The Effect of Endothelin Receptor Antagonists in Patients with Eisenmenger Syndrome: A Systematic Review

The efficacy of endothelin receptor antagonists (ERAs) in the management of Eisenmenger syndrome (ES) remains controversial. The aim of this study is to systemically review the safety and effects of ERAs in improving the quality of life and basic cardiac functions of these patients.

Twelve databases were searched, including PubMed, Web of Science, Scopus, Virtual Health Library, World Health Organization (WHO) Global Health Library, Google Scholar, POPLINE, Systems for Information of Grey Literature in Europe, New York Academy of Medicine, ClinicalTrials.gov, metaRegister of Controlled Trials and the WHO International Clinical Trials Registry Platform, through August 2016. We included randomized clinical trials addressing the effect of ERAs on cardiac functions in patients with ES. The quality of studies was assessed using the Cochrane Collaboration tool.

We included two trials represented by four papers, of which three papers reported the efficacy of bosentan against placebo and one paper reported the results of a combination of bosentan and sildenafil versus placebo and bosentan. One trial showed a significant effect of bosentan treatment over placebo on indexed pulmonary vascular resistance and mean pulmonary artery pressure, but a non-significant increase in 6-min walk distance and a non-significant effect on systemic pulse oximetry. The other trial reported the safe but non-significant effect of combination therapy of bosentan and sildenafil compared with bosentan and placebo.

This study demonstrated safety and improved hemodynamic effects of bosentan in ES, with a controversial effect on exercise capacity. Further randomized controlled trials with longer follow-up duration are needed to confirm these results.