Efficacy and Safety of Long-Term Oral Bosentan in Different Types of Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis.

OBJECTIVE

This systematic review and meta-analysis was conducted to identify if long-term bosentan is an effective and safe treatment for pulmonary arterial hypertension (PAH) regardless of type, including idiopathic PAH (IPAH), and PAH associated with congenital heart disease (APAH-CHD), connective tissue disease (APAH-CTD), and human immunodeficiency virus (APAH-HIV).

METHODS

All relevant observations were systematically searched by two independent investigators and obtained from three databases, including PubMed, EMBASE and the Cochrane Library, from the inception of each database to February 2020. Currently, long-term administration was defined as no less than 12 months. A random-effects or fixed-effects model was selected according to outcomes of the heterogeneity test for meta-analysis, where standardized mean difference (SMD) with 95% confidence intervals (CIs) was used for continuous outcomes, in addition to the estimated effect (ES; 95% CI) for the synthesized survival rate. Furthermore, subgroup analysis was applied to analyze the differences of efficacy and survivals in each type of PAH cohort.

RESULTS

Fifteen studies including a total of 659 subjects undergoing oral bosentan administration for at least 12 months were pooled in this quantitative review. Meta-analysis and subgroup analysis indicated that significant clinical benefits existed, including an improved 6-min walk distance (6MWD) and functional class (FC), in patients with APAH-CHD (6MWD: SMD 0.72, 95% CI 0.52-0.93, p < 0.0001; functional benefits: 50.4%, 95% CI 43.7-57.1%), APAH-HIV (6MWD: SMD 0.83, 95% CI 0.36-1.30, p = 0.001; functional benefits: 80.4%), and IPAH (SMD 0.54, 95% CI 0.28-0.80, p < 0.0001; functional benefits: 61.4%, 95% CI 54.2-68.5%), but a non-significant change in APAH-CTD (6MWD: SMD 0.18, 95% CI - 0.60 to 0.95, p = 0.656; functional benefits: 27.5%). Furthermore, among the hemodynamic parameters, long-term bosentan led to a significant decrease in mean pulmonary artery pressure (SMD - 0.86, p < 0.0001) in APAH-CTD, and a decrease in pulmonary vascular resistance (SMD - 0.65, p < 0.0001) and elevated oxygen saturation (SMD 0.30, p = 0.006) in APAH-CHD. Importantly, in all pooled studies, the overall survival indicated 1-, 2-, and 3-year survival rates of 94.3%, 88.8%, and 81.7%, respectively, in all-cause PAH, and subgroup analysis demonstrated a relative decreasing trend in patients with HIV, from a 2-year survival of 89.8% to a 3-year survival of 66.1%. Adverse drug reactions were relatively mild.

CONCLUSION

In this systematic review and meta-analysis, long-term administration of oral bosentan has been identified as a well-tolerated and effective agent in different types of PAH. In addition, we conclude that long-term oral bosentan should be considered for patients with CTD to achieve a satisfactory exercise capacity, and for those with APAH-HIV to improve survivals, where more attention on adverse events is required.