Previous meta-analyses of PAH-specific therapy for pulmonary arterial hypertension (PAH) pooled PAH-specific combination therapy and monotherapy together. The flaw might threaten the authenticity of their findings.
PubMed, Embase, and the Cochrane Library were searched for randomized controlled trials (RCTs) that evaluated any PAH-specific medications in the treatment of PAH. We calculated odds ratio (OR) with 95% confidence intervals (CIs) for dichotomous data and standardized mean differences for continuous data.
In total, 35 RCTs involving 6,702 patients were included. In monotherapy vs placebo/conventional therapy, significance was obtained in mortality reduction (OR:0.50; 95%CI:0.33-0.76; P=0.001), six-minute walk test (6MWD) (MD:31.10m; 95%CI: 25.40 to 36.80; P <0.00001), NYHA/WHO functional class (OR:2.48; 95%CI:1.51-4.07; P=0.0003), hemodynamic based on mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index (CI), and incidence of withdrawal due to adverse effects. In combination therapy vs monotherapy, significance was reached for 6MWD(MD:19.96m; 95%CI:15.35-24.57; P<0.00001), functional class(OR:1.65; 95%CI:1.20-2.28; P=0.002), hemodynamic, incidence of withdrawal due to adverse effects(OR: 2.01; 95%CI:1.54-2.61; P<0.00001 ), but not for mortality reduction(OR:0.98; 95%CI:0.57-1.68; P=0.94).
Our meta-analysis revealed that PAH-specific medications monotherapy could improve mortality, exercise capacity, functional class and hemodynamic when compared with placebo or conventional therapy. However, combination therapy could further improve exercise capacity, functional class and hemodynamic status compared with monotherapy, but had no proven effect on mortality. Combination therapy had a much higher incidence of withdrawal due to adverse effects than monotherapy.