Background Pulmonary Hypertension has a poor prognosis and therapy is limited to symptomatic relief. Apelin, a new therapy, has the potential to address the underlying pathology whilst also providing relief of symptoms. NT-proBNP a marker of disease severity is commonly used to assess treatment effect.

Aims and objectives This study aimed to investigate, for the first time, the effects of apelin on serum NT-proBNP concentration in groups of pulmonary hypertension patients and controls. The hypothesis of the study was that apelin would cause a change in NT-proBNP.

Methods Serum samples from patients recruited for a haemodynamic investigation of apelin were used. The groups studied were controls, pulmonary arterial hypertension and pulmonary hypertension due to left heart failure. In the haemodynamic study each patient was given an apelin and placebo infusion separately over a period of several minutes. Serum samples were taken pre and post infusion. NT-proBNP concentration in the samples was determined using the ABNOVA ELISA kit.

Results There was no significant change in NT-proBNP levels due to apelin infusion across all groups (P = 0.830). On sub group analysis there was no significant change detected in any group as shown in Figure 1.

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Abstract P267 Figure 1

Mean change in NT-proBNP levels post apelin infusion with 95% C.I. There was no significant change in NT-proBNP levels caused by apelin in any group

Conclusion NT-proBNP levels do not immediately change in response to several minutes of apelin infusion. This is consistent amongst control and pulmonary hypertension patients. Despite the lack of change in NT-proBNP levels seen in this study, the haemodynamic response pattern reported for apelin¹ has been associated with NT-proBNP changes in other drug studies. The main difference between these studies and this study was investigation of therapy effect over a longer time period. From our results we cannot conclude that apelin has no effect on NT-proBNP levels. Investigation of therapy over a longer time period is required.

Reference 1 Brash L, Church C, Gibbs JS, Howard LSGE, Johnson MK, Welsh DJ, Wilkins MR, Newby DE, Peacock AJ. Apelin improves cardiac output in patients with pulmonary arterial hypertension. Submitted to ERS 2015 Conference