For certain people, coronary artery disease can be treated without surgery. Angioplasty is a non-surgical procedure that doctors can use to open blocked heart arteries. Specialized cardiologists and teams of cardiovascular nurses and technicians perform the procedure in a cardiac catheterization laboratory.
Angioplasty, also know as percutaneous transluminal coronary angioplasty (PTCA), has become a common procedure in large medical centers in the United States. The goal of the procedure is to increase blood flow to the heart muscle tissue. Angioplasty is less invasive and has a shorter recovery time than bypass surgery, which requires open-heart surgery. According to the American Heart Association, about seventy to ninety percent of angioplasty procedures involve the placement of a stent.
After an anesthesiologist sedates the patient, the surgeon inserts a thin flexible tube, known as a catheter through an artery in the groin or arm and carefully guides the tube up the blocked coronary artery. Usually, doctors perform a cardiac catherization or coronary angiography to identify any blockages. These procedures require doctors to inject the patient with a dye that contains iodine. The dye makes the coronary arteries visible on a digital X-ray screen, allowing for accurate assessment of blockages.
If the patient has a blockage, the doctor advances the catheter to the blocked portion, and inflates a small balloon at the end of the catheter. The balloon remains inflated for twenty seconds to three minutes, and is then deflated and removed. The pressure from the inflated balloon presses the plaque, which causes the blockage, against the wall of the artery, creating more room for blood to flow.
Frequently, a small, expandable wire-mesh tube called a stent is permanently inserted into the artery during angioplasty. The angioplasty balloon is placed inside the stent and inflated, which opens the stent and pushes it into place against the artery wall, keeping the narrowed artery open. The stent's mesh-like design allows the cells lining the blood vessel to grow through and around the stent to help secure it.
The procedure is designed to open up the artery and press the plaque against its walls, improving blood flow. The stent keeps the artery open after the surgeon deflates and removes the balloon. The stent also serves to seal any tears in the artery wall, prevent the artery wall from collapsing or closing off again (restenosis), and prevent small pieces of plaque from breaking off that might cause a heart attack.
Angioplasty procedures last about one to two hours, excluding preparation and recovery times. A patient usually can begin walking within twelve to twenty-four hours after angioplasty. The average hospital stay lasts one to two days for procedures free of complications, and doctors allow the patient to resume exercising and driving within several days of the procedure.
Doctors usually prescribe aspirin
after angioplasty to help prevent the formation of blood clots.
When surgeons also use a stent, doctors prescribe an antiplatelet
medication (such as ticlopidine or clopidogrel) in addition to
the aspirin. Aspirin therapy is generally continued long-term,
while the antiplatelet medication therapy usually last for a
two to four week period after the stent placement.
Although many factors are involved, angioplasty is most often
used if you have frequent or severe chest pain (angina) that
is not responding to medication. Doctors also look for evidence
of severely reduced blood flow (ischemia) to an area of heart
muscle caused by one or more narrowed coronary arteries.
Doctors do not recommend angioplasty
in cases where no evidence of reduced blood flow to the heart
muscle exists, or when only small areas of the heart are at risk,
and the patient exhibits no disabling chest pain (angina). Doctors
are also reticent to perform the procedure when the patient suffers
from other health problems that increase the risk of death or
other complications during and after the surgery. In addition,
there are cases in which the surgeon cannot reach the affected
artery with the angioplasty catheter.
Successful angioplasty relieves chest pain and improves blood
flow to the heart. People who have angioplasty combined with
stenting and certain medications have better long-term outcomes
than those who have angioplasty alone. According to some research,
when used to repair one artery, angioplasty and bypass surgery
have similar success rates.
Emergency angioplasty with or without stenting is typically the
first treatment choice for a heart attack.
Bypass surgery may be a better
option for some people, such as those with diabetes. Studies
show that bypass surgery reduces the death rate in people who
have diabetes and heart attack when compared with angioplasty
or thrombolytic therapy, a therapy involving clot-busting drugs.
Bypass surgery may also yield greater benefits for people with
extensive coronary atherosclerosis or blockage. Additionally,
bypass surgery may represent the best option when surgeons cannot
reach blockages in the coronary arteries during angioplasty or
when angioplasty did not sufficiently widen the blood vessel.
Though considered a routine and safe procedure, angioplasty does
bring with it the risk of certain complications. With any angioplasty
procedure sudden closure of the repaired artery can result on
serious complications, including heart attack. A need for additional
procedures may arise in such case. Angioplasty may also increase
the risk that doctors may have to perform urgent bypass surgery.
In addition, if the repaired artery narrows again, a repeat angioplasty
may be needed. While death is not a common complication, the
risk of death is higher when doctors perform angioplasty on more
than one artery.
The procedures performed during coronary angioplasty open blocked arteries, but they do not cure coronary artery disease. A patient must still work to modify lifestyle factors that can worsen coronary artery disease, such as smoking, diet, and exercise.
Each year cardiologists perform 800,000 angioplasty procedures in the United States to open clogged coronary arteries. In approximately fifteen to thirty percent of patients, the artery becomes clogged again (a condition called restenosis) within a year, and must be treated again with a procedure such as angioplasty or bypass surgery.
Restenosis of the artery is much less likely to occur after stenting than with angioplasty alone. As a result, stent placement is rapidly becoming the standard practice during most angioplasty procedures. New stents coated with a medication called Sirolimus, including Cordis' Cypher Stent, inhibits cells in the artery from growing; thereby prevent restenosis due to tissue regrowth. Many in the medical community consider these stents even more effective than standard stents.
Sirolimus, the active drug released from the Cypher Stent, is an immunosuppressant drug marketed by Wyeth Pharmaceuticals under the name Rapamune and is used to prevent organ rejection in patients receiving kidney transplants.