Looking Into Arteries

[lars999]

There is no really good place to put this post, so, I put it here. If you really want to know if you have plaque-encrusted arteries, or not, there are some very effective, non-invasive methods of assessing this. These are breifly described below.

While these tests do not 100% eleminate the presence of serious plaque buildup somewhere in your arteries (not seen in the areas actually analysed), the do provide a major, objective measure of information. No need to rely on the junk-science pronouncements of the cholesterol scam, based on blood serum levels of cholesterol and the zoo of lipo-protein particles.

There are two major arteries that are close enough to our skins that non-invasive ultrasound doppler methods can be used to determine the extent, if any, of obstruction of these arteries by plaque, etc. One is the carotid arteries on each side of out neck, the other is the femoral arteries than extend down the inside of each thigh. The femoral arteries, as well as their extensions into calf muscles and into feet, etc. can also be studied by a series of blood pressure measurements, allowing assessment of degree of imparement, if any, of blood flow.

I have had both done and am quite pleased with results -- no or very little plaque. Highly useful information to negate doctors prescribing statins!!

Lars

[lars999]

I have recently become aware that there are two versions of ultrasound measurements on carotid arteries.

The older method, which I have undergone, measures the flow velocity of blood in each carotid artery, using doppler measurements. With this method a finding of low flow rates and clean doppler signals is the desired result because this is an excellent indication of little or no plaque, allowing minimal flow velocities and little or no turbulent flow.

The newer method claims to directly measure thickness of the arterial wall on opposite wall of each carotid artery. As best I can tell, this measurement can be reliably done and is quite sensitive. Thinner arterial walls, for a person's age, is the desired result. A finding of local areas of thick walls is considered clear evidence of serious build-up of plaque, most likely the Vulnerable Plaque that is suseptable to rupture, followed by formation of blood clots and stroke.

I am now shopping for a vender that does the latter version, often called Media Intima Thickness measurement. I am having some serious problems with learning enough, because most (all?) implementations of this method involve propriatary means of calculating thickness of arterial walls and especially interpretation of those thicknesses.

My Cholesterol Quack GP says that IF Media Intima Thickness measurements find little or no plaque in my carotid arteries, then he will shut up his yammering about my "high" total cholesterol. That would indeed be a nice, positive side effect of this method!!

Lars

[lars999]

Here is reference to most compact description I have yet found of one of two very valuable ultrasound methods to determine the actual condition of your arterial walls. The most widespread name for this propietary method is "Carotid Intima-Media Thickness (CIMT)".

Webbsite: http://www.physioage.com/diagnostics/CIMT.php

Enjoy,
Lars

[cjbrooksjc]

Lars: Excellent article. Thanks.

Brooks

[lars999]

Brooks,

That nice article answered one of my major questions: what is uncertainty to "age" of one's arteries -- simple eye-balling the graph in that artical suggest one sigma of about +/- 10 years and about twice that for two sigma. Great for cocktail party chit-chat and bragging rights, but how much more?

The plaque that kills is is vulnerable plaque, that is "plaque boulders" that bust and release a bunch of biochemical garbage that results in formations of blood clotts, leading to strokes or heart attacks. I am pretty confident that this Carotid-Intima-Media-Thickness measurement will detect them, as will doppler measurements of blood velocities and "smudging" (nice scientific term!!) of doppler return signals, resulting from much increased turbulent flow.

SO, my question for you or anyone else --"Where is reference in medical literature describing actual detection of vulnerable plaque by ultrasound?" I look, no find yet.

Thanks,
Lars

[lars999]

Here is one of my "near misses" on an Internet search for information about detecting vulnerable plaque using external, non-invasive ultrasound. The artcle referenced below use miniturized ultrasound hardware that is inserted into major arteries. This article also provides a lot of information about vulnerable plaque, which is main reasion I am posting about it here.

