Patients with systemic lupus erythematosus who develop pulmonary arterial hypertension (PAH) have a poorer prognosis, according to a review from the Peking Union Medical College & Chinese Academy of Medical Science, which strongly recommended clinicians pay attention to the simultaneous presence of these conditions, as early diagnosis and management might improve survival.
PAH is a rare, but serious, complication of lupus, and the third leading cause of death in lupus patients. Without specific treatment, lupus patients who develop PAH are thought to live about two years after diagnosis, although previous studies of survival rates in this group produced highly variable results.
The study, “Survival and prognostic factors of systemic lupus erythematosus-associated pulmonary arterial hypertension: A PRISMA-compliant systematic review and meta-analysis,” analyzed published data investigating the prognosis or survival of adults with lupus and PAH.
Researchers searched medical databases for relevant studies published up to April 2015. They then assessed the quality of the studies using validated tools, and judged six to be of high enough quality to allow an analysis. The studies included a total of 323 patients with lupus-associated PAH.
Findings, published in the journal Autoimmunity Reviews, showed that the one-year survival rate for these patients was 88 percent. This value dropped during subsequent years, with three-year survival found to be 81 percent, and five-year survival 68 percent. However, the results were, again, highly variable.
The research team investigated whether the high variability could be explained by the presence of different subgroups of these lupus-PAH patients. They found that age, race, country, WHO functional class of PAH, cardiovascular parameters, and treatment could not explain the high variability. The team could also not find evidence for so-called publication bias, or the tendency of researchers to publish only selective findings, so that the published data are unrepresentative of total outcomes.
Interestingly, the study identified a number of factors that could be used to predict a worse prognosis. Higher mean pulmonary arterial pressure and vascular resistance, lower six minute walking distance scores, higher brain natriuretic peptide (BNP), and higher NT-proBNP levels were all related to poorer survival rates.
WHO functional classes III and IV were associated with poor survival in several of the included studies, and were confirmed as a risk factor in the present analysis. The severity of lupus was not found to be predictive of survival.