Coronary artery disease is one of the leading causes of death worldwide, often progressing silently until a life-threatening event such as a heart attack occurs. In fact, in Malaysia, coronary artery disease is one of the top 4 causes of death, with stroke, peripheral vascular disease and aortic disease being the other three.

Hence, this topic requires immense attention. With the right awareness and knowledge, you can work towards preventing it as well as obtain medical help before it gets too late. And that’s exactly what we are going to do in this article. Read on to gain a comprehensive perspective of this disease.

Causes and Risk Factors of Coronary Artery Disease

Several factors contribute to the development of coronary artery disease. While some risk factors are genetic, others are linked to lifestyle choices and can be controlled to reduce the likelihood of CAD.

• Unhealthy Diet: Diets high in saturated fats, trans fats, cholesterol, and processed sugars can lead to plaque buildup. High sodium intake raises blood pressure, increasing the risk of artery damage.
• Lack of Physical Activity: Sedentary lifestyles lead to obesity, hypertension, and poor circulation, all of which increase CAD risk. Regular exercise helps maintain healthy blood vessels and improves heart function.
• Smoking and Tobacco Use: Smoking damages blood vessels, reduces oxygen in the blood, and increases cholesterol levels. Second-hand smoke exposure can also contribute to CAD.
• High Blood Pressure (Hypertension): Increased blood pressure strains the artery walls, making them more susceptible to plaque buildup.
• High Cholesterol Levels: Low-density lipoprotein (LDL) cholesterol contributes to plaque formation. High-density lipoprotein (HDL) cholesterol helps remove excess cholesterol from the blood.
• Diabetes and Insulin Resistance: High blood sugar damages arteries and increases inflammation, accelerating atherosclerosis.
• Obesity: Excess weight puts strain on the heart and leads to higher cholesterol and blood pressure levels.
• Family History of Heart Disease: A genetic predisposition can increase the likelihood of developing CAD.
• Chronic Stress: Long-term stress can raise blood pressure and contribute to unhealthy lifestyle choices like smoking and overeating.
• Age and Gender: Men are at higher risk at an earlier age, while women’s risk increases post-menopause. Ageing naturally leads to stiffened arteries and increased heart disease risk.

Stages of Coronary Artery Disease

Coronary artery disease progresses through different stages, often without noticeable symptoms in the early phases.

Stage 1: Endothelial Dysfunction (Early Stage)

The endothelium, which is the inner lining of blood vessels, can begin to malfunction as a result of risk factors such as high cholesterol or smoking. Unfortunately, this dysfunction often occurs without any noticeable symptoms, making it challenging to detect early on.

Stage 2. Fatty Streak Formation

Cholesterol and immune cells gradually buildup in the walls of arteries, creating streaks that can lead to the narrowing of the arteries. This process, known as atherosclerosis, often goes unnoticed as it remains asymptomatic.

Stage 3. Plaque Formation (Atherosclerosis)

The accumulation of fatty deposits can cause arteries to become rigid, resulting in arterial stiffness. This can manifest in symptoms such as chest discomfort or fatigue.

Stage 4. Plaque Rupture and Blood Clot Formation

The rupture of a plaque can lead to the formation of blood clots that block arteries, potentially resulting in angina or heart attacks. This is a critical stage which requires immediate emergency intervention.

Stage 5. Complete Blockage and Heart Attack

Complete blockage of an artery results in a myocardial infarction, commonly known as a heart attack, which can cause significant damage to the heart muscle. This is a critical and life-threatening situation that necessitates prompt medical intervention.

Types of Coronary Artery Disease

Coronary artery disease does not manifest the same way in every patient. It can be of different types such as:

1. Stable Coronary Artery Disease

Characterised by predictable chest pain, known as angina, which is typically triggered by physical exertion, this condition can be effectively managed through lifestyle modifications and medication.

2. Unstable Coronary Artery Disease

In this type of CAD, patients experience unpredictable and increasingly severe chest pain, even while at rest. These symptoms are a clear indicator of an elevated risk of a heart attack.

3. Silent Ischemia

Although there may not be any noticeable symptoms, a reduced supply of oxygen to the heart can have a significant impact on its function. This condition is typically identified through stress tests or imaging studies.

4. Acute Coronary Syndrome (ACS)

This condition encompasses unstable angina and heart attacks caused by the sudden blockage of arteries. It necessitates immediate emergency intervention.

Coronary Artery Disease Diagnosis

Diagnosing coronary artery disease involves a combination of medical history, physical examinations, and specialised tests to assess heart function and detect blockages in the arteries. Here are the key diagnostic methods:

Medical History and Physical Examination

Assessment of symptoms such as chest pain, shortness of breath, and fatigue is crucial in determining a patient’s cardiovascular health. Additionally, evaluating risk factors such as smoking, diabetes, high blood pressure, and family history of heart disease provides valuable insight into potential heart issues. Furthermore, measuring blood pressure, heart rate, and cholesterol levels helps in identifying any underlying conditions that may be affecting the heart.

Electrocardiogram (ECG or EKG)

This device records the electrical activity of the heart, allowing for the detection of abnormal heart rhythms, previous heart attacks, and areas of poor blood flow.

Stress Test (Exercise or Pharmacological)

This test evaluates heart function during physical activity, such as using a treadmill or stationary bike. In cases where patients are unable to exercise, alternative tests involve using medication to simulate the effects of physical exertion. This test is important in identifying any decrease in blood flow to the heart muscle.

Echocardiogram (Heart Ultrasound)

Utilising sound waves, echocardiography generates detailed images of the heart to assess its structure, valve functionality, and overall pumping efficiency.

