Findings from the multinational European League Against Rheumatism Scleroderma Trial and Research (EUSTAR) study show that systolic pulmonary arterial pressure (sPAP) is an important prognostic factor for patients with systemic sclerosis (or scleroderma). More specifically, lead author Eric Hachulla, MD, National Reference Center for Scleroderma, Department of Internal Medicine, University of Lille Nord de France, told Rare Disease Report that “an sPAP above 36 mm Hg is an independent predictive factor of death” in this patient population.
The retrospective study included 1476 individuals with systemic scleroderma from the EUSTAR patient database documented as having a baseline echocardiogram after January 2005 to measure sPAP and who made at least one follow-up visit between January 2005 and December 2011. The investigators excluded patients found to have pulmonary arterial hypertension (PAH) or pulmonary hypertension (PH) during a right-heart catheterization (RHC) procedure prior to January 2005. Mean follow-up was 2 years.
The study team evaluated PH risk according to 2009 recommendations from the European Society of Cardiology/European Respiratory, which suggest that PH is unlikely with an sPAP <36 mm Hg, possible with an sPAP >36 mm Hg but <50 mm Hg, and probable with an sPAP >50 mm Hg. The investigators also examined how many patients with an index sPAP >36 mm Hg—suggesting an elevated risk of PH—subsequently received RHC.
A total of 273 patients had a baseline sPAP ≥36 mm Hg. Of the 44 patients (16.1%) sent for RHC, 24 had PAH, 6 had post-capillary PH, and 4 had PH due to interstitial lung disease. Rates of 5-year overall survival (OS) varied significantly depending on baseline sPAP (Figureabove; log-rank P <.0001). The estimated 5-year OS rate for patients with an index sPAP below the threshold of 36 mm Hg was 86% versus 57% for patients with an index sPAP at or above the 36 mm Hg threshold. Differences in OS based on an index sPAP above versus below the 36‑mm Hg threshold were also evident at 1, 2, and 3 years’ follow-up. Overall, patients with an index sPAP ≥36 mm Hg were 3 times more likely to die than those with an index sPAP <36 mm.
The authors were surprised to discover that 16% of patients with an sPAP >36 mm Hg during the baseline echocardiogram never received a follow-up RHC even though they had an increased risk of PH. In patients with systemic sclerosis, PAH is associated with high rates of morbidity and mortality, especially if it goes untreated.
“When PAH in patients with systemic sclerosis is suspected, RHC should be discussed; it is the only way to confirm the diagnosis of precapillary PH,” said Hachulla. He added that treatment is available for patients found to have PAH Group 1 (PH not associated with interstitial lung disease). He recommended that physicians who manage patients with sclerosis “do echocardiography regularly” to measure sPAP, which is an important tool for predicting prognosis.
Hachulla E, Clerson P, Airo P, et al. Value of systolic pulmonary arterial pressure as a prognostic factor of death in the systemic sclerosis EUSTAR population. Rheumatology (Oxford). 2015 Jan 17. [Epub ahead of print]