[ACC2015]心脏影像学非侵入性成像最新进展 ——Pennsylvania大学医学院Victor A. Ferrari教授专访
专家介绍:Victor A. Ferrari,Pennsylvania心血管研究所心脏磁共振(CMR)主任,心血管磁共振学会(SCMR)创始会员,现任SCMR秘书长-财务官。研究兴趣包括右室和左室功能的非侵入性评估、心室重构、啮齿动物心脏病模型的成像。
International Circulation: As a cardiovascular imaging expert, could you briefly outline the status of recent progress in this field? What are the unresolved problems and challenges?
Dr Ferrari: As far as challenges are concerned, the lack of satisfactory randomized clinical trial data related to non-invasive imaging such as for looking at patients with large degrees of ischemia, is relevant to my work. The aptly named ISCHEMIA trial will evaluate those patients. This study will look at an optimal medical therapy regimen versus an interventional strategy to see what the impact upon outcomes is between the groups. There are a number of challenges with that particular trial in terms of patient recruitment, but all-in-all, I think there will be important data to help guide our treatment directions. There are other challenges, particularly with cardiac MR, where we are well advanced in gathering critical masses of patients towards studying the utility of cardiac MR in several areas. For example, the CE-MARC trial showed that in all degrees of coronary disease, a strategy of using perfusion cardiac MR with scar imaging eclipsed the role of SPECT imaging in assessing these patients. The authors of a Lancet article from 2012 demonstrated that the CMR strategy was in the best area of the curve for all types of coronary disease, whether it was one-, two-, or three-vessel disease and so on. These data are extremely important in moving forward in defining the role stress perfusion MR imaging will have in the future and also to look at outcomes. I think that cardiac MR gives the most detailed assessment and characterization of the myocardium not just for transmural differences between endocardial and epicardial blood flow, but also whether there is scarring or diffuse fibrosis is present, and in assessing the different kinds of cardiomyopathies. CMR provides a robust assessment of the myocardium as well as cardiovascular physiology and the state of perfusion of the myocardium. All of these metrics will have important impacts on outcome and we just need larger trials and comparative trials to prove that. At the end of the day, using a test that does not use radiation, is non-invasive and is relatively efficient in gathering data now that we have improved our rapid imaging, are factors that will come into play in making this an available imaging tool in the future.
《国际循环》:作为心血管影像学专家,您能概述一下该领域的最新进展吗?目前存在哪些问题和挑战?
Ferrari教授:采用非侵入性成像评估缺血程度较重的患者的随机临床试验数据尚缺乏,我参与的ISCHEMIA试验将评估这些患者。这项研究将比较最佳药物治疗方案与介入策略,以了解其对结果的影响。这项特殊的试验在患者招募方面面临很多挑战,但无论如何,我认为会有重要的数据来帮助指导我们的治疗方向。还有其他的挑战,尤其是心脏磁共振(CMR),在研究CMR在数个领域的效用方面,我们收集患者的工作进展顺利。CE-MARC试验表明,在所有程度的冠状动脉疾病中,灌注CMR疤痕成像在评估这些患者方面使SPECT成像黯然失色。2012年《柳叶刀》的一篇文章证实,对所有冠状动脉疾病类型无论是单支、两支或三支血管病变等等,CMR都处于最佳策略区域。在确定负荷灌注MR成像在未来的作用以及对结果的影响方面,这些数据至关重要。我认为,CMR提供了最详细的心肌评估和特征描述,不仅是心内膜和心外膜血流量的差异,还有是否存在疤痕或弥漫性纤维化,并且可以评估不同类型的心肌病。CMR提供了对心肌、心血管生理学以及心肌灌注状态的有力评估。所有这些指标会对结果产生重要影响,我们只是需要更多的试验和对比试验来证明。我们最终想要的是无辐射、非侵入性且相当有效的检测,目前快速成像已经得到改善,未来我们终将会拥有这样的成像工具。
International Circulation: What developments have occurred in congenital heart disease in recent years?
Dr Ferrari: There has been a lot of progress in this field. From the imaging standpoint and what imaging is able to provide, we have seen advances in the planning of surgical procedures. One important paper by one my colleagues at the Children’s Hospital in Philadelphia, Dr Mark Fogel (in conjunction with his colleagues at Georgia Tech), demonstrated that using principles of computer-based modeling and then actually measuring flows using different types of modeling, they could simulate different placements of surgical therapies in the return flow from the bicaval system in patients that required redirection of flow. They were able to model the flow to each lung and to provide important feedback to surgeons about the balance in the circulation between the right and left lungs in these individual patients. That is one of the most exciting areas I have seen I think using a combination of physiology, computer modeling and surgical strategies for the better outcomes of patients. In this way, one lung is not over-circulated while the other is under-circulated. I believe we will see more of these developments along the way. Another area that is very exciting is the use of 3D printing to demonstrate anatomical abnormalities and give surgeons a preview of the heart before going to the operating room. The fewer surprises the surgeons face in the OR the better and the more comfortable they will feel with the work they need to do. This work has been spearheaded by Mark Fogel as well. Another area I have to mention is 4D flow using cardiac MR. This is time resolved flow looking at streamlines and measuring shear stresses in the aorta. This allows us to design better heart valves, and better aortic and pulmonary artery surgeries. There are also some new applications being developed in Sweden looking at intraventricular blood flow from the atrium across the mitral valve to the left ventricle and then out via the aortic valve, quantifying different stages of flow and also looking at ventricular function. We may be able to use these techniques to assess potential improvements in ventricular function with heart failure therapy, or to provide better information on the overall performance of the ventricle using a non-invasive tool. So 4D flow provides another exciting area for potential application in general heart disease and also in heart failure.
《国际循环》:先天性心脏病领域近几年有哪些进展?
Ferrari教授:先天性心脏病领域取得了很多进展。从影像学角度以及影像学所能够提供的内容来看,我们在手术过程规划上有所进展。费城儿童医院Mark Fogel博士及其同事证实,采用基于计算机的建模原理,然后利用不同类型的模型实际测量流量,在需要的血流重定向的患者中,可以模拟下腔静脉系统回流中不同手术疗法的定位。他们能够模拟向两侧肺的血流,并给外科医生提供重要的有关这些患者个体右肺与左肺之间循环平衡的反馈。这是我所看到的我认为最令人兴奋的领域之一,为改善患者预后而将生理学、计算机建模和手术策略相结合。这种情况下,在一侧肺循环不足时,另一侧肺不会循环过量。在这个方向上我相信还会看到更多的发展。
第二个令人兴奋的领域是利用3D打印来展示解剖异常,让外科医生在去手术室前可以预览心脏。外科医生在手术室所面对的“惊喜”越少越好,这样他们可以更轻松地完成所需要做的工作。Mark Fogel率先开展了这项工作。
另一个不得不提的领域是利用心脏磁共振(CMR)的4D血流,这是时间分辨的血流,观察主动脉血流并检测剪切应力。这使得我们能够设计出更好的心脏瓣膜,并开展更好的主动脉和肺动脉手术。4D血流提或可应用于一般心脏疾病以心力衰竭。
另外,瑞典正在开发的一些新的应用,观察从心房跨二尖瓣到左室,然后经主动脉瓣流出的室内血流,量化血流的不同阶段,并体现心室功能。我们也许可以利用这些技术来评估心力衰竭治疗下心功能的潜在改善,或利用非侵入性工具提供更好地饿关于心室整体性能的信息。