Coronary Angiography (Cardiac Catheterization)

Coronary angiography is a procedure that involves injecting contrast dye into the coronary arteries through a catheter. This allows for the production of detailed X-ray images, known as angiograms, which can reveal any blockages or narrowing in the arteries. Coronary angiography is widely regarded as the gold standard for diagnosing coronary artery disease.

CT Coronary Angiography (CTCA)

A non-invasive imaging test utilising a CT scanner and contrast dye is available to detect early plaque buildup and assess artery narrowing.

Blood Tests

• Lipid Profile: This test measures levels of cholesterol (LDL and HDL) and triglycerides in the blood, providing valuable information about heart health.
• Cardiac Enzymes (Troponin Test): This test is used to detect damage to the heart muscles, particularly in cases of suspected heart attacks.
• C-reactive Protein (CRP) Test: This test identifies inflammation that is associated with heart disease, helping to assess the risk of cardiovascular events.

Myocardial Perfusion Imaging (Nuclear Stress Test)

This technique utilises radioactive tracers and imaging to assess blood flow to the heart muscle, pinpointing areas with decreased oxygen supply.

Coronary Artery Disease Treatment

Coronary artery disease (CAD) treatment aims to restore proper blood flow to the heart, relieve symptoms, and prevent complications such as heart attacks. The treatment approach depends on the severity of the condition and includes lifestyle changes, medications, medical procedures, and surgical interventions.

Lifestyle Modifications

Healthy lifestyle changes are the first line of treatment and can help slow the progression of CAD, improve heart function, and reduce complications.

Heart-Healthy Diet

Focus on increasing intake of fruits, vegetables, whole grains, lean proteins, and healthy fats such as olive oil and nuts, while reducing intake of saturated fats, trans fats, processed foods, salt, and refined sugars. Heart-friendly foods include oats, salmon, walnuts, green leafy vegetables, and dark chocolate in moderation.

Regular Physical Activity

To improve cardiovascular health, aim for 150 minutes of moderate-intensity exercise per week, such as brisk walking or cycling. Also, engage in strength training twice a week and avoid prolonged sitting by incorporating movement throughout the day.

Smoking Cessation

Quitting smoking can lower the risk of heart attacks and improve blood flow. Consider using nicotine replacement therapy or counselling for support.

Stress Management

Engaging in activities such as meditation, yoga, deep breathing, and mindfulness can help reduce stress. Additionally, getting 7-9 hours of sleep each night can support heart health.

Weight Management

Maintaining a healthy BMI between 18.5 and 24.9 can lower the risk of coronary artery disease, and losing excess weight can reduce strain on the heart.

Alcohol Moderation

To stay healthy, women should limit alcohol to one drink per day and men to two drinks per day. Drinking too much alcohol can raise blood pressure and cholesterol levels.

Medications for Coronary Artery Disease

Once a patient develops coronary artery disease, a cardiologist usually uses a combination of different kinds of medications including:

Cholesterol-Lowering Drugs

• Statins (Atorvastatin, Rosuvastatin) – Reduce LDL (bad cholesterol) and slow plaque buildup.
• Ezetimibe – Lowers cholesterol absorption.
• PCSK9 Inhibitors – Used in high-risk patients for aggressive cholesterol reduction.

Blood Pressure Medications

• Beta-blockers (Metoprolol, Atenolol) – Reduce heart rate and blood pressure.
• ACE Inhibitors (Lisinopril, Enalapril) – Help relax blood vessels and lower blood pressure.
• Calcium Channel Blockers (Amlodipine, Diltiazem) – Improve blood flow and reduce chest pain.

Blood Thinners (Antiplatelet and Anticoagulants)

• Aspirin – Prevents blood clots and reduces heart attack risk.
• Clopidogrel, Ticagrelor, Prasugrel – Used for patients with stents or high clot risk.

Diabetes Medications

These medicines control blood sugar levels to prevent further artery damage.

Medical Procedures and Interventions

Stage 4 & 5 coronary artery disease usually requires medical interventions. The most commonly used interventions include:

Angioplasty and Stent Placement (Percutaneous Coronary Intervention – PCI)

A balloon is used to open narrow arteries, then a stent is placed to keep them open. This procedure helps restore blood flow and relieve chest pain (angina).

Coronary Artery Bypass Grafting (CABG or Heart Bypass Surgery)

In bypass surgery, a healthy blood vessel from another part of the body is used to redirect blood flow around blocked coronary arteries. This procedure is typically recommended for individuals with severe coronary artery disease or multiple blockages.

Enhanced External Counterpulsation (EECP)

A non-invasive therapy involving the inflation of cuffs around the legs to improve blood flow, this is primarily used for patients with persistent angina who are not suitable for surgery.

Cardiac Rehabilitation

This program focuses on improving heart function through supervised exercise, promoting better dietary habits through nutritional counselling, and providing emotional support and stress management techniques.

Experimental and Advanced Treatments

Research is currently being conducted on gene therapy and stem cell therapy for regenerating heart tissue. Additionally, robotic-assisted surgery is being used as a minimally invasive method for bypass surgery.

Sources:

• https://www.mayoclinic.org/diseases-conditions/coronary-artery-disease/diagnosis-treatment
• https://my.clevelandclinic.org/health/diseases/coronary-artery-disease
• https://www.ncbi.nlm.nih.gov/books/NBK564304/
• https://www.nhlbi.nih.gov/health/coronary-heart-disease
• https://www.healthline.com/health/coronary-artery-disease
• https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronary-artery-disease-prevention-treatment-and-research