Clinical and echocardiographic predictors of medical therapy failure for patent ductus arteriosus closure in preterm infants: Insights from a risk-based treatment approach.

Objective: This study aims to identify initial clinical and echocardiographic markers in preterm infants which may predict failure of medical therapy to close a high-risk patent ductus arteriosus (PDA).

Study Design: This was an observational cohort study conducted in a level III NICU. Infants born <29 weeks gestation were treated with medical therapy if they were deemed high-risk as per the EL-Khuffash PDA Severity Score (PDAsc). Treatment-failure infants were compared to treatment-success infants.

Results: 110 infants were high-risk (58 responders, 52 non-responders). Initial differences in clinical and echocardiographic characteristics between infants in the treatment-failure and treatment-success groups, respectively, included a lower gestational age (25.2 ± 1.3 vs 25.9 ± 1.4; p < 0.01), higher PDAsc (7.8 ± 1.9 vs 7.0 ± 1.5; p < 0.01), lower incidence of pre-eclampsia (3 (6 %) vs 12 (21 %); p = 0.02), lower mitral E:A ratio (0.78 ± 0.13 vs 0.90 ± 0.27; p = 0.02), higher LA:Ao ratio (1.7 ± 0.6 vs 1.4 ± 0.5; p = 0.02), lower celiac artery systolic velocity(m/s) (0.36 ± 0.12 vs 0.46 ± 0.20; p = 0.02) and higher global longitudinal strain (GLS) (%) (20.8 ± 3.1 vs 18.1 ± 4.4; p < 0.01). In a multivariate logistic regression model, GLS remained the only independent predictor of medical therapy failure (OR 0.83, 95 % CI 0.70-0.98, p = 0.03).

Conclusion: These findings highlight a distinct subgroup of high-risk preterm infants who are unlikely to respond to medical therapy, emphasising the need for an individualised approach to PDA management. Integrating clinical and echocardiographic markers with risk-based scoring systems may improve early identification of treatment non-responders and guide alternative therapeutic strategies.