The Nation's Health + [Heart scans]

Stenosis detection vs. plaque detection

One of the most common misunderstandings encountered by both physicians and the public is that, to create an effective heart disease prevention program, we need tools for atherosclerotic plaque detection . What we do not need is a tool for stenosis detection . (Stenosis means percent blockage. A 50% stenosis means 50% of the diameter of an artery is reduced by atherosclerosis.)

This issue came to mind recently with the ongoing conversation at Heart.org forum, in which the conversation predictably degenerated into a "what good are heart scans when there are better tests to detect blockage" sort of mentality.
They are right: There are better tests to detect stenoses or blockages, such as stress tests, heart catheterization, and CT coronary angiography. If someone is having chest pain or breathlessness, these tests are useful to help understand why. These tests are preludes to stents, bypass surgery, and the like. They are the popular tools in hospitals, the ones that provide entry into the revenue-yielding world of heart disease procedures.

Plaque detection, on the other hand, is principally a tool for the person without symptoms. In this regard, it is more like cholesterol testing. I doubt my colleagues would bash cholesterol because it doesn't reveal blockages. Plaque detection identifies the person who has already started developing atherosclerosis.

Dr. William Blanchett of Colorado articulates this idea well:

EBT calcium imaging not only identifies the vast majority of individuals at risk, it also identifies individuals with minimal risk. In other words, it distinguishes those who are likely to benefit from treatment . . .and it identifies those unlikely to benefit from treatment. Furthermore, the greatest value of EBT calcium imaging is that with serial imaging you can determine who is and who is not responding to treatment.

Those patients not responding to the initial treatment are identified by progression of their calcified plaque on a subsequent scan are then placed on additional therapies. The net result is a remarkable reduction in heart attack rates.

Ahh, the voice of reason. Plaque detection empowers you in your prevention program. If you know how much plaque your begin with, you can track that value to know whether you have having a full effect or not. Stenosis detection , on the other hand, empowers your doctor and provides the irresistible impulse to stent.

Another common objection raised to plaque detection is "why bother if you're going to give everybody a statin anyway?" We know the origins of that argument, don't we? If the only strategy known to your doctor is cholesterol reduction with statin drugs, then perhaps that's right. But, with awareness of all the things that go beyond statin drugs, often make them unnecessary, then knowledge of who should engage in an intensive program of prevention or not is enabled by plaque detection.