PAH Treatments Cannot Overcome Low Life Expectancy of SSc-PAH Patients, Study Suggests

Alice Melão, MSc avatar

by Alice Melão, MSc |

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SSc-PAH therapies and survival

Scientific advances have allowed researchers to develop therapies for pulmonary arterial hypertension (PAH) that have been shown to benefit patients with PAH related to systemic sclerosis (SSc).

However, the median survival of these patients remains short, with a life expectancy of only four years from the time of diagnosis, according to a study recently published in the journal Arthritis Research & Therapy.

SSc, also known as scleroderma, is a multi-organ disease that most commonly affects the skin, but it can also affect the lungs, heart, blood vessels, and other organs. PAH occurs in about 8 to 15 percent of SSc patients and is associated with a poor outcome, reflected in an average life expectancy of two to three years from diagnosis if it is left untreated.

Several therapies are available to treat PAH that have proven to be effective. However, the survival rate of SSc-PAH patients is still low when compared to that observed in patients with similar conditions, such as idiopathic PAH or connective tissue disease-associated PAH.

In the study “Survival and quality of life in incident systemic sclerosis-related pulmonary arterial hypertension,” the authors tried to identify potential predictors of mortality among SSc-PAH patients from data collected from a fairly large cohort.

From 2009 until 2015, a total of 132 patients with SSc-PAH from the Australian Scleroderma Cohort Study (ASCS) were followed. During this period, 45.5% of patients died, with a survival time from diagnosis of 2.2 to 6.2 years.

The authors identified several independent predictors of mortality in the SSc-PAH population. Older age and higher mean pulmonary arterial pressure at PAH diagnosis were independent contributors for poor patient outcome.

Also, those with mild co-existent interstitial lung disease had a 2.8-fold increased risk of death; a worse WHO functional class led to a risk twice as high; and the presence of digital ulcers increased the risk of mortality by 3.1-fold.

Despite the poor life expectancy the team observed in these patients, the use of anticoagulation medicines or the combination of PAH therapies like PDE5 inhibitors (Sildenafil, for example) and an endothelin receptor antagonist (ERA; such as Bosentan), among other treatments, was shown to offer a survival benefit for SSc-PAH patients.

The most effective therapeutic regimen was combined PAH therapy plus an anticoagulation treatment. Still, despite the survival benefits of the therapies, the authors of the study did not find any benefits in terms of improving the patients’ quality of life.

“The lack of improvement in the physical component of HRQoL [health related quality of life] following PAH treatment may reflect the complex, multifactorial and individual nature of HRQoL, which is impacted upon by a variety of factors that are difficult to measure and adjust for,” the researchers wrote.

Overall, the study showed there is still a need for improved therapies for SSc-PAH patients, not only to prolong their life expectancy, but also to improve their quality of life and physical capacities. Recognizing potential risk factors can help define personalized treatment and improve SSc-PAH patient care.