Coronary Artery Angioplasty

Coronary angioplasty restores blood flow through a narrowed or blocked artery in the heart. A catheter containing a balloon is passed through a blood vessel to the site of the blockage. At the blockage, the balloon is inflated and the plaque is compressed against the side of the blood vessel. This widens the inside of the blood vessel and restores blood flow to the heart. The balloon is then deflated and removed. Source: NHLBI.

Coronary artery angioplasty, often called simply angioplasty, is a medical procedure in which a balloon is used to open a blockage in a coronary (heart) artery that has been narrowed by atherosclerosis. The goal of this procedure is to restore or improve the blood flow to the heart.

Angioplasty is less invasive than surgery. General anesthesia is not needed. Patients are given medicines to relax, but they are awake during the procedure. Angioplasty is performed by a cardiologist in a special part of the hospital called the cardiac catheterization laboratory. The "cath lab" has special video screens and x-ray machines. The doctor uses this equipment to see enlarged pictures of the blockage.

Other Names

• Angioplasty
• Balloon angioplasty
• Coronary angioplasty
• Percutaneous coronary intervention (PCI)
• Percutaneous intervention
• Percutaneous transluminal angioplasty
• Percutaneous transluminal coronary angioplasty (PTCA)

Why Angioplasty Is Done

Atherosclerosis (when a material called plaque builds up on the inner walls of the arteries) can happen in any artery, including the coronary arteries, which carry oxygen-rich blood to the heart. When atherosclerosis affects the coronary arteries, the condition is called coronary artery disease (CAD).

Angioplasty is used to restore blood flow when the arteries have become narrowed or blocked due to atherosclerosis. Angioplasty improves symptoms of CAD, such as angina (a type of chest pain) and shortness of breath. It reduces the damage to the heart muscle caused by a heart attack. A heart attack occurs when blood flow through a coronary artery is completely blocked. Sometimes the accumulation of plaque causes the blood vessel to burst and a blood clot to form on the vessel surface. This clot can grow to block the vessel and, in an emergency procedure, a coronary angioplasty is used to restore blood flow. Angioplasty can prevent premature death due to CAD.

Preparation

Before the procedure, an intravenous (IV) line is placed in the arm to provide fluids and medications. The medicines induce relaxation and prevent blood clots from forming. Electrodes are placed on the chest and limbs to monitor heartbeat.

The groin or arm where the blood vessel will be accessed is sterilized and the skin is numbed with an anesthetic. Sometimes it is shaved. The patient is draped with sterile paper or cloth.

How Angioplasty is Done

The procedure is typically performed in the following steps:

• A small cut is made in the arm or groin that has been numbed. A tube called a sheath is placed into a blood vessel through this cut. The doctor threads a thin guide wire through the artery toward the blockage.

• The doctor passes a long, thin, flexible tube (the catheter) through the sheath, over the guide wire, and up to the heart. The catheter is moved to the blockage, and the guide wire is removed.

• A small amount of dye may be injected through the catheter into the bloodstream to take an angiogram.

• The narrowing or blockage in the coronary arteries is mapped out with an angiogram. An angiogram is an x-ray picture of the arteries in real time. During an angiogram, a small amount of dye is injected through the catheter and a live x-ray picture is taken. This picture shows the location and number of blockages. Angioplasty is often performed immediately following the angiography.

• The doctor slides a small, deflated balloon contained in a tube through the catheter to the site of the blockage. When the tube reaches the blockage, the balloon is inflated and presses the plaque against the vessel wall. The widened vessel restores blood flow to the heart.

• The balloon is deflated. Sometimes the balloon is inflated and deflated more than once to widen the artery. Afterward, the balloon, tube, and catheter are removed.

• The hole in the artery is either sealed with a special device or by applying pressure.

During angioplasty, antiplatelet (blood thinning) medicines are given through the IV to prevent formation of blood clots. The prevention of clotting reduces the risk of a heart attack. This treatment begins before the procedure and continues for 12 to 24 hours afterward.

Placement of a stent in a coronary artery with plaque buildup. Figure A shows the deflated balloon catheter and closed stent inserted into the narrowed coronary artery. The inset image on figure A shows a cross-section of the artery with the inserted balloon catheter and closed stent. In figure B, the balloon is inflated, expanding the stent and compressing the plaque to restore the size of the artery. Figure C shows the stent-widened artery. The inset image on figure C shows a cross-section of the compressed plaque and stent-widened artery. Source: NHLBI

Stent placement

A small mesh tube called a stent is usually placed in the newly widened part of the artery. The stent holds the artery open. Stents are made of metal mesh and look like small springs. To place a stent, the doctor threads another catheter to the blockage site. This catheter has an unexpanded stent wrapped around the balloon. The doctor then inflates the balloon, which causes the stent to expand against the wall of the artery. The balloon is then deflated and pulled out of the artery with the tube. The stent stays in its position and permanently expands the vessel.

Some stents, called drug-eluting stents, are coated with medicines that are slowly and continuously released into the artery. These medicines help prevent the artery from becoming blocked again from scar tissue that grows around the stent, a process called restenosis. Medications that help prevent restenosis include paclitaxel, sirolimus, and tacrolimus.

