Case Presentation: A 67 year-old-man with a history of hepatitis C cirrhosis and a recent diagnosis of hepatocellular carcinoma (HCC) presented with six months of worsening dyspnea on exertion and one month of progressive typical angina with physical activity.
Initial physical exam was notable for tachycardia, jugular venous distention, a right-ventricular heave with an S3, and cool extremities. Electrocardiogram showed sinus rhythm, right ventricular hypertrophy, diffuse ST segment depressions in the anterior and inferior leads, and a 1 mm ST segment elevation in lead aVR. Computer tomography (CT) of the chest with contrast revealed a markedly enlarged pulmonary arterial trunk (50mm) without pulmonary embolism. Initial Troponin-I level was undetectable but subsequently rose to 19 ng/mL. Coronary angiography revealed a 90% tapered stenosis of the ostial left main coronary artery (LMCA) without other significant atherosclerotic disease. Given his HCC and co-morbid cirrhosis, the patient underwent percutaneous coronary intervention (PCI) with implantation of a bare-metal stent in the LMCA.

After revascularization, the patient remained dyspneic at rest despite resolution of his angina. Transthoracic echocardiogram demonstrated severely reduced right ventricular systolic function and an estimated right ventricular systolic pressure of 90 mmHg. Right-heart catheterization revealed a mean pulmonary artery pressure of 65 mm Hg, pulmonary capillary wedge pressure of 10 mmHg, right atrial pressure of 6 mmHg, and a cardiac output of 3.3L/minute. The final diagnosis was severe porto-pulmonary hypertension secondary to cirrhosis. It was concluded that patient’s severely enlarged pulmonary arterial trunk had caused extrinsic focal compression of the LMCA, resulting in his anginal symptoms. Pulmonary vasodilator therapy was initiated with marked improvement in his exercise tolerance.

Discussion: This case illustrates a rare presentation of myocardial ischemia due to external compression of the LMCA by a severely dilated pulmonary arterial trunk. Chest pain in patients with pulmonary hypertension is most commonly attributed to right ventricle strain and demand ischemia. Therefore, this diagnosis requires a high degree of clinical suspicion in patients who have severe pulmonary hypertension and LMCA stenosis on angiography. While LMCA stenosis is traditionally treated with surgical bypass, in these cases given the co-morbid pulmonary hypertension, PCI should be considered the treatment of choice to establish patency to the LMCA from extrinsic, rather than atherosclerotic, obstruction. Definitive management requires treatment of the underlying pulmonary hypertension with the aim of reducing pulmonary arterial dilatation.

Conclusions: Pulmonary artery dilatation secondary to severe pulmonary hypertension may rarely cause external compression of the LMCA and present as acute coronary syndrome in the absence of acute plaque thrombosis.