Every 40 seconds in the United States, someone has a heart attack. And every 33 seconds, someone dies from cardiovascular disease. These staggering numbers reveal the uncomfortable truth: heart disease is still the leading killer worldwide, accounting for nearly one-third of all deaths.
Perhaps even more concerning, 1 in 5 heart attacks are completely silent, meaning the damage is done before a person even knows they’re sick.
In this episode of the Dr. Gabrielle Lyon Show, cardiologist Dr. Michael Twyman returns to discuss why traditional lab tests are failing to catch heart disease early, the critical role of the endothelial glycocalyx, and why muscle really is medicine. Together, they challenge outdated cardiovascular models and offer a proactive roadmap for prevention.
The Silent Crisis: 1 in 5 Heart Attacks Go Unnoticed
Dr. Twyman explains that most heart attacks happen without warning because standard lab panels don’t tell the whole story. Heart disease is often “silent,” with no pain or symptoms until 70% or more of an artery is blocked.
As Dr. Lyon put it, “You don’t usually feel your blood pressure until it’s dangerously high.”
Heart disease is an umbrella term for coronary artery disease, heart failure, and stroke.
Traditional risk factors — smoking, high blood pressure, diabetes, high lipids, and physical inactivity — are still the major culprits.
Yet, standard screening misses too many cases.
Globally, cardiovascular disease already claims 17.9 million lives per year and the economic toll is only growing. By 2050, projections show that over 60% of U.S. adults will have cardiovascular disease or stroke, with total costs tripling to $1.8 trillion. The burden will hit hardest among Hispanic, Black, Asian, and underserved communities.
Endothelial Glycocalyx: The Heart’s Forgotten Shield
The conversation shifts to a fascinating “forgotten” part of the cardiovascular system: the endothelial glycocalyx. This protective gel-like layer coats the inner lining of blood vessels, acting like a slimy fish skin to keep harmful particles out of artery walls.
As Dr. Twyman describes it, the glycocalyx is the “force field” of the vascular system. When it degrades, the risk of plaque buildup skyrockets, setting the stage for heart attacks and strokes. Calcium deposits aren’t the cause, but rather the scar left behind after the glycocalyx fails.
A 2022 study of 600 healthy adults found that reduced glycocalyx thickness strongly predicted major cardiovascular events over six years. Adding glycocalyx integrity to traditional risk models dramatically improved early detection of risk.
And in 2024, a cohort of 456 hypertensive patients showed that those who improved their endothelial function early had a 47% lower risk of developing silent organ damage later.
New tools are also emerging. The first chair-side glycocalyx imaging camera received European CE approval in 2023, with FDA clearance pending. But studies on glycocalyx-targeted therapies in heart disease remain scarce, though research shows certain glycocalyx-supporting nutrients (like heparin sulfate and hyaluronan) may be protective.
The key takeaway here is that protecting and restoring the glycocalyx could transform cardiovascular disease prevention. As Dr. Twyman explains:
Focus on the layer that is your first line of defense. You know, it’s your forcefield. If your forcefield is healthy, you’re not likely to develop plaque in the first place.
Muscle = Medicine
As you could have guessed, one of the key drivers of cardiovascular disease is low levels of muscle mass. As I said in the podcast:
I believe that skeletal muscle is the most important muscle… and I am very curious as to the muscle-heart connection.
Low grip strength and poor VO₂ max are strong predictors of heart disease risk and all-cause mortality. In fact, Dr. Twyman measures grip strength on nearly every patient. It’s a simple, practical gauge of muscle function.
The unfortunate reality is that a significant number of people are walking around with low amounts of functional skeletal muscle, many even meeting the threshold for sarcopenia.
A comprehensive review by the American Heart Association makes it clear that low levels of muscle mass are associated and even causal for many types of cardiovascular diseases, including heart failure, atherosclerosis, peripheral arterial disease, and the need for cardiac surgery.
Muscle mass helps regulate insulin sensitivity, reduces chronic inflammation, and supports optimal hormone levels — all critical for heart health. Even in advanced heart failure, patients with more muscle tend to do better.
If you want to protect your heart, protect your muscle.
Lab Work Isn’t Enough: ApoB, Cleerly, and Nitric Oxide
Dr. Twyman is clear that standard cholesterol panels are outdated. Instead, he looks at advanced markers like:
- ApoB (the protein marker of lipoprotein particle number)
- Lipoprotein(a)
- Myeloperoxidase (marker of oxidative stress)
- Interleukin-6 (inflammatory marker)
- Calcium scoring and Cleerly CTA (advanced artery imaging)
As he says, “Test, don’t guess.”
He also highlights nitric oxide, a crucial signaling molecule released by healthy endothelium, which supports blood vessel dilation and prevents plaque from sticking. People with low nitric oxide are more prone to stiff arteries, higher blood pressure, and heart attacks.
Simple tools like salivary nitrate test strips, pulse wave velocity measurements, and even wearables that track central blood pressure (such as the Connect QT device discussed on the podcast) can provide powerful early warnings before disease strikes.
Red Light, Hormones, and Biohacks: What Works, What’s Hype
Dr. Twyman takes a balanced view of so-called “biohacks.” Some, he says, have solid evidence:
- Red light therapy (photobiomodulation): supports mitochondrial function, nitric oxide release, pain relief, and recovery from injuries.
- Testosterone therapy: no longer taboo, recent trials show no increased cardiovascular risk in hypogonadal men, and low testosterone is itself a heart disease risk due to inflammation and poor muscle mass.
- GLP-1 medications (like semaglutide): show strong cardiovascular event reduction in obese and overweight patients, even without diabetes.
Other supplements, like niacin for raising HDL, may have limited benefit and more side effects than payoff.
Action Checklist
Here’s your action plan to become more “heart-attack proof”:
- Get a calcium score and advanced lipid markers (ApoB, LP(a))
- Measure your grip strength and VO₂ max
- Eat nitrate-rich leafy greens and other vegetables to boost nitric oxide
- Check your blood pressure trends regularly, aiming for under 115/75 if possible
- Prioritize muscle-preserving resistance training
- Consider photobiomodulation (red light) for recovery
- Protect your sleep and circadian rhythm
- Work with a practitioner who tests, not guesses
🎧 Listen to the full conversation with Dr. Michael Twyman here → Preventing Silent Heart Attacks The Tests and tools your doctor isn’t using dr michael twyman
