An Asian multicenter retrospective study on persistent pulmonary hypertension of the newborn: incidence, etiology, diagnosis, treatment and outcome

<b>Objectives:</b> To explore the incidence, etiologies, diagnostic methods, treatment options and outcomes in neonates with persistent pulmonary hypertension of the newborn (PPHN) and to identify mortality risk factors in a study from six Asian countries.<b>Methods:</b> A retrospective chart review of patients with documented PPHN from seven centers in six Asian countries (Japan, Kuwait, India, Pakistan, Singapore, and Thailand) between 1 January, 2014 and 31 December, 2016, was performed.<b>Results:</b> A total of 369 PPHN infants were identified. The incidence of PPHN ranged from 1.2 to 4.6 per 1000 live births. The all-cause mortality rate was 20.6% (76 of 369). Meconium aspiration syndrome was the primary cause of PPHN (24.1%). In most cases (84.8%) echocardiography was used to establish the diagnosis of PPHN. Sildenafil was the most commonly used pulmonary vasodilator (51.2%). Multivariate multiple regression analysis indicated gestational age <34 weeks (adjusted odds ratio (OR) = 3.27; 95% CI 1.56-6.74), congenital diaphragmatic hernia (CDH)/lung hypoplasia (LH) (adjusted OR = 6.13 (95% CI 2.28-16.42)), treatment with high frequency oscillation ventilation (HFOV) with or without inhaled nitric oxide (iNO) (adjusted OR = 3.11 (95% CI 1.52-6.34)), and inotropic agents (adjusted OR = 9.43 (95% CI 2.71-32.83)) were independently associated with increased risk of death.<b>Conclusions:</b> The incidence of PPHN in the current study was higher than in western settings. Birth weight, gestational age, CDH/LH, HFOV/iNO, and inotropic agents were significant mortality risk factors.