Minor Coronary Artery Plaques Greatly Increase Risk

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A study published in the November 5, 2014 issue of JAMA ought to remind cardiologists of a basic fact they really should have known a long time ago, but all too often have ignored. Small, non-obstructive plaques in the coronary arteries - the kind of plaques that aren’t causing angina, that are not candidates for angioplasty or stenting, and that therefore are often brushed off as being “insignificant” - do indeed pose a significant risk, and ought to be treated.

Investigators studied data from over 37,000 patients enrolled in the VA healthcare system’s CART program, which records patients’ information from cardiac catheterizations and tracks their subsequent outcomes. About a quarter of these patients had only “minor,” non-obstructive plaques in their coronary arteries, which were not candidates for invasive therapy. Over the next year, the risk of having a myocardial infarction (heart attack) was between 2 and 4.5 times higher for these patients than for patients who had no coronary artery plaques, and the risk of death was nearly twice as high for some of them.

Such information is not new. It has been known for many years that heart attacks commonly occur with the sudden rupture of a “minor” plaque that, prior to rupture, would have been considered “insignificant” on a cardiac catheterization.

Most heart attacks, it is now believed, result from the rupture of such a minor plaque. Therefore, any plaque is a significant plaque.

It is apparent that many cardiologists have obstinately refused to get this critical message, and that they persist in looking only for “significant” blockages which they can treat with invasive methods.

Treating significant blockages with stents often relieves the angina being caused by the chronic blockage itself, but often does not significantly reduce the subsequent risk of heart attack or death - because those heart attacks are commonly caused the smaller plaques which cannot be addressed by invasive therapy.

The fact that the editors of JAMA saw fit to publish this recent study - which merely reinforces what has long been known - is itself an indication that too many cardiologists haven’t yet gotten the message.

How Can You Tell Whether You Have Coronary Artery Plaques?

Cardiac catheterization is not the only way - and not the best way - to tell whether you have plaques in your coronary arteries. A non-invasive method for detecting the presence of plaques is the cardiac calcium scan. A routine calcium scan cannot tell whether the plaques are obstructive or not, but if you have calcium deposits in your coronary arteries you can be sure you’ve got atherosclerotic plaques - and thus, that you ought to be treated.

An even easier (and cheaper) way to estimate whether you might have coronary artery plaques is to do a formal cardiac risk-assessment. If your 10-year risk of developing heart disease is estimated to be around 10% or higher, the chances are excellent that you already have at least a few plaques.

How Should Small, Non-obstructive Plaques Be Treated?

The point, of course, is that any CAD - even non-obstructive CAD - poses a significant risk, and ought to be treated. Treatment can greatly reduce the risk of progression of the CAD itself, and of plaque rupture.

The treatment includes both lifestyle change and medication. It is especially critical, if you have plaques, that you stop smoking immediately - today, in fact - since the byproducts of smoking not only accelerate the process of atherosclerosis but also acutely increase the likelihood of plaque rupture. Getting down to a good weight, getting plenty of exercise, and controlling your blood pressure are also very important steps in reducing your risk.

In patients with coronary artery plaques, the statin drugs can reduce the risk of plaque rupture, and prophylactic aspirin can inhibit the blood clots that make plaque rupture so life-threatening. You should talk to your doctor about whether you ought to be on one or both of these medications.

The Bottom Line

The point is this - you can’t afford to wait until your doctor finally gets the message. (Maybe this latest JAMA article will do the trick.) You need to get the message yourself and act upon it. If you are at increased risk for CAD, you need to ask yourself if it’s time to find out whether you already have the kind of “minor” plaques that can lead to a sudden crisis at any moment - and then do something about it.


Maddox TM, Stanislawski MA, Grunwald GK, et al. Nonobstructive coronary artery disease and risk of myocardial infarction. JAMA 2014; 312:1754–1763.

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