Coronary Artery Disease
Structural Features of the Heart and the Coronary Arteries
The central organ of the entire cardiovascular system is the heart. It is a muscular organ, located on the left of the chest’s center and is approximately your fist’s size. It is a pumping organ which supplies oxygenated blood throughout the body, which is required by the cells of body for survival.
There are 4 chambers in the heart, with the left half and right half separated by a thick, muscular layer known as a septum. Two chambers are located on either side of the septum. The upper chambers are referred as atria while the lower chambers are called ventricles. The left atrium receives oxygen-rich blood from the lungs, which then reaches the left ventricle and is then supplied to the entire body. The right atrium gets deoxygenated blood from the entire body, which passes to the right ventricle and is pumped from there to the lungs. There are four valves located in your heart which prevent the blood from flowing in the wrong direction during the blood’s passage from one chamber to the other. The mitral valve and the tricuspid valve control the flow of blood from the atria to the ventricles while the aortic valve and the pulmonary valve regulates blood flow as it leaves the ventricles.
Arteries are the blood vessels carrying oxygen-rich blood from the heart to the body. The largest artery is the aorta which gets divided into smaller arteries, some of which are meant for supplying oxygen-rich blood to the heart itself. These arteries dedicated to supply of oxygenated blood to heart muscles are referred as “coronary arteries”.
Introduction to Heart Disease
You may have heart of heart diseases before or heard of the common symptoms associated to heart disease (like chest pain, fainting, breathlessness, pain in the arm etc). Some of these can be fatal, leading to permanent disability and even death. Heart diseases may be broadly of two types, in general. One set are diseases relating to the internal structures of the heart, such as the septum or the valves. The other set relate to the coronary arteries that supply the heart muscles with blood. This latter group is generally called Coronary Artery Disease (CAD) or Cardiovascular Disease (CVD). Globally, CAD is currently a major cause of death or disability. The cause of CAD is blood vessels narrowing due to a blockage developing in it over time.Coronary Artery Disease or CAD, is caused by atherosclerosis.
Atherosclerosis: With age, the inner cellular layer of the coronary arteries may suffer damage. Once the inner layer (known as the intima) suffers some damage, there is a possibility of the accumulation of cellular material, cholesterol, calcium and fibrous tissues at the site, causing a thickening and hardening of the artery wall. This is atherosclerosis, and leads to blockages that constitute CAD.
CAD can lead to multiple symptoms, ranging from breathlessness, fatigue, angina to heart attack, which can of course be fatal if not attended to immediately.
Diagnosis of Coronary Artery Disease
There are a number of diagnostic procedures to detect the presence or extent of atherosclerosis plaques in case of a patient with suspected CAD. These tests include:
- An electrocardiogram (ECG), which measures the heart’s electrical activity and monitors the heart rhythm.
- Treadmill test (TMT)/ Stress Test
- In a stress test, the patient needs to run or walk on a treadmill and during this activity, the patient’s ECG is monitored. This test detects whether the heart is getting enough oxygen during activity or stress. If a patient is not able to run or walk due to disability, the test may be performed by administering a medicine which creates a stress like situation, causing the heart to beat faster.
- The test uses sound waves to create an image of the heart as it beats.
- Radiological tests such as SPECT, PET, CT angiography, etc.
- Angiogram: A tiny tube or catheter is inserted into an artery in the abdomen or wrist and guided to the heart. A contrast dye is then injected into this catheter, so that the arteries can be seen in an X-ray. The image obtained will confirm whether there is a plaque blocking or restricting the blood flow.
Treatment of Coronary Artery Disease
Changes in lifestyle
- Quit smoking or tobacco consumption in any form
- Include plenty of fruits, green vegetables and food rich in fibers in your diet. Avoid junk food rich in fats, sugar or salt – as per guidance of the doctor.
- Engage in daily physical activity as agreed with the doctor. Simple walking for 30 minutes every day also goes a long way in prevention or management of CAD.
- Maintain a healthy body weight.
- If you carry any risk factors for getting a CAD, your doctor might prescribe certain medications to keep them in check and avoid a fatal event such as heart attack.
- These medications may include statins to lower your cholesterol levels, anti-hypertensives to control your blood pressure, blood thinners like aspirin to prevent clotting of blood and medicines for blood sugar control, in case you suffer from diabetes.
- If at all you suffer from angina (chest pain) due to CAD, you might be recommended medicines like nitrates to relieve your pain.
- Each of the above medicines must be taken strictly as prescribed by the doctor.
Coronary Artery Disease – Interventional Procedures
- If a patient’s condition of CAD worsens or if they get a heart attack, they may require a intervention as an emergency procedure to save his/her life and to prevent future events. Patients can undergo:
- Angioplasty and Stent Implantation: In this procedure, a small tube (catheter) with a balloon at its tip, is inserted in the blocked blood vessel and the block is cleared by rapid inflation-deflation of the balloon, restoring the blood flow. In most of such patients, a mesh-like structure called stent is placed inside the artery to keep it open.
