Heart Scans Miss Early Plaque Growth
48sChallenges common belief about heart scans, offering a surprising new study finding.
▶ Play ClipAI Summary
This video discusses a paradigm shift in heart disease detection, highlighting a new study from the New England Journal of Medicine that shows plaque begins growing decades before it's visible in the heart. It argues that traditional heart scans, like calcium scores, may be insufficient for early detection, and suggests looking at peripheral territories instead.
Chapters
[00:00]
Heart Scans May Miss Early Disease
A new study shows that to catch heart disease as early as possible, the heart may be the wrong place to look, as plaque starts growing decades before it's visible in the heart.
[00:17]
Heart Disease is the Leading Cause of Death
Heart disease is the number one cause of death, prompting people to get tests like calcium scores to detect obstructions before symptoms or heart attacks occur.
[00:33]
Plaque Grows Decades Before Detection
A new study in the New England Journal of Medicine shows that plaque starts growing decades before it can be seen in the heart, challenging current detection methods.
[01:46]
Peripheral Territories Show Early Signs
The study found that early plaque growth was mostly in peripheral territories, not the heart itself, suggesting a shift in where to look for early signs.
[01:46]
Paradigm Shifts in Heart Disease Prevention
The field has seen paradigm shifts, from trying to prevent heart disease to using calcium scores, but these may give false reassurance, like a calcium score of zero in your 30s or 40s.
The video concludes that relying solely on heart scans like calcium scores may give false reassurance, and early detection should focus on peripheral territories. It encourages viewers to watch a previous video for more on heart disease prevention.
Mentioned in this Video
💡 Key Takeaways
💡
Heart Scans May Miss Early Disease
Challenges conventional wisdom by suggesting the heart is the wrong place to look for early detection.
💡
Plaque Grows Decades Before Detection
Reveals a key finding from a new study that could change screening practices.
00:33
💡
Paradigm Shifts in Heart Disease Prevention
Explains how the field has evolved and why calcium scores may give false reassurance.
01:46Full Transcript
[00:00] Chances are you've gotten or at least thought about getting some kind of heart scan like a calcium score to help you prevent heart disease. But a new study shows that if we want to catch the disease as early as possible, the heart may actually be the wrong place to look.
[00:17] Heart disease is genuinely scary. It's the number one cause of death in our society. So we try to get all of these tests of heart function and scans of our coronary arteries so we can detect any obstruction before it starts causing symptoms or causes a heart attack.
[00:33] But a brand new study published in the New England Journal of Medicine shows that plaque starts growing decades before we can see anything in the heart. The scientists looked at a population of 16,000 people with no symptoms, no known cardiovascular disease,
[00:50] and they scanned their arteries, and they found that the majority already had some plaque growing, 57%, despite, again, being people with no symptoms, no diagnosed heart disease.
[01:02] So plaque in the arteries is extremely common in our society. Of course, this depended on age. by the time people were in their 60s, almost everyone had detectable plaque, over 90% of people, but even the very youngest, people between the ages of 18 and 29,
[01:19] those were the youngest people they looked at, 5 to 10% of those individuals already had detectable plaque. Another thing they found was that it was a bit more common to find detectable plaque in men than in women across all ages.
[01:33] But the most interesting result of the study, This one stopped me on my tracks, is that in the youngest people, up to their 30s, maybe even 40s, plaque usually was not found in the heart.
[01:46] It was mostly in what we call peripheral territories. And in this study, they looked at two areas outside of the heart, the neck, the carotid arteries of the neck that take blood up to the brain, and the femoral arteries of the legs.
[02:02] So if we look at their figure, this is what they published. The youngest folks here between 18 and 29, you see that of people who have plaque, almost everyone is this yellow color and
[02:16] yellow is peripheral only So these are people who only have plaque either in their carotid arteries or their femoral arteries but not in the heart Then people in their 30s and we still see that the vast majority of people who have detectable plaque
[02:31] it's still only in the periphery, only a small minority have some plaque in their heart. The red is coronary only, so only in the arteries of the heart, and the orange is both in the heart and peripheral.
[02:44] So basically in the 30s, overwhelmingly, the plaque that is found is still in the periphery, carotid arteries of the neck or femoral arteries of the leg. And even in their 40s, we still see that for women, overwhelmingly, those women who have plaque, it tends to be only in the periphery.
[03:02] And for men, by now in their 40s, between 60 and 70% of men have detectable plaque. and it's still maybe half, maybe a little over half that are only in the periphery.
[03:14] So still a minority of people, even in their 40s, who have black in the heart that is detectable. It's only in the 50s and the 60s, especially in men, that we see that most men who have black
[03:27] have some detectable in the heart. For women, even in their 50s, it's still a minority. Most are still just peripheral. and even in their 60s, it's still about 50-50.
