Difference Between Persistent Aneurysm, Regressed Aneurysm, and Coronary Dilation in Kawasaki Disease: An Optical Coherence Tomography Study

Background: Coronary artery (CA) aneurysms are a serious complication of Kawasaki disease (KD). Conventional imaging techniques often described segments with regressed aneurysms as normal, whereas studies have shown significant endothelial dysfunction. Methods: KD patients with aneurysms scheduled for routine coronary angiography underwent optical coherence tomography (OCT) imaging between 2013 and 2016. Microstructural coronary changes were compared between normal CA segments and those with dilation, regressed aneurysms, and persistent aneurysms. Results: OCT was performed on 33 patients aged 12.0 +/- 5.4 years, 8.5 +/- 5.4 years after KD diagnosis. Of the 79 segments analyzed, 25 had persistent aneurysms, 22 regressed aneurysms, 11 CA dilation, and 21 no CA involvement. Intimal thickness was 489 +/- 173 mu m, 304 +/- 158 mu m, 102 +/- 68 mu m, and 63 +/- 29 mu m, respectively (P < 0.001). There was a linear correlation between the maximum aneurysm size and the intimal thickness, as well as coronary dimension at the time of OCT. Fibrosis (54 segments, 68%) and cellular infiltration (22 segments, 28%) were found more often in segments with CA involvement, but also those without (P = 0.01; P = 0.02). Destruction of the media (34 segments, 43%), calcifications (6 segments, 8%), neovascularization (18 segments, 23%), and white thrombi (8 segments, 10%) were found almost exclusively in segments with a history of aneurysms. Conclusions: Intimal hyperplasia, fibrosis, and cellular infiltration were found in all categories of CA involvement, whereas calcification, destruction of the media, neovascularization, and white thrombi were found essentially only in segments with saccular or fusiform aneurysms. Prospective studies with outcome correlations are needed to see if this is associated with an increased risk of late adverse events.