A new study found that the use of combination therapy in patients with pulmonary arterial hypertension (PAH) considerably reduced their risk of clinical worsening, compared to using a single therapy. The study, “Combination therapy versus monotherapy for pulmonary arterial hypertension: a meta-analysis,” was published in the journal The Lancet Respiratory Medicine.
“Combining PAH-targeted therapies significantly reduced the risk of clinical worsening, as predefined in clinical studies, for patients with PAH. This effect was generally consistent across subgroups,” Annie Christine Lajoie, M.D., and her colleagues wrote in a press release from the Pulmonary Hypertension Research Group and Institut Universitaire de Cardiologie et de Pneumologie de Québec Research Center in Canada.
“Combination therapy also reduced the risk for admission to hospital, treatment escalation, and symptomatic progression, and resulted in improved patient functional status,” they wrote.
For the study, Lajoie and her team reviewed the MEDLINE, Embase, and Cochrane Library databases to look for studies analyzing combination PAH and PAH-specific monotherapy between the years 1990 and 2015.
Of the 2,017 studies that the team identified, 17 prospective, randomized, controlled trials were analyzed with a total of 4,095 patient participants. The team extracted data from these reports and assessed the primary outcome of the risk of clinical worsening, as defined a priori for every single trial, using the Mantel-Haenszel method based on a model of fixed-effects.
The team found that combined therapy was associated with a significant reduction of the risk of clinical worsening in PAH patients when compared with monotherapy. Even though the Eggers test – a statistics test used to determine if there is any sort of bias in meta-analysis studies – identified a potential publication bias favoring positive results, the researchers noted that the risk ratio stayed unchanged when four studies with positive results were removed. The team also noted that they have not observed any heterogeneity between studies.
PAH is a chronic disease that is usually characterized by an increasing blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, which together are known as lung vasculature. The condition might lead to shortness of breath, dizziness, fainting, leg swelling, among other symptoms.