The Nation's Health

What is abnormal?

What is abnormal?

You'd think that the answer would be easy and straightforward.

However, consider these instances of medical findings that I have witnessed fall repeatedly into the "normal" category:

Diameter of the thoracic aorta: 4.5 cm

Mild coronary plaque by heart catheterization

Carotid plaque of 30-50%

Why isn't a thoracic aorta (the big artery in your chest) of 4.5 cm normal? Because it can be expected to increase in diameter by about 2.5 mm (0.25 cm) per year. Even at its current diameter, it means that stroke risk is greater, since enlarged aortas are diseased aortas that commonly accumulate atherosclerotic plaque with potential to fragment and shower debris to the brain. It means that high blood pressure and/or cholesterol/lipoprotein abnormalities have been uncorrected for years that have allowed the aorta to enlarge.

How about "mild coronary plaque"? Followers of the Track Your Plaque program already know the answer to this one. Mild plaque does not mean mild risk. In fact, most plaques that cause heart attack are mild plaques, not severe blockages. While severe blockages can provide symptom warning and are detected by stress tests, it's the mild blockages that rupture without symptom warning and cause heart attack. So "mild coronary plaque" is no less dangerous than severe coronary plaque.

Likewise, carotid plaque of 30-50%, while it doesn't justify surgery, can grow within just a few years to a severity that allows it to fragment and shower debris to the brain, i.e., a stroke. As with the enlarged aorta, it means that multiple causes of carotid plaque are likely active, including high blood pressure and cholesterol or lipoprotein abnormalities.

Then why would any of these findings be labeled "normal"?

Simple. In the minds of many physicians, if a condition doesn't pose immediate risk, or if it doesn't qualify for surgical "correction," then it is labeled "normal" or "mild."

Thus, an aorta of 4.5 cm cannot justify surgical replacement until it achieves a diameter of 5.5 cm. It is therefore labeled "normal."

"Mild coronary plaque" does not justify insertion of stents or performance of bypass surgery. It must therefore be "normal."

Carotid plaque over 70% is surgically removed, but not 30-50%. 30-50% is therefore "normal."

The tragedy is that many "normal" or "mild" findings, if cast in the proper light, could lead to corrective strategies that could prevent danger long-term or keep surgery from becoming necessary.

The enlarged aorta, for instance, could be stopped and an aneurysm (defined as 5.5 cm or greater) could be prevented, along with dramatically reducing risk for stroke. Carotid plaque, more so than coronary plaque, is a controllable and manipulable condition that should trigger a program of prevention and reversal. Instead, it usually generates advice to have another ultrasound in a year to see if it has yet achieved severity sufficient to justify surgery.

Of course, "mild coronary plaque" is the reason for the Track Your Plaque approach, a chance to seize control over this disease years or decades before procedures are necessary and reduce danger now, not years from now.

Copyright 2008 House, MD