BackgroundThis systematic review and meta-analysis was conducted to investigate the efficacy and safety of the chronic administration of aerosolized iloprost for pulmonary arterial hypertension (PAH).MethodsAll the relevant studies were obtained from three databases, namely, PubMed, Web of Science and the Cochrane Library, from the inception of each database to June 1, 2018. In our study, chronic treatment was defined as a period lasting at least 3months. The rate of each event was analyzed by SPSS as a percentage with 95% confidence intervals (CIs). For the meta-analysis, a randomized effect model or a fixed effect model was applied according to the results of the heterogeneity test.ResultsTen studies were included in this study, with a total of 370 patients treated with inhaled iloprost, including 214 in five randomized controlled trials and 156 in five prospective clinical trials. Among the patients who received inhaled iloprost, there was a significant improvement in the 6-min walk distance (6MWD) in the short-medium and prolonged treatment groups. Notably, the functionality improved by at least 1 class in 48.7% of the treated patients. In all the pooled studies, the estimated 3-month, 6-month, 1-year and 2-year event-free survival rates were 96.6%, 92.3%, 62.6% and 39.6%, respectively. In addition, there were eight adverse drug responses.ConclusionIn this systematic review and meta-analysis, inhaled iloprost has been shown to be a safe and well-tolerated agent for PAH in the first 3months after diagnosis. If used for a prolonged period, aerosol iloprost monotherapy could contribute to an unsatisfactory improvement in vascular remodeling and even a decreased event-free survival rate.