What Is Coronary Angioplasty?
Coronary angioplasty is a procedure we use to open blocked or narrowed coronary (heart) arteries. The procedure improves blood flow to the heart muscle.
Over time, a fatty substance called plaque can build up in your arteries, causing them to harden and narrow. This condition is called atherosclerosis.
Atherosclerosis can affect any artery in the body. When atherosclerosis affects the coronary arteries, the condition is called coronary heart disease (CHD) or coronary artery disease.
Angioplasty can restore blood flow to the heart if the coronary arteries have become narrowed or blocked because of CHD.
Angioplasty is a common medical procedure. It may be used to:
- Improve symptoms of CHD, such as angina and shortness of breath. (Angina is chest pain or discomfort.)
- Reduce damage to the heart muscle caused by a heart attack.
- Reduce the risk of death in some patients.
Angioplasty is done on more than 1 million people a year in the United States. Serious complications don't occur often. However, they can happen no matter how careful your doctor is or how well he or she does the procedure.
How Is Coronary Angioplasty Done?
Before coronary angioplasty is done, your doctor will need to know the location and extent of the blockages in your coronary (heart) arteries. To find this information, your doctor will use coronary angiography. This test uses dye and special x-rays to show the insides of your arteries.
During angiography, a small tube called a catheter is inserted in an artery, usually in the groin (upper thigh). The catheter is threaded to the coronary arteries.
Special dye, which can be seen on an x-ray, is injected through the catheter. X-ray pictures are taken as the dye flows through your coronary arteries. This outlines blockages, if any are present, and tells your doctor the location and extent of the blockages.
For the angioplasty procedure, another catheter with a balloon on its tip (a balloon catheter) is inserted in the coronary artery and positioned in the blockage. The balloon is then expanded. This pushes the plaque against the artery wall, relieving the blockage and improving blood flow.
A small mesh tube called a stent usually is placed in the artery during angioplasty. The stent is wrapped around the deflated balloon catheter before the catheter is inserted in the artery.
When the balloon is inflated to compress the plaque, the stent expands and attaches to the artery wall. The stent supports the inner artery wall and reduces the chance of the artery becoming narrowed or blocked again.
Some stents are coated with medicines that are slowly and continuously released into the artery. These are called drug-eluting stents. The medicines help prevent the artery from becoming blocked with scar tissue that grows in the artery.
The illustration above shows a cross-section of a coronary artery with plaque buildup. The coronary artery is located on the surface of the heart. Figure A shows the deflated balloon catheter inserted into the narrowed coronary artery. In figure B, the balloon is inflated, compressing the plaque and restoring the size of the artery. Figure C shows the widened artery.
The illustration above shows the 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.
How to prepare for a Coronary Angioplasty
Don't eat or drink anything for six to eight hours before the test. If you have diabetes, discuss this with your doctor. Not eating can affect your blood sugar and adjustments may need to be made to your insulin dosage.
Discuss any medicines you are taking with your doctor. He or she may want you to stop taking them before the test, especially if you are taking a blood-thinner such as Coumadin® (warfarin) or anti-platelet medicines such as aspirin or Plavix®. It is important helpful to bring a list of your allergies, medicines and dosages to the procedure, so the healthcare team knows exactly what you are taking and how much.
It may not be safe to drive after having cardiac catheterization, so you must arrange for a ride home.
What to Expect Before Coronary Angioplasty
We perform coronary angioplasties at a hospital. Once the angioplasty is scheduled, your doctor will advise you:
- When to begin fasting (not eating or drinking) before the procedure. What medicines you should and shouldn't take on the day of the angioplasty.
- When to arrive at the hospital and where to go.
Even though angioplasty takes only 1 to 2 hours, you'll likely need to stay in the hospital overnight or longer. Your doctor may advise you not to drive for a certain amount of time after the procedure, so you may have to arrange for a ride home.
In the cath lab, you'll lie on a table. An intravenous (IV) line will be placed in your arm to give you fluids and medicines. The medicines will relax you and prevent blood clots from forming.
To prepare for the procedure, the area where your doctor will insert the catheter will be shaved. The catheter usually is inserted in your groin (upper thigh). The shaved area will be cleaned and then numbed. The numbing medicine may sting as it's going in.
During angioplasty, you'll be awake but sleepy.
Your doctor will use a needle to make a small hole in an artery in your arm or groin. A thin, flexible guide wire will be inserted into the artery through the small hole. The needle is then removed, and a tapered tube called a sheath is placed over the guide wire and into the artery.
Next, your doctor will put a long, thin, flexible tube called a guiding catheter through the sheath and slide it over the guide wire. The catheter is moved to the opening of a coronary artery, and the guide wire is removed.
Next, your doctor will inject a small amount of special dye through the catheter. This will help show the inside of the coronary artery and any blockages on an x-ray picture called an angiogram.
Another guide wire is then put through the catheter into the coronary artery and threaded past the blockage. A thin catheter with a balloon on its tip (a balloon catheter) is threaded over the wire and through the guiding catheter.
The balloon catheter is positioned in the blockage. The balloon is then inflated. This pushes the plaque against the artery wall, relieving the blockage and improving blood flow through the artery. Sometimes the balloon is inflated and deflated more than once to widen the artery. Afterward, the balloon catheter, guiding catheter, and guide wire are removed.
A drill-like device called a rotablator sometimes is used to remove very hard plaque from the artery.
Your doctor may put a stent (small mesh tube) in your artery to help keep it open. If so, the stent will be wrapped around the balloon catheter.
When your doctor inflates the balloon, the stent will expand against the wall of the artery. When the balloon is deflated and pulled out of the artery with the catheter, the stent remains in place in the artery.