What is Coronary Artery Disease?
Coronary artery disease is a condition defined by the buildup of atherosclerotic plaque—a material typically composed of fat (cholesterol), fibrous tissue, and calcium salts (a process known as atherosclerosis)—inside the walls of the coronary arteries. These arteries supply the heart muscle (myocardium) with the necessary amount of blood and oxygen to ensure its continuous and normal function.
Atherosclerosis
Atherosclerosis is the result of a chronic process that may lead to narrowing of the lumen of the coronary arteries, resulting in inadequate blood supply to the heart and the development of myocardial ischemia. In certain patients, once the atherosclerotic plaque reaches a sufficient size, it may rupture into the lumen of the coronary artery, triggering the formation of a thrombus. This can cause an acute and complete obstruction of the artery’s lumen, leading to acute myocardial infarction.
Components of Atherosclerotic Plaque
Atherosclerotic plaque is primarily composed of fat, fibrous tissue, and calcium salts. The proportion of these components varies from patient to patient. The progression of atherosclerotic plaque is influenced by various underlying cardiovascular risk factors, including:
Smoking: Smoking damages the blood vessels and significantly increases the risk of developing atherosclerotic disease and acute myocardial infarction.
Arterial Hypertension: High blood pressure stresses the artery walls and significantly raises the risk of atherosclerosis and myocardial infarction.
Diabetes Mellitus: Diabetes affects blood sugar regulation and can rapidly worsen atherosclerotic disease. It is one of the strongest risk factors for in-stent restenosis following angioplasty.
High Cholesterol: Elevated cholesterol levels promote the development of atherosclerotic plaques.
Sedentary Lifestyle: Lack of physical activity is linked to an increased risk of cardiovascular diseases and events. Regular exercise enhances the release of natural endogenous metabolites with antioxidant and vasodilatory properties that support endothelial health. It is associated with plaque stabilization and reduction, as well as decreased risk of myocardial infarction.
Stress: Stress can raise blood pressure and cholesterol levels.
Age: The risk of atherosclerosis increases with age.
Sex: Men have a higher risk of developing coronary artery disease compared to women, particularly before menopause.
Family History: A family history of cardiovascular disease, especially in men under 55 and women under 65, significantly increases the risk of its occurrence.
Conclusion
Coronary artery disease is extremely common and remains the leading cause of death in the Western world. In Europe, it is estimated that approximately 1.8 million deaths per year are attributed to coronary artery disease, accounting for 19% of all deaths in men and 20% in women.
Coronary Artery Disease: Symptoms
Coronary artery disease develops progressively over time, and its symptoms may vary from person to person. Approximately 60% of patients may not exhibit any warning signs during the course of the disease, and its first manifestation may be entirely sudden, such as the onset of an acute myocardial infarction.
Angina and Symptoms
The term angina refers to a range of symptoms that may accompany coronary artery disease. These symptoms typically emerge when the narrowing caused by the atherosclerotic plaque within the vessel’s lumen becomes significant (greater than 70%). The most common symptoms of coronary artery disease include:
Chest pain and discomfort: Often described as “tightness,” “pressure,” or “heaviness” in the chest. These sensations may radiate to other areas such as the jaw, neck, shoulders, back, and arms—most commonly the left arm. The discomfort can occur either during physical exertion or at rest and is usually intermittent, lasting a few minutes, subsiding, and then recurring.
Shortness of breath and labored breathing: May appear during physical activity or even at rest.
Lightheadedness and near-fainting: These may be accompanied by dizziness and weakness, occurring during exertion or while at rest.
Sweating and nausea: Often presents as cold sweats and a feeling of nausea, sometimes with vomiting.
Epigastric pain and burning sensation in the stomach (heartburn): These can be mistaken for symptoms of indigestion.
Additional Symptoms
In addition to the main symptoms above, coronary artery disease may also be associated with other clinical signs and symptoms that may go unnoticed or be mistakenly attributed to other causes, such as:
Fatigue and weakness: These may occur without a clear cause and persist for an extended period.
Palpitations: The patient may feel that the heart is beating rapidly or irregularly due to cardiac arrhythmias, some of which may be malignant, such as ventricular tachycardia.
Sleep disturbances: Difficulty falling or staying asleep may be related to underlying cardiovascular conditions, including coronary artery disease.
What Are the Causes of Coronary Artery Disease?
Coronary artery disease is caused by atherosclerosis—a process in which atherosclerotic plaques, composed mainly of fat, cholesterol, calcium salts, inflammatory cells, and other substances, accumulate on the walls of the coronary arteries.
These plaques can lead to narrowing or blockage of the arteries, reducing blood flow to the heart muscle and resulting in cardiac problems.
Risk Factors Predisposing to Coronary Artery Disease
The risk factors that predispose individuals to coronary artery disease are categorized into modifiable and non-modifiable factors.
Modifiable Cardiovascular Risk Factors
Arterial hypertension
High cholesterol / Dyslipidemia
Diabetes mellitus
Smoking
Excess body weight / Obesity
Sedentary lifestyle / Lack of physical activity
Psychological stress
Non-Modifiable Cardiovascular Risk Factors
Family history (genetics)
Age
Ethnicity
Sex
How Is Coronary Artery Disease Diagnosed?
The diagnosis of coronary artery disease involves a series of tests aimed at evaluating heart function and detecting the presence of atherosclerotic plaques in the coronary arteries:
Electrocardiogram (ECG):
Records the heart’s electrical activity and can detect abnormalities related to blood flow in the heart muscle. Disruptions in electrical signals may be associated with underlying coronary artery disease.
