Researchers Identify Risk Factors for PAH Progression in SSc-PAH patients

Male gender and lung function parameters have been identified as risk factors for progression of pulmonary arterial hypertension in patients with systemic sclerosis-PAH (SSc-PAH), a study shows.

Part of the larger, multi-center, DETECT study, these results are reported in the research, “Factors associated with disease progression in early-diagnosed pulmonary arterial hypertension associated with systemic sclerosis: longitudinal data from the DETECT cohort,” published in the Annals of the Rheumatic Diseases.

Researchers followed 57 patients with SSc-PAH for up to three years to see if they could identify risk factors for progression of PAH, which was defined as the occurrence of at least one of the following events during follow-up: Worsening in World Health Organization Functional Class (WHO FC, a measure of the clinical severity of PAH); presence of combination therapy for PAH; PAH-related hospitalization; and death from any cause.

Out of 57 participants, 25 (43.9%) had progressive PAH and 32 (56.1%) had stable PAH. Among the 25 patients with progressive PAH, four died, 11 were hospitalized due to the disease, 14 experienced worsening according to the WHO FC, and eight received combination treatment for PAH.

The majority of the patients had mild or no PAH symptoms. None of them had been diagnosed with PH by right heart catheterization (RHC) before the study began, and there was no cases of very severe PAH, denoted by WHO FC IV and V groups. Of the 25 patients whose PAH progressed during follow-up, 13 were in WHO FC I or II, the groups with the least severe PAH.

The authors pointed out that, based on their results, even mild PAH should be considered a high-risk complication of SSc.

Disease progression was seen more often in males. Low diffusing capacity of the lung for carbon monoxide (DCLO), and a high ratio of forced vital capacity (FVC) to (DLCO) –  both measures of lung function – were factors favoring the progression of PAH. Having a high Borg Dyspnea Index, a measure of shortness of breath in response to exercise, was also a factor.

“These factors are similar to risk factors identified for patients with more advanced PAH,” researchers wrote.

“The risk factors identified by our exploratory analysis are highly feasible to use in clinical practice. Particular attention should be given to DLCO monitoring, both for PAH screening and prognostic purposes in patients with SSc,” they added.

Overall, these results show that “patients with early SSc-PAH have a meaningful rate of disease progression over a relatively short time, requiring close follow-up,” the study concluded.