Rodés-Cabau Josep, Candell-Riera Jaume, Angel Juan, de León Gustavo, Pereztol Osvaldo, Castell-Conesa Juan, Soto Adriana, Anívarro Inocencio, Aguadé Santiago, Vázquez Manuel, Domingo Enric, Tardif Jean-Claude, Soler-Soler Jordi
Department of Cardiology, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
Am J Cardiol. 2005 Dec 15;96(12):1621-6. doi: 10.1016/j.amjcard.2005.07.077. Epub 2005 Oct 21.
Several studies have demonstrated a correlation between myocardial ischemia and severity of coronary lesions as determined by intravascular ultrasound (IVUS) and fractional flow reserve (FFR) measurements. However, their value for the assessment of mild coronary stenoses that are associated with myocardial perfusion abnormalities has not been well studied. The objective of this study was to prospectively compare the results of myocardial perfusion as determined by exercise/dipyridamole myocardial single-photon emission computed tomography with IVUS and FFR measurements in patients who had angiographically mild coronary stenosis (< 50% diameter stenosis by quantitative coronary angiography). Forty-eight patients who had stable coronary disease (61 +/- 11 years of age; 6 women) were included. All had mild coronary stenosis in the proximal/middle segment of > or = 1 coronary artery and had undergone maximal exercise myocardial technetium-99m tetrofosmin single-photon emission computed tomography within 48 hours before coronary angiography. IVUS measurements included lesion lumen area, external elastic membrane area, lesion plaque burden (calculated as external elastic membrane minus lumen area, divided by external elastic membrane, and multiplied by 100), and lumen area stenosis (calculated as reference lumen area minus lesion lumen area, divided by reference lumen area, multiplied by 100). Fifty-three coronary lesions were studied, with a mean percent diameter stenosis of 34.9 +/- 7.9% on angiography. Myocardial perfusion defects were demonstrated by single-photon emission computed tomography in 11 patients (12 myocardial regions) with no differences in lesion percent diameter stenosis compared with those without perfusion defects. The presence of reversible perfusion defects was associated with a higher lesion plaque burden as evaluated by IVUS (67.4 +/- 8.1% vs 60.2 +/- 9.3%, p = 0.01). FFR values did not differ in the presence or absence of perfusion defects (0.90 +/- 0.06 vs 0.92 +/- 0.07, respectively; p = NS). In conclusion, plaque burden as determined by IVUS may partly explain the presence of myocardial perfusion defects in cases of angiographically nonsignificant coronary lesions. However, the high FFR values associated with these lesions suggest that other mechanisms, such as endothelial/microvascular dysfunction, might also account for perfusion abnormalities in these patients.
多项研究已证实，通过血管内超声（IVUS）和血流储备分数（FFR）测量所确定的心肌缺血与冠状动脉病变严重程度之间存在相关性。然而，它们在评估与心肌灌注异常相关的轻度冠状动脉狭窄方面的价值尚未得到充分研究。本研究的目的是前瞻性地比较运动/双嘧达莫心肌单光子发射计算机断层扫描所确定的心肌灌注结果与IVUS和FFR测量结果，这些患者经血管造影显示为轻度冠状动脉狭窄（定量冠状动脉造影显示直径狭窄<50%）。纳入了48例患有稳定型冠心病的患者（年龄61±11岁；6名女性）。所有患者在≥1支冠状动脉的近段/中段均有轻度冠状动脉狭窄，并在冠状动脉造影前48小时内接受了最大运动心肌锝-99m替曲膦单光子发射计算机断层扫描。IVUS测量包括病变管腔面积、外弹力膜面积、病变斑块负荷（计算方法为外弹力膜面积减去管腔面积，除以外弹力膜面积，再乘以100）和管腔面积狭窄率（计算方法为参考管腔面积减去病变管腔面积，除以参考管腔面积，再乘以100）。共研究了53处冠状动脉病变，血管造影显示平均直径狭窄百分比为34.9±7.9%。单光子发射计算机断层扫描显示11例患者（12个心肌区域）存在心肌灌注缺损，与无灌注缺损的患者相比，病变直径狭窄百分比无差异。通过IVUS评估，可逆性灌注缺损的存在与更高的病变斑块负荷相关（分别为67.4±8.1%和60.2±9.3%，p = 0.01）。有无灌注缺损时FFR值无差异（分别为0.90±0.06和0.92±0.07；p =无显著性差异）。总之，IVUS所确定的斑块负荷可能部分解释了血管造影无显著意义的冠状动脉病变病例中心肌灌注缺损的存在。然而，与这些病变相关的高FFR值表明，其他机制，如内皮/微血管功能障碍，也可能是这些患者灌注异常的原因。
