Ladeiras-Lopes Ricardo, Bettencourt Nuno, Ferreira Nuno, Sampaio Francisco, Pires-Morais Gustavo, Santos Lino, Melica Bruno, Rodrigues Alberto, Braga Pedro, Leite-Moreira Adelino, Silva-Cardoso José, Gama Vasco
Department of Cardiology, Gaia Hospital Centre, Vila Nova de Gaia, Portugal; Cardiovascular Research and Development Centre, Faculty of Medicine of the University of Porto, Porto, Portugal.
Department of Cardiology, Gaia Hospital Centre, Vila Nova de Gaia, Portugal; Cardiovascular Research and Development Centre, Faculty of Medicine of the University of Porto, Porto, Portugal.
J Cardiovasc Comput Tomogr. 2016 May-Jun;10(3):215-20. doi: 10.1016/j.jcct.2016.01.013. Epub 2016 Jan 30.
High amounts of coronary artery calcium limit image quality and diagnostic accuracy of multidetector computed tomography (MDCT) angiography (CTA) regarding the assessment of obstructive coronary artery disease (CAD). CT myocardial perfusion imaging may represent an opportunity to overcome this limitation.
To explore the additive value of CT myocardial perfusion to CTA depending on the patient's calcium score and in comparison to the reference standard of invasive coronary angiography plus fractional flow reserve (FFR) measurement.
Symptomatic patients with intermediate pretest probability of CAD were prospectively recruited and underwent both cardiac MDCT (64-slice scanner, retrospectively-gated stress-rest protocol) and invasive coronary angiography including FFR assessment. We defined hemodynamically significant CAD by the presence of occlusive or subocclusive (99%) stenosis, >50% stenosis in left main or FFR≤0.80. Stress CT myocardial perfusion imaging was performed in all patients in addition to CTA. The additive value of CT myocardial perfusion to rule in or rule out the presence of hemodynamically relevant stenosis on a per-patient basis was assessed and analyzed relative to the patient's calcium score.
95 patients were included in the analysis (62 ± 8.2 years, 68%males). Hemodynamically significant CAD was present in 42 patients. Sixty-four patients had a fully evaluable CTA examination. Per-patient, CTA alone had a sensitivity, specificity and AUC of 100%, 59% and 0.79 respectively (77% patients correctly classified). Adding CT myocardial perfusion to evaluate uninterpretable vessel territories in CTA in 66 patients with a calcium score>100 yielded a sensitivity of 88%, a specificity of 74% and an AUC of 0.81 (81% patients correctly classified), and in 52 patients with a calcium score>400 sensitivity was 91%, specificity 70%, and AUC 0.80 (82% patients correctly classified, p = 0.733 versus using perfusion imaging in all patients).
From a pragmatic standpoint, limiting the use of CT perfusion to individuals with a calcium score above 400 might be a feasible strategy to optimize the diagnostic accuracy of CT imaging for diagnosis of obstructive CAD.
在评估阻塞性冠状动脉疾病（CAD）时，大量冠状动脉钙化会限制多排螺旋计算机断层扫描（MDCT）血管造影（CTA）的图像质量和诊断准确性。CT心肌灌注成像可能是克服这一局限性的一个机会。
探讨根据患者的钙化积分，与有创冠状动脉造影加血流储备分数（FFR）测量的参考标准相比，CT心肌灌注对CTA的附加价值。
前瞻性招募有症状且CAD预测概率中等的患者，对其进行心脏MDCT（64层扫描仪，回顾性门控静息-负荷方案）和包括FFR评估的有创冠状动脉造影检查。我们将存在闭塞性或次闭塞性（99%）狭窄、左主干狭窄>50%或FFR≤0.80定义为血流动力学显著CAD。除CTA外，所有患者均进行负荷CT心肌灌注成像。评估并分析CT心肌灌注在逐例患者中纳入或排除血流动力学相关狭窄的附加价值，并与患者的钙化积分相关。
95例患者纳入分析（62±8.2岁，68%为男性）。42例患者存在血流动力学显著CAD。64例患者的CTA检查可充分评估。逐例患者来看，单独CTA的敏感性、特异性和曲线下面积（AUC）分别为100%、59%和0.79（77%的患者分类正确）。对于66例钙化积分>100的患者，在CTA中增加CT心肌灌注以评估不可解释的血管区域，敏感性为88%，特异性为74%，AUC为0.81（81%的患者分类正确）；对于52例钙化积分>400的患者，敏感性为91%，特异性为70%，AUC为0.80（82%的患者分类正确，与对所有患者使用灌注成像相比，p=0.733）。
从实用角度来看，将CT灌注的使用限制在钙化积分高于400的个体可能是一种优化CT成像诊断阻塞性CAD准确性的可行策略。
