Plaque Erosion: The Heart Attack Mechanism Men Under 50 Are Not Being Told About

A man under 50 has a heart attack. He comes in with chest pain, the troponin rises, the ECG shows ST elevation. He goes to the catheterization laboratory, a wire crosses the culprit vessel, a stent is placed, and he goes home three days later with aspirin, ticagrelor, a beta-blocker, and a statin. The system worked. He survived.

What he is almost never told is whether the mechanism that caused his MI was plaque rupture, for which the stent was a mechanical necessity, or plaque erosion, for which the stent may not have been needed at all.

This distinction matters. It changes the downstream risk he carries. It changes how he should understand his cardiovascular trajectory. And in a substantial fraction of men under 50 who have heart attacks, the mechanism is erosion, not rupture, yet the cardiac catheterization laboratory almost never deploys the imaging needed to distinguish them.

The Two Mechanisms That Look the Same on Standard Angiography

An acute MI is caused by a coronary artery thrombus, a blood clot obstructing blood flow to heart muscle. What triggers that clot is what differs between rupture and erosion.

Plaque rupture is the mechanism that dominated cardiology’s understanding of acute MI for decades. An atherosclerotic plaque, typically large, lipid-rich, with a thin fibrous cap, fractures. The fibrous cap breaks open. Lipid core contents, including tissue factor, are exposed directly to flowing blood. The coagulation cascade activates rapidly. A clot forms over the rupture site. If the clot is large enough to obstruct the vessel, the result is MI. Rupture-mediated MI tends to occur on heavily calcified, large-burden plaques. It is the predominant mechanism in older patients and in men with long-standing hypercholesterolemia.

Plaque erosion is different. The plaque itself, smaller, less calcified, less obstructive, does not rupture. Instead, the endothelial cells covering the plaque are lost. The denuded surface beneath them is prothrombotic: it exposes the subendothelial matrix and activates platelet adhesion and clotting. The thrombus forms on the intact-but-denuded plaque surface. The fibrous cap is never breached. No lipid core is exposed.

Standard coronary angiography cannot distinguish these two mechanisms. It shows a vessel lumen, the inside of the artery, and identifies where flow is obstructed. It cannot visualize plaque microstructure. A man with an erosion-mediated MI and a man with a rupture-mediated MI can have nearly identical angiographic appearances. Without intravascular imaging, specifically optical coherence tomography (OCT), the mechanism is assumed, not determined.

How Common Is Erosion in Men Under 50?

The clinical literature on erosion prevalence depends heavily on when a study was done and what imaging was available. Earlier autopsy studies suggested erosion was predominantly a mechanism in young women. More recent OCT studies in living patients paint a different picture.

In OCT studies of men presenting with ST-elevation MI, plaque erosion accounts for approximately 25 to 35 percent of cases overall. In subgroup analyses of men under 50, erosion rates in several series approach 35 to 45 percent. A study by Jia et al. (JACC Cardiovascular Imaging, 2014) found plaque erosion in 31 percent of MI patients identified as culprit-site thrombus by OCT, with rates significantly higher in younger patients and current smokers regardless of sex.

What this means practically: if you are a man who had an MI before 50 and you smoked at the time, there is a roughly one-in-three to one-in-two chance your MI was erosion-mediated. You were almost certainly treated as if it was rupture-mediated, because that is the default. The stent was placed without confirming the mechanism.

Why Smoking Drives Erosion in Men

The strongest modifiable risk factor for plaque erosion is tobacco smoking, and this relationship is more direct than smoking’s general contribution to atherosclerosis.

Smoking causes endothelial cell apoptosis, programmed death of the cells lining the inner artery wall, through oxidative stress and inflammatory cytokines. Nicotine and tobacco combustion products directly impair the ability of endothelial cells to repair themselves. Smoking also promotes the formation of neutrophil extracellular traps (NETs), web-like structures released by inflammatory cells that contribute to the erosion-type thrombus by promoting platelet aggregation on denuded endothelial surfaces.

In the EROSION trial, 76 percent of OCT-confirmed erosion patients were current smokers. In men specifically, the erosion signal is strongly concentrated in current and recent smokers. The erosion-type MI is not simply a younger person’s rupture, it is a pathophysiologically distinct event driven primarily by endothelial damage rather than by plaque vulnerability.

