Coronary artery disease

Understanding coronary artery disease

Coronary artery disease (CAD) is the single most common reason people develop angina or have a heart attack. It happens when the coronary arteries — the blood vessels that wrap around the heart and feed the heart muscle itself with oxygen-rich blood — gradually narrow because of a build-up called atherosclerosis. The heart muscle works continuously and needs a steady blood supply to keep pumping; when that supply is reduced, the muscle struggles to keep up, especially when demand rises during exertion, emotion or illness.

Atherosclerosis is not a sudden event but a slow process that can take years or decades. It begins when the inner lining of an artery is injured or irritated — commonly by high blood pressure, high cholesterol, high blood sugar or the chemicals in tobacco smoke. Cholesterol and other fatty material seep into the artery wall at the site of that injury, and the body's own inflammatory cells arrive to deal with it. Over time this forms a plaque — a raised patch inside the artery wall, part fatty, part fibrous, sometimes containing calcium. As plaque accumulates, the channel through which blood flows becomes narrower, the way scale can narrow the inside of a pipe.

Two different problems can follow, and understanding the difference matters. A plaque that narrows an artery steadily and predictably usually causes angina — chest discomfort that appears when the heart works harder than the narrowed artery can supply, and typically eases with rest. A plaque can also become unstable: its fibrous cap can crack or tear, and the body responds to that injury by forming a blood clot right at the site. If that clot suddenly blocks the artery, blood flow stops completely and the heart muscle beyond the blockage begins to die within minutes — this is a heart attack (myocardial infarction), and it is a medical emergency. The same underlying disease, atherosclerosis, sits behind both angina and heart attack; what differs is whether the narrowing is gradual and stable, or sudden and complete.

What coronary artery disease feels like

Symptoms depend on how narrowed the arteries are and how suddenly a blockage develops. These are common descriptions patients use, offered to help you put your own experience into words for a clinician — not a checklist for diagnosing yourself.

• ●Chest pressure, tightness, heaviness or a squeezing sensation, often brought on by exertion, cold weather or strong emotion
• ●Discomfort that spreads to the arm (often the left), jaw, neck, back or upper abdomen
• ●Breathlessness, sometimes without obvious chest discomfort
• ●Unusual fatigue with everyday activity
• ●Discomfort that eases within minutes of resting (typical of stable angina)
• ●No symptoms at all — CAD can be silent, particularly in people with diabetes, until it is advanced

A useful distinction is between symptoms that follow a predictable pattern — brought on by a similar level of exertion each time, and relieved by rest — and symptoms that are new, worsening, or appearing at rest. The first pattern points toward stable angina; the second raises concern for an unstable plaque and needs urgent assessment.

What causes coronary artery disease

Atherosclerosis develops from an interaction between the artery wall and substances circulating in the blood, building up gradually over many years.

How plaque builds up

Cholesterol carried in the blood, particularly the type known as LDL ("bad" cholesterol), can enter the artery wall where the lining has been damaged or irritated. Once inside, it triggers an inflammatory response: immune cells move in to try to clear it, but in doing so contribute to a growing plaque of fat, inflammatory cells, and fibrous tissue, sometimes hardening further with calcium deposits. This plaque bulges into the artery, narrowing the space through which blood flows.

What damages the artery lining in the first place

The inner lining of an artery is normally smooth and resistant to this build-up. It becomes vulnerable to plaque formation when repeatedly exposed to high blood pressure (which puts mechanical strain on the vessel wall), high blood sugar (which damages small and large blood vessels over time), the chemicals in tobacco smoke, and persistently high cholesterol. This is why coronary artery disease is described as a condition with many contributing causes acting together rather than a single cause.

Why some plaques rupture

Not every plaque behaves the same way. Some remain stable for years, narrowing the artery gradually. Others have a thin, fragile covering that can crack under the everyday stress of blood flow, cholesterol crystals or inflammation within the plaque itself. When that covering tears, the body's clotting system responds as it would to any injury — but a clot that forms inside a coronary artery can block it outright, which is how a heart attack most often occurs, sometimes in an artery that was not severely narrowed beforehand.

Who is more likely to develop coronary artery disease

Some risk factors can be changed with treatment and daily habits; others cannot be changed but are still important to know, because they shape how closely your risk should be monitored.

Factors you can change

• ●High blood pressure — very common in Nigeria and often undiagnosed, it steadily damages artery walls
• ●Diabetes and high blood sugar — damages blood vessels and accelerates plaque formation
• ●High cholesterol, particularly high LDL cholesterol
• ●Tobacco use in any form
• ●Excess weight, especially fat carried around the abdomen
• ●Physical inactivity
• ●A diet high in salt, refined carbohydrates and unhealthy fats
• ●Chronic stress and poor sleep

Factors you cannot change

• ●Increasing age
• ●Being male, though risk in women rises significantly after menopause
• ●A family history of coronary disease, particularly at a younger age
• ●Chronic kidney disease, which raises cardiovascular risk independently

What happens if coronary artery disease goes untreated

Left unmanaged, coronary artery disease tends to progress, and each stage carries its own risks.

