Transcript:
Are there better tests to detect heart disease risk than cholesterol panels?
Has this ever happened to you because I see it all the time. You go to a doctor for a checkup and you’re told your cholesterol is high and you need to start a statin. Then you go home kind of in shock, not sure what to do and start wondering if there’s something else you can do, a better test to determine if you have or are at risk of heart disease. Well, it turns out there are better tests, coronary calcium scores, coronary CT angiograms and CT angiograms with a detailed plaque analysis. These are better tests for evaluating your cardiac health. But unfortunately, many of us aren’t told about these tests. So let’s get into the details so you can understand the differences and consider if one may be right for you. Welcome to Metabolic Mind, a non-profit initiative of Baszucki Group, transforming the study and treatment of mental disorders by exploring the connection between metabolism and brain health. Thank you for joining us on this journey.
Now before we go further though, please remember our channels are for informational purposes only, we’re not providing individual or group medical or healthcare advice, or establishing a provider-patient relationship. Many of the things we discuss can be dangerous if done without supervision, so please always consult your physician, your health-care team, before changing your lifestyle or medications. I’m Dr. Bret Scher, Medical Director of Bazucki Group and the host of the Metabolic Mind podcast and YouTube channel. But I’m also a cardiologist and lipidologist and I’ve spent over two decades preventing diagnosing and treating heart disease. And I can say my number one rule for diagnosing heart disease or estimating the risk of heart disease is to test for heart disease.
What is a coronary artery calcium (CAC) scan, and what does the calcium score tell us?
It sounds simple, right? But we often rely on surrogate lab tests as the diagnosis. But that’s not the concern. If the concern is heart disease, let’s test for heart disease. Now, I use lab tests like LDL and triglycerides, HDL, fasting insulin and others as additional information. But why guess with lab tests when you can test for the disease itself? LDL isn’t the disease. Plaque in the arteries is the disease. So we can test that. So this is a good place to start. Here’s an image of a coronary calcium scan or a CAC. You can see there is white in the LAD, left anterior descending, or the vessel that comes down the front of the heart. This is calcified plaque in the artery, something you don’t want to see. And this signifies the presence of coronary plaque. Whereas here is a pristine image with a calcium score of zero and no visible plaque. Research shows that someone with a calcium score of zero has a very low ten-year risk of having a heart attack. Now, not zero, and that’s important to realize. You may have seen examples of someone having a zero calcium score but still having a heart attack. And it’s rare, but it can happen. But a calcium score is a lot more predictive than an LDL measurement. How many people have had heart attacks with normal cholesterol levels? Far more than with zero calcium scores. So here are some details about a coronary calcium score that may be helpful. It’s a relatively low radiation scan, about 1 millisievert. Now, for reference, a mammogram is about 0.5 millisievert. And yearly radiation exposure, living at sea levels, is around 3 millisievert. So on a relative scale, the radiation is low. It’s also relatively low cost, about $75 to $200, which is much less than the CT angiogram, which I will discuss next. Now, insurance coverage in the U.S. is tricky, as it varies widely by insurance company. It’s a very quick test. From check-in to leaving as little as 10minutes, it’s pretty quick.
There’s no IV contrast, and it can usually be ordered by any physician. And as I showed, it detects calcium in the heart arteries. Now, it does not detect non-calcified plaque, and it doesn’t see inside the arteries for blockages. And that’s where a CTA has an advantage, as I will get to. But the degree of calcification correlates well with the risk of future heart events, with a zero score being very reassuring for a low 10-year risk. Now, obviously, age makes a difference.
If someone’s 40 or if someone’s 70, that’s going to mean, you know, something pretty different for that individual. But still, for 10 years, a zero risk is reassuring. So, a CAC is a great starting point for evaluating if someone has heart disease, and better assessing their risk of a heart attack, or assessing the potential benefit, or lack thereof, from taking a statin or other LDL lowering medication. So, for instance, here’s an image from a study demonstrating a small reduction in heart attacks for those with calcium scores above 100, when they’re taking a statin compared to those who didn’t take a stand Whereas from the STAME study, those with a calcium score of zero, there was no difference, as you can see here, with the lines completely overlapping. So, the calcium score results absolutely can influence if someone may or may not.