See the below video to see how it's done.

Benefits

Angioplasty is one of several treatment options for patients with CAD. Other options include optimal medical therapy, which consists of medications and changes in lifestyle, and coronary artery bypass grafting, or CABG.

Compared to optimal medical therapy

It isn't clear that angioplasty is any better than optimal medical therapy in people with stable, long-term CAD.^[1] In other words, lifestyle interventions like quitting smoking, combined with taking the right medications, may be just as beneficial as angioplasty for many people with CAD. However, during a heart attack, angioplasty is far better than medical therapy alone (except for clot-busting medications; see below).

Compared to CABG

Coronary angioplasty has several advantages over CABG:

• Fewer risks
• Does not require a large cut
• Use of relatively low-risk medications such as light sedatives and local anesthetics (numbing medicines). Unlike CABG, patients do not need to be put to sleep.
• Has a shorter recovery time.

However, CABG is a better choice for patients who have atherosclerosis in more than one coronary artery.^[2]

Compared to clot-busting medications during heart attack

Compared to clot-busting medications, angioplasty has some advantages. For example, in people who are at high risk of serious bleeding—especially in the brain—angioplasty is safer. However, angioplasty can sometimes take too long, and during a heart attack, time is of the essence. In many cases it is faster to give the clot-busting medications. These medications are used routinely as a first treatment for heart attack in Canada and Great Britain.

Risks

Although angioplasty is normally safe, there are some risks. These include:

• Bleeding from the blood vessel where the catheter was placed
• Damage to blood vessels from the catheter
• An allergic reaction to the dye given during the angioplasty
• An arrhythmia (irregular heartbeat)
• The need for emergency CABG during the procedure (less than 1% of people in recent years^[3]). This may occur when an artery closes down, instead of opening up, or ruptures.
• Damage to the kidneys caused by the dye
• Heart attack
• Stroke (less than 1% of people^[4])

Death due to complications is very rare. According to the National Heart, Lung, and Blood Institute, less than 2% of people die during angioplasty.

Sometimes chest pain can occur during angioplasty because the balloon briefly blocks off the blood supply to the heart.

The risk of complications is higher in some patients:

• Those 75 years or older
• Those with kidney disease or diabetes
• Women
• Those with poor pumping function in their hearts
• Those with extensive heart disease and blockages

Restenosis

Over time, the artery may become narrow or blocked again. This often occurs within six months of the procedure. This is called restenosis.

Restenosis of a stent-widened coronary artery. The coronary artery is located on the surface of the heart. In figure A, the expanded stent compresses plaque, allowing normal blood flow. The inset image on figure A shows a cross-section of the compressed plaque and stent-widened artery. In figure B, the plaque grows (over time) through and around the stent, causing a partial blockage and abnormal blood flow. The inset image on figure B shows a cross-section of the growth of the plaque around the stent.

When a stent is not used, 4 out of 10 people have restenosis. When a stent is used, but not coated with medicine, 2 out of 10 people have restenosis.

The growth of scar tissue in and around the stent also can cause restenosis. Medicine-coated stents, also called drug-eluting stents (DES), reduce the growth of scar tissue around the stent and lower the chance of restenosis. When DES are used, the chance of restenosis is lowered even more, to around 1 in 10 people.

Other treatments, such as radiation, can help prevent tissue growth within a stent.^[5] For this procedure, the doctor puts a wire through a catheter where the stent is placed. The wire releases radiation to stop any tissue growth that may block the artery. This technique is called brachytherapy.

Blood clots

Recent studies suggest that the risk of blood clots is higher with drug-eluting stents (DES) compared to bare metal stents (not coated with medication). The Food and Drug Administration (FDA) reports that DES usually do not cause complications due to blood clots when used as recommended.

When DES are used in people with advanced CAD, there is a higher risk of blood clots, heart attack, and death. The FDA is working with researchers to study DES, including their use in people with advanced CAD.

People with DES usually take anti-clotting drugs, such as clopidogrel and aspirin, for months to years to lower the risk of blood clots.

Recovery

During recovery, patients are reviewed for bleeding or heart complications. Most patients can leave the hospital shortly after the procedure. Most often, patients are discharged within two days. After discharge, many patients return to work a week later.

Lifestyle changes

Although angioplasty can reduce the symptoms of (CAD), it is not a cure, and it does not modify the risk factors that necessitated the procedure. Making healthy lifestyle changes can help treat CAD and maintain the good results from angioplasty. Commonly recommended lifestyle changes include the following:

• A healthy diet to prevent or reduce high blood pressure and high blood cholesterol and to maintain a healthy weight.
• Quitting smoking.
• Being physically active.
• Losing weight in patients who are overweight or obese.
• Reducing stress.
• Taking medicine to treat high blood pressure or high blood cholesterol.

Cardiac rehabilitation

Cardiac rehabilitation is often recommended to help patients with heart disease recover faster and return to work or daily activities. Cardiac rehab includes supervised physical activity, education on healthy living, and counseling to cut down on stress and help patients to return to an active life.

