Coronary Artery Disease

Causes of CAD

The main cause of CAD is atherosclerosis, a gradual buildup of plaque in the coronary arteries. Plaque narrows and stiffens the arteries, reducing blood flow to the heart muscle, which can result in:

• Chest pain (angina)
• Shortness of breath
• Heart attack (myocardial infarction)

Risk factors for CAD include both modifiable and non-modifiable factors:

Modifiable Risk Factors:

• High cholesterol levels: Elevated levels of LDL (“bad” cholesterol) contribute to plaque formation.
• High blood pressure (hypertension): Increased pressure can damage the blood vessels and promote atherosclerosis.
• Smoking: Damages the walls of blood vessels and accelerates the formation of plaque.
• Diabetes: Poorly controlled blood sugar can lead to the buildup of fatty deposits in the arteries.
• Obesity: Being overweight, especially with abdominal fat, increases the risk for heart disease.
• Physical inactivity: Lack of exercise contributes to obesity, high blood pressure, and elevated cholesterol.
• Poor diet: Diets high in saturated fats, trans fats, and refined sugars contribute to plaque buildup.
• Excessive alcohol consumption: Heavy drinking can raise blood pressure and cholesterol levels.

Non-Modifiable Risk Factors:

• Age: The risk of CAD increases with age, particularly in men over 45 and women over 55.
• Gender: Men are at higher risk at an earlier age, but the risk for women increases and equals that of men after menopause.
• Family history: A family history of heart disease increases the risk, particularly if a first-degree relative developed heart disease before the age of 55 (men) or 65 (women).
• Genetics: Inherited factors may predispose individuals to high cholesterol, blood pressure, or other heart disease risk factors.

Symptoms of Coronary Artery Disease

Symptoms of CAD can vary, but the most common include:

• Angina (chest pain or discomfort): A sensation of pressure, tightness, or fullness in the chest. It may be triggered by physical exertion, stress, or eating.
• Shortness of breath: Caused by the heart’s inability to pump enough blood to meet the body’s needs.
• Fatigue: Feeling unusually tired or weak.
• Palpitations: Irregular heartbeats or the sensation of a pounding heart.
• Dizziness or lightheadedness: This may occur during exertion or with severe narrowing of the coronary arteries.

In some cases, CAD may not cause symptoms until a heart attack occurs, making it important to manage risk factors even in the absence of symptoms.

Types of CAD and Complications

1. Stable Angina: This type of chest pain occurs predictably with exertion or stress and is typically relieved by rest or medication. It indicates that there is a blockage or narrowing of the arteries but not an immediate danger.
2. Unstable Angina: A more dangerous form of chest pain that occurs unexpectedly, even at rest, and may last longer. It suggests that a heart attack could occur soon and requires immediate medical attention.
3. Heart Attack (Myocardial Infarction): A complete blockage of a coronary artery that cuts off blood flow to part of the heart muscle, leading to tissue damage or death. Symptoms include sudden chest pain, shortness of breath, nausea, lightheadedness, and sweating.
4. Heart Failure: CAD can weaken the heart muscle over time, leading to heart failure, where the heart cannot pump blood effectively.
5. Arrhythmias: The lack of adequate blood flow can cause irregular heartbeats, which can be life-threatening if not treated.

Diagnosis of CAD

Doctors use various tests to diagnose CAD:

• Electrocardiogram (ECG or EKG): Measures electrical activity of the heart and can identify signs of a heart attack or ischemia.
• Stress Test: Evaluates the heart’s response to physical exertion, which can reveal CAD-related changes in heart function.
• Echocardiogram: Uses sound waves to create images of the heart’s structure and function, helping detect problems with blood flow.
• Coronary Angiography: A specialized X-ray test where a contrast dye is injected into the coronary arteries to reveal blockages or narrowings.
• CT Angiography: A non-invasive imaging test that provides detailed pictures of the coronary arteries.
• Blood Tests: Measure cholesterol levels, triglycerides, and markers of inflammation (like C-reactive protein), which can indicate CAD risk.

Treatment Options for CAD

The treatment of CAD aims to reduce symptoms, prevent complications, and improve heart health. Treatment strategies generally include lifestyle changes, medications, and sometimes invasive procedures.

Lifestyle Modifications:

• Diet: A heart-healthy diet low in saturated fats, trans fats, and cholesterol. Foods like fruits, vegetables, whole grains, lean proteins, and healthy fats (such as those found in olive oil and fish) are recommended.
• Exercise: Regular physical activity can help improve cardiovascular fitness, lower cholesterol, and control blood pressure.
• Smoking cessation: Quitting smoking is one of the most important steps to reduce the risk of CAD and improve overall health.
• Weight management: Maintaining a healthy weight is important to prevent obesity-related risk factors such as high cholesterol and high blood pressure.

Medications:

• Statins: Reduce cholesterol levels and stabilize plaque in the arteries.
• Aspirin: Low-dose aspirin can reduce blood clotting, helping prevent heart attacks.
• Beta-blockers: Help lower heart rate and blood pressure, reducing the workload on the heart.
• ACE inhibitors: Lower blood pressure and protect the heart and kidneys.
• Calcium channel blockers: Relax blood vessels and reduce blood pressure.
• Nitrates: Help relieve chest pain (angina) by widening blood vessels.
• Diuretics: Reduce fluid retention and lower blood pressure.

Procedures:

• Angioplasty and Stent Placement: A catheter with a balloon is used to open narrowed arteries, and a stent may be inserted to keep the artery open.
• Coronary Artery Bypass Surgery (CABG): Surgery to bypass blocked or narrowed coronary arteries using healthy blood vessels from another part of the body (such as the leg or chest).
• Enhanced External Counterpulsation (EECP): A non-invasive procedure that uses cuffs on the legs to improve blood flow to the heart.

Prevention of CAD

Preventing or managing CAD involves addressing the modifiable risk factors:

• Controlling high blood pressure
• Managing diabetes and high cholesterol
• Eating a heart-healthy diet
• Exercising regularly
• Maintaining a healthy weight
• Avoiding smoking and excessive alcohol consumption