Table 1

Morphologic Characteristics Between Sections With Versus Without Intravascular Ultrasound Attenuation

FA (n = 366)Non-FA (n = 1,577)
Attenuation
(n = 132)
No Attenuation
(n = 234)
p ValueAttenuation
(n = 67)
No Attenuation
(n = 1,510)
p Value
Grayscale IVUS
 Lumen, mm24.8 (3.3–7.0)6.0 (4.5–7.5)0.0065.7 (3.9–7.3)6.1 (4.4–8.2)0.16
 EEM, mm214.8 (12.4–20.3)14.3 (11.4–17.9)0.2914.9 (11.5–19.1)11.5 (8.5–15.5)0.009
 P+M, mm210.1 (7.6–13.4)8.2 (6.1–10.7)0.249.1 (7.2–12.0)5.1 (3.2–8.0)<0.001
 Plaque burden, %67.7 (58.1–72.8)57.1 (50.4–63.5)<0.00161.4 (54.6–66.8)46.4 (35.7–55.8)<0.001
 Arc of calcium, °16.8 (0–44.1)79.7 (0–138.5)<0.0010 (0–35)0 (0–20.5)0.010
 Calcium71 (54%)161 (69%)0.01032 (48%)413 (27%)0.46
NIRS-LCBI259.3 (97.7–408.7)144.3 (0–317.9)0.01029.2 (0–171.9)0 (0–23.5)<0.001
NIRS block chemogram
 Red34 (29%)101 (43%)45 (67%)1369 (91%)
 Orange22 (17%)36 (15%)0.0057 (10%)65 (4%)<0.001
 Tan24 (18%)38 (16%)6 (9%)41 (3%)
 Yellow52 (39%)59 (25%)9 (13%)35 (2%)
Plaque type
 AIT7 (10%)631 (42%)
 SMC rich2 (3%)109 (7%)
 Bland fibrous7 (10%)94 (6%)0.001
 Intimal xanthoma0 (0%)28 (2%)
 Fibrocalcific17 (25%)362 (24%)
 Calcified nodule1 (2%)14 (1%)
 PIT33 (29%)272 (18%)
 Early FA45 (34%)78 (33%)
 Early FA, calcified14 (11%)48 (21%)
 Late FA49 (37%)34 (14%)<0.001
 Late FA, calcified17 (13%)67 (29%)
 Thin-cap FA7 (5%)7 (3%)

Values are generalized estimating equation least-square mean (95% confidence intervals) or n (%).

Nonparametric (Mann-Whitney) test.

AIT = adaptive intimal thickening; EEM = external elastic membrane; FA = fibroatheroma; IVUS = intravascular ultrasound; LCBI = lipid core burden index; NIRS = near-infrared spectroscopy; P+M = plaque plus media; PIT = pathological intimal thickening; SMC = smooth muscle cell.