Left Main Coronary Artery Compression in Pulmonary Hypertension: Value of Multimodality Imaging in Diagnosis and Treatment

Keywords: cardiac imaging, pulmonary hypertension

A 43-year-old woman with pulmonary arterial hypertension associated with atrial septal defect, surgically repaired 5 years ago, and treated with the endothelin receptor antagonist macitentan monotherapy due to phosphodiesterase-5-inhibitor intolerance, presented for routine outpatient clinical follow-up. She complained of new exertional chest pain and progressive dyspnea (New York Heart Association class III). Physical examination was normal. Electrocardiogram showed signs of right ventricular hypertrophy. On right heart catheterization 2 months prior, she had a mean pulmonary artery pressure of 43 mm Hg, a cardiac index of 2.81 L/min/m², and a pulmonary vascular resistance of 6 WU.

Coronary computed tomography angiography (CCTA) showed significant enlargement of the pulmonary artery trunk and right pulmonary artery with secondary external compression of the left main coronary artery (LMCA) causing severe ostial/proximal LMCA stenosis. Coronary angiography and evaluation with intravascular ultrasound (IVUS) confirmed severe ostial stenosis of the LMCA. Percutaneous coronary intervention (PCI) with implantation of a 4.0 x 15-mm drug-eluting stent, with good angiographic and IVUS result, was performed. At clinical follow-up, the angina pectoris symptoms had completely resolved.

LMCA extrinsic compression should be suspected in patients with pulmonary hypertension and angina. CCTA is indicated as first investigation. Coronary angiography and intracoronary imaging are complementary techniques to confirm the diagnosis and guide therapy. In the largest prospective single center series (Galiè et al, 2017), the prevalence of a significant LMCA stenosis >50% due to dilated pulmonary artery-induced extrinsic compression was 6% in the pulmonary arterial hypertension population, and increased to 40% in patients with angina-like symptoms.

Affiliations and Disclosures

From the ¹Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium; ²Department of Pneumology, University Hospitals Leuven, Leuven, Belgium; ³Department of Radiology, University Hospitals Leuven, Leuven, Belgium.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

The authors report that patient consent was provided for publication of the images used herein.

Manuscript accepted May 9, 2022.

Address for correspondence: Leticia Barrios, MD, Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium. Email: leticia.barrios@uzleuven.be

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