Pulmonary Hemodynamic Response to Exercise in Chronic Thromboembolic Pulmonary Hypertension before and after Pulmonary Endarterectomy

Background: Pulmonary endarterectomy (PEA) is the treatment of choice in surgically accessible chronic thromboembolic pulmonary hypertension (CTEPH). An important predictor of outcome is postsurgical residual pulmonary hypertension. Objective: We aimed to use the hemodynamic response during exercise before PEA as a measurement for the hemodynamic outcome 1 year after PEA. Methods: Between January 2011 and December 2013, 299 patients underwent PEA in our center. A total of 16 patients who were assessed by means of invasive hemodynamic measurements during exercise both at baseline and 1 year after PEA were retrospectively analyzed. Results: Pre-PEA mean pulmonary arterial pressure (mPAP) increased during exercise from 35.8 ± 7.6 to 53.8 ± 5.1 mm Hg, diastolic pulmonary arterial pressure (dPAP) from 21.5 ± 5.6 to 30.3 ± 9.6 mm Hg, cardiac output (CO) from 4.4 ± 0.8 to 6.5 ± 1.9 l/min and diastolic pulmonary gradient (DPG) from 14.6 ± 4.9 to 20.7 ± 12.7 mm Hg. Post-PEA mPAP increased from 23.7 ± 6.6 at rest to 43.2 ± 7.1 mm Hg, while CO increased to a higher extent from 5.1 ± 0.9 to 8.4 ± 1.9 l/min. There were significant correlations between pre-PEA DPG/CO and dPAP/CO slopes with the pulmonary vascular resistance (Spearman r = 0.578, p = 0.019, and r = 0.547, p = 0.028) and mPAP at rest after PEA (Spearman r = 0.581, p = 0.018, and r = 0.546, p = 0.028). Conclusions: In CTEPH, the presurgical dynamic DPG/CO and dPAP/CO slopes during submaximal exercise are associated with the hemodynamic outcome 1 year after PEA.