Pulmonary arterial hypertension before closure of a persistent arterial duct (PDA) in children <12 months: clinical implications and outcome

1. ABSTRACT Background The management of patent ductus arteriosus (PDA) in infants with pulmonary hypertension (PH) remains controversial due to concerns regarding irreversible pulmonary vascular disease and post-closure hemodynamic deterioration. Evidence in children <12 months is limited. We aim to describe the hemodynamics and outcomes of infants with isolated PDA and PH undergoing invasive evaluation and to identify clinical factors associated with PH persistence after closure. Methods We retrospectively analyzed infants <12-months with isolated PDA and mean pulmonary artery pressure (mPAP) >20mmHg who underwent right heart catheterization. Hemodynamics, procedural strategy, and clinical outcomes were assessed at 6-/12-months, and last follow-up. Results A total of 220 patients were included (mean age 154±87 days; weight 5.7±1.7 kg). mPAP was 36.5±12.8 mmHg and Qp/Qs 1.9±1.0. PDA closure was performed in 214 patients (186 transcatheter, 28 surgical). Cumulative mortality was 1.8%, occurring exclusively in patients with severe comorbidities. Persistent PH was noted in 8 patients (3.6%) at 6-months and 2 patients (0.9%) at 12-months and long-term follow-up. No cases of PH relapse were observed after successful closure. All persistent PH cases were associated with developmental lung disease or severe syndromic conditions. Infants without major comorbidity demonstrated resolution of PH after closure. Conclusions In infants with isolated PDA and PH, ductal closure within the 1 year is associated with near-universal normalization of pulmonary pressures. Persistent PH is uncommon and primarily confined to patients with developmental lung disease. Clinical and echocardiographic assessment combined with invasive hemodynamic should guide operability decisions.