BNP and Pulmonary Hypertension Case Study

Milisavljevic V, Purdy I & Le C. B-type natriuretic peptide utilization as an adjunct to management in a case of conjoined twins with pulmonary hypertension. Neonatal Network (January/February 2010); 29: 5-12. |PDF|

Purpose: This article reports a case of pulmonary hypertension in 37-week–gestational-age, pygopagus conjoined twins where B-type natriuretic peptide (BNP) was used as a cost-effective and important tool to aid effective management.

Background: Pulmonary hypertension in neonates is associated with high morbidity and mortality and multiplies the challenge of caring for conjoined twins. BNP is a peptide hormone secreted by cardiac ventricles that have undergone stress related to ventricular filling, volume overload, and pressure. BNP is commonly used in adults to assess heart failure, but its utility is less established in infants receiving neonatal intensive care.

Results: In this case, BNP testing was used as an adjunct to standard assessments for rapid diagnosis which was critical to expediting appropriate treatment management for these high-risk patients.

Comments: This case study presents use of BNP levels to guide treatment when echocardiography is difficult to obtain. There has been much published in the last two years describing use of BNP and evaluation of PDA:

N-terminal pro-B-type natriuretic peptide: a measure of significant PDA

B-type Natriuretic Peptide to Guide Therapy of PDA

Early N-terminal pro-brain natriuretic peptide measurements...

Accuracy of Plasma B-Type Natriuretic Peptide to Diagnose...

... Physiologic Biomarker, But Is It a Clinical Tool?

Screening BNP levels have not become widely used in the NICU. Is this a valuable tool for evaluation in certain diagnoses? What is your practice for use of BNP – write a comment. Mindy Morris

Additional Comments

March 2, 2010
3:08 PM

I have little experience with the use of BNP and pro-BNP as a clinical tool but one of the fellows currently training with us has done original research on the topic and has kindly agreed to provide a comment. See Below:

Michael Dunn MD
NeoNotes Editorial Board

March 2, 2010
3:08 PM

From Dr. Afif El-Khuffash:

The use of BNP in guiding management where serial echocardiography is technically challenging or not feasible has been demonstrated in this case report. The use of BNP, and its active precursor N-terminal-pro-BNP (NTpBNP), is gaining interest in the neonatal field. Their use in the management of patent ductus arteriosus (PDA) has been studied. Both markers rise in the presence of a PDA, and fall following successful treatment. With cut off levels for detecting of a PDA now becoming established, these markers are an ideal screening tool for the presence of a PDA. In addition, they have been used to rationalize treatment courses of indomethacin as falling levels after the first or second dose may negate giving the complete treatment thereby minimizing potentially harmful drug side effects.

The ability of NTpBNP to predict short term outcomes in preterm infants with a PDA was assessed by our group (El-Khuffash A et al, Arch Dis Child Fetal Neonatal Ed. 2008;93:F407-12). In a study of preterm infants with a PDA at 48 hours, the group was subdivided into infants with a poor outcome (grade III/IV IVH, death or both, n=20) and infants without complications (n=25). There were no differences in the antenatal characteristics between the two groups. Infants in the poor outcome group had a significantly higher NTpBNP levels at 48 hours compared to infants without PDA-associated complications. NTpBNP levels were predictive of severe IVH and / or death as a complication of a PDA.

Medical therapy for PDA has well recognised adverse effects and neither prophylaxis nor treatment on the basis of clinical and echocardiographic signs have been shown to improve long-term outcomes. Accurately identifying infants with PDA who are at highest risk of poor outcome using NTpBNP may allow more successful trials of targeted medical therapy of PDA.

In addition to their use in PDA management, natriuretic peptides may have a therapeutic role. Animal research has shown a possible therapeutic effect of BNP in PPHN. Isolated vessel studies in fetal lambs with PPHN by induced ductal ligation found an abundance of NPR-A, a BNP receptor.

When exposed to BNP these pulmonary arteries and veins relaxed but the responses were significantly lower than in controls. Research is underway examining the therapeutic effect of recombinant human BNP on neonates with resistant PPHN unresponsive to nitric oxide.

The potential benefit of these natriuretic peptides in neonatology is immense. More studies are needed to explore the possible roles of BNP/NTpBNP in the management of PDA, the impact on outcome, and monitoring of cardiac performance.

Dr Afif EL-Khuffash MB, BA, MD, MRCPI
Neonatal-Perinatal Fellow,
Hospital for Sick Children,
Mount Sinai Hospital,
Women's College Hospital,
Toronto, Ontario
Tel: +1 416 838 5502