Angioplasty -- also called "percutaneous transluminal coronary angioplasty," or PTCA -- is a catheterization procedure aimed at relieving blockages within arteries, most commonly the coronary arteries. Angioplasty works by inflating a tiny balloon at the site of an atherosclerotic plaque, flattening the plaque and reducing the stenosis (blockage) within the artery. In most cases, angioplasty is followed by insertion of a stent.
How is Angioplasty Done?
To perform an angioplasty, the doctor uses a catheter (a long, thin, flexible tube) that has a deflated balloon attached to it. He/she passes the catheter across the narrowed portion of the artery, and expands the balloon under pressure. The expanded balloon compresses the plaque that is causing the blockage. When the balloon is deflated and removed, the plaque remains at least partly compressed, so the blockage is reduced.
When is Angioplasty Helpful?
Angioplasty is quite effective in reducing the symptoms of stable angina. However, when compared to medical therapy in people with stable angina, angioplasty (whether or not a stent is used) has not been shown definitively to reduce the risk of myocaridal infarction or to improve survival.
Angioplasty is often also used to treat patients with acute coronary syndrome (ACS). When used in ACS, the available evidence more clearly shows that angioplasty and stenting help to improve overall cardiac outcomes.
What Are the Complications?
The most common complication following angioplasty is restenosis -- the formation of a new blockage at the site of the procedure. Restenosis can occur either early (immediately following the procedure or up to a few weeks after the procedure) or late (weeks or months after the angioplasty).
Early restenosis usually results from a tear in the plaque, caused by the angioplasty procedure itself. This tear can cause blood clots to form within the artery, or bleeding into the wall of the artery, either of which can produce acute blockage of the artery. Early restenosis is a cardiac emergency, and is usually treated by immediately repeating the angioplasty, though sometimes bypass surgery is required. The risk of early restenosis can be greatly reduced by giving strong anti-clotting drugs (usually aspirin, Plavix, and heparin), during and after the procedure.
Late restenosis is usually caused by the growth of new tissue at the site of the angioplasty. This type of restenosis is not prevented by anti-clotting drugs. It can be thought of as an “over exuberant” healing process, more-or-less like scar formation, following the angioplasty. Late restenosis usually has a much more gradual onset than early restenosis, and usually shows up as a re-appearance of angina. Before the era of stents, late restenosis occured in nearly 30% of patients who had angioplasty. The use of bare metal stents reduced this risk to about 15%, and drug eluting stents reduced it further to around 10%.
Because stents have so dramatically reduced the risk of late restenosis, angioplasty is rarely performed in the United States today without also inserting a stent at the same time.
The risk of restenosis after angioplasty is higher in patients with diabetes, high LDL cholesterol levels, high blood pressure, and especially in smokers.
In addition to the coronary arteries, angioplasty can also be used in arteries in other areas of the body affected by atherosclerosis, such as the carotid arteries (which supply the brain), the renal arteries (which supply the kidneys) and the leg arteries.
Smith, SC Jr, Feldman, TE, Hirshfeld, JW Jr, et al. ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). J Am Coll Cardiol 2006; 47:e1. Available at: http://content.onlinejacc.org/cgi/content/full/47/1/e1 (accessed September 10, 2008).