The Heart Scan That Sees What Useless Bloodwork Can’t with Dr. John Osborne

Have you ever walked out of a doctor’s office with a clean bill of heart health and still had that nagging feeling that something wasn’t adding up? Have you ever been told your cholesterol is “fine” and wondered how anyone could actually know that from a number on a lab report?

I have. My cholesterol was high enough that colleagues, including lipid specialists at Johns Hopkins, told me flat out I needed to get on medication. And instead of doing that first, I asked a different question. Do I actually have plaque in my arteries? Not do my numbers look scary. Do I have the disease.

That question is exactly why I wanted to bring Dr. John Osborne on the podcast. He’s a preventive cardiologist with two doctorates, seven board certifications, Harvard training, and thirty years in the field, and he’s one of only about a hundred doctors in the country who is board certified in both cardiology and lipidology. He has spent his career on a single mission, which is trying to put himself out of business by eliminating heart disease before it ever becomes an emergency. If that sounds like the kind of health detective energy we talk about on this show all the time, that’s exactly why this conversation matters so much for you.

Why “Your Cholesterol Is High” Doesn’t Actually Tell You Anything

Here’s the thing most of us have never been told. Cholesterol is a risk factor. It is not a diagnosis. Dr. Osborne compares it to fertilizer. It has to be present for plaque to form, but its presence in your bloodstream doesn’t tell your doctor whether it’s actually sticking to your artery walls.

He uses a colonoscopy analogy that completely reframed this for me. If a gastroenterologist told you that because you had a family history of colon cancer they were going to start you on six months of chemotherapy without ever actually looking inside your colon, you would think that was insane. And yet that is essentially what happens every day in cardiology. A number on a lipid panel gets treated as proof of disease, when it’s really just a clue.

The Real Reason Stress Tests Keep Missing Heart Disease

If you’ve ever had a stress test and been told your heart looked great, you’ll want to sit with this part. Dr. Osborne doesn’t hold back on this one. Stress tests only pick up a blockage once an artery is narrowed by around 70 percent, which means they’re built to catch heart disease at the very end of a process that can take decades. On top of that, they carry a false positive and false negative rate somewhere between 25 and 40 percent.

The deeper issue is how heart attacks actually happen. Most of us picture a slow, steady narrowing of an artery until it finally closes off. But according to Dr. Osborne, the majority of heart attacks are caused by something else entirely, a rupture of soft, cholesterol-rich plaque that was never blocking blood flow in the first place and would never have shown up on a stress test at all. That’s why so many people who “pass” their cardiac workup can still have a sudden, catastrophic event. The test was never designed to look for the thing that was actually dangerous.

What Cardiac CT With AI Actually Sees

This is where the conversation got genuinely exciting to me. Cardiac CT scanning paired with AI analysis doesn’t estimate or guess. It images your actual arteries and quantifies exactly how much plaque you have, what kind it is, and whether it’s the stable, calcified kind or the soft, unstable kind that’s more likely to rupture.

Dr. Osborne explained that the human eye can only distinguish about fifty shades of gray in a scan, but the raw imaging data actually contains over two thousand gradations. AI analysis unlocks all of that hidden detail, which means it can detect and measure soft plaque that would otherwise be invisible, down to a fraction of a cubic millimeter. He calls it a living autopsy, and once you have that data, there’s no more guessing. There’s only what’s actually there.

This is also how we were able to track my own progress. I had a scan a few years ago and another one three years later, without going on any cholesterol medication in between. Left alone, plaque tends to progress by roughly ten percent a year, so mine should have grown by around thirty percent over that window. Instead, through diet, exercise, and consistent lifestyle changes, my plaque score actually improved. That’s not a guess. That’s something we could measure and compare directly.

The Cholesterol Numbers Worth Actually Knowing

If you take one practical thing away from this episode, let it be this. Standard cholesterol panels are outdated. Dr. Osborne recommends asking your doctor for two additional markers.

The first is ApoB, which measures the total number of artery-clogging particles in your blood rather than just the amount of cholesterol they’re carrying. It’s a far more accurate predictor of risk than LDL alone, and it’s now considered the superior marker in updated lipid guidelines.

The second is Lp(a), a genetically determined lipoprotein that roughly twenty percent of people carry at elevated levels. It’s typically only tested once in your life, since it doesn’t change, but if it’s high, it acts as a force multiplier that can double or triple your cardiovascular risk regardless of your other numbers. New treatments specifically targeting Lp(a) are moving through late-stage clinical trials right now, with major results expected to be reported this year, so this is a marker worth having on your radar even if there isn’t yet a dedicated treatment on the market.

Busting the HDL Myth

I know this one is going to ruffle some feathers, because most of us grew up hearing that HDL was the “good cholesterol” we wanted to be high. Dr. Osborne was blunt about this. HDL itself has no direct impact on whether plaque forms. The confusion came from the fact that HDL and triglycerides move in opposite directions, so when triglycerides were high and driving real risk, HDL just happened to be low alongside it, and HDL got credit it never actually earned.

Multiple large clinical trials involving over a hundred thousand people have tested drugs specifically designed to raise HDL, and none of them reduced cardiovascular risk. If your HDL is high and you’ve been told that means you’re protected, that’s not something to lean on. The only way to actually know your risk is to look at the arteries themselves.

Where This Leaves You

This episode is a perfect example of what it means to become your own health detective. You don’t have to accept a single lab value as the final word on your heart health, and you don’t have to live with the anxiety of not really knowing. Ask your doctor about ApoB. Ask about Lp(a). Ask whether a calcium score or a cardiac CT with AI analysis makes sense for you, especially if heart disease runs in your family or you’ve ever felt like your numbers and your gut instinct didn’t quite match up.

And keep leaning into the diet, movement, and lifestyle habits we talk about on this show constantly, because as Dr. Osborne pointed out, those choices alone can lower cardiovascular risk by up to fifty percent, even in people who are genetically predisposed to heart disease. You are not powerless here. You just need better information than a single cholesterol number was ever able to give you.

Learn more about the test that sees what bloodwork misses at https://www.midlifeconversations.com/heartprevention 

The contents of the Midlife Conversations podcast is for educational and informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider. Some episodes of Midlife Conversations may be sponsored by products or services discussed during the show. The host may receive compensation for such advertisements or if you purchase products through affiliate links mentioned on this podcast.