Screening for PAH in Systemic Sclerosis Patients May Improve Health-related Outcomes

Screening patients with systemic sclerosis (SSc) for pulmonary arterial hypertension (PAH) may help identify patients with both conditions sooner to start appropriate treatments, ensuring a better outcome, according to new research.

The study, “Epidemiology And Disease Characteristics Of Systemic Sclerosis-Related Pulmonary Arterial Hypertension: Results From A Real-Life Screening Programme,” was published in the journal Arthritis Research & Therapy.

SSc is a multisystem autoimmune disease characterized by the development of fibrosis in the skin and internal organs, blood vessel anomalies, and dysregulation of the immune system. Mortality rates among SSc patients are mainly due to cardiorespiratory complications, primarily PAH, which is why patients are recommended to have an annual screening with an echocardiogram.

The study enrolled 1,636 Australian SSc patients between 2007 and 2016 to determine the incidence of PAH among patients and evaluate the factors influencing the adherence to PAH screening guidelines by physicians.

To determine whether the screening program was successful in detecting PAH at an earlier stage, the team divided the patient cohort into those whose PAH was detected on first screening and those whose PAH was detected on the second or subsequent screen.

Results indicated that, among the SSc patients analyzed, 194 (11.9 percent) had PAH, with 160 of the cases being detected through screening. The annual incidence of PAH was found to be 1.4 percent.

Compared to those with PAH diagnosed on the first screen, patients with PAH diagnosed on subsequent screens:

• Were more likely to have diffuse cutaneous SSc;
• Presented a better World Health Organization (WHO) Functional Class at PAH diagnosis;
• Had less advanced PAH (measured by higher mean six-minute walk distance, a exercise capacity test);
• Had lower mean pulmonary arterial pressure;
• Had lower mean pulmonary vascular resistance;
• Had fewer nontrivial pericardial effusions (abnormal accumulation of fluid in the pericardial cavity).

Patients with PAH diagnosed on subsequent screenings also had significantly improved survival and a longer mean time to death, compared to those diagnosed on the first test (4.7 years vs. 2.3 years, respectively).

“We believe that PAH detected on first screen were likely to be a ‘delayed diagnosis’ in patients who were referred … due to symptoms or clinical suspicion of PAH, whereas PAH detected on subsequent screens was more likely to be an ‘incident’ PAH identified on earlier screening,” the researchers wrote.

Of note, doctors’ adherence to annual PAH tests was found to be poor among Australian rheumatologists. Fewer than half of the rheumatologists performed PAH screens in patients with more than 10 years of systemic sclerosis.

“Of those who did not perform [transthoracic electrocardiogram] for PAH screening, 50 percent reported this was due to difficulty assessing the right heart pressures with [transthoracic electrocardiogram]. Referral of these patients to a tertiary screening center may overcome this obstacle,” the team wrote.

“SSc-PAH is a tragic consequence of SSc, which despite advances in therapy, is the leading cause of SSc-related death,” the researchers concluded. “Screening … can identify patients with earlier PAH and improve outcomes. Identifying modifiable barriers to screening may improve adherence and ultimately patient outcomes.”