“…In their article of Annals of Translational Medicine , Ignatov et al describe their results regarding their early experience with pulmonary endarterectomy (PEA) in Bulgaria for chronic thromboembolic pulmonary hypertension (CTEPH) ( 1 ). While acute pulmonary embolism (APE) is a widely recognized entity, CTEPH is much more difficult to diagnose ( 1 , 2 ). The symptoms of CTEPH are attributed to obstruction of pulmonary arteries by chronic organized fibrotic clots ( 3 ).…”