Madder Ryan D, VanOosterhout Stacie, Klungle David, Mulder Abbey, Elmore Matthew, Decker Jeffrey M, Langholz David, Boyden Thomas F, Parker Jessica, Muller James E
From the Frederik Meijer Heart and Vascular Institute, Spectrum Health, Grand Rapids, MI (R.D.M., S.V., D.K., A.M., M.E., J.M.D., D.L., T.F.B., J.P.); and Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (J.E.M.).
Circ Cardiovasc Imaging. 2017 Oct;10(10). doi: 10.1161/CIRCIMAGING.117.006282.
This study sought to determine the frequency of large lipid-rich plaques (LRP) in the coronary arteries of individuals with high coronary artery calcium scores (CACS) and to determine whether the CACS correlates with coronary lipid burden.
Combined near-infrared spectroscopy and intravascular ultrasound was performed in 57 vessels in 20 asymptomatic individuals (90% on statins) with no prior history of coronary artery disease who had a screening CACS ≥300 Agatston units. Among 268 10-mm coronary segments, near-infrared spectroscopy images were analyzed for LRP, defined as a bright yellow block on the near-infrared spectroscopy block chemogram. Lipid burden was assessed as the lipid core burden index (LCBI), and large LRP were defined as a maximum LCBI in 4 mm ≥400. Vessel plaque volume was measured by quantitative intravascular ultrasound. Vessel-level CACS significantly correlated with plaque volume by intravascular ultrasound (=0.69; <0.0001) but not with LCBI by near-infrared spectroscopy (=0.24; =0.07). Despite a high CACS, no LRP was detected in 8 (40.0%) subjects. Large LRP having a maximum LCBI in 4 mm ≥400 were infrequent, found in only 5 (25.0%) of 20 subjects and in only 5 (1.9%) of 268 10-mm coronary segments analyzed.
Among individuals with a CACS ≥300 Agatston units mostly on statins, CACS correlated with total plaque volume but not LCBI. This observation may have implications on coronary risk among individuals with a high CACS considering that it is coronary LRP, rather than calcification, that underlies the majority of acute coronary events.
本研究旨在确定冠状动脉钙化积分（CACS）较高的个体冠状动脉中富含脂质的大斑块（LRP）的发生率，并确定CACS是否与冠状动脉脂质负荷相关。
对20名无症状个体（90%服用他汀类药物）的57条血管进行了近红外光谱和血管内超声检查，这些个体无冠心病病史，筛查CACS≥300阿加斯顿单位。在268个10毫米的冠状动脉节段中，分析近红外光谱图像以检测LRP，LRP在近红外光谱化学图上定义为亮黄色块。脂质负荷通过脂质核心负荷指数（LCBI）进行评估，大LRP定义为4毫米内最大LCBI≥400。通过定量血管内超声测量血管斑块体积。血管水平的CACS与血管内超声测得的斑块体积显著相关（r=0.69；P<0.0001），但与近红外光谱测得的LCBI无关（r=0.24；P=0.07）。尽管CACS较高，但8名（40.0%）受试者未检测到LRP。最大LCBI在4毫米内≥400的大LRP很少见，仅在20名受试者中的5名（25.0%）以及分析的268个10毫米冠状动脉节段中的5个（1.9%）中发现。
在CACS≥300阿加斯顿单位且大多服用他汀类药物的个体中，CACS与总斑块体积相关，但与LCBI无关。考虑到大多数急性冠状动脉事件的基础是冠状动脉LRP而非钙化，这一观察结果可能对CACS较高的个体的冠状动脉风险具有影响。
