Left Main Coronary Artery Compression Syndrome Caused by Chronic Mitral Valve Disease

A 72-year-old man suffered from syncope and congestive heart failure. Transthoracic echocardiography showed severe aortic valve stenosis, mitral valve stenosis and regurgitation, requiring dual valve replacement. Coronary angiography (CAG) was performed, and when the catheter was inserted into the left main coronary artery (LMCA), the catheter tip pressure changed to ventricularization (Figure A), suggesting an ostial stenosis. CAG revealed LMCA stenosis (Figure B). Intravascular ultrasound showed no stenosis with intimal plaque, but a flattening (minimum lumen area of 3.96 mm²) of the LMCA caused by compression from the left atrium (LA) (mean pulmonary artery wedge pressure of 22 mmHg) and aorta (Figure C). The fractional flow reserve was 0.64 in the left anterior descending artery (LAD), revealing myocardial ischemia (Figure D). Contrast-enhanced computed tomography demonstrated the LMCA arising from a dorsal position in the left coronary sinus, and being compressed by both the giant LA and the aorta (Figure E–G).

Figure.

(A) The catheter tip pressure changed to ventricularization when it was inserted into the left main coronary artery (LMCA). (B) Left coronary angiography shows LMCA stenosis. (C) Intravascular ultrasound does not show stenosis due to intimal plaque, but there is flattening of the LMCA caused by compression from the left atrium (white asterisk) and aorta (red asterisk). (D) Fractional flow reserve was 0.64 in the left anterior descending artery, revealing myocardial ischemia. (E–G) Contrast-enhanced computed tomography shows the LMCA arising from the dorsal position in left coronary sinus, and being compressed (yellow arrow) by the giant left atrium.

Although compression of the LMCA is commonly caused by main pulmonary artery enlargement,¹ being caused by enlargement of the LA is rare. Coronary bypass surgery (LAD and left circumflex artery) in addition to valve replacement was planned.

Disclosure

T.I. is a member of Circulation Journal’s Editorial Team. The other authors have no conflicts of interest.

Grant

None.

Reference

• 1.   Ikegami R, Ozaki K, Ozawa T, Hirono S, Ito M, Minamino T. Percutaneous coronary intervention for a patient with left main coronary compression syndrome. Intern Med 2018; 57: 1421–1424.