Hemodynamic and metabolomic responses to infusion of GLP-1 agonist exenatide in pulmonary arterial hypertension.

Preclinical studies suggest beneficial effects of GLP-1 agonists in pulmonary arterial hypertension (PAH). This first-in-disease study evaluated acute hemodynamic effects of GLP-1 agonist, exenatide administered i.v. in patients with idiopathic PAH and CTEPH as well as in a PAH rodent model. Seventeen patients (9 idiopathic PAH) received an exenatide infusion during right heart catheterization, which included multisite sampling for circulating metabolites. Acute effects of exenatide were also assessed by cardiac magnetic resonance imaging in monocrotaline (MCT) PAH and control rats. In the clinical study, exenatide was well tolerated, reduced mean pulmonary artery pressure (45 ± 15 mmHg versus 40 ± 18 mmHg), and improved cardiac index (2.1 ± 0.6 L/min versus 2.4 ± 0.9 L/min/m2) and pulmonary vascular resistance (7.8 ± 8.0 WU versus 5.9 ± 5.0 WU) across all patients. Right ventricular (RV) contractility and afterload improved in a subset of patients undergoing pressure-volume measurements. In an exploratory metabolomics analysis, 47 metabolite levels changed after exenatide infusion, predominantly in free fatty acid pathways. Six metabolites with prognostic relevance in PAH within myocardial glycolytic and lipid oxidation pathways were also altered after exenatide. In MCT rats, exenatide improved RV stroke-volume, RV ejection fraction, and RV-arterial coupling. These findings support the further evaluation of exenatide within chronic studies as a potentially novel pulmonary vasodilator therapy.