[03:39] So the implication here is pretty eye-opening. This is showing that a lot of people can have completely clean heart scans even though they are actively laying down plaque in other territories.
[03:51] And many of those people go on to grow plaque in the heart later in life as we saw. And if we're just looking at a heart scan, the disease could go undetected for decades in many cases
[04:03] while it's actively growing silently. So this is a significant change in how we think about this disease. And this is just the last chapter of all these paradigm shifts that we've had in the field.
[04:16] Back a generation or two ago, you wouldn't worry about your arteries or your heart until you started feeling symptoms, chest pain or something like that. That's when you went to the doctor. And then we realized by the time you actually feel symptoms,
[04:30] the disease has already been growing for decades. So we started trying to prevent it And then at some point the calcium score became popular and some people would go on social media people in their 30s and 40s with the calcium score of zero and say oh I home free I completely clear There we understood wait a second the calcium score is a pretty late event in the disease progression and you can have a calcium score of zero and have substantial plaque even in your arteries
[05:00] and you can even have heart attacks with a calcium score of zero. So then people started talking about these CAT scans, the angiograms, that detect not just the calcified plaque, but also the soft plaque. So they're much more sensitive.
[05:13] And now we're realizing that even that can be a late occurrence, because by the time something pops up in the heart, you can have disease and plaque growing for decades in other peripheral territories. So, is there a way to detect this plaque growing in the periphery, in the legs, or the carotids?
[05:30] In this study, they used ultrasound, both of the neck of the carotid arteries and the legs, the femoral arteries. For the heart, they used CTA, so these angiograms. So that is an option if you have risk factors for heart disease.
[05:46] Your doctor might prescribe an ultrasound of the carotids, for example. I've gotten one in the past. They're sometimes called CIMTs or carotid intimal medial thickness. So it's basically measuring the thickness of the artery wall.
[05:59] And it can tell you whether that thickness is normal for your age range. And it can essentially give you an estimate of whether you see any detectable plaque or not. You can also get an ultrasound of the legs again. I'm not saying that every healthy 25-year-old should get one of these, but if there is a reason to suspect either family history or risk factors, then your doctor might get one of these tests.
[06:22] And for your legs, there's actually a simple, at-home, completely free, non-invasive test that you can do that tells you if there's obstruction in your leg arteries that has grown enough to affect your blood flow.
[06:35] It's not the most precise test in the world, as you might imagine, but it's a quick and dirty that you can run at home that gives you a first pass information for free. So this test is called the Ankle Brachial Index, or ABI, and here's how you do it.
[06:49] So all you need is a blood pressure measuring device, and you lay down on your back, and you put the cuff on your arm as usual, but lying down, face up, and you measure the blood pressure on your arm. either arm first. We're going to do both. And the blood pressure gives you two values. The higher
[07:04] value is what we call the systolic blood pressure So that the one you take So let say your blood pressure is 120 over 60 So you take the 120 Then you do the other arm Let say it 125 over 60 So you take the 125 the higher value again the systolic
[07:20] And now you're going to take the highest value out of the two arms. So you got 120 and 125. Obviously, 125 is higher. So that's going to be your reference value for the arms. Now you're going to put the cuff on your ankles, either one first.
[07:34] We're also going to do both. and you can measure the blood pressure on your ankles. Start with either side, let's say left leg, and let's say on the leg it's also 125 over 60. Again, you're going to take the systolic value, the 125,
[07:48] and you're simply going to divide that by your reference value from the arms. So 125 divided by 125, that's what we got for the arms, is 1. So here are the reference ranges from 1 to 1.4 is a normal ADI,
[08:04] and it's suggesting that there's no blockage in your leg arteries, at least not enough to affect blood flow to a level that can be detected. If it's 0.9 or under, it's an abnormal value and that's suggesting that there's blockage of the leg arteries.
[08:18] From 0.9 to 1, it's a borderline value, so your arteries of the legs may be starting to narrow, but they haven't significantly affected blood pressure, blood flow yet. And over 1.4 actually suggests stiff, calcified, uncompressible arteries in the legs.
[08:37] And we sometimes see that in people with diabetes or chronic advanced kidney disease. So that's the result for the one leg. Then you're going to do it on the other leg. You're going to do both legs separately to test if there's meaningful obstruction in either one.
[08:52] Each time, you're dividing the systolic blood pressure of one leg by your reference systolic blood pressure of the arms, which is the higher systolic blood pressure of both arms.
[09:04] Make sense? So again, this test is looking for a meaningful obstruction. If you have a small amount of plaque, this is not going to pick it up. It's going to give you a normal ABI. So if you have symptoms or some other reason to believe that you have peripheral arterial disease,
[09:21] That's what we call it when you have meaningful obstruction plaque in the legs and absolutely get it checked, even if your ABI numbers look totally normal. And for a lot more on heart disease prevention and how I personally go about it, check out this previous video, and I'll see you in there.
