What Is Angioplasty With Stenting?
About a half million angioplasty procedures (also called percutaneous coronary intervention, or PCI) are performed in the United States each year.
This potentially lifesaving procedure allows blood to flow through previously blocked arteries, limiting damage to the heart muscle that is already in progress or preventing a heart attack from happening altogether. The intervention is also used to combat unstable angina.
Angioplasty does not remove plaques from the coronary arteries. Instead, it widens the channel (lumen) through which blood flows. About 90 percent of people notice an immediate improvement in symptoms when the lumen is at least 50 percent open after an angioplasty procedure.
Performed in a cardiac catheterization lab, angioplasty takes about 30 minutes to two hours. The procedure does not require general anesthesia. After you receive a sedative and a local anesthetic in the groin area, a tiny catheter with a deflated balloon at its tip is inserted into the femoral artery through a small incision in the groin.
Guided by X-ray images on a monitor, the cardiologist threads the catheter toward the heart and positions the balloon at the site of the plaque obstruction in the coronary artery.
The cardiologist then inflates the balloon repeatedly for 30 seconds or more to compress the plaque and open the artery. An alternative to the femoral approach is the transradial approach, in which the catheter is threaded through an artery in your wrist. This procedure has a lower bleeding risk.
Angioplasty with stenting
In most cases, a small, metal, scaffold-like device called a stent is permanently placed in the artery during angioplasty to help keep the artery open over the long term. Without a stent, the rate of restenosis (narrowing of the artery after angioplasty) ranges from 30 to 40 percent. Stents reduce the restenosis rate to generally 3 to 10 percent, if the stent is optimally expanded.
However, stents can increase the risk of blood clots, and tissue growth can occur on the stent. Your doctor will take steps to lower the risk of these problems. For example, you will receive powerful anticlotting drugs called glycoprotein IIb–IIIa inhibitors to prevent blood clots after the procedure. These drugs are usually given intravenously for about 12 hours. You will also take an antiplatelet drug such as Plavix for one month or longer to reduce the risk of blood clots.
Types of stents
Three kinds of stents are currently available:
These are coated with a medication that helps keep the blood vessel from reclosing and forming scar tissue. With drug-eluting stents, there’s just a 2 to 4 percent chance of restenosis. If you have a drug-eluting stent, Plavix or a similar antiplatelet agent is generally given for 12 to 18 months, while low-dose aspirin is given indefinitely.
Bare metal stents These stents are not coated with medicine and require only a month or so of anti-platelet therapy, but have at least a 15 percent risk of restenosis. These stents may be needed for patients who cannot take anti-platelet therapy for an extended time, such as those who are anticipating surgery.
If you have a drug-eluting stent, as compared to a bare metal stent, Plavix or a similar antiplatelet agent is generally given for 12 to 18 months, while low-dose aspirin is given indefinitely.
A stent that is absorbed by the body after it is no longer needed is now an approved treatment for patients undergoing angioplasty. The Absorb GT1 Bioresorbable Vascular Scaffold System (BVS) was developed as an alternative to permanent metal stents.
The BVS, which releases the drug everolimus to limit the growth of scar tissue, is made of a biodegradable polymer that is similar to materials used in other types of absorbable medical devices, such as sutures. It dissolves in about three years.
One theoretical limitation of traditional metal stents is that they do not permit the blood vessels to expand and contract normally, which can potentially damage the vessels over time. Absorbable stents were created in an effort to avoid this problem.
In clinical studies, the absorbable stent performed nearly as well or just as well as its metal drug-releasing counterpart. Still, in each study, the dissolving heart stent failed to show superiority over a conventional drug-eluting stent.
It remains to be seen whether absorbable stents will ultimately prove to be better than metal ones. In one study, the risk of developing a blood clot near the stent was slightly higher with absorbable stents than with metal ones in patients with angina. In another, people who received absorbable stents were less likely to develop angina but more likely to have a heart attack.
If your doctor recommends angioplasty with stenting, be sure to discuss the pros and cons of the various types of stents.
A serious complication during angioplasty with or without stenting is total closure of the coronary artery due to a blood clot, spasm, or tear in the artery wall. Closure of the artery can cause a heart attack in about 3 to 5 percent of patients or require emergency bypass surgery in 1 to 2 percent. Because of this risk, if you require angioplasty in several vessels, you will probably need to recover for at least a day after angioplasty on the first artery before the procedure is repeated on another blood vessel.
Few other major risks are associated with angioplasty. Less than 1 percent of individuals die during the procedure (that risk is concentrated in older patients with advanced coronary artery disease and other medical problems), and complication rates are lower when angioplasty is performed by an experienced doctor.
However, doctors who perform fewer angioplasties can still have low complication rates if they perform the procedure only on people at low risk for complications.
Find out if you are a candidate for angioplasty or bypass surgery.