Preventing Cardiovascular Diseases

Your Heart Attack Is 20 Years in the Making

Cardiovascular disease kills around 160,000 people in the UK every year — roughly one every three minutes. Most of those deaths follow a process that began not in old age but in middle life, or earlier. Atherosclerosis — the gradual hardening and narrowing of arteries caused by plaque accumulation — is well underway in many people by their 40s. It produces no symptoms. It doesn't show up in a standard health check. And by the time it announces itself — as a heart attack, a stroke, or chest pain on exertion — the disease is typically well-established. The clinical event is rarely the beginning of the story. It is closer to the end of a very long chapter.

This matters because it reframes the question. Cardiovascular prevention isn't about reacting to a diagnosis. It's about understanding a slow biological process and interrupting it at the right points — ideally long before any damage becomes irreversible. The good news is that the process is interruptible, that the interventions are well understood, and that people who take them seriously in midlife see measurable, significant reductions in risk. The less good news is that the standard picture most people have of cardiovascular risk — high cholesterol, high blood pressure, family history — is incomplete in ways that matter.

Cardiovascular Risk

The Plaque Timeline — and Where to Interrupt It

A heart attack takes minutes. The plaque that causes it takes 20–30 years to develop — and can be disrupted at multiple points along the way.

How Atherosclerosis Progresses

Endothelial Injury — 20s–40s

Smoking, high blood pressure, high glucose, and oxidised LDL damage the thin inner lining of arteries. No symptoms. No test will catch it.

✓ Don't smoke ✓ Control blood pressure ✓ Manage blood sugar

LDL Penetration & Foam Cells — 30s–50s

LDL particles — especially small, dense ones — enter the damaged wall and oxidise. Immune cells (macrophages) engulf them, becoming foam cells that form fatty streaks.

✓ Know your ApoB ✓ Test Lp(a) once ✓ Statins if indicated

Plaque Formation — 40s–60s

Fatty streaks grow into fibrous, calcified plaques that narrow arteries and restrict flow. Still mostly silent. A coronary artery calcium (CAC) scan can detect this stage.

✓ CAC score if high risk ✓ Zone 2 exercise ✓ DASH diet pattern

Plaque Rupture & Clot — the event

A vulnerable plaque — thin cap, large lipid core — ruptures. The body clots the wound. In a coronary artery: heart attack. In a brain artery: stroke. Minutes, not decades.

The Four Numbers That Actually Matter

ApoB

Counts every atherogenic particle — more predictive than LDL-C alone. Two people can have identical LDL but very different risk.

Not standard — request it

Lp(a)

Genetically determined. Affects 1 in 5 people. Doesn't respond to diet. Doesn't change over time — test once, know for life.

Not standard — request it

Blood Pressure

Target: below 130/80. Lifestyle alone can reduce systolic by 10–15 mmHg — equivalent to a first-line drug.

Check regularly

CAC Score

Coronary artery calcium scan. Detects plaque before symptoms. Score of zero = very low near-term risk, even with elevated cholesterol.

If family history or high risk

Exercise Dose for Cardiovascular Protection

2–4 hrs

Zone 2 per week — steady aerobic, conversational pace. Builds endothelial nitric oxide, lowers resting BP, raises HDL.

1–2 sessions

Higher intensity per week — pushes VO2 max adaptations that Zone 2 alone doesn't reach.

Weeks

Until measurable improvements in endothelial function appear — not months, not years. The benefit is fast.

How atherosclerosis actually develops

The process begins with damage to the endothelium — the thin layer of cells lining the inside of blood vessel walls. Smoking, chronically elevated blood pressure, high glucose, oxidised LDL particles, and inflammation all injure the endothelium. Once the lining is compromised, LDL particles — particularly the small, dense variety — penetrate the vessel wall and become oxidised. The immune system responds by sending macrophages to engulf them. These macrophages become engorged with lipid and turn into what pathologists call foam cells, which accumulate to form fatty streaks. Over years, these streaks develop into plaques — fibrous, calcified structures that narrow the artery and restrict blood flow.

The most dangerous moment is not necessarily the most narrowed artery. It is the rupture of a vulnerable plaque — a plaque with a thin fibrous cap and a large lipid core. When such a plaque ruptures, the body responds as it would to any wound: by forming a clot. In an artery, that clot can be catastrophic. If it blocks the coronary artery feeding the heart muscle, the result is a heart attack. If it blocks an artery supplying the brain, the result is a stroke. The heart attack itself takes minutes. The plaque that caused it took decades.

The cholesterol conversation — what most people are getting wrong

The standard NHS lipid panel reports total cholesterol, HDL, LDL, and triglycerides. This is useful but incomplete. As covered in the screenings page, ApoB — the protein that coats every LDL, VLDL, and IDL particle — is a more direct measure of cardiovascular risk than LDL cholesterol concentration. Two people can have identical LDL readings but very different particle counts. More particles mean more opportunities for penetration of the arterial wall. Large studies including INTERHEART have consistently found ApoB to be more predictive of cardiovascular events than LDL-C.

