Cath Lab Digest - March 2008 - (Page 20)

20 CARDIAC IMAGING MARCH 2008 65 beats per minute or less. Optimally, we even try to get the heart rate down to 60 beats per minute or less, which usually requires pre-medication. In most cases, beta blockers are used to lower the heart rate. With the dual source CT, it is still the case that image quality might be slightly better if the heart rate is low, but you get diagnostic image quality at almost any heart rate, and this has been confirmed by several studies. Patients who come with a higher heart rate can also be scanned. While it is my feeling that the dual source CT image quality is better than conventional 64-slice CT, even for low heart rates, the main impact of the dual-source CT is mostly the fact that having a low heart rate is not as crucial. What types of vascular or cardiac exams might see the greatest improvement with dual source scanning? In peripheral arterial disease, a potential advantage with dual source CT is that the two tubes can be used with two different energies (called “dual energy” scanning). This can help to identify calcium and remove it from the data set, done in post-processing. Dual energy scanning is mainly done for peripheral arterial disease, not so much for coronary disease, where the high temporal resolution is the big advantage. How is the patient base expanding as the technology grows? We are still looking, in most cases, for the same information. Do the coronary arteries have stenosis or can we rule it out? Of course, as scanners become more advanced, we can send more and more patients to have these examinations. Previously, with the older scanner generations, there was a real challenge in interpreting the data sets of patients who had large amounts of calcification inside the coronary arteries; today, with scanners that can eliminate artifact caused by motion, calcification is less of a problem. In the future, it may be possible to use CT in patients who have arrhythmias or atrial fibrillation, which so far has not been possible. It’s not that we are looking for completely different diseases, but by making the scanners better, we can have more and more patients with suspected coronary disease scanned by CT. What types of patients do you see in your own practice? I work in a university hospital, department of cardiology, in Germany. The way in which we use CT is what I outlined before: first, patients who come to our hospital, our outpatient setting or are sent to us with symptoms, stable symptoms that are not typical. Maybe they had a stress test that really didn’t help, because either the stress test was contradictory to the clinical presentation or the stress test itself was not interpretable, and there is a possibility of coronary disease. In these cases, if the likelihood of stenosis being present is not very high, then we use CT to avoid the invasive angiogram. The other type of patients we see are of course from the emergency room, where we have patients every day coming in with acute chest pain. We do a CT scan in many cases, and can often discharge the patient immediately after showing that the coronary arteries are free of coronary artery disease. Is there something you would like the interventional community to know about CT and the interpretation of images? First of all, I think it would be great, and in our institution it is the case, that the interventional people (I am an interventionalist myself) work closely with CT, because it can provide information to the interventionalist that is not so easily obtainable from the invasive angiogram. For example, the amount of calcification, the exact angle of bifurcations and the distribution of plaque. Often, CT can help visualize occluded vessels or side branches that are not easily identifiable in the invasive angiogram. I would think that the interventional cardiologist should not be negative about CT, but in fact should welcome it as an option to learn more about the exact coronary anatomy of the patient. I do see that the interest in cardiac CT is increasing in more and more interventional centers, as well as at the big interventional conferences. What I would like to see on the side of the vendors is the ability to very easily integrate the CT information into the cath lab so you can, as you are in the cath lab, pull up the CT images and look at the CT. That is possible, but so far not available in a widespread fashion, so it is something that should be improved. Do you see diagnostic catheterizations eventually being eliminated by cardiac CT? No, I don’t think they will ever be completely eliminated. There is always a tradeoff. As soon as the likelihood that the patient has coronary artery disease is above a certain threshold, the CT doesn’t make a lot of sense anymore, because you expect a stenosis will be present. It’s better in this case to send the patient to invasive angiography, because then if there is a stenosis confirmed, a stenosis that had been expected with very high likelihood, then the intervention can be done immediately. CT is really for those patients where the likelihood of stenosis is considered to be rather low and CT is done to avoid the invasive angiogram. Many patients have typical chest pain and a positive stress test. In these cases, the likelihood for having a coronary stenosis is often more than 80% or 90%. At this point, it makes more sense to send the patient to the cath lab, because then you can do the diagnosis and intervention right away. It really depends on the likelihood of disease, so I do not think that diagnostic angiograms will ever go away completely. Diagnostic angiography is very safe, it is not awfully expensive and it is quite accurate. CT will help in reducing the number of negative angiograms.

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

Cath Lab Digest - March 2008 Are You Being Paid Fair Market Value in 2008? A Cardiac Cath Lab Professionals Survey by Cath Lab Digest and the Society of Invasive Cardiovascular Professionals Saint Joseph’s Hospital Invasive Imaging Tools for Optimizing Coronary Stent Deployment Contents Clinical Editor’s Corner A Workflow Revolution in Cath Lab Reporting Advantages of a New Digital Lab at Baystate Medical Center Cardiac Computed Tomography: What Does it Mean for the Cath Lab? The Latest in Cardiac Magnetic Resonance Imaging (MRI) Cellular Cardiomyoplasty and Cardiac Regeneration Intravascular Ultrasound in the Cath Lab: A Powerful — and Underutilized — Tool to Improve Patient Outcomes The Stentplus™ Patient Success Program Cardiac Cath Lab Clutter — or, Spring into Action! Groin Bleeds and Other Hemorrhagic Complications of Cardiac Catheterization: A List of Relevant Issues Ask the Clinical Instructor: A Q&A Column for Those New to the Cath Lab What Do You Think? Experience with a New Guidewire: The Terumo Runthrough NS The Ostial Pro™ Stent Positioning System: Perfecting Aorto-Ostial Stent Placement Precious Minutes The Ten-Minute Interview with…Mark Bowles, BSN, CCRN Vascular Care in the Cath Lab: Planning a Smooth Transition Cath Laughs CMS 2008 OPPS Final Rule Review An Extensive Set of Review Courses for the CCI Basic Science, Non-Invasive Echocardiography and Vascular, and ARDMS Ultrasound Exams Meetings Calendar CEU Education Center Clinical & Industry News STEMI Interventions Classifieds Advertisers Index

Cath Lab Digest - March 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.