Plaque, Atherosclerosis & Silent Heart Disease: What You Cannot Feel Can Still Kill You

Most heart attacks happen in people who had no prior warning. Here is why — and what modern cardiovascular medicine can do about it.

The Question I Am Asked Most Often

After public talks on cardiovascular disease, one question comes up more than any other: "Doctor, I feel perfectly fine. Do I really need to check my heart?"

The honest answer is: feeling fine tells you very little about the state of your coronary arteries. The most dangerous stage of heart disease is the stage when it produces no symptoms at all.

What Is Atherosclerosis?

Atherosclerosis is the progressive buildup of plaque — a mixture of cholesterol, inflammatory cells, calcium, and fibrous tissue — within the walls of arteries. It begins not as a visible blockage, but as a microscopic injury to the inner lining of the artery (the endothelium), triggered by elevated LDL cholesterol, hypertension, smoking, diabetes, or chronic inflammation.

Once the endothelium is damaged, LDL cholesterol particles infiltrate the arterial wall. Immune cells arrive to contain them, become engorged with lipid, and transform into foam cells — the building blocks of early plaque. Over years, this process silently progresses: the plaque grows, accumulates calcium, develops a fibrous cap, and slowly narrows the arterial lumen.

This is the critical insight: the artery remodels outward as plaque accumulates, maintaining a near-normal internal diameter for years. Blood continues to flow. The patient feels nothing. The ECG is normal. The stress test is negative. And yet significant disease is already present.

Why the First Symptom Is Often a Heart Attack

The most dangerous plaque is not the most obstructive one. Research consistently shows that the plaques most likely to rupture and trigger a heart attack are often only moderately stenotic — narrowing the artery by 40–60% — not the tight 90% blockages that cause angina on a stress test.

These vulnerable plaques have a large lipid-rich core, thin fibrous cap, and active inflammatory infiltrate. When the cap ruptures, the lipid core is exposed to circulating blood, triggering acute clot formation — a complete arterial occlusion — within minutes. This is a STEMI. And in many patients, there was no preceding chest pain, no abnormal ECG, no positive stress test. The first warning was the heart attack itself.

This is why the standard stress test — excellent for detecting flow-limiting stenosis — does not reliably identify the patient at highest risk of an acute coronary event.

Who Is at Risk of Silent Atherosclerosis?

Silent coronary artery disease is more common than most patients realise. Risk is cumulative and driven by:

Elevated LDL cholesterol — particularly small dense LDL particles — is the primary driver of plaque initiation and growth. Hypertension accelerates endothelial injury. Diabetes and insulin resistance promote inflammation and accelerate plaque progression. Smoking damages the endothelium directly and promotes a pro-thrombotic state. A family history of premature coronary artery disease — a first-degree relative with a heart attack or coronary intervention before age 55 in men or 65 in women — signals an inherited susceptibility to accelerated atherosclerosis that standard risk calculators underestimate.

The important clinical point: many patients with significant subclinical atherosclerosis fall into the "intermediate risk" category on standard tools like the Framingham Risk Score — not high enough to automatically trigger treatment, not low enough to dismiss. These are the patients where direct plaque imaging changes clinical management.

How to Detect Plaque Before a Heart Attack

Modern cardiovascular medicine offers several evidence-based tools to identify subclinical atherosclerosis before it becomes clinically manifest.

• Coronary artery calcium (CAC) scoring is a low-dose CT scan that quantifies calcified plaque in the coronary arteries without contrast or needles. A CAC score of zero in a patient over 50 carries a very low annual cardiac event rate and may allow deferral of statin therapy with watchful monitoring. A score above 300 — or above the 75th percentile for age and sex — indicates significant plaque burden and justifies aggressive preventive therapy regardless of conventional risk factor levels. The CAC score is the single strongest non-invasive predictor of future cardiac events in asymptomatic individuals.
• CT coronary angiography (CTCA) goes further — providing anatomical detail of both calcified and non-calcified plaque, characterising stenosis severity, and identifying vulnerable plaque features including low-attenuation lipid-rich lesions. CTCA with CT-FFR can determine not only whether plaque is present, but whether it is haemodynamically significant — without catheterisation.
• Carotid intima-media thickness (IMT) measured on carotid duplex ultrasound detects subclinical atherosclerosis in the carotid arteries as a surrogate marker of systemic vascular disease, providing information on arterial age independent of traditional risk factors.
• Lipoprotein(a) — Lp(a) is a genetically determined, largely untreatable cardiovascular risk factor that is not captured in a standard lipid panel. Elevated Lp(a) — present in approximately 20% of the population — significantly increases plaque burden and rupture risk. Every patient with premature cardiovascular disease, a strong family history, or unexplained high CAC despite controlled conventional risk factors should have Lp(a) measured at least once.

What You Can Do

The key insight from modern preventive cardiology is that atherosclerosis is not inevitable — it is modifiable. The earlier intervention begins, the more effectively progression is slowed or halted.

LDL reduction is the cornerstone: statins reduce plaque progression and — critically — stabilise vulnerable plaque by increasing the fibrous cap thickness and reducing the lipid core. Blood pressure control, smoking cessation, glycaemic optimisation, and weight management address the other principal drivers of endothelial injury. For patients with elevated Lp(a), aspirin and aggressive LDL reduction provide partial mitigation while RNA-based therapies targeting Lp(a) are advancing through clinical trials.

The goal is not to wait for a first event — it is to prevent it from ever happening.

When to Seek Assessment

Consider a cardiovascular evaluation with subclinical atherosclerosis screening if you have one or more of the following: a family history of heart attack or coronary intervention before age 60; a personal history of hypertension, diabetes, or hyperlipidaemia; a CAC score previously reported as elevated; persistent high-normal LDL despite lifestyle modification; or unexplained exertional breathlessness or fatigue without a clear non-cardiac explanation.

Concerned about cardiovascular risk or silent heart disease? Dr. Peter Chang provides comprehensive atherosclerosis assessment — including CAC scoring, CTCA, carotid IMT, and Lp(a) testing — at Paragon Medical Centre, Orchard Road. Book a consultation today.