Acutely inhaled iloprost improves right ventricular (RV) function in terms of RV volume, right ventricular ejection fraction (RVEF), and RV stroke volume in patients with idiopathic pulmonary arterial hypertension (IPAH) and pulmonary arterial hypertension (PAH) associated with connective tissue disease (CTD-PAH), according to study results published in Frontiers In Pharmacology.
Right ventricular function is an important prognostic factor in patients with PAH and inhaled iloprost has demonstrated efficacy in the treatment of severe PAH and acute RV failure. RV physiologic changes during acute iloprost inhalation are not well known; therefore, researchers in China investigated the effects of acute iloprost inhalation on the RV in 69 patients with incident PAH, including 23 patients with IPAH, 26 patients with CTD-PAH, and 20 patients with PAH associated with congenital heart disease (CHD-PAH).
All patients underwent both right heart catheterization and cardiac magnetic resonance imaging (MRI) at baseline and 20 minutes after 5 µg iloprost inhalation. They observed that RVEF improvements are proportional to pulmonary vascular resistance (PVR) reduction in patients with IPAH; however, PVR and RVEF changes are not correlated with each other in patients with CTD-PAH and CHD-PAH.
Thus, a modest decline of PVR would mean little to RVEF improvement for these patients and thus more effective treatment may be suggested.
“In conclusion, the clinical importance of this study is to provide a detailed knowledge of how RV physiology is changed during acute iloprost inhalation, by combining hemodynamic assessment and [cardiac magnetic resonance] imaging,” stated the investigators.
Because this was an acute drug-effect study, long-term follow-up data would be needed to enhance the clinical value of these findings.
Li JH, Zhang HD, Wang ZZ, et al. Acute iloprost inhalation improves right ventricle function in pulmonary artery hypertension: a cardiac magnetic resonance study. Front Pharmacol. 2019;9:1550.