Cardiovascular disease (CVD) consisting of heart attack continues to be the leading cause of death for American men and women, surpassing all cancers, stroke, accidents and diabetes. Traditional risk factors including cholesterol, high blood pressure, smoking and diabetes don’t identify the majority of people dying from heart disease. About 64% of individuals already diagnosed with heart disease present with 0 to 1 of these major risk factors. Despite better treatment and recognition we are still not very good at predicting whom among us is at risk.
What the Cardiac CT Scan tells us
Coronary artery calcification (CAC) as measured by a cardiac CT scan is an accurate assessment of the total amount of plaque in the coronary arteries. The general relationship between the CAC and the total amount of plaque or atherosclerosis has been studied over the years in large groups of patients and autopsy studies. Studies in cardiology journals describe the risks of having a heart attack with various CAC scores and the probabilities of having artery blockages.
The CAC score is a much more powerful predictor of an individual’s risk of having heart disease than any conventional risk factor such as cholesterol. The score needs to be interpreted in the context of age, as it is normal for some calcium to accumulate over time. The CAC score is not perfect in predicting risk as the amount of calcium does not predict the amount of inflamed soft plaque overlying the calcium or the amount of artery blockage.
CAC testing is a “window of opportunity” that can alert the unsuspecting that artery disease is present and allow for more thorough screening and more aggressive treatment. It can also reassure someone with higher risk that the amount of plaque is not as bad as they might have guessed. CAC can also be used to “track your plaque” by reassessing every 3-4 years or so and making sure the CAC score is stable or declining.
How is CAC Performed?
The CAC score is obtained with a quick CT scan of the chest with focus on the heart. A CT scan is essentially a 3-dimensional x-ray that involves very limited radiation and is done very fast taking only a few minutes for the scan. Immediately after the test a computer analyzes the results and comes up with a “calcium score” for each of the individual coronary arteries and in total. This total score is the basis for risk prediction. A radiologist later reviews the scan for further interpretation and notes any incidental findings such as a lung nodule, etc
CAC Results and Risk
Patients with higher CAC scores have a higher risk for cardiac disease than those with lower scores. However, the CAC score is not a perfect prediction tool as there are many people with high scores who do not go on to have a heart attack, and some people with favorable CAC scores who will go on to have a heart attack. The value of the test is in determining whether an individual has much more calcification than would have been anticipated by standard risk factors.
A score of zero or negligible (0-1) indicates that no calcified plaque was detected and the likelihood of artery narrowing or a cardiac event in the near term is extremely low. Health advice includes continuing good health habits such as eating a healthy diet, exercising regularly, maintaining ideal weight and avoiding tobacco. Retesting would be recommended no sooner than 5 years if at all depending upon age. Studies suggest that 98% of individuals with a zero score will not have a cardiac event in the next decade.
A score that indicates minimal (1-10) plaque is reassuring and generally needs no special treatment. Health advice as above and retesting in 4-5 years may be recommended.
A score that indicates mild (11-100) plaque is an early sign that the process has really begun. Health advice should now add a more thorough search for risk factors and treatment with supplements, aspirin or medications. Retesting should be considered in about 3 years.
A score that indicated moderate (101-400) plaque suggests the process is further along and it is time for the above advice plus more “aggressive risk factor modification”. This is the chance to stabilize and stop the plaque process before it is too late. Increased treatment and very close attention to risk factors (especially smoking, high blood pressure and diabetes) is warranted. Sometimes a cardiac stress test may be ordered to reassure there is no silent blockage. Retesting in 2-3 years is recommended.
A severe score (over 400) or a score greater than 75% for your age and gender warrants special attention. Immediate and aggressive intervention is indicated as studies suggest that 30-50% of individuals with a severe score will proceed to have a cardiac event within the next 3-5 years. Cardiac stress testing and referral to a cardiologist are often indicated. Retesting in 2-3 years is recommended.
The cardiac CT scan has a margin of error of about 5-10% and studies show the average calcium score increases about 20 points per year in progressive disease. This is why there is not much sense in repeating the test on a yearly basis. And though the radiation exposure is considered minimal there is no sense in overdoing it.
If the CAC score that is higher than anticipated I recommend advanced testing to precisely identify the risk factors leading to plaque formation. The traditional lipid panel focuses on only three markers – the total, LDL (bad) and HDL (good) cholesterol. My “cardiovascular risk” panel has 22 markers including a more sophisticated analysis of the lipid components, inflammatory markers, vitamins D and K, fatty acids and hormones such as testosterone, estrogen and insulin.
The cardiac CT scan is available at Community Hospital for a cash price of about $200 (last I heard) and can be scheduled only with a doctor’s order. After getting the ok from your doctor, simply call 256-6216 to schedule. The folks at Community do a great job and patients routinely report how easy the study was. I encourage you to get the test and then make a visit with your doctor to review the results.
Atherosclerosis, once detected, does not have to lead to heart problems or an early death. There are tests and treatments that lead to an effective strategy to stop the process. In many cases, the plaque buildup measured by the cardiac CT is the only clue to alert you and your physician that there is life-saving work to be done.
Scott Rollins, MD, is Board Certified with the American Board of Family Practice and the American Board of Anti-Aging and Regenerative Medicine. He specializes in bioidentical hormone replacement for men and women, thyroid and adrenal disorders, fibromyalgia and other complex medical conditions. He is founder and medical director of the Integrative Medicine Center of Western Colorado (www.imcwc.com) and Bellezza Laser Aesthetics (www.bellezzalaser.com). Call (970) 245-6911 for an appointment or more information.