Coronary artery disease Angina, heart attack, and narrowing of the arteries that supply the heart muscle

What coronary artery disease is

Your heart is a muscle, and like any muscle it needs its own blood supply. That comes from the coronary arteries, three main vessels that run across the surface of the heart.

Coronary artery disease (CAD) is the build-up of fatty plaque inside the walls of those arteries, a process called atherosclerosis.

Plaque builds slowly, usually over decades. As an artery narrows, blood flow is still adequate at rest but can’t increase enough when the heart works harder. That mismatch is what produces angina: chest discomfort brought on by exertion or stress and relieved by rest.

A heart attack (myocardial infarction) is different. It happens when a plaque suddenly ruptures and a blood clot forms on top of it, blocking the artery within minutes. Heart muscle beyond the blockage starts to die. This is why sudden, severe, or rest-onset symptoms are an emergency, while stable exertional symptoms are something to have assessed promptly but not by ambulance.

CAD is common and, importantly, treatable.

Modern treatment does two separate jobs: relieving symptoms, and lowering your risk of a future heart attack. Those are not the same thing, and the treatments that make you feel better are not always the ones that keep you alive longer.

Symptoms

Typical angina:

• Less typical presentations

  A significant proportion of people with CAD never have classic chest pain. Breathlessness on exertion, unusual fatigue, nausea, indigestion-like discomfort, or jaw and back pain can be the only symptoms. This is more common in women, people with diabetes, and people over 75. Symptoms that don’t fit the textbook are still worth investigating.

• Less likely to be angina

  Pain that is sharp and momentary, reproducible by pressing on the chest wall, clearly worse with deep breathing or a change in position, or that lasts for hours at a constant level unchanged by activity, is usually something other than CAD. That said, this distinction is not one to make on your own.

Risk factors

Modifiable:

Not modifiable:

The unmodifiable list is not a verdict. It sets your starting point; the modifiable list is where the outcome is actually decided, and the effect of addressing it is large.

How CAD is diagnosed

1. 01

   History and examination

   The description of your symptoms, what brings them on, how long they last, what relieves them, carries more diagnostic weight than any single test. This is why the consultation itself matters, and why a symptom diary is useful.

2. 02

   ECG and blood work

   An ECG records the heart’s electrical activity and may show evidence of previous or ongoing injury, though a normal ECG at rest does not exclude CAD. Blood work covers a lipid profile, hemoglobin A1c or glucose, kidney function, thyroid, and hemoglobin.

   Lipoprotein(a) is checked once in a lifetime in most people, as it is inherited and identifies a risk that cholesterol testing alone misses.

3. 03

   Echocardiogram

   An ultrasound of the heart. It measures pumping function, shows whether any region of the heart muscle moves abnormally, a clue to previous damage or reduced flow, and assesses the valves. Painless, no radiation, and normally 45 minutes to 1 hour.

4. 04

   Exercise treadmill test (ETT)

   You walk on a treadmill that becomes progressively faster and steeper while your ECG, heart rate, and blood pressure are monitored. It shows whether symptoms or ECG changes appear at a reproducible workload, and how much exercise you can genuinely do.

   Wear comfortable shoes and clothing, avoid caffeine and a heavy meal beforehand, and ask about holding beta blockers on the morning of the test. You can stop at any point.

5. 05

   Stress imaging, when the treadmill test is not enough

   If you can’t walk far enough, if your baseline ECG is uninterpretable, or if the result is ambiguous, imaging is added: a nuclear perfusion scan, or an ultrasound of the heart recorded during stress. These show which region of the heart is short of blood flow, not just that something is abnormal.

6. 06

   CT coronary angiography

   A CT scan with intravenous contrast that pictures the coronary arteries directly. It is particularly good at ruling CAD out in people at lower risk, and a coronary calcium score can refine risk estimates when the decision about starting a statin is borderline.

7. 07

   Invasive coronary angiogram

   A catheter passed from the wrist or groin injects dye directly into the coronary arteries under X-ray. It is the definitive test, and it is the same procedure during which a stent can be placed if a significant blockage is found. It is reserved for people with high-risk findings, ongoing symptoms despite medication, or an acute presentation.

Of these, the ECG, the echocardiogram and the treadmill test are performed here. Stress imaging, CT coronary angiography and an invasive angiogram are arranged elsewhere and reported back to your cardiologist.

Not everyone needs every test. The sequence is chosen based on how likely CAD is in your case and what would actually change management.

How CAD is treated

Treatment is built in layers. The first two layers do most of the work in preventing heart attacks, even though they are the least dramatic.

1. 01

   Stopping smoking

   The single highest-yield thing you can do, with risk beginning to fall within weeks. Nicotine replacement, varenicline, and bupropion roughly double or triple success rates compared with willpower alone, and combining medication with counselling works better than either.

   Ask for help rather than repeating unassisted attempts.

2. 02

   Lowering cholesterol

   Statins reduce heart attacks and death in established CAD, and the benefit comes from lowering LDL, not from how you feel on the medication. Where a statin alone isn’t enough or isn’t tolerated, ezetimibe, and in selected patients a PCSK9 inhibitor, are added. Muscle aches are common but frequently not caused by the statin itself; this is worth testing systematically rather than abandoning treatment.

3. 03

   Blood pressure and diabetes

   Both accelerate plaque. Blood pressure control is usually straightforward with one or two medications. In diabetes, SGLT2 inhibitors and GLP-1 receptor agonists reduce cardiovascular events beyond their effect on glucose, and are preferred in people who also have CAD. This clinic offers cardiac risk factor management alongside cardiology.

4. 04

   Antiplatelet therapy

   Low-dose aspirin, or clopidogrel, reduces clot formation on plaque. After a stent or a heart attack you will usually take two antiplatelet agents for a defined period.

   Tell any dentist or surgeon that you are on them, and check with your cardiologist before any interruption.

   Do not stop these on your own. Stopping early after a stent carries a real risk of the stent clotting off.

5. 05

   Anti-anginal medication

   Beta blockers, calcium channel blockers, and long-acting nitrates reduce how often angina occurs. Short-acting nitroglycerin spray or tablets treat an episode as it happens. These medications relieve symptoms; they are separate from the ones that lower your long-term risk.

6. 06

   Exercise and cardiac rehabilitation

   A supervised program combines graded exercise with education and risk factor management, and reduces future events. Ask about a referral: it is under-used and one of the more effective parts of treatment. The general target is 150 minutes a week of moderate activity, built up gradually.

7. 07

   Revascularization: stent or bypass

   A stent (PCI) props open a narrowed segment; bypass surgery (CABG) routes blood around blockages using grafted vessels. Both reliably relieve angina. In stable disease they do not always reduce heart attacks beyond what good medication achieves, which is why the decision depends on the pattern of blockages, your symptoms, and your pumping function.

   In an acute heart attack, urgent revascularization is unequivocally life-saving.

Your own targets may differ, and your cardiologist will confirm them.

Using nitroglycerin, and when to call 911

Sit or lie down before taking it, because it can drop your blood pressure. Take one spray or tablet under the tongue.

If the discomfort has not gone five minutes later, call 911. While waiting, you may take a second dose at five minutes and a third at ten if you have been instructed to do so and your symptoms allow.

Never take nitroglycerin within 24 to 48 hours of sildenafil, tadalafil, or a similar medication. The combination can cause a dangerous fall in blood pressure.

Keep the spray with you rather than at home, and check the expiry date.

What to expect at your appointment

Your first visit is a consultation with a cardiologist. Expect it to take about an hour.

Testing may be arranged the same day or booked shortly afterward. A letter goes back to your referring doctor, usually within 1 to 7 days.