Researchers in Turkey evaluated the two drug therapy approaches commonly used to treat pulmonary arterial hypertension (PAH) and found no substantial difference between the two in the patients observed. The study, titled “Combination Therapy in Pulmonary Arterial Hypertension: Single Centre Long-term Experience“ appeared in May 2015 in the West Indian Medical Journal.
PAH is a vascular disease marked by high blood pressure in the lungs that can eventually result in right heart failure, and is currently treated with medications targeting three molecular pathways. Doctors now generally adopt one of two different strategies for their patients: either a “first-line, up-front” path that initiates a double or triple drug therapy as treatment, or a “sequential add-on” path that begins with a single drug and later adds a second or third drug as treatment. Both strategies are common, but little clarity exists as to which might be the safer and more effective approach.
In this study, researchers set out to evaluate the treatment approaches at a single center. They diagnosed PAH in patients using clinical, echocardiographic and right heart catheterization measurements, and study participants were given medications that included including bosentan, sildenafil, and iloprost. The research team defined clinical worsening as PAH-related hospitalization, a 15% decrease in distance in the six-minute walking test (6 MWT), a deterioration in function, and signs of right heart failure.
The effects of single medication add-on therapy were found to be similar as initial combination drug therapy. According to the study report, “At the end of the follow-up period, clinical and echocardiographic findings, [brain naturitic peptide] levels and oxygen saturation were similar between patients who completed the study with monotherapy and with combination therapy. The follow-up period was significantly longer in patients who required combination treatment. Two patients (6.9%) died and four patients (13.8%) were hospitalized due to recurrent symptoms and findings of right heart failure. At the end of follow-up, 10 patients (34.5%) completed the study with a single drug, 15 patients (51.7%) with two drugs and four patients (13.8%) with three drugs.”
Based on the researchers’ conclusions, it appears that the best approach is the one most appropriate for the individual, and the two approaches can be equally effective. However, this study did not examine how the selection of therapies for a given PAH patient should best proceed.