Are Angioplasties Really Necessary?
Ok, this is huge.
As this article shows: http://www.nytimes.com/2007/03/26/he...hp&oref=slogin
there are now indications that conservative medical therapy may be just as efficacious as stent placement in the treatment of coronary artery lesions, as far as reducing the chance of eventual heart attacks. Currently, thousands of people who have coronary blockages detected during examinations get stent placements as a method of avoiding heart attacks. This means thousands of procedures and billions of dollars spent on these procedures may be unnecessary; the same results might be achieved through simple drug therapy. Angioplasty can still save lives when a person is having a heart attack, as an emergency method of reopening blocked arteries, but in terms of doing it to AVOID them, it could just be a wasted procedure. Let's look at the basics of this issue:
What is coronary blockage?
The heart is supplied by the coronary arteries, which are the very first branches off the aorta, the main artery of the body. Basically, as soon as oxygenated blood is pumped out of the left ventricle of the heart, some of it takes a U-turn is goes through the arteries to supply the heart itself. There are two main coronary arteries: the right and the left (RCA and LCA). The LCA comes off the aorta, and splits into two main branches, the left anterior descending (aka anterior interventricular) and circumflex arteries. The right mainly stays as a big vessel without splitting. Both LCA and RCA give off smaller branches to completely supply the heart.
This is an elegant system, but there's a problem: it's known as an end-arterial system; basically, blood flow to any one part of the heart ultimately depends on keeping the entire vessel open. If one vessel fails, there's no other artery from a different source that can pick up the slack (this occurs in other parts of the body, and is known as collateral circulation). If a coronary artery is totally blocked, depending on how far upstream it is, a large chunk of heart could be totally starved for nutrients and oxygen and die. This is a heart attack, or myocardial infarction.
What is an angioplasty?
Modern angioplasties prop open the coronary arteries by inflating a balloon inside the vessel. Fitted around the balloon is a stent, a metal strut that is basically jammed into the vessel wall by the force of the inflation, and which holds the vessel open.
The way an angioplasty is usually performed, the interventional cardiologist opens up the femoral artery, threads a catheter up the artery, around the aorta, into the coronary arteries, and to the site of the blockage. They use saline to inflate the balloon, then pull it out. The stent remains behind. It's an ingenious procedure, and stents have gotten very sophisticated now. Because it's a foreign body, it tends to form blood clots on it, but the newest ones have special coatings that are supposed to stop this from happening.
Stents have been in the news for a while now, because these newest ones have had some problems with clots actually being WORSE than the older ones, and now this latest bombshell has been dropped. This spells a lot of trouble (read: money issues) vis a vis the big stent making companies and the interventional cardiologists, for whom angioplasties are their bread and butter. I'm sure the cardiac surgeons are getting a good chuckle; after all, when angioplasties were introduced, THEIR bread and butter, namely bypass surgeries, went down significantly. Things should get very interesting, indeed!
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