EBCT -- Does a '91st percentile' negative result assure heart disease??

EBCT is getting a lot of press lately.  (As doctors know, EBCT is a procedure that provides supposedly valuable images of coronary arteries. A "high" score on the test indicates likely coronary artery disease -- or so say those who now aggressively market this procedure.)

I had an EBCT scan 3 years ago.  It indicated a high calcium score (just under 400) for my anterior descending coronary artery.  (The other arteries showed calcium scores ranging from low single digits to 50 -- relatively low #'s for a then
53-year old male.)

The nurse who explained the score to me at the time said it was indicative of severe coronary plaque.  She also indicated that the total calcium score (the sum of all the artery readings) put me in the 91st percentile of all those who have taken the test (i.e. I had calcium buildup worse than 91% of the rest of those who had taken the test over several years.)

Sheepishly, I notified my cardiologist that I had taken this test on my own (for $450.) With a calming look of "What did you do that for??", he suggested that a thallium stress test might tell him more...and ease my fears.

My thallium test results were normal.  

Two years later, an echo stress test.

My echo stress was normal.

Now -- a 42-year old friend just had the EBCT and showed a 77th percentile ranking.  He is scared to death (as I had been in the past.)

So now I wonder: what is the latest on EBCT?  Am I wise to think that an angiogram is the ONLY procedure that will settle this question in my "heart" once and for all.

Thank you for this great site.

[CCF-M.D.-CRC]

Dear John,
Electron beam computed tomography (EBCT) is currently an area of intense controversy and as you so aptly said "marketing".  Unfortunately the jury is still out on the issue of its usefulness.  

There may be a link between calcium and coronary artery disease. And we know that most middle aged men have some degree of coronary disease. However, there is no evidence that the presence of calcium itself predicts heart attacks or increased mortality.  Thallium on the other hand does predict increased mortality and if one has a normal thallium test their risk is lower.  An angiogram is still the "gold standard" for the detection and treatment of coronary artery disease.  

I think until further studies have been done on EBCT its use as a screening tool is limited.  However, if it convinces someone to change their lifestyle then maybe it is a good thing.  I guess the bottom line is that your friend should do as you did and go to see a cardiologist.  He can evaluate his risk and determine what (if anything) further needs to be done.

[JohnJoseph]

Correction: The left anterior descending indicated a calcium score of 341.  The next highest was the circumflex @ 67.  The left main and right coronary showed <50 scores.

(Scores of 11 to 100 are, according to the testers, indicative of "mild plaque burden."   101 to 400 is "moderate plaque burden."  Since my total score was 449.7, the test suggests "Extensive plaque burden. There is a high liklihood of the presence of at least one coraonrary stenosis greater than 50%."  That's what it says on the report, anyway.

Thanks again for your perspectives, doctor.