Cath Lab Digest - February 2008 - (Page 14)

14 IN DEVELOPMENT FEBRUARY 2008 A 3D CT Vessel “Roadmap” Over Live Fluoroscopy for Chronic Total Occlusions Cath Lab Digest talks with Jeffrey W. Moses, MD, Director of the Center for Interventional Vascular Therapy, New YorkPresbyterian Hospital/Columbia University Medical Center; Director, Cardiac Catheterization Lab, New YorkPresbyterian/Columbia University Medical Center; Professor of Medicine at Columbia University College of Physicians and Surgeons, New York, New York. During a live case at TCT 2007, Dr. Jeffrey Moses demonstrated a unique new technology currently under development by GE Healthcare, (Chalfont St Giles, United Kingdom). Using a next-generation GE Advantage Windows workstation, a patient’s prior cardiac computed tomography angiography (CTA) images can be superimposed on live fluoroscopy as a “roadmap” for guidewire advancement, chronic total occlusion (CTO) crossing and therapy delivery. Dr. Moses discusses the increasing use of CTA, the treatment of CTOs and his thoughts on where this technology is headed. Figure 1. From the live case performed at TCT 2007. CTA curved view of the right coronary artery (RCA), reformatting the vessel into a single plane. The proximal RCA stent procludes slightly in the aorta (CardIQ software). What is the first step in using this technology? It has two aspects. First of all, CTA is the foundation. We are building on an emerging treatment paradigm for total occlusions that uses cardiac CTA as a primary planning tool. The final step, that of using an investigational tool to superimpose CTA images, evolved from something we are using every day, which is cardiac CTA. At Columbia, we mainly use the GE 64slice LightSpeed VCT, which has a new SnapShot Pulse mode that cuts the radiation by a significant amount. Dr. Andrew Einstein from our institution recently published an article in JAMA1 showing that dosimetry calculation for CTA is actually obsolete. With GE’s new technology, the radiation dose is down about 75%, which is an important message.2-4 Using CT as our planning tool in CTO cases, we can then visualize the path of the artery. Even though there is no dye penetration, we can see the vessel calcification and tortuosity, and whether there is any distortion from a previous bypass graft, which can sometimes tent the arteries. Many of these arteries have had previous bypasses. The collaterals are also visible if retrograde techniques are an option. Mainly, however, CT analysis allows the assessment of calcification and the tortuosity. When you look at the contemporary reasons for failure to cross a CTO, the most contemporary analyses cite calcification and tortuosity as the main predictors of failure. With CT technology, the complete vessel is visible, which is key. Simply performing a regular cardiac CT isn’t enough to provide an accurate analysis. Some image tweaking is necessary. It is important to notify the person who is actually analyzing the CT so they know to specifically visualize the necessary segment, because there is work that will need to be done in optimization. In other words, all the information isn’t necessarily there just by sending the patient through the usual algorithm with any CT. CT is very popular, it’s very dispersed now, but still, some specialization is required and attention needs to be paid by the individual doing the exam to really tweak the CTA if possible. They need to optimize the views of the occluded segment, because it frequently has very little dye in it. So you can get a lot more information if you focus on that specifically and tell the operator who is acquiring the CT to do so. You can also pick your optimal view in which to work as well, off the CT. This means before you walk into the cath lab procedure room, you have a good idea of what Figure 2. From the live case performed at TCT 2007. Volume Rendering view of the entire arterial tree (CardIQ software). views you will work in (generally at least two), and also that which best elongates the artery. This ability is actually accessible to anybody with a sophisticated coronary CT. Importantly, it all takes place before you get to the cath lab. We are doing investigational work with GE engineer Laurence Gavit, on an Advantage Windows workstation. The software CardIQ allows us to have a volume rendering of only the segment in which we are interested. Let’s say, for instance, that it is the

Table of Contents Feed for the Digital Edition of Cath Lab Digest - February 2008

Cath Lab Digest - February 2008 Bay Regional Medical Center ENDEAVOR IV: A Zotarolimus-Eluting Stent Versus a Paclitaxel-Eluting Stent in a Randomized Clinical Trial A 3D CT Vessel “Roadmap” Over Live Fluoroscopy for Chronic Total Occlusions Contents Clinical Editor’s Corner An Evaluation of Cath Lab Turnaround Time Commentary: An Evaluation of Cath Lab Turnaround Time Excerpts from Chapter 19. STEMI Interventions – Future Perspectives The Potential Clinical Utility of Intravascular Ultrasound Guidance in Patients Undergoing Percutaneous Coronary Intervention With Drug-Eluting Stents The Ten-Minute Interview with…Debbie Charlton, RN The Society of Invasive Cardiovascular Professionals (SICP) at Transcatheter Cardiovascular Therapeutics (TCT) 2007 The Cath Lab is a Business: Do You Have the Knowledge to Stay Afloat? Incidence and Predictors of Vascular Complications after Invasive Coronary Procedures: A Prospective Analysis Ask the Clinical Instructor: A Q&A Column for those New to the Cath Lab Volunteer Survey SICP* Section Meetings Calendar What Do You Think? CEU Education Center Clinical & Industry News Classifieds Advertisers Index

Cath Lab Digest - February 2008

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