Statistics

Angioplasty is performed on more than 1 million people a year in the United States.

Alternatives

The first approach to prevention and treatment of CAD is lifestyle changes and medications. Lifestyle changes are modifications to daily living. Examples include a healthy diet, smoking cessation, and physical activity. When lifestyle and medication are insufficient, interventions that restore blood flow (revascularization) are considered. These interventions include angioplasty and CABG.

Other procedures

The choice of intervention is based on several factors. These factors include the severity of the arterial blockages, the number of blood vessels involved, the location of CAD, and the presence of other diseases. Angioplasty is often used with less severe narrowing or blockage in the coronary arteries, when two or less of the three main arteries supplying the heart are involved, and when the blockage can be reached during the procedure.

Coronary artery bypass grafting

Coronary artery bypass grafting (CABG) is often performed in patients who have severe heart disease, multiple blocked arteries, or have diabetes or heart failure. CABG can be used in left coronary artery disease, where blockage cannot be relieved with balloon angioplasty.

The risk of artery re-narrowing is lower following CABG. The chance of this happening is lower when cardiac stents are used, especially medicine-coated stents. However, these stents are not without risk. In some cases, blood clots can form in the medicine-coated stents and cause a heart attack.

Atherectomy

In some cases, plaque is removed during angioplasty. In a procedure called atherectomy, a catheter with a rotating shaver on its tip is inserted into the artery to cut away plaque. Lasers also are used to dissolve or break up the plaque. These procedures are now rarely done because balloon angioplasty gives better results for most patients.

Clinical Trials

For a list of clinical trials on coronary angioplasty, visit here.

Controversy

A 2007 British study found that angioplasty, in the socialized-medicine setting of the British National Health Service, may not be cost-effective when compared to CABG or therapy with medicines and lifestyle changes.^[6] But a study in the American Veterans' Affairs system found that, at least in patients for whom medicines and lifestyle changes hadn't helped, angioplasty was more cost-effective than CABG.^[7]

A Canadian editorial has criticized the popularity of this treatment, arguing that its very widespread use is having unintended consequences and that it should be used more selectively.^[8]

There is some debate over whether it is worthwhile to routinely stent everyone who undergoes angioplasty.^[9][10]

References

1. ↑ Boden WE, O'Rourke RA, Teo KK et al; COURAGE Trial Research Group. Optimal medical therapy with or without PCI for stable coronary disease. N Engl J Med. 2007 Apr 12;356(15):1503-16. Epub 2007 Mar 26. Abstract | Full Text
2. ↑ Hannan EL, Racz MJ, Walford G et al. Long-term outcomes of coronary-artery bypass grafting versus stent implantation. N Engl J Med. 2005 May 26;352(21):2174-83. Abstract | Full Text
3. ↑ Seshadri N, Whitlow PL, Acharya N, Houghtaling P, Blackstone EH, Ellis SG. Emergency coronary artery bypass surgery in the contemporary percutaneous coronary intervention era. Circulation. 2002 Oct 29;106(18):2346-50. Abstract | Full Text
4. ↑ Kawamura A, Lombardi DA, Tilem ME, Gossman DE, Piemonte TC, Nesto RW. Stroke complicating percutaneous coronary intervention in patients with acute myocardial infarction. Circ J. 2007 Sep;71(9):1370-5. Abstract | Full Text
5. ↑ Popma JJ, Suntharalingam M, Lansky AJ et al; Stents And Radiation Therapy (START) Investigators. Randomized trial of 90Sr/90Y beta-radiation versus placebo control for treatment of in-stent restenosis. Circulation. 2002 Aug 27;106(9):1090-6. Abstract | Full Text
6. ↑ Griffin SC, Barber JA, Manca A et al. Cost effectiveness of clinically appropriate decisions on alternative treatments for angina pectoris: prospective observational study. BMJ. 2007 Mar 24;334(7594):624. Epub 2007 Mar 5. Abstract | Full Text
7. ↑ Stroupe KT, Morrison DA, Hlatky MA et al; Investigators of Veterans Affairs Cooperative Studies Program #385 (AWESOME: Angina With Extremely Serious Operative Mortality Evaluation). Cost-effectiveness of coronary artery bypass grafts versus percutaneous coronary intervention for revascularization of high-risk patients. Circulation. 2006 Sep 19;114(12):1251-7. Epub 2006 Sep 11. Abstract | Full Text
8. ↑ Bogaty P, Brophy JM. Acute ischemic heart disease and interventional cardiology: a time for pause. BMC Med. 2006 Oct 11;4:25. Abstract | Full Text
9. ↑ King SB 3rd. Why have stents replaced balloons? Underwhelming evidence. Ann Intern Med. 2003 May 20;138(10):842-3. Abstract | Full Text
10. ↑ Brophy JM, Belisle P, Joseph L. Evidence for use of coronary stents. A hierarchical bayesian meta-analysis. Ann Intern Med. 2003 May 20;138(10):777-86. Abstract | Full Text | Patient Summary

External Links

• MedlinePlus–Patient Education Institute:Coronary Angiogram and Angioplasty: Interactive Tutorial