Importance of Cardiovascular Disease
Cardiovascular disease is the single leading cause of death in western society, accounting for 1 in 3 deaths in the U.S. alone.
One in every six healthcare dollars is spent on cardiovascular disease through expensive diagnostic testing, medications, procedures and surgeries, such as coronary artery stenting and coronary artery bypass grafting surgery.
We now know that atherosclerosis, or the presence of cholesterol plaques in the walls of the arteries that supply blood to every organ of our body, is caused by inflammation.
The arterial walls become inflamed and fat and calcium build up, eventually narrowing the pathway for blood to get through to the intended organ. In the case of the arteries going to the brain this can lead to strokes, in the leg arteries to pain in the extremities when walking, leg infections and, when severe, the potential need for amputations. When the inflammation and resulting narrowing of the arteries involves the coronary arteries we call this coronary artery disease. Advanced coronary artery disease leads to heart attacks, heart failure, life-threatening heart rhythm disturbances, and recurrent chest pains with exertion.
Determining Your Heart Disease Risk
There are many services that offer a multitude of screening tests for a fee, such as ultrasounds of the neck and abdominal arteries and blood pressures measurements of the legs. When it comes to coronary artery atherosclerosis, in my opinion, one of the best tests for diagnosing and, in turn, determining one’s future risk for major cardiovascular events such as heart attacks and strokes, is the Coronary Artery Calcium score (CAC score).
Coronary artery calcium scoring (CAC score) is a low-radiation cat scan of the chest. Most hospitals and radiology centers charge around $100 for the score and the information can be priceless in terms of knowledge about your health. The amount of calcium directly correlates with the severity of atherosclerosis and the score in turn has significant prognostic information regarding a person’s risk for having a major cardiovascular event over the next few years.
A score ranges from 0 to 1000, depending on the amount of calcium that is present within the coronary arteries. A score below 100 is considered low risk for cardiac events over the next 5 years, whereas a score above 400 is high risk. Intermediate-risk is between 100 and 399. A score of 0 has been associated with a very low risk (<1%) for cardiac events, such as heart attacks and the need for stents and bypass surgery. The so-called warranty period of this very low risk can extend out to as long as 10 years.
Once the score is available to the patient and his or her physician, they can develop a plan moving forward. Lifestyle changes such as increased exercise, weight loss, and better eating habits can often be employed for non-high risk scans, whereas additional testing is often required for high-risk scores.
A score below 100 is considered low risk for cardiac events over the next 5 years, whereas a score above 400 is high risk.
The reports to these studies often provide a comparison of a person’s score to other age and gender-matched people in the population. For example, if someone has a score of 100, this may place them in the 80th percentile for younger women, however it could place a middle aged man in 50th percentile. Based upon the information obtained
Since the study is a CT chest there is other useful information that can be obtained, such as the size of the aorta, concerning findings in the lung fields, and sometimes the overall size of the heart itself (although this is not the ideal test evaluating any of these organs).
No study is without its faults, however.
The calcium score is a CT which is essentially a collection of simultaneous x-rays taken in different views. As such, there is radiation exposure to the patient and different facilities use different protocols so that amount of radiation exposure can vary between performing locations. While the risks for developing cancer from this relatively small amount of radiation is extremely low (<1%), it is not zero and, as such, risks vs benefits must be considered, especially in those who have undergone extensive testing using ionizing radiation in the past, as doses are cumulative over a lifetime.
Secondly, beware of “incidental-omas”. Oftentimes, small nodules are discovered that require additional testing to better characterize the lesion and then surveillance scans in several months to assure no interval growth is necessary. These usually benign findings lead to unnecessary worry and fear, additional radiation exposure from further testing, and procedures such as biopsies to confirm lack of a more ominous disease.
Coronary artery calcium scores is a very useful diagnostic and prognostic tool when used in correct situations. I would urge anyone with risk factors for cardiovascular disease to have a discussion with their physician about how this might be useful for them.
Jared Corriel, MD is the Director of Echocardiography and Cardiac CT at Nyack Hospital in Rockland County, NY. In his free time, Dr. Corriel enjoys playing sports with his three children and entertaining blog post requests by his not-at-all nagging wife, also a doctor and blogger.