Coronary-to-Pulmonary Artery Collateralizations in Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

A man in his 40s underwent cardiac catheterization to confirm a diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH). Coronary artery contrast injection revealed a normal right (left panel) and left (center panel) coronary artery with presence of collateralizing vessels (arrow) spanning from the left circumflex to right pulmonary artery, allowing direct filling of the distal pulmonary circulation (asterisk) from the coronary circulation (right panel) thereby bypassing the thrombosed proximal pulmonary artery. This rare phenomenon, known as coronary-to-pulmonary artery collateralization, has been described in up to 18% of CTEPH cases and represents remodeling resulting from chronically decreased pulmonary blood flow secondary to large thromboembolism. Click the related article link for complete details.