECTIVE

Evaluation of the prognostic value of early echocardiographic studies with respect to PDA in later life.

METHODS

Sixty preterm infants with a mean birth weight of 1,087 g and mean gestational age of 28.5 weeks were included in a prospective study. Cardiac scans were performed in all newborns on entry into the study (within 12-48 h after birth) and further in case of clinical suspicion of PDA or obligatorily on the 7th and 28th days of life. There was no prophylactic or treatment use of any PSI during the study period. Newborns were divided into 2 cohorts: with significant left to right shunt requiring surgical ligation of PDA (n = 16) or without significant PDA during follow-up (control group, n = 44).

RESULTS

On entry, the mean internal diameter of the ductus arteriosus (2.6 vs. 0.91 mm/kg; p < 0.01), mean cardiac index across aortic valve (2.96 vs. 2.37 l/min/m(2); p < 0.01) and early filling peak velocity (43.1 vs. 33.7; p = 0.01) were significantly higher in babies who later needed surgical ligation of PDA. There was no difference in the mean values of the other echocardiographic parameters studied. An early ductal diameter of >1.5 mm/kg predicted symptomatic PDA with a sensitivity of 94% and a specificity of 73%, and its positive predictive value equaled 57% and negative predictive value amounted to 97%.

CONCLUSIONS

Early echocardiographic studies possess negative predictive value and may decrease unnecessary surgical ligation of PDA in very low birth weight infants.