In response to an earlier Heart Scan Blog post, I don't care about hard plaque!, reader Dave responded:
Hello Dr Davis,
Interesting post about hard and soft plaque. I recently had a discussion with my GP regarding my serious increase in scan score (Jan 2006 = 235, Nov 2007 = 419).
After the first scan we started aggressively going after my LDL, HDL and Trig...196,59,221
And have them down to 103, 65, 92 - we still have a way to go to 60/60/60 [The Track Your Plaque target values]-
So the increase is a surprise, but my doctor said that the increase could in part be cause some of the soft plaque had been converted to hard plaque and the scan would show that conversion.
Dave's doctor then responded to him with this comment:
"Remember that although your coronary calcium score has gone up, this does not mean that you are at greater risk than you were a year ago. Remember that the most dangerous plaque is the not-yet calcified soft plaque, which will not show up on an EBT [i.e., calcium score]. It is only the safe, calcified plaque that can be measured with the EBT. [Emphasis mine.] For your score to go up like it did, while your lipids came down so much, what had to happen was that lots of dangerous unstable plaque was converted to stable, calcified plaque . There are no accepted guidelines for interpreting changes in calcium scores over time, because the scores tend to go up as treatment converts dangerous plaque to safer plaque . We do know that aggressively lowering LDL reduces both unstable and stable plaque, and we know that risk can be further lowered by adjuvant therapy such as I listed above."
This bit of conventional "wisdom" is something I've heard repeated many times. Is it true?
It is absolutely NOT true. In fact, the opposite is true: Dave's substantial increase in heart scan score from 235 to 419 over 22 months, representing a 78% increase, or an annualized rate of increase of 37%. This suggests a large increase in his risk for heart attack, not a decrease. Big difference!
Dr. Paulo Raggi's 2004 study, Progression of coronary artery calcium and risk of first myocardial infarction in patients receiving cholesterol-lowering therapy in 495 participants addresses this question especially well. Two heart scans were performed three years apart, with a statin drug initiated after the first scan, regardless of score.
During the period of study, heart attacks occurred in 41 participants. When these participants were analyzed, it was found that the average annual increase in score over the three year period was 42%. The average annual rate of increase in those free of heart attack was 17%. The group with the 42% annual rate of increase--all on statin drugs--the risk of heart attack was 17.2-fold greater , or 1720%.
The report made several other important observations:
--20% of the heart attack-free participants showed reduction of heart scan scores, i.e., reversal. None of the participants experiencing heart attack had a score reduction.
--Only 2 of the 41 heart attacks occurred in participants with <15% per year annual growth, while the rest (39) showed larger increases.
--The intensity of LDL reduction made no difference in whether heart attacks occurred or not. Those with LDL<100 mg/dl fared no better than those with LDL>100 mg/dl.
Dr. Raggi et al concluded:
"The risk of hard events [heart attack] was significantly higher in the presence of CVS [calcium volume score] progression despite low LDL serum levels, although the interaction of CVS change and LDL level on treatment was highly significant. The latter observation strongly suggests that a combination of serum markers and vascular markers [emphasis mine] may constitute a better way to gauge therapeutic effectiveness than isolated measurement of lipid levels."
This study demonstrates an important principle: Rising heart scan scores signal potential danger, regardless of LDL cholesterol treatment. Yes, LDL reduction does achieve a modest reduction in heart attack, but it does not eliminate them--not even close.
These are among the reasons that, in the Track Your Plaque program, we aim to correct more than LDL cholesterol. We aim to correct ALL causes of coronary plaque, factors that can be responsible for continuing increase in heart scan score despite favorable LDL cholesterol values.
So, Dave, please forgive your doctor his misunderstanding of the increase in your heart scan score. He is not alone in his ignorance of the data and parroting of the mainstream mis-information popular among the statin-is-the-answer-to-everything set.
Just don't let your doctor's ignorance permit the heart attack that is clearly in the stars. Take preventive action now .