In my view, heart attacks represent a failure of the medical system – they should be almost entirely preventable. It’s a case that was persuasively laid out in a recent cardiology journal article, “Eradicating Atherosclerotic Events by Targeting Early Subclinical Disease.” The article’s subtitle is the kicker: “It Is Time to Retire the Therapeutic Paradigm of Too Much, Too Late.” https://pubmed.ncbi.nlm.nih.gov/37970716/ That is, by failing to look for early disease, we’ve resigned ourselves to battling later-stage disease with the heavy artillery of modern medicine, from angioplasty/stenting to coronary bypass procedures, with success far from assured.
In my previous post, I discussed lipoprotein (a), a very important, and very under-appreciated, risk factor for atherosclerosis. But Lp(a) – as well as other factors like family history, HDL/LDL levels, blood pressure, hemoglobin A1C – can only tell us about risk. That is, one or more of these factors suggest that the disease process may be taking root inside the coronary arteries, even in a younger patient with no obvious signs or symptoms of atherosclerosis. But to go beyond risk assessment, we need to know what’s really going on inside those arteries -- we need to see what’s going on.
The good news is that we have the imaging technology to do just that, including the CTA (computed tomography angiogram) with Cleerly AI-powered analysis, the most sophisticated tool in the preventive cardiology toolbox, which I’ll get to in a minute.
The reason that advanced cardiac imaging is so valuable is that, unlike so many other lethal diseases, atherosclerosis, the number one killer in the Western world, moves at a snail’s pace. If you catch it early, you can address it early with diet and exercise, and when indicated, medications. You can slow the snail’s advance, or stop it, or, case studies suggest, even possibly reverse its course. Waiting to look for the atherosclerosis until patients are in their 40s or 50s or older, and the disease has announced itself on a stress test or manifests as symptoms, makes zero clinical sense.
So, how best to get a diagnostically useful picture of the arteries? These days, my first-line imaging study is a Cleerly CTA. Contrary to recommendations from most cardiology organizations, I’ll order even for younger patients with significant risk factors.
As with a standard CTA, contrast dye is introduced via IV so that any arterial plaque inside the arteries plainly lights up. But the analysis provided by the Cleerly software offers up more actionable information. The visual images are interpreted by AI-generated algorithms which calculate how much of the plaque we see is calcified (more stable, less dangerous) and how much is soft (less stable, more dangerous) and spits out numerical values for the density (hence, the dangerousness) of all the plaque that shows up on the screen. An added safety bonus: the Cleerly CTA makes use of the latest lower-radiation CT technology which, admittedly, is roughly about twice what you’d get from a mammogram or a coronary artery calcium (CAC) study.
The CAC is sort of a junior varsity version of cardiac imaging. It’s cheaper, faster and, dispensing with the contrast dye, it only gives you a calcium score, based on the amount of visible calcified plaque. But it’s an acceptable alternative to a CTA for patients over 50, even more so, over 60. If older patients have a low calcium score, ideally zero, there’s only a relatively small chance that significant amounts of soft plaque are collecting in their arteries. A zero score for a younger patient is not as reassuring as we once thought. We may be missing the chance to identify the first stages of atherosclerosis – it takes years, even decades, for soft plaque to calcify and reveal itself on the CAC.
Given how bullish I am on the Cleerly CTA, do I recommend it for all of my patients? No.
At the low end of the risk spectrum, for a younger person with no known cardiac risk factors, it’s probably not worth the $1,250 and the radiation exposure. And at the high end, let’s say, someone with symptoms of heart disease, it’s usually time to move on to a catheterization procedure. Where the Cleerly CTA comes into its own is shedding light on the ambiguous middle ground.
Take a person with one or more risk factors, let’s say a high Lp(a) or LDL level. Any visible, measurable plaque on the scan provides us with a time window to nip atherosclerosis in the bud, charting a more aggressive path forward with lifestyle modifications and possibly medications. Here’s another case: the person who, in the past, has received a high calcium score and has taken the recommended steps to address their arterial health. The Cleerly CTA results give us a progress report. How well is their program working? Do we need to be more aggressive in our efforts to drive LDL down. The results can also provide hard metrics to describe the trajectory of the disease. A patient who has had a standard CTA in the past can have those images run through the Cleerly software to get a numerical read-out on plaque deposition, and then compare those numbers with the results from a new CT angiogram.
When my patients look at those colorful 3-D images of the coronary artery tree and take note of the numbers on the screen, if they don’t like what they see, they’re motivated to do better. And so am I, on their behalf.