Previous meta-analyses of pulmonary arterial hypertension (PAH)-specific therapy for PAH pooled PAH-specific combination therapy and monotherapy. This flaw may threaten the authenticity of their findings.
PubMed, Embase, and the Cochrane Library were searched for randomized controlled trials that evaluated any PAH-specific medications in the treatment of PAH. We calculated ORs with 95% CIs for dichotomous data and standardized mean differences for continuous data.
In total, 35 randomized controlled trials 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 to 0.76]; P = .001), 6-min walk test (mean difference, 31.10 m [95% CI, 25.40 to 36.80]; P < .00001), New York Heart Association/World Health Organization functional class (OR, 2.48 [95% CI, 1.51 to 4.07]; P = .0003), and hemodynamic status based on mean pulmonary artery pressure, pulmonary vascular resistance, cardiac index, and incidence of withdrawal due to adverse effects. In combination therapy vs monotherapy, significance was reached for the 6-min walk test (mean difference, 19.96 m [95% CI, 15.35 to 24.57]; P < .00001), functional class (OR, 1.65 [95% CI, 1.20 to 2.28]; P = .002), hemodynamic status, and incidence of withdrawal due to adverse effects (OR, 2.01 [95% CI, 1.54 to 2.61]; P < .00001) but not for mortality reduction (OR, 0.98 [95% CI, 0.57 to 1.68]; P = .94).
Our meta-analysis revealed that PAH-specific monotherapy could improve mortality, exercise capacity, functional class, and hemodynamic status compared with placebo or conventional therapy. However, combination therapy could further improve exercise capacity, functional class, and hemodynamic status compared with monotherapy, but it had no proven effect on mortality. Combination therapy had a much higher incidence of withdrawal due to adverse effects than monotherapy.