Conference: 2018 PHA International PH Conference & Scientific Sessions
Release Date: 06.28.2018
Presentation Type: Abstracts
File Download: Conference 2018_1038
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Abstract presented at the 2018 International PH Conference and Scientific Sessions in Orlando, Fla., June 28-July 1, 2018.
At present, there are no established tools for risk prediction in patients with chronic thromboembolic pulmonary hypertension (CTEPH). For patients with pulmonary arterial hypertension (PAH), 2015 ESC/ERS treatment guidelines recommend regular risk assessment using a multidimensional approach incorporating clinical, exercise, imaging, and hemodynamic variables. Abbreviated versions of this risk assessment were found to discriminate between prognostic groups in PAH cohorts of the French, Swedish, and COMPERA registries.[1–3] We therefore conducted an exploratory assessment of the ESC/ERS risk models in patients with inoperable or persistent/recurrent CTEPH receiving riociguat in the CHEST studies.
In CHEST-1, patients received placebo or riociguat adjusted up to 2.5 mg three times a day (tid) for 16 weeks. For patients entering the CHEST-2 open-label extension study, risk was assessed at baseline and Week 16 according to three methods: 1. French registry invasive analysis: quantified the number of ESC/ERS low-risk criteria present based on WHO functional class (FC), 6-minute walking distance (6MWD), right atrial pressure (RAP), and cardiac index. 2. French registry non-invasive analysis: quantified the number of low-risk criteria present for three non-invasive parameters: WHO FC, 6MWD, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP). 3. COMPERA analysis: assessed WHO FC, 6MWD, NT-proBNP, RAP, cardiac index, and mixed venous oxygen saturation; each criterion was graded 1–3 (1=low risk, 3=high risk) and the rounded mean defined the risk category. The association between meeting low-risk criteria at Week 16 of CHEST-1 with long-term outcomes in CHEST-2 was assessed by Kaplan–Meier analyses of observed data. Differences in the long-term outcome between risk groups were analyzed using the log-rank test.
After 16 weeks in CHEST-1, patients treated with riociguat (n=155) met a greater number of the low-risk criteria (French invasive and non-invasive) or improved their risk status (COMPERA) compared with baseline. The number of low-risk criteria at Week 16 discriminated between prognostic groups for both survival (French invasive p<0.0001; French non-invasive p=0.0231) and clinical worsening-free survival (p<0.0001 for both methods [Figure shows non-invasive analysis]). The COMPERA method discriminated between prognostic groups for both survival and clinical worsening-free survival (p<0.0001 for both).
In this exploratory analysis, abbreviated versions of the ESC/ERS risk assessment were able to discriminate between prognostic groups when applied to patients with inoperable or recurrent/persistent CTEPH receiving riociguat in CHEST-2. Further evaluation of risk prediction in patients with CTEPH is therefore warranted.
1. Boucly A, et al. Eur Respir J 2017;50:1700889;
2. Hoeper MM, et al. Eur Respir J 2017;50:1700740;
3. Kylhammar D, et al. Eur Heart J 2017; doi: 10.1093/eurheartj/ehx257.
Figure 1: Clinical worsening-free survival in CHEST-2 stratified by the number of low-risk non-invasive criteria at Week 16 in CHEST-1.