Unexpected cause of acute coronary syndrome in a patient with idiopathic pulmonary arterial hypertension

Excerpt

A 59-year-old female patient who had been diagnosed with primary pulmonary arterial hypertension (PAH) 15 years earlier was admitted to our emergency department with complaints of squeezing chest pain and exertional dyspnea. Her functional capacity was New York Heart Association class II. Medications included sildenafil citrate (20 mg t.i.d.), warfarin (5 mg/day), and furosemide (40 mg/day). Her past medical history and family history were unremarkable except for the diagnosis of PAH. Examination revealed blood pressure of 100/60 mmHg, pulse of 90 bpm, 2/6 systolic murmur at the left lower sternal border, jugular venous distension, and 2+ pretibial edema. Electrocardiography on admission showed sinus rhythm (88 bpm) with precordial 1 mm ST segment depression. Transthoracic echocardiography revealed normal LV systolic functions, moderate tricuspid regurgitation, systolic pulmonary artery pressure of 50 mmHg, and main pulmonary artery diameter of 81 mm (Fig. 1). The biochemistry panel was normal, but the cardiac panel revealed increased CK-MB (13 ng/ml; N: 0–2.88) and troponin-T (1.2 ng/ml; N: 0–0.014) levels. Multidetector computerized tomography (CT) revealed a markedly enlarged main pulmonary artery with a diameter of 80 mm with impingement on the origin of the left main coronary artery (LMCA) (Fig. 2). Conventional coronary angiography showed normal coronary arteries except for 99% ostial stenosis of the LMCA (Fig. 3). The patient was therefore referred for aortocoronary bypass surgery. …