734 Have I lost my large rupture cavity? The fingerprint of atherosclerotic plaque healing detected by serial optical coherence tomography imaging
Abstract A 64-year-old man, prior smoker, with a history of paroxysmal atrial fibrillation was referred to our hospital due to worsening dyspnoea, progressively worsening angina, and a positive stress EKG testing. Coronary angiography (CAG) showed an angiographically intermediate stenosis of the mid left anterior descending (LAD) artery and a focal, complex lesion of the distal right coronary artery (RCA) (Figure 1A and B, red arrow). Treatment of the LAD stenosis was deferred based on a negative fractional flow reserve value (i.e. 0.85). Optical coherence tomography (OCT) imaging (ILUMIEN OPTIS, Abbott Vascular, Santa Clara, CA) was performed to better characterize the RCA lesion, which disclosed a ruptured thin-cap fibroatheroma (TCFA) with a large ‘empty’ cavity (Figure 1C–G, red arrows) and overlying ‘layered’ tissue (Figure 1H, white arrowheads). Based on these OCT findings, suggestive of initial plaque healing, and on a large residual lumen dimension (i.e. minimum lumen area, MLA, at the rupture site: 7.7 mm2), this lesion was not treated with percutaneous coronary intervention. The patient was discharged on aspirin, edoxaban, metoprolol, rosuvastatin, and ezetimibe, and remained clinically stable for more than 1 year. Due to angina recurrence, a new CAG was performed 18 months after the first admission, revealing a progression of the mid LAD stenosis that was treated with a 2.5/28 mm drug-eluting stent, and an improvement of the RCA lesion angiographic appearance (smooth contour) (Figure 1A′–B′). RCA OCT imaging was repeated demonstrating a complete healing of the large rupture cavity with all the hallmarks of the reparative process (Figure 1C′–H′): (1) re-established fibrous cap integrity and smooth vessel lumen profile; (2) thickening of the fibrous cap and reduction of lipid burden (i.e., transformation of TCFA into thick-cap fibroatheroma, ThCFA); (3) replacement of the ‘empty’ cavity with new ‘granulation tissue’; (4) initial calcification of the plaque; (5) heterogeneous signal-rich layers with distinct optical-signal intensity (layered, ‘onion-like’ pattern); and (6) mild lumen narrowing (MLA at the rupture site: 6.9 mm2).
