Patient Education Material
Coronary Artery Disease (CAD)
The heart is a beating muscle that continually pumps blood to the rest of the body. The coronary arteries supply the heart itself with the necessary oxygen and nutrients it needs to function effectively. Over time, fatty deposits called plaque can build up inside the arteries, clogging the passages and reducing the flow of blood. If the coronary arteries develop plaque, blood flow to the heart can be compromised.
Eventually, blood flow to your heart muscle gets reduced, and because blood carries much needed oxygen, your heart muscle is not able to receive the amount of oxygen it needs. Reduced or cut off blood flow and oxygen supply to your heart muscle may lead to problem like.
Angina: Chest pain or discomfort that occurs when your heart does not get enough blood.
Myocardial Infarction (MI): MI happens when a blood clot at the site of narrowing in a coronary artery suddenly cuts off most or all the blood supply to the part of the heart muscle. Cells in the heart muscle begin to die if they do not receive enough oxygen rich blood. This can cause permanent damage to the heart muscle and may even result in death.
Over time if untreated, CAD can weaken the heart muscle and contribute to:
Heart failure: In heart failure, the heart can’t pump blood effectively to the rest of the body. Heart failure does not mean that the heart has stopped or is about to stop. Instead, it means that the heart is failing to pump enough blood the way that it should.
Arrhythmias: Arrhythmias are abnormalities in the normal beating (rhythm) of the heart. Some of them can be quite serious/ life threatening.
Symptoms of CAD
- The following are the symptoms a person with significant narrowing in coronary arteies may experience:
- A squeezing/ suffocating pain arising in the center of your chest and sometimes migrating to your arm, neck, back, throat, or jaw.
- Shortness of breath
- Loss of sensation/ abnormal sensation in your arms, shoulders, or wrists
How is CAD Diagnosed?
After taking your detailed medical history, your doctor will conduct a thorough physical check-up and may advise you the following tests.
ECG (Electrocardiogram): Your heart’s electrical activity (while you rest) will be recorded as a graph on an ECG sheet. It will record any abnormality of heart rhythm.
Echocardiography: It uses ultrasound waves to produce an image of your heart to see functioning of various chambers and valves of heart.
Exercise ECG/ Treadmill Test (TMT): During this test your ECG and BP are recorded while you walk on a treadmill. If abnormal, this test suggests reduction of blood supply to your heart when you exert yourself.
Exercise Thallium Test: An advanced test, which is similar to TMT, in which a radioactive substance is injected into your bloodstream at the peak of exertion. This enables your doctor to see the blood flow to various regions of your heart.
Coronary Angiography: During this test your doctor will inject a dye through a catheter into your coronary arteries (arteries supplying blood to heart muscles). He will then take serial X-ray images to see the blood flow through your coronary arteries. This test will enable your doctor to choose the right treatment for you, depending on the number and extent of blockages.
What is the treatment of CAD?
Depending on the severity of the blockages and your general health condition, there will broadly be four treatment options to choose from:
- Lifestyle changes.
- Percutaneous Coronary Interventions (angioplasty and stenting)
- Bypass Surgery
- Making lifestyle changes can help treat CAD. For some people, these changes may be the only treatment needed.
- Eat a healthy diet to prevent or reduce high blood pressure and high blood cholesterol and to maintain an appropriate weight.
- Quit smoking, if you are a smoker
- Exercise, as directed by your doctor
- Lose weight, if you are overweight or obese
- Reduce mental stress
Your doctor may prescribe one or a combination of medicines. Some medicines decrease the workload on the heart while others decrease the chances of having a heart attack.
Percutaneous Coronary Interventions / Angioplasty:
If lifestyle changes and medications do not change the status of your symptoms or your disease, you may have to resort to a percutaneous coronary intervention to restore the blood supply to your heart muscles.
Coronary artery bypass surgery will involve “bypassing” blood flow around one or more narrowed vessels of yours by using a vein or artery from another part of your body as a graft.
Percutaneous Coronary Intervention- Angioplasty
Percutaneous coronary intervention (PCI), commonly known as coronary angioplasty is a therapeutic procedure to treat the stenotic (narrowed) coronary arteries of the heart found in coronary heart disease. These stenotic segments are due to the build up of cholesterol-laden plaques that form due to atherosclerosis. PCI is usually performed by an interventional cardiologist.
Treatment with PCI for patients with stable coronary artery disease reduces chest pain, but does not reduce the risk of death, myocardial infarction, or other major cardiovascular events when added to optimal medical therapy.
Balloons are used in the majority of interventional procedures. These devices are inflated to compress the plaque against the artery wall, in a procedure called “balloon dilatation”, sometimes “PTCA” (percutaneous transluminal coronary angioplasty).
In almost all interventions today, a stent (a tiny metal structure which comes in a variety of sizes and designs) is also used, usually following or as part of a balloon angioplasty.
Even if the stent is utilized as the primary therapy, the process still involves a balloon, for the stent itself is mounted on an angioplasty balloon in order for it to be delivered to the diseased area and deployed. The balloon is inflated, and the stent along with it. When the balloon is deflated and withdrawn, the stent remains in place, serving as a permanent scaffolding for the newly widened artery. Within a few weeks, the natural lining of the artery, called the endothelium, grows over the metallic surface of the stent.
Drug Eluting Stents (DES)
A newer type of Stent, the Drug-Eluting Stent or DES, has recently become the overwhelming choice of cardiologists. Drug Eluting Stents are basically a bare metal stent that has been coated with a slow-to-moderate-release drug formulation, embedded in a polymer. It has been shown the medicine used prevents or at least reduces Restenosis, reclosure of the coronary artery, one of the biggest limitations of angioplasty and causes for repeat procedures.
When the stent is placed, the drug is released over time directly to the area most likely to reblock. Two types of drugs currently are being used: an immunosuppressive agent, Sirolimus, and a chemotherapeutic drug, Paclitaxel. Both have proven effective in clinical trials, bringing the Restenosis rate from the 25-30% range down to low single digits, However Sirolimus Eluting DES are more popular among doctors. If the very positive results from these devices prove to be durable over time, many have said that drug-eluting stents will revolutionize the treatment of coronary artery disease.