Transthoracic Echocardiography:
Uses ultrasound waves to produce images of the heart and its valves, helping assess heart function and structure.
Severe coronary artery disease with significant arterial narrowing may result in myocardial dysfunction and heart failure—findings that may be revealed through echocardiography.
Coronary CT Angiography (CCTA):
A non-invasive method where a single intravenous dose of contrast agent is administered to directly visualize the lumen and walls of the coronary arteries.
When technically adequate, this test has very high sensitivity and specificity in diagnosing or excluding coronary artery disease. Its main advantage over other non-invasive functional tests (such as stress testing, stress echocardiography, or myocardial perfusion imaging) lies in the early detection of even minor arterial stenoses or early-stage coronary disease—something that is practically impossible with functional tests.
Exercise Stress Test (Treadmill Test):
A non-invasive functional test in which the patient exercises on a treadmill with gradually increasing intensity every 2 minutes. Symptoms such as chest pain or discomfort, shortness of breath, fatigue, dizziness, and ECG changes (ischemic alterations or arrhythmias) are monitored during exercise and recovery. The patient remains continuously monitored via ECG leads during the test.
Stress Echocardiography (Stress Echo):
A non-invasive functional test involving transthoracic echocardiography at rest and during stress, which may be induced pharmacologically (e.g., with dobutamine) or via exercise on a bike.
The level of stress is increased gradually until the target heart rate for the patient’s age is reached. Symptoms, ECG changes, and—most importantly—wall motion abnormalities of the myocardium are assessed.
For improved accuracy, especially in patients with poor acoustic windows, an intravenous contrast agent is administered, which significantly enhances image quality and diagnostic precision. Continuous ECG monitoring is maintained throughout.
Myocardial Perfusion Imaging (SPECT):
A non-invasive functional test where the patient is assessed before and after administration of a vasodilator agent (e.g., regadenoson or dipyridamole) or during exercise on a bike or treadmill.
The uptake of a radiotracer (e.g., thallium or technetium) by myocardial cells is measured. Reduced uptake during stress compared to rest indicates reversible ischemia and possible significant coronary stenosis.
Stress Cardiac Magnetic Resonance Imaging (Stress Cardiac MRI):
A non-invasive functional imaging technique performed before and after administration of a vasodilator agent (e.g., adenosine, regadenoson, or dipyridamole) and/or a stress-inducing drug like dobutamine.
The test evaluates uptake of contrast agent (gadolinium) during vasodilation and detects wall motion abnormalities during stress compared to rest. Abnormal findings indicate reversible ischemia and potential critical stenoses.
Stress cardiac MRI is considered more accurate than other non-invasive functional tests.
Invasive Coronary Angiography (ICA):
A minimally invasive procedure performed via puncture of the radial (wrist) or femoral (groin) artery. A thin, specially shaped catheter is inserted into the coronary artery opening, through which contrast agent is injected into the artery.
X-ray imaging then visualizes the coronary artery lumen in black, allowing identification of stenoses or complete blockages.
Additional invasive diagnostic tools such as Fractional Flow Reserve (FFR) and intravascular imaging techniques (e.g., Intravascular Ultrasound or Optical Coherence Tomography) may be used for near-perfect precision in assessing stenosis severity.
Following coronary angiography, ad hoc intervention can be performed with angioplasty and stent placement to treat the identified stenoses.
How Is Coronary Artery Disease Treated?
The treatment of coronary artery disease depends on the severity of the condition and includes medical therapy and interventional or surgical revascularization through percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).
Medical Therapy
Patients with coronary artery disease require specific medications to manage angina symptoms and reduce the risk of acute myocardial infarction. These include:
Antiplatelet agents (e.g., aspirin, clopidogrel, ticagrelor, prasugrel) to prevent blood clot formation.
Statins and PCSK-9 inhibitors, lipid-lowering drugs to reduce cholesterol levels.
Antihypertensives to control blood pressure.
Nitrates to relieve angina.
Beta-blockers to reduce heart workload and control angina.
Calcium channel blockers to alleviate angina symptoms.
Percutaneous Coronary Intervention (PCI) and Stent Placement
An interventional procedure in which a catheter with a balloon is inserted into the narrowed artery. The balloon inflates to dilate the artery, and a stent is then placed to keep the artery open.
Recent advancements allow PCI using bioresorbable scaffolds, which are absorbed by the body within 12 months, allowing the artery to regain its natural structure and function. Drug-coated balloons are also used in some cases without placing a permanent stent.
Coronary Artery Bypass Grafting (CABG)
A surgical procedure in which grafts from other arteries (such as the internal mammary or radial artery) or veins are used to create a new pathway that bypasses the narrowed or completely blocked coronary segment, allowing blood to reach the heart muscle.
Coronary Artery Disease and Exercise
Exercise is a key component in managing and preventing coronary artery disease. Although it may seem counterintuitive to recommend physical activity to individuals with heart problems, well-designed and supervised exercise programs can offer significant benefits.
Aerobic exercise improves heart function and enhances physical endurance. It can also reduce high blood pressure, lowering the heart’s workload at rest. Furthermore, it helps decrease levels of bad cholesterol (LDL) and increase good cholesterol (HDL).
Regular exercise helps regulate blood glucose levels, which is especially important for people with diabetes. It also supports maintaining a healthy body weight, reducing the risk of further cardiac complications. Lastly, physical activity has been shown to reduce stress levels and improve overall mood.
