Consider this: Patients turn 50 and they are asked to have a colonoscopy to look directly at the colon for masses. They are asked to have a mammogram to look directly at the breast for growths. But their hearts – these are still never looked at directly in similarly at-risk populations. Rather, the recommendations indicate measuring blood pressure and cholesterol and maybe performing an ECG, all of which are very indirect examinations of the coronary arteries.
I believe there is a better approach for these asymptomatic patients with risk factors, and it’s one that has been promoted by the Society for Heart Attack Prevention and Eradication (SHAPE), the American College of Cardiology, and hundreds of peer reviewed research studies.
It’s low-cost ($75 in my community) and offers a direct examination of heart arteries using a coronary artery calcium scan (CACS) using a fast multi-slice CT scanner. No contrast or IV injection is used and the test takes about 1 minute. The amount of radiation exposure is certainly higher than a chest X-ray, but it is 1/10th or less than that of a cardiac catheterization or a stress nuclear perfusion scan. Endorsements and facts like these are, in my opinion, a call-to-action help you take better care of your patients or your own heart. Here is the nitty gritty:
Who should not have the coronary calcium scan?
If someone already knows they have coronary artery disease such as a previous cardiac catheterization showing blockage, a previous heart stent, or a previous heart bypass surgery, there would be no need for a screening test of this type. People who know that they have blockage in other parts of the body, like an artery of the brain called the carotid artery or the arteries of the leg, remain debatable candidates for the CT scan. However, in my practice, I find that if I can use the scan results to really demonstrate to patients how their disease affects heart arteries, they get even more motivated to adhere to a prevention and reversal lifestyle. The American College of Cardiology has given a high endorsement (IIA) to the use of coronary artery calcium scans in persons with known risk factors for silent coronary disease.
What about risks of the CT scan?
Other than the cost – which tends to run between $100 and $200, and is rarely covered by insurance – the only other concerns are the possibility of creating undue stress, missing soft plaque without calcium, and radiation. For decades cardiologists have relied on exercise nuclear testing using treadmill examinations.One measure of the dose of radiation is called a milliSievert or mSv. An exercise test with Cardiolite may expose a patient to 12 to 15 mSv of radiation. By comparison, a cardiac catheterization done in an efficient manner may expose a patient to about 10 mSv of radiation. In centers with the most advanced multislice scanners, that now are often 64 slice, 128 slice, 256 slice, and beyond, the imaging has gotten so fast that the radiation dose may be 1 mSv or less.
Why do it?
A coronary artery calcium scan may provide life-changing information. For example, the European Society of Cardiology said that “there is overwhelming evidence that coronary calcification represents a strong marker of risk for future cardiovascular events in asymptomatic individuals and have prognostic power above and beyond traditional risk factors.” The same position statement indicated that in asymptomatic individuals a calcium score of zero was associated with a very low risk of heart events over the next 3 to 5 years (less than 1 percent per year). Individuals with a coronary calcium score greater than 1000 have an eleven-fold increase in risk of major events even if they are without symptoms. This is a huge difference.
And now the best part – what can we do with the results?
A study group of 1005 patients with an abnormal coronary calcium score was treated with aspirin, and some received a statin to lower their cholesterol. The average score was 370 units. After four years of follow-up, patients who received a statin had a seven percent rate of heart events like a heart attack versus 12 percent of those who received a placebo. Other studies demonstrate that omega 3 fatty acids, aged garlic, and fruit and vegetable concentrates slow or reverse the calcification. The TACT trial published in 2013 demonstrated benefits from chelation therapy in a different patient population. Weneed more studies geared to determining how the risk can be lowered by specific treatments, to be sure. Yet these studies give a glimpse to the power of finding and treating silent heart disease at an early stage.
Heart disease remains the number one killer for men and women alike in the US, and it is time to perform direct arterial examinations like CACS for at-risk or older patients, roughly every 7-10 years as part of a routine wellness exam. In this regard, we can think of CACS as the “colonoscopy” of the heart. Combining it with recent studies showing that half a dozen or so lifestyle habits prevent 80-90 percent of heart attacks should leave our CCUs empty and extend the lives of so many who erroneously think their hearts are healthy.
Dr. Joel Kahn practices interventional and preventive cardiology in Detroit. A summa cum laude graduate of the University of Michigan School of Medicine, he lectures widely on the role of nutrition in health and medicine. He writes for Readers Digest Magazine as the Holistic Heart Doc, and is the author of The Whole Heart Solution.