Porter T R, Sears T, Xie F, Michels A, Mata J, Welsh D, Shurmur S
Section of Cardiology, University of Nebraska Medical Center, Omaha 68198-2265.
J Am Coll Cardiol. 1993 Dec;22(7):1858-65. doi: 10.1016/0735-1097(93)90770-2.
We hypothesized that intravascular ultrasound may identify significant coronary artery narrowing in the mildly diseased coronary artery of patients with insignificant or one- or two-vessel coronary artery disease.
Necropsy studies have revealed that coronary angiography may underestimate stenosis severity in vessels that appear mildly diseased. Intravascular ultrasound has been shown to detect atherosclerotic changes in angiographically normal coronary arteries and to correlate better with histologic findings.
In 20 patients, we performed intravascular ultrasound imaging (3.5F catheter, 30-MHz transducer) in 37 coronary arteries that were considered mildly diseased (<50% diameter narrowing) by qualitative angiography. The angiographic diagnosis was no significant coronary artery disease in eight patients, one-vessel disease in seven and two-vessel disease in five. Each vessel, except for the left main coronary artery, was divided into proximal, mid and distal segments. Percent area narrowing and minimal lumen diameter were subsequently quantified by both ultrasound and quantitative angiography.
Mean maximal arterial area narrowing by ultrasound in the 67 segments studied was 36 +/- 20% (range 0% to 80.2%) and 19 +/- 23% (range 0% to 82%) by quantitative angiography of these same segments (p < 0.001, paired t test). Mean minimal lumen diameter of the segment was 3.3 +/- 0.9 mm by ultrasound and 2.7 +/- 0.8 mm by quantitative angiography. In 10 patients there were 19 angiographically mildly diseased segments where the percent arterial area narrowing by ultrasound was > or = 50%. Intravascular ultrasound revealed that the more proximal (reference) segment had > 25% intimal thickening in 12 of the 19 underestimated segments. In six stenosed segments (32%), total vessel area increased compared with that of the adjacent proximal vessel segment because of compensatory dilation.
Intravascular ultrasound identifies potentially significant coronary artery disease in vessels that appear to be only mildly diseased by angiography.
我们推测血管内超声可能会在无显著病变或单支或双支冠状动脉疾病患者的轻度病变冠状动脉中识别出显著的冠状动脉狭窄。
尸检研究表明，冠状动脉造影可能会低估看似轻度病变血管的狭窄严重程度。血管内超声已被证明可检测造影正常冠状动脉中的动脉粥样硬化变化，并且与组织学结果的相关性更好。
在20例患者中，我们对37支经定性冠状动脉造影被认为轻度病变（直径狭窄<50%）的冠状动脉进行了血管内超声成像（3.5F导管，30MHz换能器）。冠状动脉造影诊断为8例无显著冠状动脉疾病，7例单支血管疾病，5例双支血管疾病。除左主冠状动脉外，每支血管均分为近端、中段和远端节段。随后通过超声和定量冠状动脉造影对节段面积狭窄百分比和最小管腔直径进行量化。
在所研究的67个节段中，超声测量的平均最大动脉面积狭窄为36±20%（范围0%至80.2%），这些相同节段的定量冠状动脉造影测量值为19±23%（范围0%至82%）（p<0.001，配对t检验）。节段的平均最小管腔直径超声测量为3.3±0.9mm，定量冠状动脉造影测量为2.7±0.8mm。在10例患者中，有19个造影轻度病变节段，其超声测量的动脉面积狭窄百分比≥50%。血管内超声显示，在19个被低估节段中的12个节段中，更靠近近端（参考）节段的内膜增厚>25%。在6个狭窄节段（32%）中，由于代偿性扩张，与相邻近端血管节段相比，血管总面积增加。
血管内超声可在造影显示仅轻度病变的血管中识别出潜在的显著冠状动脉疾病。
