New guidelines for managing pulmonary hypertension: what the pediatrician needs to know

Controversies in neonatology: The efficacy of inhaled nitric oxide in preterm infants with persistent pulmonary hypertension

Introduction: There is limited and conflicting information in literature regarding use of inhaled nitric oxide (iNO) in preterm infants. In this study we examined the characteristics of preterm infants with persistent pulmonary hypertension (PHT) who responded and did not respond to iNO therapy . Material and Method: We retrospectively reviewed data of infants

Cardiovascular complications in cystic fibrosis: A review of the literature

Cystic fibrosis is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, leading to dysfunction of the CFTR protein. CFTR dysfunction leads to disease in the respiratory and gastrointestinal systems. Disorders of the cardiovascular system in individuals with CF are usually attributed to secondary effects from progressive lung disease. However, CFTR has been localized to vascular endothelium and smooth muscle, suggesting that CFTR dysfunction may directly impact cardiovascular function. As treatments for CF improve and life-expectancy increases, the risk of vascular disease may increase in prevalence related to primary and secondary CFTR dysfunction, chronic systemic inflammation, nutritional health and hyperglycemia in individuals with CF related diabetes. Here we review the available literature on CF and the cardiovascular system, examining the secondary effects and evidence for direct CFTR dysfunction in the heart, aorta, pulmonary vessels, and vasculature, as well as future directions and treatment options.

The efficacy of inhaled nitric oxide treatment in premature infants with acute pulmonary hypertension

BACKGROUND

Although inhaled nitric oxide (iNO) therapy in term infants with pulmonary hypertension (PHT) has demonstrated definite benefit, the use of iNO in preterm infants remains inconclusive.

AIMS

To evaluate the impact of iNO treatment in premature infants with acute PHT.

STUDY DESIGN

Retrospective cohort.

SUBJECTS

Infants < 34 weeks' gestational age, admitted during 2010-2016 to two neonatal units, having treated with iNO for confirmed PHT. A positive response was defined by FiO₂ reduction ≥20% within 3-h post iNO initiation. Early PHT was defined when developed within the first 72 h of age.

OUTCOME MEASURES

The primary outcome was the evaluation of the acute response to iNO administration. Secondary outcomes included the comparison of neonatal characteristics and outcomes between positive and negative responders, and early or late PHT infants.

RESULTS

Of the 55 infants of our cohort, 39 (71%) had a positive response to iNO administration. No differences noted regarding bronchopulmonary dysplasia, intraventricular haemorrhage or other morbidities; however, positive responders had significantly higher survival rate in overall (77 vs 21%, p = 0.001) and within early PHT subgroup (74 vs 33%, p = 0.044). Regression analysis revealed that oligohydramnios (OR 2.834, 95%CI 1.652-6.070) and early PHT (OR 1.953, 95%CI 1.377-2.930) were significantly related with a positive response.

CONCLUSIONS

Preterm infants with confirmed acute PHT respond in significant proportion to the iNO administration, especially in the background of oligohydramnios or the development of early PHT.

The Action of Smooth Muscle Cell Potassium Channels in the Pathology of Pulmonary Arterial Hypertension

Many different types of potassium channels with various functions exist in pulmonary artery smooth muscle cells, contributing to many physiological actions and pathological conditions. The deep involvement of these channels in the onset and exacerbation of pulmonary arterial hypertension (PAH) also continues to be revealed. In 2013, KCNK3 (TASK1), which encodes a type of two-pore domain potassium channel, was shown to be a predisposing gene for PAH by genetic mutation, and it was added to the PAH classification at the Fifth World Symposium on Pulmonary Hypertension (Nice International Conference). Decreased expression and inhibited activity of voltage-gated potassium channels, particularly KCNA5 (Kv1.5), are also seen in PAH, regardless of the cause, and facilitation of pulmonary arterial contraction and vascular remodeling has been shown. The calcium-activated potassium channels seen in smooth muscle cells also change from BKca (Kca1.1) to IKca (Kca3.1) predominance in PAH due to transformation and have effects including the facilitation of smooth muscle cell migration, enhancement of proliferation, and inhibition of apoptosis. Elucidation of these roles for potassium channels in pulmonary vasoconstriction and remodeling may help bring new therapeutic strategies into view.