Sildenafil therapy in bronchopulmonary dysplasia-associated pulmonary hypertension: a retrospective study of efficacy and safety

Abstract

Bronchopulmonary dysplasia (BPD) is associated with a high incidence of pulmonary artery hypertension (PAH) and is frequently treated with sildenafil. The objective was to investigate the echocardiographic and clinical efficacy and safety of sildenafil in this setting. The hypothesis was that treatment would result in significant echocardiographic and clinical improvements. This was a retrospective study of the cohort of infants who were born between 2004 and 2012 and administered sildenafil as in-patients for BPD-associated PAH. Medical records and archived echocardiographic data were reviewed. Twenty-two infants fulfilled the inclusion criteria and had a mean (±SD) gestation age and birth weight of 25.6 (±1.3) weeks and 631 (±181) g, respectively. Six (27 %) infants died before discharge (predominantly due to respiratory failure; in three of them, a concomitant viral respiratory infection was thought to be an aggravating factor). Amongst survivors, no mortality was noted up to 1 year follow-up. Significant improvement in echocardiographic markers of pulmonary hypertension was noted in the echocardiogram performed 27.5 days (interquartile range 24, 31) post-initiation of therapy, two thirds showing ≥20 % decline in the right ventricular systolic pressure. Left ventricular fractional shortening did not alter significantly. At initiation, all infants had 'severe' BPD. The fraction of inspired oxygen (FiO2) decreased significantly from 0.57 (SE ± 0.05) to 0.42 (SE ± 0.03) (p = 0.02), and no significant alteration was noted over the timeframe in mean pCO2 (64.4 ± 3.3 to 63.2 ± 3.3 mmHg). The number of infants needing endotracheal intubation and mechanical ventilation decreased (from 3 to 1) over the same time. No serious adverse effects were noted.

Conclusion: Sildenafil therapy was associated with a significant improvement in the echocardiographic markers of PAH and a reduction in FiO2. The medication was well tolerated.