Intravenous sildenafil for treatment of early and late pulmonary hypertension in preterm infants

Objectives: Data is lacking on the effect of continuous intravenous sildenafil treatment in preterm infants with early- and late-pulmonary hypertension (PH), especially in extremely low birth weight (ELBW) infants. Patients and Methods Preterm infants (<37 weeks of gestational age) with intravenous sildenafil treatment and diagnosis of PH between 01/12 and 12/21 were retrospectively screened for analysis. The primary clinical endpoint was defined as response to sildenafil according to the improvement of the oxygenation index (OI), the saturation oxygenation pressure index (SOPI) and PaO 2 /FiO 2 -ratio. Early-PH was defined as diagnosis <28 day of life (DOL), late PH ≥28 DOL. Main Results 60 infants were finally included, with 47% ELBW infants. Early-PH was diagnosed in 97% and the primary endpoint was reached in 58%. The likelihood to die during in-hospital treatment was more than three times higher (72 vs 20%, p<0.001) in infants without response to sildenafil. The echocardiographic severity of PH and right-ventricular dysfunction (RVD) decreased significantly from baseline to 24 h (p=0.038, and p=0.009, respectively). Conclusion Sildenafil treatment leads to significant improvement of the oxygenation impairment in 58% of the preterm infants, with similar response rates in ELBW infants. Intravenous sildenafil treatment is associated with a significant decrease of the PH-severity and RVD.