RESUMO
Pulmonary hypertension (PH) is a major health problem with increasing awareness. Although most common cause of PH is left heart disease (Group 2 PH), life-threatening complications occur mostly in Group 1 (pulmonary arterial hypertension) and Group 4 (chronic thromboembolic PH) patients. Although external compression of the left main coronary artery (LMCA) due to pulmonary artery dilatation is rare, it is a life-threatening complication since it causes myocardial ischemia and sudden cardiac death. In addition, PH is more than a single clinical entity due to its complex mechanism in which more than one subgroup may develop over time in the same patient. This complex mechanism challenges us when diagnosing the patient and faces us with life-threatening complications. In this case; we report a pulmonary arterial hypertension patient applied to our clinic with progressive dyspnea and recent angina, after detection of LMCA ostial stenosis, the patient was treated with intravascular ultrasound-guided stent implantation. In the further follow-ups, the patient underwent the pulmonary endarterectomy operation due to the diagnosis of chronic thromboembolic pulmonary hypertension secondary to newly diagnosed primary antiphospholipid syndrome.