Case Series—Left Main Coronary Artery Compression by Dilated Main Pulmonary Artery in Patients with Pulmonary Arterial Hypertension

Extrinsic compression of the left main coronary artery (LMCA) by a dilated main pulmonary artery (MPA) is an important condition, and it should be looked for in patients with pulmonary arterial hypertension (PAH) with anginal symptoms. Left main coronary artery compression is defined as LMCA stenosis >50% with downward displacement of the vessel seen in coronary angiography due to dilated pulmonary artery (PA). Patients with PAH, irrespective of etiology, start to develop significant dilatation of the MPA. This enlarged PA results in compression of the LMCA, causing angina, syncope, heart failure, or arrhythmias, and they are at times responsible for sudden cardiac death. Here we have four patients with PAH of different etiologies. After evaluation with cardiac catheterization study and coronary angiogram, they were found to have LMCA compression. Two of them underwent percutaneous coronary intervention (PCI) for the LMCA disease, one of them underwent surgery for chronic thromboembolic pulmonary hypertension with PA reduction, and the last patient is under medical management. With this case series, we would like to highlight the need for having a low threshold for coronary angiogram irrespective of the age of the patient when patients with long-standing PAH present with exertional chest pain. Though the prognosis of severe PAH patients is guarded, this is a correctable condition and can offer patients a better quality of life after the PCI or surgery.