Coronary artery disease and angina pectoris

What coronary artery disease is

The heart is a muscle that works without rest and needs a constant supply of oxygen. It is delivered by the coronary arteries, two main vessels (with their branches) that run over the surface of the heart. When these arteries narrow, the muscle receives less blood than it needs, especially when the heart works harder, for example during brisk walking, climbing stairs, strong emotions or in the cold.

The most common cause of narrowing is atherosclerosis: over the years, plaques made of cholesterol, inflammatory cells and fibrous tissue build up in the inner wall of the arteries. Small plaques cause no symptoms, but larger ones restrict blood flow. A plaque can also rupture and form a clot that blocks the artery; this is the mechanism of a myocardial infarction.

Not all angina comes from large plaques. Some patients have artery spasm (the artery narrows temporarily, often at rest or at night) or a disorder of the small vessels of the heart, while the main arteries look free of significant narrowing on tests. These forms are told apart with specific tests and are treated differently.

How angina feels

Angina is far more often described as pressure, tightness, heaviness or burning behind the breastbone than as a stabbing pain. Patients often say “it feels like a stone on my chest” or “like a belt squeezing me”. The chest discomfort may spread to the left arm (or both arms), neck, jaw, back or upper stomach, and may come with dyspnea, sudden fatigue, nausea or sweating.

Stable angina has three features: it appears with a similar level of exertion or emotion each time (for example after 200 meters of walking or one flight of stairs), it usually lasts a few minutes, and it goes away with rest or with nitroglycerin under the tongue. This form is important, but it usually allows time for a planned assessment.

Unstable angina is different: the pain appears for the first time, appears at rest, becomes more frequent, stronger or lasts longer than usual. This can be a warning of a heart attack and needs immediate assessment. If pain at rest lasts more than a few minutes, call 127.

In women, older adults and people with diabetes the signs may be less typical: only dyspnea on exertion, unusual fatigue, nausea or pain in the back or jaw. These symptoms should not be explained away as “age” or “nerves” without assessment.

What the risk factors are

Coronary artery disease develops from the interaction of several factors, many of which can be changed:

• Smoking damages the artery wall and makes blood more prone to clots. Risk falls quickly after quitting.
• Arterial hypertension strains the vessel wall and the heart itself.
• Dyslipidemia: high LDL cholesterol is the main cause of plaques; high triglycerides and low HDL cholesterol add to the risk.
• Diabetes speeds up atherosclerosis and makes angina less obvious (see diabetes and the heart).
• Excess weight, physical inactivity, a diet rich in saturated fat and salt, chronic stress and excess alcohol.
• Family history: early coronary disease in first-degree relatives (men under 55, women under 65) raises the risk.
• Age and sex: risk rises with age and in women after menopause.

Controlling these factors is as important as the medicines prescribed for angina.

How it is assessed by the cardiologist

The visit begins with a detailed history: where the pain occurs, what triggers it, how long it lasts, what relieves it, since when it has been present and whether it is changing. The character of the pain is often the biggest help in making the diagnosis. A clinical examination, blood pressure measurement and assessment of risk factors follow.

The basic tests, depending on the case:

• The ECG records the electrical activity of the heart. It may show signs of ischemia or of a previous heart attack, but at rest it can be completely normal.
• Echocardiography shows the pumping strength of the heart, the thickness of the wall and the valves; it also helps to exclude other causes of pain or dyspnea.
• Blood tests: lipid profile, glucose or HbA1c, hemoglobin, kidney and thyroid function.
• Holter ECG, when an arrhythmia or pain at rest is suspected.

A normal resting ECG does not rule out coronary artery disease, because narrowed arteries cause ischemia mainly during exertion. When doubt remains, the cardiologist may recommend tests that show the blood supply of the heart or the appearance of the arteries (for example exercise or imaging tests, CT of the coronary arteries or coronary angiography). These are performed at specialized centers; our specialists recommend them when indicated and interpret the result with you.

How it is treated

Treatment has two aims: to relieve symptoms and to lower the risk of heart attack and death. It has four parts that work together.

1. Lifestyle. Complete smoking cessation; a Mediterranean-style diet (vegetables, fruit, whole grains, olive oil, fish, little red meat and salt); a healthy weight; regular physical activity according to ability and your doctor’s advice; little alcohol. Cardiac rehabilitation helps a lot after coronary events.

2. Medicines to lower risk. Statins (often with other medicines) lower LDL cholesterol and stabilize plaques; for patients with coronary disease, European guidelines aim for very low LDL values. Aspirin or other antiplatelet medicines prevent clots; control of blood pressure and diabetes is just as important.

3. Medicines for symptoms. Beta blockers, calcium channel blockers and nitrates reduce the work of the heart or widen the arteries. Nitroglycerin under the tongue is used for an attack: stop the activity and sit down, use it as your doctor instructed; if the pain does not go away after 5 minutes, repeat once; if it has not gone 5 minutes after the second dose, call 127. Do not use it if you have taken medicines for erectile dysfunction (PDE5 inhibitors) without asking your doctor.

4. Revascularization. When symptoms persist despite medicines, or when the arteries have significant narrowings linked to higher risk, the doctor may propose angioplasty with a stent (widening the artery with a catheter and placing a metal mesh) or coronary bypass (surgery that creates a new route for the blood). The choice depends on the number and location of the narrowings, diabetes and the function of the heart, and is made together with the cardiac surgeon and the patient.

Do not start or stop medicines on your own, even when you feel well: many of them give no sensation but protect the heart. Always carry your list of medicines.

Follow-up and when to contact your doctor again

After the diagnosis, regular follow-up assesses symptoms, tolerance of medicines, blood pressure, cholesterol and blood sugar. Contact the cardiologist without waiting for the routine check-up if the pain appears more often, occurs with less exertion, lasts longer or you need nitroglycerin more often; if dyspnea, leg swelling (edema), dizziness or fainting appear, or if you have side effects from medicines.