Heart disease remains the #1 killer for women and men, despite that we can prevent 90% of heart disease with lifestyle changes.
The primary cause for heart attacks and strokes is the growth of arterial plaque. In an ideal world, you would know the age of your arteries, how much arterial plaque load you carry, and whether your arterial plaque was growing, shrinking, or staying the same.
There are several ways to assess for arterial plaque growth.
- ECG stress treadmill testing
- CT Heart Scan (with or without angiography)
- Carotid Intimal-Media Thickness (IMT—performed with ultrasound)
ECG Stress Treadmill Testing
The most common plaque measure for people at high risk for a heart attack, or those with symptoms of artery blockage, such as angina, is a treadmill test with continuous ECG monitoring. Once your arteries are 70-80% blocked, you typically display an abnormal test, as the changes noted suggest blocked blood flow. Once you reach 70-80% blocked, you may also qualify for additional procedures, such as a heart catheterization, designed to diagnose and potentially open a blocked artery. The problem is that many people can have a heart attack, stroke, or even die before they reach a 70% blockage. From my perspective, waiting until a person has a 70% blockage is way too late, as this should have been diagnosed at least 10-20-30 years sooner.
Despite the limitations, I really enjoy performing ECG stress testing with my patients, as it is an excellent way to assess their fitness, heart rate recovery, and blood pressure response to exercise. My goal is that they always have a negative stress test, and we use the results to focus on optimizing their fitness and cardiovascular function.
CT Heart Scanning
A CT scan of the heart is one option to diagnose arterial plaque growth long before someone has a 70% blockage. Chest computed tomography (CT) scan is an imaging method that uses X-rays to create a detailed picture of the heart and its blood vessels. The results are measured as a calcium score of the heart arteries. The higher the calcium score, the more calcified plaque exists. Thus, cardiac CT scanning helps you clarify if you have excessive arterial plaque, and to predict your risk for a future heart attack or stroke.
If you have had a heart scan and your score is high, that means you are at elevated risk for a heart attack or stroke, so clearly you should take action and follow my recommendations to help stop arterial plaque growth, and for the potential to start shrinking your arterial plaque load.
However, there are three reasons that I seldom order a CT heart scan. First, is that each heart scan comes with a dose of radiation. Each heart scan increases your lifetime risk of cancer by about 0.3%. Obviously not a huge risk, but if you had 10 heart scans in your lifetime, you’d increase your risk for a serious cancer by 3%.
Second, CT heart scans do not measure the most dangerous plaque, namely soft plaque growth that can pop like a pimple (called plaque rupture) and cause a heart attack or stroke. Instead, they measure old calcified plaque. If you were to repeat a CT heart scan, you won’t know for sure if your dangerous soft plaque is shrinking, growing, or staying the same. However, if your calcium plaque score increases over time, that does suggest that you are growing more arterial plaque.
The third issue is cost—Heart CT scans are fairly expensive, and most of the time they are not covered by medical insurance.
Carotid IMT Testing:
The plaque in your carotid arteries (the big arteries in your neck going from your heart to your brain) are much easier to measure than the arteries in your heart. Recent studies have shown that when a person has their carotid arteries measured with carotid IMT and a CT heart angiogram (catheterization) of the heart at the same time, 95-97% of the time they produce the exact same results. So this is a super easy, risk-free and effective way to identify body wide arterial plaque growth.
While performing a carotid IMT test in my office, the patient simply lies comfortably on an exam table. I apply warm ultrasound gel on his/her neck over the carotid artery. I gently pass a measuring device from the ultrasound machine over the skin and take pictures of the carotid arteries, which are just beneath the surface. Typically I’ll take 12 or more pictures from the right and left carotid arteries, with different views and angles. The whole process usually takes 10 to 12 minutes. At this point, the patient’s job is done.
I transfer the images to my computer, enlarge them on my screen, and use extremely fancy software to measure the artery lining thickness. These measurements are accurate to hundredths of millimeters. Multiple studies published in major medical journals have already calculated average carotid artery plaque thickness in thousands of men and women. Once I’ve calculated my patient’s score, I can use these figures to project the average age of their arteries. A 50- year- old man/woman, for instance, might have the plaque of a 40, 50, or 60 year- old . . . or someone older, and might never know it (unless he/she was tested).
The cost for this type of testing can vary from $200-$400, depending on the technique and experience of the person performing the test.
I prefer to monitor artery age over time (checking every year or two) to clarify whether my patient’s plaque is growing, staying the same, or (if he/she follows my recommendations long- term) actually shrinking.
The Prevention Group of the American Heart Association considers carotid IMT testing to be an excellent way to assess future cardiovascular disease risk. The group recommends it as a safe and dependable tool. Several studies have confirmed their recommendations.
If performed regularly over years, repeated carotid IMT scans can project the age at which one will become high risk for a heart attack or stroke and, most important, can give us time to recommend the appropriate therapy to prevent and reverse this aging process.
In the past, in fact several years ago, I had the experience of testing my patients with both a CT heart scan and a carotid IMT during a full day comprehensive assessment. With time, and having performed hundreds of each testing modality, my impression was that heart scans did not provide any “extra” useful information. So over time, I stopped ordering heart scans for the following reasons:
- I have never had an abnormal heart scan and a normal carotid IMT. Plus, sometimes the heart scan missed critical information. As an example, I had a few patients who showed increased arterial plaque growth on carotid IMT testing with yearly repeat testing, yet their Heart CT scan results stayed the same.
- The heart scan typically costs patients twice as much as the carotid IMT.
- As noted above, a heart scan adds a dose of radiation exposure that increases the lifetime risk for cancer.
The biggest limitation with arterial plaque measurements is that they are not readily covered by insurance (keep in mind that medical insurance covers the diagnosis and management of a disease—it doesn’t pay for measuring how you age).
One additional drawback of carotid IMT testing is that it isn’t readily available. Though I have people fly from all over the USA and Canada for testing at my clinic, The Masley Optimal Health Center, that isn’t feasible for most. A national company that I think does a great job with carotid IMT testing nationwide is Vasolabs.
If you’d like to assess your lifetime risk for a heart attack or stroke, especially if you have risk factors for heart disease (such as hypertension, high blood sugar, or high cholesterol levels) I’d highly recommend that at least once, you have a direct measure of your arterial plaque load and hope that your results are normal.
My first choice would be carotid IMT testing. However, if carotid IMT testing is not available in your area, CT Heart Scanning likely is. I do not recommend annual testing with CT Heart Scans (due to the radiation exposure), but it can be a useful tool when performed once to identify if you have elevated arterial plaque load.
If you do have increased arterial plaque, the good news is that hundreds of my patients have shown that you can shrink your arterial plaque over time by following the recommendation outlined in my 30-Day Heart Tune-Up, and Better Brain Solution books.
I wish you the best of health!
Steven Masley, MD, FAHA, FACN, FAAFP, CNS