Balloon angioplasty is one of three standard treatments for coronary artery disease (CAD) – a disease in which the blood flow to the heart is restricted due to hardened arteries (atherosclerosis) that are clogged with plaque deposits. The other standard treatments for CAD are medication and bypass surgery.

The goal of balloon angioplasty is to push the fatty plaque back against the artery wall to make more room for blood to flow through the artery. This improved blood flow results in the improvement of cardiac symptoms and function. Balloon angioplasty may also be used as treatment for a heart attack in some emergency facilities.

Balloon angioplasty is a catheter-based procedure. It begins with the physician using a local anesthetic to numb a specific area of the patient’s body – usually the upper thigh or groin area where the femoral artery is located. The physician then inserts a long, thin tube with a deflated balloon at the tip (balloon-tipped catheter) into the artery and guides it to the heart. When the balloon-tipped catheter is at the site of the blockage, the balloon is rapidly inflated, pushing the plaque in the artery back against the wall of the artery. The balloon-tipped catheter is then removed. In most cases, a stent (wire mesh tube) will then be permanently implanted to hold the artery open. The patient is then given time to recover. Most patients are free to go home after about 24 hours.

Balloon angioplasty, also known as percutaneous transluminal coronary angioplasty (PTCA), is a widely used catheter-based technique for opening blocked arteries and treating coronary artery disease. The first balloon angioplasty was performed in 1977 by the Swiss physician Andreas Gruentzig. About 664,000 PTCA procedures were performed in the United States in 2004 (the last year for which figures are available), according to the American Heart Association.

Balloon angioplasty opens arteries that have been narrowed due to plaque buildup (atherosclerosis) along the artery walls. To restore normal blood flow, a balloon-tipped catheter is guided into one of the clogged arteries, and the balloon is rapidly inflated. This action helps blood flow more freely through the vessel in one or more of the following ways:

• Pushes the plaque back against the artery wall.
• Creates small cracks or fissures called plaque fractures within the brittle, fatty deposit.
• Stretches the artery.

A successful intervention will result in a wider artery with an improved blood flow. It will not result in a completely “clean” artery, but the plaque will be pushed aside or cracked in such a way that blood can pass through the vessel more freely. This often helps reduce chest pain (angina) associated with coronary artery disease.

In most angioplasty procedures, a stent is placed in the blocked artery. A stent is a small metal mesh tube that is implanted in the arteries to help keep the blood vessel open. Stents may be coated with drugs that help keep the artery open. Advances in stent technology have greatly increased the success rate of balloon angioplasty, making it a more attractive option for many patients. Other procedures may include atherectomy (excision of plaque material).

Balloon angioplasty may also be used as a treatment for a heart attack in some hospitals and emergency care facilities. The American College of Cardiology and the American Heart Association guidelines maintain that angioplasty and clot-buster medications are equally effective in certain settings. The guidelines note that angioplasty is the treatment of choice only when patients are treated within two to six hours of the onset of their symptoms in facilities where surgical backup is available.

Compared to surgical interventions (e.g., bypass surgery), balloon angioplasty is a relatively low-risk and low-cost procedure. Studies have shown that patients who undergo balloon angioplasty recover much more quickly than patients who undergo bypass surgery. In most cases, a patient may return to normal activities within a few days of angioplasty, whereas full recovery from surgery often takes months.

Because bypass surgery and angioplasty treat the same condition (e.g., coronary artery disease), there is always the question of which patients are suitable for which procedure. In general, many cardiologists will recommend balloon angioplasty with stenting in most patients in whom it is possible before referring the patient for open-heart surgery.

A form of balloon angioplasty called peripheral percutaneous transluminal angioplasty may be used to treat clogged arteries in areas of the body other than the heart. These areas include the following vessels:

• Cerebral (brain)
• Carotid (neck)
• Renal (kidney)
• Visceral (abdominal)
• Iliac (hip)
• Femoropopliteal (thigh)
• Infrapopliteal (knee)

Balloon angioplasty is a relatively quick procedure, taking only one to two hours in a cardiac catheterization laboratory. An overnight hospital stay is often required. The patient may be discharged that evening or the following morning.

The day of the procedure, patients should discuss their medical history with their physician, and inform him or her of any medications currently being taken. Certain medications (e.g., anticoagulants, antiplatelets) may need to be stopped or reduced. Patients with diabetes should consult their physician about food and insulin intake, because patients are usually asked to stop eating or drinking after midnight before the procedure.

A number of tests may be performed before a patient undergoes balloon angioplasty, including blood tests, an electrocardiogram (EKG) and a chest x-ray. These routine tests are usually performed on the day before the procedure.

On the day of the procedure, the patient is taken to a cool and sterile catheterization laboratory that may resemble an operating room with abundant monitoring devices, video display equipment and x-ray cameras. A nurse or physician will explain what is going to happen, and the patient is encouraged to ask questions.

After the patient is made comfortable, the physician inserts an intravenous (I.V.) line into the patient’s arm. The I.V. allows the physician to administer a calming medication (sedative) and other necessary medications during the procedure. Small devices will be taped to the patient’s body, which allow the physician to monitor heart rate and blood pressure.

The physician then selects the artery that will be used to deliver the balloon-tipped catheter to the clogged artery. Typically the femoral artery (in the groin or upper thigh) is chosen. However, studies have found that it is also safe and feasible to use the radial artery (in the lower arm near the wrist). Other arteries in the arm, including the ulnar (in the lower arm) and the brachial (in the upper arm) are used in some cases. Whichever area is chosen is cleaned, shaved and numbed with a local anesthetic. The catheter is then passed into the artery and up into the heart using a video monitor to guide the process. There may be some minor discomfort during this process.

