CT-proET1 predicts pulmonary hemodynamics in Scleroderma-associated pulmonary hypertension.

Abstract

Systemic sclerosis (SSc) is an important risk factor for the development of pulmonary hypertension (PH). The presence of PH in SSc patients, especially pulmonary arterial hypertension (PAH), harbors a poor prognosis and is one of the most frequent causes of death in SSc [1]. Consequently, early diagnosis is an important goal. Right heart catheterization (RHC) is mandatory to confirm the diagnosis of PH. However, this is an invasive procedure, which is only performed when PH is suspected. The initial suspicion of PH is raised by non-invasive methods including echocardiography, cardiopulmonary exercise testing and biomarkers. The most widely used biomarker is N-terminal pro-brain natriuretic peptide (NT-proBNP), which is more stable than BNP itself. In PH, NT-proBNP levels correlate with pulmonary hemodynamics and with outcome [2]. However, many factors influence serum levels of NTproBNP, including gender, age, and, most importantly, renal function. Consequently, correlation with hemodynamics was lost with impaired renal function in a recent study [3]. Despite these issues, NT-proBNP is the bestinvestigated biomarker in PH and the European Society of Cardiology guidelines suggest that NT-proBNP should be measured in every PH patient. Other biomarkers that may be helpful for early PH diagnosis include Copeptin, Midregional portion of pro-ANP (MR-proANP), midregional portion of pro-adrenomedullin (MR-proADM) and carboxy-terminal pro-endothelin-1 (CT-proET1) [4, 5]. Here, we sought to investigate whether these novel biomarkers provide additional benefit over NT-proBNP in the non-invasive detection of PH in this high-risk population. Thirty-one patients with SSc and clinical indication for RHC due to clinical suspicion of PH during SSc screening were included. PH was defined according to current guidelines by a mean pulmonary arterial pressure (PAPmean) of C25 mmHg. Transthoracic echocardiography (TTE) was performed in all patients using the Philips iE33system. Measurements of CT-proET1, Copeptin, MRproANP und MR-proADM were performed by Thermo Fisher Scientific, Clinical Diagnostics, BRAHMS GmbH, Hennigsdorf, Germany [6]. Quantitative data were summarized by mean ± standard deviation (SD) or median (range), contingent on distributional characteristics (e.g. skewness). Diagnostic accuracy of biomarkers was evaluated by receiver operating characteristic (ROC) H. ten Freyhaus and D. Dumitrescu contributed equally to this manuscript.