Comparison of the effectiveness of oral sildenafil versus oxygen administration as a test for feasibility of operation for patients with secondary pulmonary arterial hypertension

Hemodynamic assessment and acute pulmonary vasoreactivity testing in the evaluation of children with pulmonary vascular disease. Expert consensus statement on the diagnosis and treatment of paediatric pulmonary hypertension. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

Invasive assessment of haemodynamics (ventricular, pulmonary) and testing of acute vasoreactivity in the catheterisation laboratory remain the gold standard for the diagnosis of pulmonary hypertension (PH) and pulmonary hypertensive vascular disease. However, these measurements and the interpretation thereof are challenging due to the heterogeneous aetiology of PH in childhood and potentially confounding factors in the catheterisation laboratory. Patients with pulmonary arterial hypertension (PAH) associated with congenital heart disease who have a cardiovascular shunt need to undergo a completely different catheterisation approach than those with idiopathic PAH lacking an anatomical cardiovascular defect. Diagnostic cardiac catheterisation of children with suspected PH usually includes right and left heart catheterisation, particularly for the initial assessment (ie, at the time of diagnosis), and should be performed in experienced centres only. Here, we present graded consensus recommendations for the invasive evaluation of children with PH including those with pulmonary hypertensive vascular disease and/or ventricular dysfunction. Based on the limited published studies and our own experience we suggest a structured catheterisation protocol and two separate definitions of positive acute vasoreactivity testing (AVT): (1) AVT to assess prognosis and indication for specific PH therapy, and (2) AVT to assess operability of PAH associated with congenital heart disease. The protocol and the latter definitions may help in the systematic assessment of these patients and the interpretation of the obtained data. Beyond an accurate diagnosis in the individual patient, such a structured approach may allow systematic decision making for the initiation of a specific treatment and may assist in estimating disease progression and individual prognosis.

Safety of sildenafil in infants*

OBJECTIVE

In view of the recent U.S. Food and Drug Administration's warning against the use of sildenafil in pediatric patients, we aimed to provide an updated overview of the dosing and safety of sildenafil in infants and to explore the relevance of the present safety concerns to the infant population.

DATA SOURCE

The National Library of Medicine PubMed and Cochrane Database of Systematic Reviews were searched using the following terms: Sildenafil AND (infant OR infants OR newborn OR newborns OR child OR children OR childhood OR pediatric OR pediatrics OR paediatric OR paediatrics).

STUDY SELECTION

Studies presenting original clinical data regarding the dosing, use, or safety of sildenafil in infants with pulmonary hypertension would be included.

DATA EXTRACTION

Of the 49 included studies, case reports and case series were the most common type of publications (n = 25). The identified trials included 625 children, with more than 140 infants. Persistent pulmonary hypertension of the newborn and pulmonary hypertension associated with other conditions were the most common underlying diagnoses.

CONCLUSION

There is currently no evidence of serious adverse event in infants exposed to sildenafil. Present safety concerns regarding the use of sildenafil in pediatric patients should be further explored before being applied to infant population. Sildenafil remains a valuable option for the treatment of pulmonary hypertension in young infants. Prospective studies should be designed in such a way that they include a safety assessment to evaluate potential adverse outcomes of sildenafil therapy in this population.

Current practices in the use of sildenafil for pulmonary arterial hypertension in Brazilian hospitals

Background

Sildenafil is a cyclic guanosine monophosphate-specific phosphodiesterase-5 inhibitor used for treating pulmonary hypertension. Although the use of sildenafil in patients under 18 years old is off-label, this inhibitor has been widely prescribed for children treatment at hospitals in Brazil. In this work we evaluated the current practices in using sildenafil in the three main reference hospitals of Rio de Janeiro to design a clinical trial. Then we analyzed the content of sildenafil in powder paper preparations used in these institutions.

Methods and Results

We assessed the data about the use of sildenafil in three reference hospitals including Instituto Nacional de Cardiologia – INC, Instituto Estadual de Cardiologia Aloysio de Castro – IECAC and Hospital Pro-Cardíaco – HPC. The pharmacy records were analyzed from April 1st, 2008 to April 30th, 2008 and interviews with the pharmacists were also performed. Our results showed that INC used the greatest amount of sildenafil in: treatment of pulmonary arterial hypertension (PAH), management of transient PAH during surgery, preparation for cardiac transplantation and haemodynamic studies during cardiac catheterization. Meanwhile IECAC and HPC used sildenafil only for treating PAH in few patients during the period evaluated. In INC and IECAC, sildenafil was available in tablets, and powder papers prepared by two private pharmacies and one public hospital pharmacy. In contrast all patients of HPC received sildenafil in tablets with no external manipulation. Our quantification analysis results using reverse-phase high performance liquid chromatography method showed that powder papers prepared by the private pharmacies from the sildenafil tablets presented only 58.5 to 89.3% of the declared concentration in contrast to samples from the public hospital pharmacy (104.4 to 105.3%).

Conclusion

Few patients received the prescribed sildenafil dose at the reference hospitals evaluated in Rio de Janeiro, which may importantly compromise this inhibitor effect in the current treatment. This study reinforced the need of checking the practices of preparing and administering sildenafil continually.