Background Pulmonary Hypertension has a poor prognosis and therapy is limited to symptomatic relief. Apelin, a new therapy, has the potential to provide both symptomatic relief and address the underlying pathology. Disease severity, in pulmonary hypertension, is measured using NT-proBNP. This study investigated the effects of apelin on serum NT-proBNP levels in groups of pulmonary hypertension patients and controls.

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 infusions. NT-proBNP concentration in the samples was determined using the ABNOVA ELISA kit.

Results Across all groups there was no significant change in NT-proBNP levels due to apelin infusion (P = 0.830). There was no significant difference in pre-infusion levels between groups (P = 0.287).

Conclusions Apelin infusion, over a period of several minutes, has no effect on NT-proBNP levels in serum. This is consistent amongst control and pulmonary hypertension patients. Despite the lack of change in NT-proBNP seen in this study, the haemodynamic results for apelin were positive. These haemodynamic results have been associated with a decrease in NT-proBNP in other drug studies. The main difference in these studies was a longer time period. As a result, investigation of therapy over a longer time period is required to assess if apelin has any effect on NT-proBNP levels.