Coronary Artery Disease
Coronary artery disease (sometimes referred to as heart disease) is a narrowing of the arteries of the heart muscle. It's usually caused when fatty deposits accumulate along a section(s) of the inner walls of an artery. Over time, the deposits form a hardened substance called plaque. Eventually, the plaque accumulates and the artery narrows. When blood flow is blocked, a heart attack occurs. That part of the heart muscle beyond the point of blockage is deprived of oxygen and dies.
According to the American Heart Association, heart disease is the leading cause of death in the U.S. This year, about 1.1 million Americans will have a heart attack. About 47 percent of them will die within a year of the event.
Balloon Angioplasty for Heart Disease
One treatment for coronary artery disease is balloon angioplasty. A balloon-tipped catheter is inserted into a blood vessel in the groin area. The catheter is fed through the circulatory system up to the area of blockage in the heart. Then the balloon is inflated. As the balloon expands, it compresses the plaque, opening up or widening the vessel to allow more blood flow. The balloon is then deflated and the catheter withdrawn.
To keep the plaque from expanding again and re-closing the artery, doctors sometimes use a device called a stent. A stent is a hollow, expandable wire-mesh tube. Prior to angioplasty, it's placed in a closed position over the top of the balloon. When the balloon is inflated, the stent expands. After the balloon is deflated, the stent remains open, acting as a secure scaffolding to prevent the artery from closing again.
More than 561,000 balloon angioplasties are performed every year in the U.S. About 70-90 percent a renarrowing (called restenosis) in the area of the stent. Restenosis is believed to occur when the artery is damaged during angioplasty. The body responds by trying to repair the damage, leading to a buildup of scar tissue and a narrowing of the vessel. Patients with small arteries, large areas of blockage, multiple blockages, and those with diabetes appear to have a higher risk of restenosis.
Vascular brachytherapy is a method that aims to reduce or prevent restenosis after angioplasty and stent placement. After the balloon is deflated, radiation seeds are delivered to the site. The radiation targets cells that divide rapidly, such as those that make up scar tissue. When placed in the artery, the treatment is believed to inhibit cell proliferation that eventually leads to blockage of the blood vessel. Although it's not 100 percent effective, vascular brachytherapy appears to reduce the risk of in-stent restenosis by up to 70 percent.
Coronary Artery Disease