Left Main Coronary Artery Stenting to Relieve Extrinsic Compression by a Giant Pulmonary Artery Aneurysm in a Patient with Idiopathic Pulmonary Artery Hypertension.

Pulmonary artery aneurysm (PAA) is a rare but lethal disease. We present a female patient with idiopathic pulmonary artery hypertension (IPAH)-related PAA, who suffered from unstable angina pectoris. Multi-detector computed tomography and coronary angiogram revealed extrinsic compression of the left main coronary artery (LMCA) caused by a giant PAA with severe ostial stenosis. Intravascular ultrasound showed an oval-shaped ostium of the LMCA, indicating extrinsic compression. After successful LMCA stent implantation, chest pain was greatly relieved. This case illustrates that beyond right ventricle ischaemia and coronary atherosclerotic disease, LMCA compression by PAA should be considered in the differential diagnosis of angina in patients with IPAH related PAA. In addition, intravascular ultrasound can be used to confirm the diagnosis and guide the stent implantation safely.