Gabriel Joseph, Klimach Stefan, Lang Peter, Hildick-Smith David
Brighton and Sussex Medical School, Brighton, East Sussex, UK
Brighton and Sussex Medical School, Brighton, East Sussex, UK.
Interact Cardiovasc Thorac Surg. 2015 Aug;21(2):231-9. doi: 10.1093/icvts/ivv078. Epub 2015 Apr 29.
Invasive coronary angiography (ICA) has long been the established gold standard in assessing graft patency following coronary artery bypass graft (CABG). Over the past decade or so however, improvements in computed tomography angiography (CTA) technology have allowed its emergence as a useful clinical tool in graft assessment. The recent introduction of 64-slice and now 128-slice scanners into widespread distribution, and the development of 320-detector row technology allowing volumetric imaging of the entire heart at single points in time within one cardiac cycle, has increased the potential of CTA to supersede ICA in this capacity. This study sought to examine the evidence surrounding this potential. A best evidence topic was constructed according to a structured protocol. The enquiry: In [patients who have undergone coronary artery bypass graft surgery] is [computed tomography angiography or invasive coronary angiography] superior in terms of [graft patency assessment, stenosis detection, radiation exposure and complication rate]? Four hundred and twenty-four articles were identified from the search strategy. Four additional articles were identified from references of key articles. Seventeen articles selected as best evidence were tabulated. The reliability of CTA as a tool in the detection of graft patency and stenosis has continued to improve with each successive generation of multislice technology. The latest 64- and 128-slice CTA techniques are able to detect graft patency and stenosis with very high sensitivities and specificities comparable with ICA, while remaining non-invasive procedures associated with fewer complications (ICA carries a 0.08% risk of myocardial infarction and 0.7% risk of minor complications in clinically stable patients). Present limitations of the technology include the accurate visualization of distal anastomoses and clip artefacts. In addition, the capacity of diagnostic ICA to be combined simultaneously with percutaneous coronary interventions is an important advantage and a further limitation of CTA alone. Recent developments, however, including the derivation of fractional flow reserve and perfusion assessment from CTA as functional measures of stenosis severity have given CTA at present the capacity to become a first-line tool in the assessment of patients with suspected graft dysfunction. Novel computer-automated diagnostic software, though currently in infancy, has shown promise in facilitating and speeding image interpretation. With further improvements in scanning technologies, CTA is likely to supersede ICA for graft assessment in the near future.
有创冠状动脉造影术（ICA）长期以来一直是评估冠状动脉旁路移植术（CABG）后移植血管通畅情况的既定金标准。然而，在过去十年左右的时间里，计算机断层扫描血管造影术（CTA）技术的进步使其成为移植血管评估中一种有用的临床工具。最近，64层及现在的128层扫描仪广泛应用，以及320排探测器技术的发展，能够在一个心动周期内的单个时间点对整个心脏进行容积成像，这增加了CTA在这方面取代ICA的潜力。本研究旨在检验围绕这一潜力的证据。根据结构化方案构建了一个最佳证据主题。问题是：在[接受过冠状动脉旁路移植手术的患者]中，[计算机断层扫描血管造影术或有创冠状动脉造影术]在[移植血管通畅评估、狭窄检测、辐射暴露和并发症发生率]方面是否更具优势？通过检索策略共识别出424篇文章。从关键文章的参考文献中又识别出4篇文章。17篇被选为最佳证据的文章被制成表格。随着多排技术的不断更新，CTA作为检测移植血管通畅和狭窄的工具的可靠性持续提高。最新的64层和128层CTA技术能够以与ICA相当的非常高的灵敏度和特异性检测移植血管通畅和狭窄，同时仍然是无创检查，并发症较少（在临床稳定的患者中，ICA有0.08%的心肌梗死风险和0.7%的轻微并发症风险）。该技术目前的局限性包括远端吻合口和夹子伪影的准确可视化。此外，诊断性ICA能够同时与经皮冠状动脉介入治疗相结合，这是一个重要优势，也是单独CTA的一个进一步局限性。然而，最近的进展，包括从CTA中得出分数血流储备和灌注评估作为狭窄严重程度的功能指标，目前已使CTA有能力成为疑似移植血管功能障碍患者评估的一线工具。新型计算机自动诊断软件虽然目前尚处于起步阶段，但已显示出在促进和加快图像解读方面的潜力。随着扫描技术的进一步改进，CTA在不久的将来可能会取代ICA用于移植血管评估。