This has implications for risk modification after an erosion-mediated MI. Smoking cessation is not merely a standard lifestyle recommendation in this context; it is the primary intervention targeting the mechanism that caused the event. Stopping smoking after an erosion-mediated MI reduces the likelihood of recurrence by addressing the dominant driver of the mechanism.

What OCT Shows That Angiography Misses

Optical coherence tomography uses near-infrared light to image coronary artery walls at 10 to 15 micrometer resolution, approximately ten times finer than intravascular ultrasound. At that resolution, the difference between an intact fibrous cap (erosion) and a fractured fibrous cap with visible lipid core (rupture) is directly visible.

OCT findings that indicate erosion:

• An intact fibrous cap without fracture or discontinuity
• A thrombus overlying an endothelially denuded but structurally intact plaque
• Often a relatively small plaque burden at the culprit site
• Absence of the lipid pool visualization seen in rupture

OCT findings that indicate rupture:

• Clear fibrous cap fracture with an identifiable break
• Visible lipid core behind the fractured cap
• Often larger plaque burden, greater calcification
• The thrombus typically filling the cap defect and beyond

The distinction requires a guidewire to be advanced through the culprit lesion and OCT catheter imaging performed before stent placement, which adds procedural time and skill requirements, and is not standard practice in most US catheterization laboratories during primary PCI for STEMI.

The EROSION Trial: What Stent-Free Management Showed

The EROSION trial (Jia et al., JACC 2017) was the proof-of-concept study for mechanism-guided management of erosion-mediated MI. Sixty patients with OCT-confirmed plaque erosion, no fibrous cap fracture, intact plaque structure, were treated with aggressive antithrombotic therapy (aspirin plus ticagrelor) without stenting, regardless of residual thrombus burden at the start of the procedure.

At one year follow-up, 92.5 percent of patients had no major adverse cardiovascular events. OCT at 30 days showed thrombus resolution in the majority. The vessel remodeled. The lumen improved. No rupture-type event occurred because there was no structural plaque defect requiring mechanical repair.

The trial enrolled approximately 80 percent men. It was not a randomized controlled trial, there was no stenting comparison arm, which limits definitive conclusions about whether the favorable outcomes were due to erosion management or patient selection. But the 92.5 percent one-year event-free rate in a population with acute MI managed without stenting is clinically significant.

Why Men Are Less Likely to Have This Conversation

The erosion-as-women’s-disease narrative, which emerged from earlier autopsy data, has partly shifted awareness of erosion into the women’s cardiovascular health space. While erosion is indeed more prevalent in younger women than in men, the narrative has had an unintended consequence: men presenting with MI are systematically less likely to trigger OCT evaluation, even when their clinical profile, young, smoker, less plaque burden than expected for event severity, would support it.

A man under 50 who has an MI tends to be framed clinically as a rupture event with a modifiable risk factor overlay. The conversation at discharge centers on statins, blood pressure, diet, and exercise, appropriate secondary prevention elements, without addressing the possibility that the mechanism was erosion and the stent was potentially unnecessary.

This is not a criticism of individual physicians managing acute STEMI, where speed to reperfusion is the primary objective. It is a comment on the post-event conversation that should happen when the dust settles: what actually caused this? Was OCT performed? If not, what does the angiographic appearance suggest? And what is the right secondary prevention framework given the probable mechanism?

After Erosion: Secondary Prevention With Mechanism in Mind

After a rupture-mediated MI with significant plaque burden and obstructive disease, aggressive long-term lipid lowering is the primary secondary prevention strategy, because there is more plaque to stabilize and the risk of recurrence is proportional to plaque burden.

After an erosion-mediated MI in a young man with minimal residual plaque burden, the pharmacological framework is similar but the dominant modifiable risk is not plaque burden, it is endothelial health. Smoking cessation is the highest-yield single intervention. Blood pressure control is important for endothelial protection. Antiplatelet therapy remains appropriate given the thrombotic event. Statin therapy has anti-inflammatory and endothelial-protective effects beyond lipid lowering that are relevant in the erosion context.

