Department of Cardiology and Intensive Care Unit, Compiègne Hospital, Compiègne, France.
J Am Soc Echocardiogr. 2011 Apr;24(4):374-81. doi: 10.1016/j.echo.2010.12.007. Epub 2011 Feb 26.
Assessment of the functional significance of left anterior descending coronary artery (LAD) stenosis of intermediate severity (50%-70% diameter stenosis) is challenging. The aim of this study was to compare the value of noninvasive coronary flow reserve (CFR) with that of invasive fractional flow reserve (FFR) in the setting of LAD stenosis of angiographic intermediate severity.
Fifty stable consecutive patients (mean age, 63 ± 13 years; 11 women; mean left ventricular ejection fraction, 61 ± 10%) with angiographic proximal LAD stenoses of intermediate severity (55.5 ± 5% diameter stenosis on quantitative coronary angiography), no previous anterior myocardial infarction, and various vascular risk factors were prospectively studied. They underwent FFR assessment with intracoronary bolus adenosine (150 μg), and CFR assessment using intravenous adenosine (140 μg/kg/min over 2 min) in the distal part of the LAD on the same day in nearly all patients. CFR was defined as hyperemic peak diastolic LAD flow velocity divided by baseline flow velocity (normal value >2), and FFR was defined as distal pressure divided by mean aortic pressure during maximal hyperemia (normal value >0.8).
The mean FFR and CFR were 0.84 ± 0.07 and 2.7 ± 0.75, respectively, in the whole population. Concordant results between FFR and CFR were seen in 44 patients (88%) and discordant results in six patients (12%). There was a significant correlation between CFR and FFR (r = 0.59, P < .01). A better correlation was found between FFR and percentage LAD diameter stenosis, and lesion length (all P values < .05), than between CFR and the same anatomic markers of stenosis severity (all P values = NS). The sensitivity, specificity, and positive and negative predictive values of CFR >2 to detect a nonsignificant lesion defined by normal FFR were 95%, 69%, 90%, and 82%, respectively.
In patients with LAD stenosis of intermediate severity, discordant results between noninvasive CFR and FFR were not unusual, and the anatomic determinants of the stenosis were better correlated to FFR than to CFR. However, CFR, which is a global evaluation of the coronary tree, has very high sensitivity to detect a nonsignificant lesion, despite the high prevalence of vascular risk factors.
评估中等严重程度（50%-70%直径狭窄）左前降支（LAD）狭窄的功能意义具有挑战性。本研究的目的是比较非侵入性冠状动脉血流储备（CFR）与血管内血流储备分数（FFR）在中等严重程度 LAD 狭窄中的价值。
连续 50 例稳定的患者（平均年龄 63 ± 13 岁；11 例女性；平均左心室射血分数 61 ± 10%），经定量冠状动脉造影检查，存在近端 LAD 狭窄的中等严重程度（定量冠状动脉造影检查中 55.5 ± 5%的直径狭窄）、无先前前壁心肌梗死和各种血管危险因素。在几乎所有患者中，当天在 LAD 远端经冠状动脉内推注腺苷（150μg）进行 FFR 评估，经静脉推注腺苷（140μg/kg/min，持续 2 分钟）进行 CFR 评估。CFR 定义为充血期 LAD 舒张末期峰值流速与基础流速之比（正常比值>2），FFR 定义为最大充血时远端压力与平均主动脉压之比（正常比值>0.8）。
在整个人群中，平均 FFR 和 CFR 分别为 0.84 ± 0.07 和 2.7 ± 0.75。在 44 例患者（88%）中，FFR 和 CFR 的结果一致，在 6 例患者（12%）中结果不一致。CFR 与 FFR 之间存在显著相关性（r = 0.59，P<.01）。与 CFR 相比，FFR 与狭窄程度的百分比 LAD 直径和病变长度的相关性更好（所有 P 值均<.05），而 CFR 与相同的狭窄严重程度的解剖学标志物的相关性较差（所有 P 值均= NS）。CFR>2 检测正常 FFR 定义的非显著性病变的敏感性、特异性、阳性和阴性预测值分别为 95%、69%、90%和 82%。
在 LAD 狭窄程度中等的患者中，非侵入性 CFR 和 FFR 之间的不一致结果并不罕见，并且狭窄的解剖学决定因素与 FFR 的相关性优于 CFR。然而，CFR 是对冠状动脉树的全面评估，尽管血管危险因素的患病率很高，但它对检测非显著性病变具有非常高的敏感性。
