Coronary Artery Disease or CAD is a common heart disease involving a reduced supply of oxygen–rich blood to the heart muscles. This condition occurs due to the accumulation of plaque (waxy–like substance) in the larger coronary arteries of the heart. 

Types:

• Obstructive coronary artery disease – Gradual narrowing and blockage of the arteries supply oxygenated blood to the heart.
• Non – Obstructive coronary heart disease – Endothelial dysfunction or inappropriate vasoconstriction without narrowing of the arteries.
• Coronary Microvascular disease – Obstruction of blood flow occurs due to damage to the inner walls of the tiny coronary arteries.
• Spontaneous coronary artery dissection – Artery splits to form a false channel that reduces the blood supply to the heart.

Causes:

The common causes of CAD are:

• Accumulation of plaque in the coronary arteries resulting in over 50 % blockage of the heart.
• The buildup of small plaques in the tiny coronary artery blood vessels.
• Narrowing of the arteries due to damage to the wall lining.
• Injury to the artery walls due to chronic inflammation, high blood pressure, or diabetes.
• Normal ageing–related changes in the coronary blood vessels.

Risk factors:

• Age – Risk of developing CAD increases with age, significantly above 45 years of age.
• Gender – Women have a lower risk when compared to men before menopause but this increases in women above 55.
• Occupational factors – Sedentary work, working for more than 55 hours a week, and work involving exposure to toxins, radiation, and other hazards increase the risk.
• Environment – Air pollution increases the risk in older adults, women, and people with diabetes or obesity.
• Genetics – The likelihood of developing CAD is high if the male relative was diagnosed before age 55, or the female relative was diagnosed before age 65.
• Unhealthy lifestyle habits – Physical inactivity, lack of quality sleep, unhealthy eating habits, and stress are other risk factors.
• Smoking – Long – term smokers and exposure to secondhand smoke for extended periods elevate the chances of developing CAD.
• Other medical conditions – The presence of congenital coronary artery defects, chronic kidney disease, Crohn’s disease, and certain other diseases also raises the risk.
• Ethnicity – African Americans, Hispanics, and people of South Asian ancestry are at a higher risk.

Signs and symptoms:

• Chest pain or discomfort during physical activity
• Chest tightness, numbness, or heaviness
• Shortness of breath
• Extreme fatigue
• Indigestion
• Anxiety
• Sleep disturbances
• Neck pain

Complications:

CAD causes some severe complications if left untreated. This includes:

• Angina
• Heart attack
• Heart failure
• Cardiogenic shock
• Sudden cardiac arrest
• Arrhythmia

Diagnosis:

• The doctor assesses medical history – Diet, physical activity, and other risk factors for CAD.
• Diagnostic tests – Commonly performed tests are:
  • Blood tests – To check the levels of cholesterol, triglycerides, sugar, lipoproteins, or C – reactive proteins.
  • Coronary calcium scan – This is a cardiac CT scan used to measure the buildup of calcium in the walls of the coronary arteries.
  • Cardiac MRI – To detect tissue damage or obstruction to blood flow in the heart.
  • Cardiac PET scanning – It is a nuclear heart scan used to diagnose coronary microvascular disease.
  • Coronary angiography – Helps to visualize the insides of the coronary arteries.
  • Coronary computed tomographic angiography – Non – invasive coronary angiography.
  • Exercise ECG – Stress test – To assess the working of the heart while walking on a treadmill.
  • Electrocardiogram (ECG) – Electrical activity, rate, and regularity of the heartbeat.
  • Echocardiography (stress echocardiography) – Ultrasound is used to visualize the heart.

Treatment:

Lowering the risk for heart attack and preventing the aggravation of CAD are the main goals of treatment. Depending on the health status and goals, CAD is treated as follows:

• Surgery – Damage to the arteries can be repaired by:
  • Coronary angioplasty
  • Atherectomy
  • Coronary artery bypass surgery
• Minimally invasive procedures – Hybrid coronary revascularization is done if the patient has several blockages. This involves stenting some blockages and bypassing some, depending on the medical needs of the patient.
• Medications – Drugs that are frequently used for the treatment and management of CAD are:
  • Statins – Atorvastatin, lovastatin, etc. These lower cholesterol levels and reduce the risk of CAD.
  • Calcium channel blockers – Amlodipine, bepridil, etc. These increase the blood supply to the heart and reduce cardiac workload.
  • Beta-blockers – Bisoprolol, metoprolol, etc. lower blood pressure, cardiac workload, and prevent angina.
  • Antiplatelet drugs – Aspirin, ticlopidine, etc. are used to prevent ischemic events in CAD.
  • Vasodilators – Nitroglycerin is used to widen coronary arteries and increase blood flow to the heart.

Prevention:

• Living with CAD –
  • the patient must perform routine medical checkups.
  • Do not skip any dose of the prescribed medication.
  • Quit smoking.
  • Consuming low sodium and a low-fat diet.
  • Increasing physical activity.
  • Maintaining a healthy weight and stress.
  • Cardiac rehabilitation is advised post-surgery. 
• Preventing CAD –
  • Decreasing obesity and cholesterol levels.
  • Treating high blood pressure.
  • Stopping smoking.
  • Increasing the levels of physical activity.
  • Decreasing psychosocial stress.
  • Avoiding consumption of trans fat and weight control.

When to see a doctor?

Prolonged or severe chest pain not relieved by nitroglycerin, or shortness of breath, or upper body discomfort along with lightheadedness are some of the alarming signs of CAD. When any of these are experienced by the patient, it is advisable to consult with a cardiologist immediately. The average cost of angioplasty with stenting ranges from Rs. 4 to 6 lakhs.

References:

• CDC website
• References