Higher Mortality Rates in Patients With Systemic Sclerosis-Associated Pulmonary Hypertension

A higher mortality rate was reported in systemic sclerosis (SSc)-related pulmonary hypertension (PH), according to a study published in Advances in Rheumatology.¹ Early diagnosis and subsequent treatment of PH is crucial in this patient population.

“SSc is associated with high morbidity and mortality related to multiple organ complications,” investigators explained. “PH is a frequent complication of SSc and is currently one of the primary causes of death in patients with this disease.”

Investigators reviewed PubMed and Embase databases for studies focused on SSc-associated PH through May 2021. Search terms included “systemic scleroderma,” “systemic sclerosis,” and “pulmonary hypertension.” Outcome parameters were pooled and analyzed via a random-effects model utilizing a generic inverse-variance weighting in both conventional and cumulative meta-analysis. Articles included were cohort studies of adult patients with SSc meeting the American College o Rheumatology (ACR) criteria, defined PH as mean pulmonary arterial pressure of > 20 mmHg on right heart catheterization (RHC), and risk ratios (RRs) or odds ratios (ORs) with 95% confidence intervals (Cis), or the precise number of patients in each group.

Of 1161 citations and 54 full-text studies examined, 16 articles, including 7857 patients with SSc and 1140 patients with SSc-associated PH were included in the analysis. Patients with SSc-associated PH had a higher risk of mortality when compared when patients with SSC without PH, with a pooled RR of 3.12 (95% CI [2.44, 3.98], I2 = 64%), indicating moderate heterogeneity. Sensitivity and subgroup analyses yielded similar results.

The study was hindered by its observational nature, which is generally unbalanced regarding clinical characteristics of patients. Another limitation was that 7 studies had a short follow-up period of less than 10 years, and 4 studies were published more than 10 years ago, opening the possibility of bias. However, investigators minimized this by performing subgroup analyses, which yielded similar results, thus solidifying the stability and reliability of the results.

PH has been commonly considered a main cause of death in limited cutaneous systemic sclerosis (lcSSc), but not in diffuse cutaneous SSc (dcSSc). However, studies have reported that the pulmonary vascular complication is a common manifestation across all SSc subsets. Unfortunately, mortality between lcSSc-PH and dcSSc-PH patients could not be compared because most articles included in the study did not include data on mortality or frequency data in these patient populations. Finally, lead-time bias may have affected results.

“The results of this meta-analysis confirm that patients with SSc and PH have a higher risk for poor outcomes,” investigators concluded. “PH should be seen as a red flag for an increased risk of mortality and physicians should strive to diagnose SSc-associated PH early, so that early treatment may be initiated.”

Reference:

Xiong A, Liu Q, Zhong J, et al. Increased risk of mortality in systemic sclerosis-associated pulmonary hypertension: a systemic review and meta-analysis. Adv Rheumatol. 2022;62(1):10. Published 2022 Mar 30. doi:10.1186/s42358-022-00239-2