- Coronary Artery Bypass Grafting or Bypass Surgery: a portion of an alternate blood vessel is removed and then it is attached to the blocked blood vessel bypassing the clot portion. It leads to re-routing of the normal blood flow where the blood was not reaching due to the clogged artery.
How Coronary Stents Work
Coronary stents are small, metallic wire mesh tubes (stent) or temporary plastic jackets (scaffold) that help in open a clogged artery and restore adequate blood flow to the heart.
During the stent implantation procedure, cardiologist will place the stent or scaffold over a thin, long tube with a balloon tip called a catheter and insert it into an artery in your groin or arm. Once the stent reaches the clogged artery, your doctor will inflate the balloon to expand the stent or scaffold. When the stent or scaffold reaches the desired location to widen the clogged artery, your doctor will deflate and remove the balloon.
The stent will stay in place permanently or scaffold will elute once stabilizing the coronary vessel, and decrease its chance of narrowing again. Over time, the inside lining of the artery (the endothelium) will grow over the surface of the stent or scaffold, making it a normally functioning artery.
Meril cardiovascular provides innovations for the treatment of coronary artery disease. Meril Cardiovascular's coronary stents work to open clogged coronary arteries and help treat coronary artery disease (CAD).
Types of Coronary artery Stents
- Bare-metal stents
Bare-metal stent is a stent without a coating polymer. It is a mesh-like tube of thin wire. This type of stent may be used in patients who are allergic to either the polymer or drugs used in drug-eluting stents.
- Drug-eluting stents
Drug-eluting Stents (DES) are coated with a polymer that gradually releases a drug over the time. This helps the artery to remain open, ensuring good blood flow and reduces the chances of the artery re-narrowing or restenosis. There are two types of drug-eluting stents:
- i) Permanent Polymer Drug-Eluting Stent: In this type of stent, the polymer stays on the stent permanently, even after all the drug has been released.
- ii) Bioabsorbable Polymer Drug-Eluting Stent: In this type of stent, the polymer degrades shortly with release of drug. This help better healing by eliminating long-term polymer exposure.
- Bioresorbable scaffold system: The bioresorbable scaffold system (BRS) is a drug eluting system/device on a dissolvable type of scaffold platform which can be absorbed by the body over time. BRS is coated with a drug released from a polymer that disappears over time to reduce the chances of the artery re-narrowing (restenosis). The scaffold itself is absorbed overtime.
After treatment, you may be asked to stay in hospital for maximum of 3 to 5 days depending upon speed of recovery. You can find some general recovery tips for recovering from a stent procedure below. It is essential to consult your doctor and follow post-operative instructions.
Activities and Exercise
After your procedure, you can return to normal activities gradually. Your doctor can provide advice on simple lifestyle changes that can help improve heart health.
After a stent procedure, medications to thin your blood and prevent blood clot are likely to be recommended. These medicines help prevent blood clots from forming in the stent. You should not stop taking these medications unless you are asked to stop by the doctor who implanted your stent. If you stop taking these medications before being instructed to do so by your cardiologist, the chances of blood clot formation on the stent, subsequent heart attack, a stroke or other serious problems are increased.
Regular Follow-Up Visits
It is important to keep your follow-up appointments after post-procedure, even if you’re feeling well. The first visit is usually two to four weeks after your stent is implanted, with follow-up appointments every six months for the first year. During these visits, your doctor will monitor your progress, evaluate your medications, check the status of your coronary artery disease and determine how the stent is working for you.
Stent Implant Card
Carry your Stent Implant Card at all times. If you receive dental or medical care or report to an emergency room/center, show your Stent Implant Card.
When to Call Your Doctor
Your doctor will provide specific schedule for when you should contact them. But if you have any of these following symptoms call your doctor immediately:
- Chest pain (angina) or more severe or frequent chest discomfort, especially in the first month after your procedure, as these symptoms may indicate a re-narrowing of your coronary arteries
- Shortness of breath
- Sudden weakness or paralysis of the face, arm or leg
- Pain, bleeding or infection at the entry site in your arm or leg
- Any other unexplained symptoms
It is often advised to avoid vigorous exercise and heavy lifting for a short time after a stent procedure
Living with a Coronary Stent
Coronary stent will help restore adequate blood flow to your heart so you can enjoy a healthier, more active life. Learn about precautions you may need to take living with an implanted device and find out how to help prevent the progression of coronary artery disease (CAD).
For the healthy life style, at least 2.5 hours of physical activities per week of moderate intensity such as fast walking are recommended.
Healthy Diet Plan
- Eat a variety of nutrient rich foods including vegetables, fruits, whole grain high-fibre foods and fish.
- Quit smoking, alcohol drinking and avoid use of tobacco product.
- Limit saturated fat, trans-fat and cholesterol. Choose lean meats and poultry without skin and prepare them without added saturated and trans-fat. Switch over to low-fat (1%) and low fat dairy products.