When the catheter is in place, an x-ray of the coronary arteries (coronary angiogram) is taken to measure the narrowing of the arteries. This special x-ray helps the physician visualize and evaluate the extent and severity of the arterial narrowing. Once the physician has located the blockage, a guide wire is advanced to the location of the blocked artery, and a second, smaller balloon-tipped catheter is passed over the guide wire. When the balloon catheter reaches the target area, the balloon is inflated for a period of several seconds to several minutes. After deflation of the balloon, the same area may be treated with one or more other additional inflations.

To perform this procedure, the physician will choose to use either a compliant or a noncompliant balloon, depending on the type of the blockage. Balloon compliance describes the degree to which the balloon will inflate as pressure inside the balloon increases. Most balloons used in balloon angioplasty have some level of compliance. The cardiologist will match the balloon to the situation. For example, a cardiologist might use a 3-millimeter noncompliant balloon to treat a blockage in a 3-millimeter artery because he or she would not want the balloon to continue expanding to 4 millimeters in a 3-millimeter artery.

In most cases, a stent is implanted following the angioplasty. A stent is a small wire-mesh tube delivered to the artery by a catheter. Just as scaffolding supports a weak building, stents support the damaged artery walls and hold the crushed plaque in place, greatly reducing the chance that the vessel will close again (restenosis) following the angioplasty.

Stents are typically inserted on a balloon-tipped catheter. The balloon is expanded, deflated and removed, leaving the stent behind to reinforce the wall of the artery. Drug-coated (also called drug-eluting) stents were approved for clinical use by the U.S. Food and Drug Administration (FDA) in 2003. These stents have been shown to significantly decrease the chance of restenosis. However, both traditional and drug-eluting stents may cause the formation of blood clots. Research continues into medications and other substances (e.g., antibodies) that can be used with stents.

After the procedure is completed, the patient will be moved to a cardiac recovery room. He or she may feel groggy from the sedative. The catheter insertion site may be bruised and sore.

If the groin area was used as the point of catheter insertion, the patient will be instructed to lie in bed with legs out straight. The physician may choose to use one of two techniques for removing the sheath that was placed at the initiation of the procedure. The traditional technique is to wait until the effects of the anticoagulant have passed (four to six hours) and then to apply pressure while removing the sheath from the femoral artery. A newer technique allows the sheath to be removed immediately after the procedure through the use of hemostatic devices that seal or stitch the femoral artery.

If the wrist or arm was used as the point of catheter insertion, then the patient does not need to stay in bed. Throughout the post-procedure monitoring, the point of catheter entrance will be checked for bleeding, swelling or inflammation. Vital signs will be continuously monitored during this observation period. Usually, the patient will stay overnight for further observation and is then typically free to go home.

Patients are given instructions from the medical staff regarding the following:

There is one main, relatively rare complication associated with balloon angioplasty: abrupt vessel closure. Abrupt vessel closure occurs when the vessel that was treated becomes blocked. It typically strikes within 24 hours of the procedure, often within 15 minutes of the final balloon inflation while the patient is still in the catheter laboratory. If it does occur, emergency bypass surgery may be appropriate. However, the risk of this complication is reduced if a stent is also implanted during the angioplasty.

Other rare complications, usually resulting from an abrupt vessel closure event, include:  

• Heart attack
• Sudden cardiac death
• Stroke
• Injury of the access artery

It should be noted that the need for emergency bypass surgery following the angioplasty ranges from 2 to 5 percent with balloon angioplasty to approximately 0.5 percent with stent placement.

The other significant risk associated with balloon angioplasty is the development of blood clots. The combination of aspirin and clopidogrel, a type of antiplatelet, has shown to significantly reduce the risk of blood clots when taken for up to one year following angioplasty. Moreover, studies have shown additional benefit if this regimen is begun one to three days prior to the procedure itself. Other types of stents and coatings are currently being studied to prevent the formation of blood clots (and renarrowing of the artery) following stent placement during angioplasty.

Finally, there is also the risk of restenosis, or reclosure of the artery. The use of stents has helped reduce the restenosis rate, but it is still a relatively common occurrence. Older, bare-metal stents have a restenosis rate of about 50 percent, while the newer drug-eluting stents have a restenosis rate of less than 15 percent. Studies have shown that restenosis often occurs when the plaque buildup returns at either end of the stent, or if no stent was used, at the site of the original angioplasty. In these cases, a second angioplasty may be performed. If the coronary artery disease is widespread, however, the physician may recommend conventional coronary artery bypass graft surgery.

Drug-coated angioplasty balloons are presently being studied. If found safe and effective, these devices may eventually replace drug-coated stents as a means to prevent restenosis.     

Preparing questions in advance can help patients have more meaningful discussions with their physicians about their conditions. Patients may wish to ask their doctors the following questions about balloon angioplasty:

1. Am I a good candidate for angioplasty? Why?
   
   
2. Why should I have angioplasty instead of bypass surgery?
   
   
3. Should I have angioplasty in place of clot-busting drugs?
   
   
4. How long will you monitor my condition before deciding on angioplasty?
   
   
5. How long will the procedure take?
   
   
6. If I have either angioplasty or bypass surgery now, can I have the other procedure in the future?
   
   
7. Will I be able to feel the stent placement?
   
   
8. Will the stent make any lifestyle differences to me, like setting off a metal detector?
   
   
9. Can stents break loose and move?
   
   
10. Will a stent ever need to be replaced?