More Evidence that Coronary Artery Disease Is Different In Women

In Women, Heart Attacks May Be Due to Erosions

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For several years, cardiologists have known that coronary artery disease (CAD) in women can be quite different than it is in men. Women's symptoms may be different, the diagnostic tests that are used for CAD can give the "wrong" answer in women, and the underlying disease itself can be quite different.

It now appears that a new, possibly more significant difference has turned up.

Researchers have recently discovered that in younger women who have died suddenly from coronary thrombosis (blood clots that form in the coronary artery and obstruct blood flow), these fatal blood clots can be quite different than those in men who have suffered sudden death.

How Coronary Thrombosis Is Thought to Occur

Typically, acute coronary syndrome is caused by the rupture of an atherosclerotic plaque. The rupture exposes the "gunk" inside the plaque (cholesterol, calcium, inflammatory cells, and other material) to the bloodstream - and this can trigger the formation of a clot.

The if the clot causes complete (or nearly complete) obstruction of the coronary artery, blood flow to the portion of heart muscle supplied by that artery is shut off. This obstruction can lead to a heart attack (also known as a myocardial infarction), and all too often, can produce sudden cardiac death.

New Difference In CAD In Women

The new evidence suggests that in women under about 50 years of age (in particular, in pre-menopausal women), plaque rupture is often not the cause of the blood clot.

Instead, the clot may be triggered by erosion of the blood vessel wall.

What's the difference between a rupture and an erosion? Well, a rupture of a plaque is like a pimple that pops open. (In fact, the stuff inside a typical zit is not entirely unlike the stuff inside an atherosclerotic plaque.) But an erosion is more like a shallow ulcer - the plaque associated with an erosion may be quite small, or there may not be a plaque at all.

An erosion, like a plaque rupture, can cause the formation of a blood clot.

What The New Finding Means

This new information may partially explain why younger women with coronary thrombosis tend to do worse than men. Clots that form due to an erosion are often more dangerous than clots that form due to rupture. Erosion clots appear to form less suddenly, which means the clots have time to mature. So, when they cause obstruction, the obstruction is more likely to be difficult to reverse. 

Further, coronary artery erosions are difficult or impossible to see during cardiac catheterization or stress/thallium testing. So coronary artery erosions is yet another kind of coronary artery disease associated with "normal" coronary arteries. 

Who Gets Coronary Artery Erosions?

Coronary artery erosions is a condition almost always seen in premenopausal women, often in premenopausal smokers. So, while smoking is a risk factor for anyone, it is an especially strong risk factor for coronary artery erosions.

Coronary after erosions also may be more likely in women who have repeated spasms of the coronary arteries, such as in Prinzmetal's angina.

Summary

It is becoming increasingly obvious that CAD in younger women is very often a different disease than the "classic CAD" that is seen in men and in older women. The recognition of this fact is leading, at last, to efforts to gain a full understanding of those differences and to develop more effective strategies for treatment.

Sources:

Kramer MCA, Rittersma SZH, de Winter RJ, et al. Relationship of thrombus healing to underlying plaque morphology in sudden coronary death. J Am Coll Cardiol 2009; DOI:10.1016/j.jacc.2009.09.007.

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