What is a CT angiogram and how does it compare to a CAC?
benefit from a lipid lowering medication. It’s always a risk-benefit analysis. But as with any attest, its results aren’t absolute, and should be used, you know, with one’s physician in combination with other determinants of risk, such as metabolic health, blood pressure, family history of heart disease, chronic inflammation, and others. Okay, but now, let’s compare the CAC to a CT angiogram. So, here you can see much greater detail, being able to visualize the whole artery, not just the calcium in the wall. We can see some signs of non-calcified plaque, and we can tell if there’s any narrowing within the vessel. All in all, it’s a much more detailed evaluation. So, as you may expect, there are some differences with a CAC. A CT angiogram has higher radiation than a CAC, but still relatively low compared to what it used to be. You see, nowadays, a CT angiogram could be like 2 to 5 millisievert, but when I started over two decades ago, they were like 15 to 20, so relatively low. It’s much more expensive than a calcium score, $800 to $2,000, depending where you get it, and rarely covered by insurance. And most CT angiograms depend on a slow heart rate, so it may require a medication to take beforehand, and with the prep time and the monitoring after the test, can take an hour or more. It also involves an iodine-based IV contrast, which is very safe, but there are rare cases of allergies or kidney damage, especially for someone who has diabetic kidney disease, so that’s something to consider. And CT angiograms are often ordered by cardiologists, less commonly by primary care doctors, so may be harder to access.
What is a Cleerly Evaluation and how does it add information to a CT angiogram?
But as I showed, a CT angiogram detects calcified and non-calcified plaque, looks inside the arteries to detect the degree of narrowing, and the exact location of plaque. So, you can see it has added value to a calcium score, but not without its limitations. But there’s one last test I want to mention. So here’s an image done by a company called Cleerly Health, and what you can see is a much more detailed look at the plaque, with better detection of non-calcified plaque and even low-density non-calcified plaque, which is really the most concerning of the plaque types. And the Cleerly Report objectively quantifies the amount of plaque, which makes it very helpful to follow over time. Now, a Cleerly evaluation is not a separate scan. It’s an additional evaluation of a CT angiogram that’s already been performed, so there’s no additional radiation involved, because it’s an after-the-fact analysis. But there is usually an additional cost, about $850 in some cases, in addition to the CT angiogram, so it can be pricey. Now, there are some locations, like the Lundquist Center or many Simon Med facilities, that provide a bundled discount price, so that’s worth looking into. And it provides cutting-edge analysis of coronary plaque with quantitative scores for total, calcified, non-calcified, and low-density plaque, which is a very helpful quantitative analysis for follow-up serial scans. So I hope that this information was helpful. If you want to know more about your heart arteries and your risk for heart disease, consider discussing these tests with your physician. You can measure your heart disease, not just surrogate lab markers. And you can watch our other videos here at Metabolic Mind, that dig a little deeper into the concepts of Metabolic health, LDL, and heart disease. Those may be helpful as well. And please leave us a comment, as we would love to hear your experience with these tests, and what information you want more of on our channel. So thank you for watching. I’m Dr. Bret Scher, and we will see you here next time at Metabolic Mind, a nonprofit initiative of Baszucki Group. I want to take a brief moment to let our practitioners know about a couple of fantastic free CME courses developed in partnership with Bazucki Group by Dr. Georgia Ede and Dr. Chris Palmer. Both of these free CME sessions provide excellent insight on incorporating metabolic therapies for mental illness into your practice. They are approved for AMA category 1 credits, CNE nursing credit hours, and continuing education credits for psychologists, and they’re completely free of charge on myCME.com. There’s a link in the description. I highly recommend you check them both out.
