215 - The Clinical Utility of Ratio of Systolic to Diastolic Flow Velocity of Hemodynamically Significant Ductus Arteriosus in Preterm Infants with Respiratory Distress

Poster Number: 215
Publication Number: 215.220

Kyu Hee Park, Korea university College of Medicine, Ansan-si, Kyonggi-do, Republic of Korea; Hye Won Cho, Korea university of medical college, Ansan, Kyonggi-do, Republic of Korea; Dan Bea Park, korea university of medical college, ansan, Kyonggi-do, Republic of Korea; Eui Kyung Choi, Korea university, Seoul, Seoul-t'ukpyolsi, Republic of Korea; Byung Min Choi, Department of Pediatrics, Korea University Ansan Hospital, Korea University College of Medicine, Ansan-si, Kyonggi-do, Republic of Korea

Background: The presence of a persistent ductus arteriosus in preterm infants is associated with increased mortality and several significant morbidities including intraventricular hemorrhage, pulmonary hemorrhage, necrotizing enterocolitis, and chronic lung disease or bronchopulmonary dysplasia.  The echocardiography is the investigation of choice to diagnose PDA, estimating the magnitude of shunt volume and assessing its hemodynamic significance.

Objective: To investigate the clinical utility of ratio of systolic to end-diastolic flow velocity as a guide to diagnosis hemodynamic significant patent ductus arteriosus (hsPDA) compared with other echocardiographic parameters in preterm infants with respiratory distress.

Design/Methods: 110 preterm infants with respiratory distress who underwent serial echocardiographic evaluations were enrolled. A hsPDA was defined by echocardiography if ductal size ≥1.5mm or ratio of the left arterial diameter to the aortic diameter (LA/Ao ratio) ≥ 1.4. We used univariate linear regression to determine the association of ratio of systolic to end diastolic flow velocity with ductal size and LA/Ao ratio compared with B-type natriuretic peptided (BNP) and other echocardiographic parameters:  max velocity of ductus(Vmax), anterograde diastolic flow velocity of the left pulmonary artery, Mitral valve early diastolic to Atrial contraction wave ratio(E/A ratio), Isovolumic relaxation time(IVRT), retrograde diastolic flow of descending aorta, Left ventricular output (LVO)Receiver operator characteristic (ROC) curve was used to evaluation the predictive performance of ratio of systolic to end diastolic flow velocity, other echocardiographic parameters and BNP.

Results: Total 435 echocardiographic records were reviewed from 110 infants. Significant correlations were found between ratio of systolic to end diastolic flow velocity and ductal size for overall study period(R2= 0.297 on day of life(DOL) 1-3, 0.87 on DOL 4-7, 0.223 on DOL 8-14, 0.05 on DOL≥15). Ratio of systolic to end diastolic flow velocity has better discriminating power for detecting hsPDA compared with other echocardiographic parameter on DOL 1-3(AUC 0.789, 95% CI 0.701-0.877, cut-off 2.17), DOL 8-14(AUC 0.749, 95% CI 0.614-0.884, cut-off 1.89), DOL≥15(AUC 0.708, 95% CI 0.570-0.845, cut-off 1.92).Conclusion(s): In preterm with respiratory distress, ratio of systolic to end diastolic flow velocity could reliably be useful parameter for detecting hsPDA.