SESSION TITLE: Hot Topics in PAH
SESSION TYPE: Original Investigation Slide
PRESENTED ON: Wednesday, October 28, 2015 at 04:30 PM - 05:30 PM
PURPOSE: In patients with chronic thromboembolic pulmonary hypertension (CTEPH), the definitive treatment remains surgical resection with a pulmonary thromboendarterectomy (PTE). However, upwards of 10% of patients will have residual pulmonary hypertension, presumably due to small vessel arteriopathy beyond the level of the resection. To date, no pre-operative biomarkers exist to identify those patients with small vessel arteriopathy prior to PTE.
METHODS: After informed consent, pre-operative systemic arterial, venous and pulmonary arterial blood samples were obtained from 50 patients undergoing PTE. Two potential biomarkers for small vessel arteriopathy, angiopoietin-2 (Ang-2) and endothelin-1 (ET-1), were measured. Clinical data including pre- and post-operative hemodynamics was collected from all patients. The Pearson correlation between both pre- and post-operative pulmonary vascular resistance (PVR) and each pre-operative biomarker was examined. Residual pulmonary hypertension was defined as a post-operative PVR of greater than 400 dyn.cm5. A reciever-operator curve was used to identify the optimal cut-off value for determining the sensitivity and specificity of residual pulmonary hypertension.
RESULTS: Pre-operative Ang-2, regardless of sampling site, is significantly correlated with pre-operative PVR, but does not predict post-operative PVR. Of the variables assessed, pre-operative arterial ET-1 had the strongest relationship with post-operative PVR (r=0.416, 95% CI: 0.096 - 0.645, p=0.007). Using a pre-operative ET-1 cut-off of 1.5 pg/ml to identify patients with residual pulmonary hypertension (defined as PVR >400 dyn.cm5) had a sensitivity of 100% and a specificity of 69%.
CONCLUSIONS: Ang-2 was associated with only pre-operative PVR but not post-operative PVR. There is a strong positive correlation between pre-operative arterial endothelin-1 level and both pre- and post-operative PVR.
CLINICAL IMPLICATIONS: Knowledge of the systemic arterial ET-1 level may help identify patients pre-operatively at risk for residual pulmonary hypertension due to small vessel arteriopathy and would be useful in counseling patients with CTEPH about expected post-PTE outcomes.
DISCLOSURE: Timothy Fernandes: Grant monies (from sources other than industry): The CHEST Foundation, Grant monies (from industry related sources): Actelion Pharmaceuticals, Consultant fee, speaker bureau, advisory committee, etc.: Bayer William Auger: Grant monies (from industry related sources): Bayer Kim Kerr: Grant monies (from industry related sources): Bayer The following authors have nothing to disclose: Dina Bates
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