Chinese who develop pulmonary arterial hypertension (PAH) from primary Sjogren’s syndrome have worse survival rates if their PAH appears late or if they have poorer cardiac function, a new study shows.
The findings, published in the journal Lupus, also show that patients taking immunosuppressants have better survival rates.
Sjogren’s syndrome, systemic lupus erythematosus, and systemic sclerosis are autoimmune disorders that are grouped together as connective-tissue disorders (CTDs).
PAH is a frequent complication of CTDs. While it is more commonly caused by systemic sclerosis and lupus in Caucasians, primary Sjogren’s syndrome is the major cause of PAH in people in Korea and Japan.
In Chinese CTD-PAH patients, primary Sjogren’s syndrome and lupus were the most common CTDs causing PAH. The differences in CTDs in Western and Asian populations suggest either a genetic or environmental factor in the development of CTD-PAH, the researchers observed.
Information on the prognosis of pSS-PAH patients is still scarce.
Researchers decided to examine disease properties and hemodynamic (blood flow) characteristics, as well as treatment regimens of patients with pSS-PAH, to determine their prognostic value.
The study, “The prognosis of pulmonary arterial hypertension associated with primary Sjogren’s syndrome: a cohort study,” covered 29 Chinese women between 2007 and 2015.
All of the patients’ PAH had been diagnosed with right heart catheterization (RHC). RHC is the gold standard for diagnosing PAH, but its use in patients with pSS-PAH has yet to be determined.
Patients were followed every three to six months. Scientists defined survivors as those who reached the study cut-off of May 15, 2015.
“To our knowledge, our study reports the largest cohort of patients with pSS-PAH confirmed by RHC, and is the first to identify prognostic factors of pSS-PAH,” the researchers wrote.
The mean age of pSS onset was about 34, while the mean age at PAH diagnosis was about 41. Researchers did not find any significant difference in age, disease duration, and hemodynamic findings between survivors and non-survivors.
One year after PAH diagnosis, 80.2% of patients were alive. After three years it was 74.8%, and after five years 67.4%.
Importantly, delayed onset of PAH in pSS and lower cardiac index (an assessment of cardiac output based on the body’s surface area) were predictors of mortality. In contrast, the use of immunosuppressants correlated with better survival.
“According to our findings, it is necessary to introduce immunosuppressants as part of standardized treatment strategies for pSS-PAH,” the researchers wrote.
In comparison with other studies, the team observed that their group of patients had higher pulmonary arterial pressure and lower cardiac index. This may indicate a more advanced stage of PAH, they suggested.
Future multi-center studies with larger groups of patients are needed to clarify the relationship between specific causes of pSS and survival, as well as to elucidate the reasons for the different findings in Western and Asian patients, the researchers noted. Further studies are also needed to determine the efficacy of specific immunosuppressants.