Abstract 2605: Necrotic Core and Dense Calcium, not Fibrous, Components Contribute to an Increased Plaque Burden Associated with Localized Stenosis in Patients Long after Kawasaki Disease: Quantitative Gray Scale- and Virtual Histology-Intravascular Ultrasound Study
Late progression of localized stenosis (LS) is of clinical importance in patients long after Kawasaki disease (KD). Whether fibrous, calcified, or athermatous components (fibrofatty or necrotic core) contribute to such lesion formation is unknown. Gray scale- (GS-) and Virtual histology-intravascular ultrasound (VH-IVUS) was recently introduced to assess coronary plaque composition and morphology. We investigated whether different coronary artery lesions (CALs) in patients long after KD are associated with any specific plaque components and morphological changes, as assessed by GS- and VH-IVUS quantitatively. IVUS was performed in 12 Japanese KD patients (age: 18y8m (mean) ±4y2m (SD); an interval after KD: 16y7m±4y6m) with CALs. We investigated each segment and/or coronary artery lesion in each patient: 5 sites with LS, 15 sites with an aneurysm (AN), 26 sites with a regressed aneurysm (RA), and 36 sites with normal coronary artery (N) from the onset. After coronary angiography, IVUS data acquired by using a 20 MHz, 2.9F IVUS catheter were reconstructed by an IVUS recorder. In GS-IVUS analysis, plaque burden (%PB) was determined as (vessel area, encircled by the media-adventitia interface,-lumen area)/vessel area × 100. In VH-IVUS analysis, plaque components were categorized into four parts: fibrous (F), fibrofatty (FF), necrotic core (NC), and dense calcium (DC) areas. Percentage of the area of each component in each cross-sectional plaque area was determined. FF and NC areas were not infrequently found, in addition to F and DC areas: %F: 63 (median); %FF: 22; %DC: 3; %NC: 9. Compared with in RA, both %DC and %NC were higher, but %F was lower, in LS (p<.05, respectively), while %FF were similar among 4 lesions. %PB was higher in LS than in AN and RA (p<.01, respectively). %PB was correlated with %DC (r=0.46), %NC (0.37), and %F (−0.36) (p<.01, respectively), but not with %FF. The present study demonstrated that LS was characterized by increased PB, which was correlated positively with NC and DC, but negatively with F. These findings suggest that IVUS-defined calcified and atheromatous, not fibrous, components may characteristically contribute to the progression of PB associated with LS in patients long after KD.