Cardiac rehabilitation is appropriate for both mechanisms. Exercise training improves endothelial function through nitric oxide-mediated mechanisms, directly relevant to the endothelial dysfunction that underlies erosion. The physiological adaptations from structured aerobic exercise after an erosion-mediated MI are not merely cardiovascular conditioning; they are treating the mechanism.

The Clinical Profile of an Erosion-Mediated MI in Men

Men whose MI was caused by plaque erosion tend to present with a distinct clinical pattern when compared to the rupture-mediated presentation, though the overlap is sufficient that the distinction cannot be made clinically without imaging.

The erosion presentation in men typically involves:

Younger age. Most published OCT erosion series show the peak erosion prevalence in men under 50, with the highest erosion rates in men between 30 and 45. After 50, rupture becomes the dominant mechanism in both sexes as plaque burden increases.

Active or recent smoking. The single strongest predictor of erosion in men is current smoking. A man who has never smoked and has a large plaque burden on angiography is more likely to have had a rupture. A man who currently smokes and has less plaque burden than expected for the severity of his event should raise suspicion for erosion.

Relatively clean angiogram for the severity of presentation. Men with erosion-mediated MI frequently have an angiogram showing less overall plaque burden, fewer obstructive lesions, and a culprit vessel with less calcification than would be expected in a rupture-mediated event of equivalent severity. The culprit lesion may have a large thrombus relative to the underlying plaque, the thrombus itself creating the obstruction, not the mechanical bulk of an atherosclerotic plaque.

Absence of the classic risk factor burden. The man with rupture-mediated MI often has years of documented hypercholesterolemia, hypertension, family history of premature CAD, and a progressively accumulating plaque burden. The man with erosion-mediated MI may have a cleaner metabolic history, with smoking as the dominant risk factor. This cleaner baseline sometimes leads to the event being classified as unexplained or cryptogenic, when the mechanism was erosion.

Younger-pattern symptoms. Erosion-mediated MI in young men sometimes presents with atypical features, jaw pain, throat tightness, or arm heaviness without classic substernal pressure, which can delay recognition. This is not unique to erosion but is more common in the younger-male erosion population where the diagnosis is less expected.

None of these features conclusively identifies erosion without OCT. They are clinical signals that should prompt the conversation about whether imaging was or should be performed.

What to Ask If You Had a Heart Attack Before 50

The most important question is whether OCT was performed during your catheterization. If it was, ask what was found: rupture or erosion? If erosion was identified, ask whether the stent was placed on the basis of the OCT finding or on the basis of residual stenosis or flow compromise, and what the long-term antiplatelet plan is.

If OCT was not performed, ask your interventional cardiologist what the angiographic appearance suggested about the mechanism. A small, relatively non-calcified culprit lesion with a thrombus but minimal plaque burden in a young smoker is consistent with erosion. That context should inform the conversation about what the primary risk factor was and what the most important secondary prevention intervention is.

If you are a smoker or were smoking at the time of your MI, smoking cessation is the intervention with the highest direct relevance to the mechanism, not just the general cardiovascular benefit. Make that conversation explicit with your cardiologist.

What to Do This Week

If you have had a heart attack before 50 and you smoked at the time, ask your cardiologist directly: was imaging beyond standard angiography performed during my procedure? What does the catheterization report describe about the culprit lesion, its size, calcification, and plaque burden? What was the assumed mechanism?

If the mechanism is unknown and the angiographic appearance was unusual, a less calcified, less obstructive lesion with a thrombus disproportionate to the plaque size, that is an appropriate basis for requesting a conversation about whether the event may have been erosion-mediated and what that means for long-term management.

The goal is not to retroactively question the acute management, which was appropriate for the clinical situation at the time. The goal is to ensure the secondary prevention strategy is calibrated to the mechanism, so that the intervention targeting what actually caused your MI is the one you’re prioritizing. A man who had an erosion-mediated MI and improves statin therapy but continues smoking has addressed the wrong variable. The mechanism he does not know about will not be the mechanism he addresses.

The Signal Check is fifteen questions mapping the male cardiovascular risk pattern, including the physiological domains most commonly missed in standard screenings. It produces a specific starting point for your next clinical conversation.