ObjectiveTo systematically review the efficacy and safety of prostacyclin for patients with pulmonary arterial hypertension (PAH).MethodsWe searched PubMed, EMbase, The Cochrane Library, WanFang Data, CBM and CNKI databases for randomized controlled trials (RCTs) compared prostacyclin with placebo from inception to April 2018. Two reviewers independently screened literature, extracted the data and assessed the risk of bias of included studies. Then meta-analysis was performed using RevMan 5.3 software.ResultsEleven RCTs including 2 549 participants were included. The results of meta-analysis showed that, compared with placebo group, prostacyclin group was superior to the placebo group in 6-min walk distance (MD=31.10, 95%CI 16.89 to 45.30, P<0.001), mortality (RR=0.62, 95%CI 0.41 to 0.94,P=0.03), Brog score (MD=–0.88, 95%CI –1.28 to –0.49, P<0.001), mean pulmonary arterial pressure (MD=–3.31, 95%CI –4.34 to –2.29,P<0.001) and cardiac index (MD=0.32, 95%CI 0.14 to 0.51,P<0.001). However, there were no differences between two groups in reducing delaying time to clinical deterioration (RR=1.27, 95%CI 0.99 to 1.63,P=0.06), tolerability (RR=0.74, 95%CI 0.42 to 1.31, P=0.30) and pulmonary vascular resistance (MD=–4.35, 95%CI –8.85 to 0.15, P=0.06).ConclusionsCurrent evidence reveals that prostacyclin therapy appears to be superior to the placebo in reducing the mortality, improving excise capacity, respiratory and cardiac function, and ameliorating mean pulmonary arterial pressure for pulmonary arterial hypertension. However, the efficacy of prostacyclin in delaying time to clinical deterioration, tolerability and pulmonary vascular resistance for PAH is not clear. Due to the limited quality and quantity of included studies, more high quality RCTs are required for further verification.