Heart Scan Curiosities #7




Here's a situation that crops up once in a while, occurring in perhaps 2% of heart scans.

The white within the circled area represents calcium, and thereby atherosclerotic plaque, situated immediately at the "mouth", or opening, of the the right coronary artery. What is somewhat unusual is that this plaque is not principally coronary, but aortic. That is, the plaque is mostly situated in the large vessel called the aorta. The three coronary arteries arise from the aorta.

In this instance, the aortic plaque involves the mouth of the right coronary artery. (In views not shown, the plaque also extends into the artery as well.) I call this a "double whammy" because the same plaque can post risk for heart attack and stroke.

Generally, aortic plaques pose risk for stroke. When aortic plaque fragments, little bits and pieces can travel upward to the brain and block an artery, thus a stroke.

In the coronaries, disrupted ("ruptured") plaques don't generally shower debris, but permit blood clot formation, resulting in heart attack.

This plaque, however, poses the theoretical risk of both heart attack and stroke because of its strategic location.

Should a plaque like this be handled any differently? I don't think so. But it does provide another reason to take atherosclerotic plaque in any artery seriously.

Comments (1) -

  • Anonymous

    11/12/2008 5:12:00 AM |

    I just had my first heart scan at Boulder, CO.  My heart scan score was zero, but my descending aorta showed as mildly calcified.

    I wonder what conditions determine whether plaque builds up in the coronary arteries versus in the aorta.  

    And I also wonder how mildly calcified would score if it was in the coronary arteries rather than in the aorta.  I know how to interpret the zero heart scan score, but I don't know how to interpret the mildly calcified aorta.  Since it is in the descending aorta, I believe it is less dangerous than the case discussed here.

    Lynn

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A curious case of coronary plaque regression and progression

A curious case of coronary plaque regression and progression

John received a coronary stent in 2003 following a small heart attack. The artery causing the heart attack was a diagonal artery, a branch of the important left anterior descending coronary artery (in the front of the heart). His cardiologist at the time advised him, "Take Lipitor and we'll do stress tests every year. Come back if you have any more chest pain." That was the full extent of John's preventive care.

He came to me for a second opinion and, naturally, we enrolled him in our program. We began by obtaining a CT heart scan score, though we had to exclude the stented diagonal artery. His score: 471. At age 51 and physically active, John had 7 additional abnormal lipoprotein patterns identified. We counseled John on better approaches to food choices, his weight target, fish oil, and correction of all lipoprotein patterns.

Two years later, John's repeat heart scan score: 511 . John was initially disappointed with the increase. But a closer look yielded something entirely different: the right coronary artery and circumflex (no stents) showed 20-30% reduction in their scores. The increase in total score was entirely due to substantial increase in score just outside the stent, in the left anterior descending artery. In other words, all of the increase in score was due to growth of a plaque at the mouth of the stent in the diagonal artery.

This is curious: profound regression of plaque with a big drop in score in the "un-instrumented" arteries, but tremendous growth of plaque and an increase in score in the "instrumented", or stented, artery, all in the same person's heart.

I don't know how controllable this specific situation in the left anterior descending and stented diagonal will be, and I'm unaware of any specific strategies to impact on this situation. The whole world of tissue growth within or around stents is littered with high hopes followed by failures. The drug-coated stents have been the only partial solution to this problem, though that's precisely the sort of stent John received.

Is there a message here? The message I take from this is that you and I should work like mad to keep from receiving a stent. Once they're implanted, we have less control over our coronary future. We can indeed regress ("reverse") coronary plaque. But we may not be able to regress the sort of tissue that grows in response to a stent implantation.
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