Dr. Sheikh: Diagnosing CHD With Heart CAT Scan
By Khalid Sheikh, MD, MBA // April 26, 2014
CAT SCAN AFFORDS LESS INVASIVE AND EXPENSIVE APPROACH THAN CATHETERIZATION
BREVARD COUNTY • VIERA, FLORIDA — For the evaluation of coronary heart disease (CHD), a picture is worth a thousand words…and so much more!
The only reliable way to determine if there is plaque build-up inside the arteries of the heart is to get pictures of the coronary arteries that show the accumulation of the cholesterol plaque that can lead to angina, heart attacks and death. CHD exists in nearly 15 million Americans, with over 1.5 million experiencing a heart attack each year, and over 500,000 dying each year from CHD.
A coronary angiogram is one such way to get these pictures. However, this procedure typically requires the invasive method of cardiac catheterization. In this type of examination, a cardiologist threads a small tube, or catheter, inside the arteries of the body.
Entering the body using a needle puncture through the skin overlying either an artery in the arm or leg, the catheter is snaked inside the body, eventually reaching the arteries inside the heart. Once the catheter is in position, iodine dye is injected through the catheter to obtain x-ray pictures of the coronary arteries.
Each year, there are over 2 million such examinations performed in the U.S. Each exam incurs small but not insignificant risks, such as causing a stroke, blood clot, heart attack or injury to the heart and coronary arteries that is associated with manipulation of catheters inside the body.
CCTA IMAGES COMPARABLE TO CATHETERIZATION
The search for the Holy Grail in cardiology has been the ability to obtain high quality pictures of the coronary arteries without the need to enter the body. CAT scans are specialized x-rays that have been used to obtain images of many body parts. Through powerful computer processing techniques, the images provide realistic representations of many internal organs.
The ability of CAT scans to obtain pictures of the heart has been limited by one unique property of the heart that distinguishes it from any other organ in the body…it continuously moves! The heart beats on average 60 times a minute without interruption. To obtain high quality pictures of a constantly beating heart has been a major challenge.
The latest generation of high speed x-ray imaging systems and computer processors now enable exactly this. Using “multiple slice, multiple detector” technology, external images of the beating heart of sufficiently high quality to be comparable to coronary angiograms can now be obtained. With this technology, there is no need to push catheters inside the body.
Coronary CT angiograms (CCTA) reliably show the level of plaque inside coronary arteries just like a cardiac catheterization, and so much more.
They also provide more information about the internal features of plaque, have the ability to detect plaque at very early stages and also show more about the interior of the heart than do the angiograms from a cardiac catheterization. The CCTA does all of this in a painless, 14 second examination that requires the patient to simply lie inside a hollow chamber and briefly hold their breath.
The CCTA has lower doses of radiation, lower risk and is less expensive than a catheterization. It is also more accessible as it can be done more quickly and in more facilities than can an angiogram. The major limitation to the CCTA examinations is access to the high quality CAT scanners, as well as highly qualified and experienced cardiologists to perform and interpret these examinations.
Training programs have long waiting lists for interested cardiologist to obtain the necessary didactic and practical training required to conduct these sophisticated examinations. Many insurance companies still do not routine cover the CCTA procedure, but many will approve it as a method to avoid cardiac catheterization.
CCTA ‘RULES OUT’ CHD, AVOIDING UNNECESSARY CATHETERIZATIONS
The greatest value of the CCTA examinations is to exclude, or “rule-out” CHD. In patients with suspected coronary heart problems, the CCTA has nearly 100% accuracy in the ability to detect any level of plaque. This is a tremendous accomplishment, since nearly one out of three patients in the U.S who have a cardiac catheterization turn out to not have any serious blockages. The CCTA potentially could eliminate many of these unnecessary catheterizations.
The CCTA is still unable to completely replace conventional coronary angiography. An angiogram is still needed to perform angioplasty and put in heart stents. It is still necessary to evaluate patients for the need of possible heart bypass surgery.
The costs and radiation exposure of CCTA make it unsuited for everybody as a widely available “screening” examination, but for the appropriate patient, the CCTA can be life-saving, and may also avoid an unnecessary catheterization. If you have any concerning symptoms or significant risk factors for CHD, check with your cardiologist to see if a CCTA would be of value for you.
To learn more about prevention, treatment and reversal of heart disease, get the book Don’t Let Your Heart Attack!, available on Amazon, Barnes & Noble and iTunes.
ABOUT THE AUTHOR
Dr. Khalid Sheikh, a member of Health First Medical Group, directs a cardiology practice on the Space Coast specializing in lipid management and cardiovascular disease prevention, treatment and reversal, and has received advanced certification in performance and evaluation of coronary artery CAT scan imaging. He was a Professor of Cardiology at Duke University before entering private practice, and is currently on the clinical faculty at the University of Central Florida College Of Medicine. Dr. Sheikh, who was recognized by the Consumers’ Research Council of America as one of America’s Top Cardiologists, is board certified in both Internal Medicine and Cardiovascular Diseases, and is a Fellow of the American College of Cardiology. He is also a certified clinical lipid specialist, board certified in adult echocardiography and has completed level I training in cardiac CT imaging. He has served as the principal investigator in over 100 national and international clinical research trials, and authored over 150 scientific abstracts, peer-reviewed journal articles, book chapters and subject reviews.
For more information about Don’t Let Your Heart Attack and Dr. Sheikh’s practice go to SheikhHeartCare.com