Early Changes in Echocardiographic Variables of Patients With Pulmonary Hypertension Undergoing Bilateral Pulmonary Thrombo-Endarterectomy: Experience of a Tertiary Care Center in Latin-America at 8660 Feet Above Sea Level

Introduction: Chronic thromboembolic pulmonary hypertension (CTEPH) is a reversible cause of pulmonary hypertension when patients undergo bilateral pulmonary thrombo-endarterectomy (BPT). We aim to compare TTE findings before and after BPT in a tertiary care center with an unusual altitude above sea level in Bogota, Colombia. Methods: Retrospective cohort, including CTEPH patients undergoing BPT between 2016 and 2021. We compared TTE done pre and post-operatively. We evaluated TTE volumetric and functional data including inter-ventricular dependence using the ratio of end-systolic diameter of right and the left ventricle (RV/LV). Results: We included CTEPH 17 who underwent BPT in our institution and compared studies done before and within the first 6 months after the procedure. Compared to the pre-op studies, the post-op TTE′s showed lower basal and middle diameters of the RV, lower TAPSE and higher CAF values with no changes in tricuspid S’ wave. The LVEF and right atrium area were similar to pre-operative TTE′s. Of notice, diastolic parameters such as E/A and E/e’ ratios improved to a normal diastolic filling pattern. Higher left atrium volume was also noticed. Finally, we observed lower PASP, a longer pulmonary valve acceleration time and lower RV/LV end-systolic diameter ratio in the early post-operative state (Table 1). Conclusions: In a tertiary care center with an altitude of 8660 feet above sea level, early TTE post BPT in CTEPH patients demonstrated decrease in the size of the right-sided chambers, higher volumes in left-sided chambers, normalization of diastolic parameters, decrease in PSAP, increase in the pulmonary valve acceleration time, and decrease of inter-ventricular dependance. Our findings suggest early remodeling phenomena after BPT despite the high altitude of where the surgery was performed.