PMC10462445_01
(a and b) Coronary CT angiography demonstrating proximal left circumflex artery blockage. (c) Coronary angiography showing 70% stenosis of the left circumflex artery. (d and e) Discrepant iFR and FFR results. (f) Intravascular ultrasound showing normal reference segment distal to the proximal lesion. (g) Eccentric narrow orifice without atherosclerotic plaque with a minimal lumen area of 6.7 mm2. (h) Color-flow image of eccentric narrow orifice without evidence of atherosclerotic plaque.
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fig1
The patient underwent coronary computed tomography (CT) angiography demonstrating severe, isolated stenosis of the proximal left circumflex artery (Figures 1(a) and 1(b)). CT, and the calcium score was 0. Coronary angiography confirmed left coronary dominance and ostial circumflex stenosis of 70% (Figure 1(c)). The instantaneous wave-free ratio (iFR) was normal (0.93), but the fractional flow reserve (FFR) obtained with intravenous adenosine was abnormal (0.69; Figures 1(d) and 1(e)). Due to these discrepant findings, intravascular ultrasound (IVUS) was performed, which did not reveal any atheromatous plaque, calcification, or intramural hematoma (Figures 1(f), 1(g), and 1(h)).
(a-c) Curved multiplanar images by coronary CT angiography noting the kink in the ostial left circumflex artery delineated by the red arrow. (d and e) CT 3D volume reconstructions of the proximal left coronary vessels and the left main artery illustrate the ostial left circumflex kink (oval) about the left main coronary bifurcation.
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fig2
Curved multiplanar images by coronary CT angiography and CT three-dimensional (3D) volume reconstructions of the proximal left coronary vessels also illustrated an ostial left circumflex artery kink (Figure 2).