How to Proceed?

If you fall into the age groups that I discussed in my last blog, what should you do?  First, remember that this discussion is only about asymptomatic patients. Those that do not have a history of heart attack, stroke or do not suffer from claudication, which is pain in the legs on exertion. 

First and foremost, if you are smoking stop, and after you stop, stay stopped.  Believe me it is not so simple if you judge from what my patients tell me.  Cholesterol levels are not the whole answer.  There is no such thing as a normal cholesterol level.  Each patient’s level is a number and then an atherogenicity potential. Although these can be determined by particle testing and such, our knowledge remains incomplete and our methods crude.

What has been proposed is finding a simple and reliable method to identify which patients have evidence of atherosclerotic changes in their vessels and then try to prevent the furtherance of the disease process by medical i.e. lipid lowering treatment.  We have these methods available to us now and the article cited in my previous blog provides the background for these methods.  One is calcium scoring by electron beam imaging. 

It is fast, simple and accurate.  However, it provides individuals with a small dose of radiation (median 2.3 mSv).  If negative, it virtually excludes significant atherosclerosis and the chance of a cardiovascular event in 5-10 years is .6% at the greatest.

Another modality is carotid ultrasound which is done slightly differently than normal and looks at the intima- media and measures the thickness of it.  This measurement has been shown to correlate with the disease process.  It is not as predictive as calcium scoring but does not use radiation.  It is not clear whether both tests are additive.

Imaging in this manner and using the SHAPE guidelines, it is estimated that almost 50% of the patients screened would be in a higher class and eligible for lipid lowering therapy.  The cost of this screening varies, but some institutions offer it at around $150.

All of the information we have to date supports screening for all patients who have intermediate risk based on Framingham Risk Scores in addition to those patients with low HDLs.  It is very unlikely that a large randomized study will ever be done.  Who wants to be in the placebo group?  We just have to manage with common sense.

Is it true that lipid lowering therapy saves lives?  In my next blog I will explore that.

Tags: calcium scoring, Carotid Ultrasound, Framingham Risk Scores, SHAPE Guidelines
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More On Calcium Scores

My last blog concerned the use of calcium scores to determine whether a patient did or did not have coronary artery disease.  An article has been published that I would like to share with you because it compares the Framingham risk calculator and the use of calcium scoring to determine which is better in defining patient illness.

This article titled “The detection of any coronary calcium outperforms Framingham risk score as a first step in screening for coronary atherosclerosis” was published in the Am J Roentgenol 2010: 194:1235-1243.  The study details that 1416 men and 707 women were included.  The mean age of the men equaled 51.4 years, and the mean age of the women equaled 56.9 years.

In those patients who had a presence of a segment plague score of 4 or higher, any calcium was 98% sensitive in men and 97% sensitive in women.  In the same population if you had a Framingham risk score of 10% or higher, it correlated with the findings only 74% of the time in men and 36% of the time in women.

If your plague segment score was 3 or higher, the presence of calcium was 97% sensitive in men and 92% sensitive in women.  In contrast, the Framingham score of 10% or greater was found in 88% of men and 35% in women.

This is not really surprising as I explained before that the presence of any calcium infers that the patient has the illness and needs to be treated.  It does not mean that they have symptomatic disease but the data can be used to propel the patient to “make the right decision” and stop smoking, control their blood pressure and take statins.  In much the same way the Framingham calculator does that because you input the blood pressure, the smoking status and the LDL level as some of the information to achieve a score.  By “manipulating” the data, one can point out that lowering numbers or stopping smoking reduces risk considerably.

Why the disparity in women and men scores is so great, I do not know.  It is widely understood that the diagnosis of coronary disease in women lags behind men, although equal numbers of men and women die each year.  Perhaps women should have scoring and men the Framingham test and then the numbers would be more reflective of need. 

Technology may help us lead the way to better patient care in both men and women.

Tags: blood pressure, calcium scoring, coronary atherosclerosis, Framingham Risk Calculator
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What Does a Calcium Score Mean?

Technology now aids cardiologists in making decisions as to which patients may or may not have coronary artery disease.  In the past, this was quite difficult and led to many needless tests and the repetition of tests that provided no value to patient care.  As the readers of my blogs know, many pieces of a patients illness can be placed into risk calculators and then a risk can be assigned that will help cardiologists in decision making.  The Framingham calculator is one such tool.  The higher the score the more risk and the more concern with a work up.  There is no one right way to do it.

It has become more and more difficult to do this without substantial interference from insurance companies.  Many now require pre authorization before any work up and this includes cardiac cath.  They are essentially practicing the medicine of NO.  It is very complicated and time consuming to accomplish any sort of work up and this is likely to be the tip of the iceberg.

Now an article in the J AM COLL Cardiol 2010 55:1110-1117 has been published discussing the technique of calcium scoring and its usefulness in both determining who is at risk and when they would need to be tested again.  As it is claimed in the article “what is the warranty for a negative score?”

When atherosclerosis starts in an artery, the artery first gets larger in a process known as positive remodeling.  Only when this process stops does the obstructive phase of atherosclerosis begin so in general angina caused by blocked arteries is a very late phenomenon in the illness.  Calcium is deposited and can be visualized in coronaries early on and this is what is seen on the CT scans.  Using high speed scanners and one pass of the gantry a score can be assigned from zero to over a 1000.  The higher the score
The more risk there is.  If your score is zero, then you are likely to remain free of coronary events for four years according to the article.

This kind of work is useful for both determining the burden of illness and the limiting of downstream tests in an individual patient.  It should in theory allow us to control costs in a meaningful way.  That is if the insurance companies let us.

Tags: Atherosclerosis, calcium scoring, Coronary artery disease
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