Worsening angina. As narrowing increases, symptoms can appear with less and less exertion, and eventually at rest — a pattern that itself needs urgent assessment.

Heart attack. Sudden complete blockage of a coronary artery starves part of the heart muscle of oxygen; the longer it goes untreated, the more muscle is permanently lost.

Heart failure. Muscle damaged by one or more heart attacks, or starved of adequate blood flow over a long period, can lose pumping strength, leading to breathlessness, fatigue and fluid retention.

Arrhythmias. Damaged or oxygen-starved heart muscle can trigger abnormal electrical rhythms, some of which are dangerous.

Cardiac arrest. Rarely, a dangerous rhythm arising from damaged heart muscle can stop the heart pumping effectively without warning — a key reason unstable symptoms are never safe to ignore.

How Cardiocare finds the cause

The right pathway depends on your symptoms, examination and overall health. It typically draws on some or all of the following:

• 01
  History and examination. Details of your symptoms, their triggers and pattern, plus an examination of your heart, pulse, blood pressure and general health.
• 02
  12-lead ECG (electrocardiogram). A painless recording of the heart's electrical activity from pads on the chest and limbs, taking minutes; it can show past damage or an active problem.
• 03
  Blood tests. A cholesterol profile, blood sugar, and — if a heart attack is suspected — troponin, a protein released when heart muscle is injured.
• 04
  Exercise or pharmacological stress testing. Monitors the heart's electrical activity and symptoms while demand is increased, to see whether blood flow becomes inadequate.
• 05
  Echocardiogram. A painless ultrasound scan showing the heart's structure, pumping strength and any areas of damaged muscle.
• 06
  Coronary CT angiography. A CT scan that can show plaque and narrowing in the coronary arteries for selected patients.
• 07
  Coronary angiography. Performed in Cardiocare's on-site cath lab, a thin catheter guided to the heart arteries injects contrast dye so narrowings are seen directly on X-ray — the definitive test for confirming and mapping coronary artery disease.
• 08
  Heart-team review. For confirmed disease, cardiologists and cardiac surgeons jointly consider whether medicine, a stent procedure or bypass surgery best suits your pattern of disease.

How coronary artery disease is treated

Treatment aims to relieve symptoms, slow the underlying atherosclerosis and reduce the risk of heart attack. Most people need a combination of lifestyle change, medicines and, for some, a procedure.

Lifestyle foundations

Controlling blood pressure, blood sugar and cholesterol; stopping smoking completely; regular physical activity as advised; and a diet lower in salt, refined carbohydrate and unhealthy fat all slow the pace of atherosclerosis, alongside any medicine prescribed.

Medicines, by class

Where medicine is needed, it is chosen by what it does, and your clinician will discuss the right option and dose for you:

• ●Antiplatelet medicines (such as aspirin) — make blood platelets less likely to clot at a plaque site
• ●Statins — lower LDL cholesterol and help stabilise existing plaque
• ●Beta blockers — slow the heart rate and reduce its workload, easing angina
• ●Nitrates — widen blood vessels to relieve angina, including a fast-acting form for an angina episode
• ●ACE inhibitors or ARBs — protect the heart and blood vessels, particularly with high blood pressure, diabetes or reduced pumping function

Procedures

Available through Cardiocare's on-site cardiac catheterisation ("cath") laboratory and cardiac surgery service:

• ●Angioplasty and stenting (PCI) — a catheter guides a small balloon, usually followed by a stent, to open a narrowed artery from within; see our angioplasty and stent guide
• ●Coronary artery bypass surgery (CABG) — a surgeon creates new routes for blood to reach heart muscle beyond significant blockages, generally used for more extensive disease; see our bypass surgery guide

Living with coronary artery disease: everyday self-care

Coronary artery disease is a long-term condition to manage, not a single problem to fix — consistent daily habits make a real difference alongside treatment.

• ✓Take every prescribed medicine as directed, even once you feel well — these medicines work by preventing progression, not only by treating symptoms
• ✓Keep blood pressure, blood sugar and cholesterol checks on schedule
• ✓Stop smoking completely; ask your care team for support if needed
• ✓Build regular activity into your week, at the level your clinician advises
• ✓Favour home-cooked meals with less salt and oil, more vegetables, fruit and whole grains
• ✓Attend cardiac rehabilitation if it is recommended after a procedure or heart attack
• ✓Know your own angina pattern, and what to do if it changes

Preparing for your appointment

What to bring

• ✓A list of all medicines you take, including herbal and over-the-counter preparations
• ✓Any previous ECGs, blood test results, angiogram reports or hospital letters
• ✓Your HMO card or payment details
• ✓A valid means of identification

What we will ask

When your symptoms started, what brings them on, how long they last, what relieves them, and your personal and family history of heart disease, blood pressure, diabetes and cholesterol.

Questions worth asking us

• ●How narrowed are my arteries, and where?
• ●Do I need a stent, bypass surgery, or can this be managed with medicine for now?
• ●What result should my cholesterol and blood pressure be aiming for?
• ●What should I do if my chest discomfort changes?