FIBROUS CAP AND HEART ATTACK: CORONARY ARTERY: MORE THAN A PLUMBING PROBLEM

WHAT DOES PLAQUE RUPTURE HAVE To DO WITH A HEART ATTACK?

A clogged artery is and is not like a clogged pipe, You go to the doctor and they explain why it is important to avoid trans fats and cholesterol to prevent blocked arteries. The heart depends on it's own blood supply, the coronary arteries to feed the heart muscle itself with oxygen rich blood. The impression is that the arteries which feed the heart become clogged with cholesterol like debris. Lowering cholesterol and trans fats definitely helps your heart but the picture is more complicated than the doctor may tell you.

WHAT CAUSES A BLOCKED ARTERY IN THE HEART?

As Jane Brody pointed out in a NY Times column "Most heart attacks do not occur because an artery is closed by a large plaque. Rather, a relatively small, unstable plaque ruptures( something called a fibrous cap breaks off) and attracts inflammatory cells and coagulating(clotting) agents,leading to an artery blocking clot."

WHAT IS A PLAQUE IN A HEART ARTERY?

A plaque in the blood vessel is a complex of cholesterol and various cells and other chemicals that builds up in the wall of the blood vessel. As Brody pointed out "most Americans of middle age and older have small plaques ubiquitous in coronary arteries." Actually evidence has been accumulating for years that the reason for many blockages is that cholesterol is deposited in the lining of the artery and triggers an inflammatory cascade in the lining of the artery. That inflammation builds up in the lining and is covered by a cap. When that cap breaks, the contents beneath the cap, cause a blood clot to form in the blood that is passing by in the lumen of the artery and voila it's a blockage.

WHY DO DOCTORS RECOMMEND ASPIRIN TO PREVENT A HEART ATTACK? HOW DOES ASPIRIN WORK?

Most doctors recommend aspirin to lower the chance of a heart attack. Thus, you see the so called low dose 81mg aspirin sold at drug stores "for the heart." How does aspirin work to lower the risk of a heart attack? They don't know but it may be because aspirin interferes with the formation of blood clots or because it an an anti inflammatory agent and lowers inflammation.

As Dr. Peter Libby has pointed out "sometimes a plaque grows so large that it virtually halts the blood flow in an artery and generates a heart attack or stroke. (he means a stroke caused by a blockage, a thrombotic stroke, but there's also another kind called a hemorrhagic stroke which is due to bleeding) Yet only 15% of heart attacks happen in this way. By carefully examining vessel walls of people who died from heart attacks, pathologists have demonstrated that most attacks occur after a plaque's fibrous cap breaks open" attracting a blood clot that leads to the blockage of the artery. See the fascinating and instructive article by Dr. Libby Atherosclerosis The New View.

Aspirin in Heart Attack Prevention

Brody Coronary Care