Monotherapy Likely Enough to Help Manage Atypical PAH, Study Says

Treatment with a single medication (monotherapy) may be sufficient to help manage people with “atypical” pulmonary arterial hypertension (PAH), according to an analysis from four clinical centers in Germany.

One-year survival of adults diagnosed with “atypical” PAH — those older than 65 and with multiple risk factors for heart disease — did not differ for patients on monotherapy compared with patients taking dual or triple combination therapies.

The study, “Monotherapy in patients with pulmonary arterial hypertension at four German PH centres,” was published in the journal BMC Pulmonary Medicine.

While early combination treatments are the standard option in PAH, they are not suitable for older patients with atypical PAH. In such cases, the rate of side effects is generally higher and the combo therapy less effective.

In Germany, single therapy is recommended for atypical PAH patients with low or intermediate risk of estimated one-year mortality.

To assess the prevalence of single therapy prescriptions to atypical PAH patients, researchers in Germany conducted a retrospective analysis of data from four German PH centers.

They reviewed data collected up to three months of follow-up (baseline), from four to eight months at first follow-up, and from nine to 15 months at the second follow-up. The median follow-up duration was 22 months.

In total, their analysis included 131 patients treated between 2016 and 2018 (50.4% female, mean age 64 years). Among this group, 63.4% were diagnosed with PAH and 36.6% with idiopathic (no known cause) PAH.

At the start of the analysis, or at baseline, 90 patients (68.7%) were classified as World Health Organization Functional Class III, characterized by marked limitation of normal activities.

The scientists defined atypical PAH as being older than 65 and having three or more cardiovascular risk factors, including high blood pressure, heart disease, diabetes, obesity, diastolic dysfunction (when the heart is not able to relax fast enough after each beat), or atrial fibrillation — irregular and often abnormally fast heart rate. According to these criteria, 45 patients (34.4%) were classified with atypical PAH.

At baseline, the majority of patients (117 or 89.3%) were treated with a targeted therapy, 83 of whom (70.9%) received monotherapy, 27 (23.1%) dual therapy, and seven (6%) triple therapy.

At the first follow-up, 95% (125 patients) were treated with PAH therapy, including 57.6% on monotherapy. At the second follow-up, data available from 111 patients revealed that monotherapy was maintained for 45%, while 55% were getting dual or triple therapy.

The use of combination treatments increased significantly over time in atypical PAH patients.

While monotherapy was significantly more frequent among older patients (older than 65) than among younger participants (72.2% vs. 52.5%) at baseline, no such difference was seen at the first and second follow-ups. In fact, the older group was treated with an increasing proportion of combination treatments over time.

No differences were found in survival with the number of PAH medicines. Survival at one year for the atypical PAH group did not differ between the group on combination treatments and those on monotherapy. It also did not differ between atypical and typical PAH participants.

Overall, these results suggest that combination treatments may not be required for “atypical” PAH patients, since “monotherapy in these patients appears to be comparable to that of dual or triple therapy in ‘typical’ PAH patients,” the scientists concluded.