The other piece most people miss is Lp(a) — lipoprotein(a), a genetically determined variant of LDL that is particularly prone to arterial wall penetration and clot promotion. Elevated Lp(a) affects roughly one in five people and is associated with significantly higher cardiovascular risk that is largely independent of other factors. It doesn't respond meaningfully to diet or exercise. It is not measured in standard NHS panels. And because it's genetic, knowing your level is especially important if you have a family history of early heart disease. It needs to be tested once — it doesn't change — and the result should inform how aggressively you manage everything else.

Blood pressure: the silent damage accumulator

Hypertension is responsible for more cardiovascular deaths than any other single modifiable risk factor. It causes damage through sheer mechanical force — the repeated stress of elevated pressure on vessel walls promotes endothelial injury, accelerates atherosclerosis, and over time causes the heart muscle to thicken and stiffen. What makes it particularly dangerous is that it is entirely asymptomatic until it isn't. People can carry blood pressure of 150/95 for years with no awareness. The target for most adults is below 130/80 — a threshold that has been revised downward as the evidence on harm at higher levels has strengthened.

Lifestyle interventions for blood pressure are more effective than most people realise. A sustained reduction in sodium intake, regular aerobic exercise, weight loss in those who are overweight, and the DASH dietary pattern (high in fruit, vegetables, low-fat dairy, and low in saturated fat) can collectively reduce systolic blood pressure by 10–15 mmHg — equivalent to the effect of a first-line antihypertensive drug. For many people in the borderline-high range, this is enough to avoid medication entirely. For those already on medication, it can mean fewer drugs at lower doses.

What exercise actually does to cardiovascular risk

Exercise reduces cardiovascular risk through multiple simultaneous mechanisms, not one. It lowers resting blood pressure and resting heart rate, reduces circulating triglycerides and raises HDL, improves insulin sensitivity, reduces systemic inflammation, promotes collateral blood vessel development in the heart muscle, and improves endothelial function directly. Aerobic exercise in particular stimulates the production of nitric oxide in the endothelium, which relaxes blood vessels, reduces the adhesion of inflammatory cells to vessel walls, and promotes repair. This is not a vague effect. It is a specific, measurable biological response that begins within weeks of starting regular training.

The dose matters. The cardiovascular benefit of exercise follows a broadly dose-dependent curve, with the largest gains occurring when moving from sedentary to lightly active. But the curve continues upward into moderate and vigorous activity. Zone 2 training — steady aerobic work at an intensity where you can hold a conversation but wouldn't choose to — is particularly efficient for cardiovascular adaptation. Two to four hours per week of Zone 2, combined with one to two sessions of higher-intensity work, represents the approach most consistently associated with strong cardiovascular outcomes in the research literature.

Statins, aspirin, and the medication conversation

For people with established cardiovascular disease or very high risk, statins are among the most well-evidenced drugs in medicine. Large meta-analyses involving hundreds of thousands of patients show consistent reductions in cardiovascular events, strokes, and all-cause mortality. The controversy around statins — much amplified online — is largely overstated. Muscle side effects occur in a minority of patients, are usually mild, and often resolve with a dose change or switch to a different statin. The benefit-to-risk ratio for people with elevated cardiovascular risk is well established.

For primary prevention — people without established disease — the picture is more nuanced. Statins reduce cardiovascular events in high-risk primary prevention populations, but the absolute risk reduction for any individual is smaller than in secondary prevention. The decision should be made in conversation with a clinician who can quantify your actual risk level, not on the basis of a cholesterol number in isolation. Coronary artery calcium scoring, Lp(a), ApoB, and a family history assessment all contribute to a more accurate risk picture than standard panels alone.

Daily low-dose aspirin for primary prevention is no longer recommended for most people under current guidelines. Three large trials published between 2018 and 2019 found that the bleeding risk largely offsets the cardiovascular benefit in people without established disease. It remains appropriate for secondary prevention. If you're currently taking it on the basis of older advice, it's worth discussing the current evidence with your GP.

'Cardiovascular disease doesn't arrive without warning — it arrives without symptoms. Those are very different things, and understanding the distinction changes what you do about it.'

The practical bottom line

Cardiovascular risk is not a binary. It's a trajectory — and trajectories can be changed. Know your ApoB and Lp(a), not just your LDL. Know your blood pressure, and if it's above 130/80, take it seriously. Exercise consistently, with enough aerobic work to genuinely stress the cardiovascular system. Don't smoke. If you have a family history of early heart disease, get a coronary artery calcium score before symptoms develop. And if medication is indicated, take it — the evidence base for statins in appropriate populations is among the strongest in preventive medicine.

The window between now and a cardiovascular event is wide for most people reading this. What happens in that window is largely a function of what you know and what you do with it.