Title: Imaging Vulnerable Plaque by Ultrasound, J Am Coll Cardiol, 2006; 47:32-39, doi:10.1016/j.jacc.2005.11.047
© 2006 by the American College of Cardiology Foundation

Internet link: http://content.onlinejacc.org/cgi/content/full/47/8_Suppl_C/C32

One of drivers for my search for information about detection of vulnerable plaque is a heart attack that happened to a friend of mine. It was result of a vulnerable plaque that ruptured, leading to formation of clot that blocked one of his cornary arteries, leading to heart attack. He survived. When they enplaced a stint at the location where the clot blocked the artery, they found quite plaque-free artery and never did develop any information about location of the vulnerable plaque that ruputred. He had no "risk factors" for heart attack, including quite acceptably low total cholesterol, LDL, etc.

Did he simply get "struck by lightening, or, can vulnerable plaques that are good candidates for rupture be located and treated? IF SO, sounds like a more rational approach than feeding hundreds of millions of folks poisions like statins to combat a fake problem.

Scanning several additional articles about detection of vulnerable plaques leads to conclusion that what progress is ongoing is using intravascular methods NOT non-invasive as I have been interested in. Kind of a bummer!! I will continue this search till I get a definitive answer. However, I am begining to suspect that I will not be spending my health insurance money on Carotid-Intima-Media-Thickness data, just to get a low-resolution "age" of my carotid arteries.

Lars

[lars999]

Internet searching today yielded a few more peices of information about Carotid-Intima-Media-Thickness method. Again, from one of the vendors of this method.
LINK: http://coastalcimt.com/physicians.html

This propriety webbsite contains a couple of assertations whose source I hope to track down.
"We now know most heart attacks are caused by the rupture of vulnerable plaque in arteries that are about 50% occluded." It is the "50% occluded" statement that I have not noticed before.
AND
"Studies involving over 37,000 patients have shown a 90% correlation between the common carotid artery IMT and coronary arteries." A 90% correlation -- in medical data -- this I really want to see in data I can analyse myself!! WAY better than most medical data.

Taken together, these two statements, IF valid enough, make CIMT imaging a really GEE WHIZ way to sort out which of us really are at risk of a heart attack and/or stroke. How true are they?

Here is link to Executive Report, Part III, From Vulnerable Plaque to Vulnerable Patient.
LINK: http://coastalcimt.com/images/shapeSummary.pdf

For more complete information go to :
LINK: *www.shapesociety.org.

Read with care,
Lars

[lars999]

Here is a rather informative Wikipedia article about artheroma, including nice discussion of methods to determine and monitor growth of artheromoa.
LINK: http://en.wikipedia.org/wiki/Atheroma

This Wikipedia article contains one sentence that most posters here will agree with, perhaps even applaud. QUOTE; "However, in spite of popular belief, cholesterol is not the villain that causes atherosclerosis[citation needed]]. "

This Wikipedia article also contains a reference "Questioning the benefits of statins"
LINK: http://www.cmaj.ca/cgi/content/full/173/10/1207-a

So much for today -- time is up,
Lars

[lars999]

Hello!

In today's electronic version of New England Journal of Medicin is following article "A Prospective Natural-History Study of Coronary Atherosclerosis"
LINK: http://www.nejm.org/doi/full/10.1056/NE ... ?query=TOC

CONCLUSIONS
In patients who presented with an acute coronary syndrome and underwent percutaneous coronary intervention, major adverse cardiovascular events occurring during follow-up were equally attributable to recurrence at the site of culprit lesions and to nonculprit lesions. Although nonculprit lesions that were responsible for unanticipated events were frequently angiographically mild, most were thin-cap fibroatheromas or were characterized by a large plaque burden, a small luminal area, or some combination of these characteristics, as determined by gray-scale and radiofrequency intravascular ultrasonography. (Funded by Abbott Vascular and Volcano; ClinicalTrials.gov number, NCT00180466.)

Note that this study used INTRAVASCULAR ultrasonography, not the non-invasive doppler ultrasound I am slowly collecting information about, to find and define these plaque "boils" that are/were subject to rupture (commonly known as vulnerable plaque).

When time permits, I will be looking into the clinical trial referenced above and hoping to obtain the published report(s). LINK to this clinical trials is: http://clinicaltrials.gov/show/NCT00180466

I have not yet taken time to look for similar clinical trial using non-invasive doppler ultrasound. I keep getting pulled/pushed in new or different directions.

Good reading,
Lars