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
Posted in Cardiac Imaging | No Comments »

Can We Do Better?

A considerable number of strategies in American medicine are troubling.  One of the most troubling is our insistence on spending large amounts of resources treating illnesses that might be able to be prevented at an earlier stage.  Simple examples are providing better treatment of diabetes and hypertension by making the drugs and materials needed more readily available to patients.

As the readers of my blogs know, a large proportion of this country’s resources go to treating coronary artery disease and its consequences.  Couldn’t we do better if we prevented this?  Roughly 50% of the major cardiovascular events that occur in this country every year, which by the way amounts to over 700,000, occur without warning.  At the time of writing in 2006, it was felt that by implementing the SHAPE recommendations 21.5 billion dollars could be saved.

This subject has been discussed before.  In 2006 a taskforce was developed to address this problem and provided the SHAPE guidelines.  SHAPE stands for Screening for Heart Attack Prevention and Education.  It was a committee set up by big Pharma mostly Pfizer and never received much support mostly because it would make heavy use of drugs i.e. Lipitor, made by Pfizer, in its prevention mode.

This past week one of the editorial leaders of the SHAPE study Dr. Prediman Shah was the lead author on an article published in the Journal of the American College of Cardiology titled Screening Asymptomatic Subjects for Subclinical Atherosclerosis .  I want to point out that Dr. Shah, who practices at Cedars Sinai in Los Angeles, is a widely published and respected researcher.

Screening for disease, although it sounds like a perfect solution, is sometimes no solution at all.  One can point to the use of the PSA test for prostate disease.  Screening with it has not led to changes in the diagnosis of advanced prostate disease or lowered the death rate of prostate cancer.  Recently, the physician who invented the test wrote that he thought our use of it should be reevaluated.

SHAPE recommended that all asymptomatic men 45-75 years old and all women 55-75 years old be screened.  There are two main ways this is done.  The first is the Framingham Risk Score that I have blogged about in the past.  This score which identifies the risk of events in ten and twenty year periods has been found to be useful.  It is highly dependent on blood pressure and cholesterol values as those were the only modalities available at the time.  If you go to the online calculator fiddle with the numbers so you can see the changes in risk that occur.  Guess what?  This approach has never been subjected to a randomized clinical trial and at this point never will be because it is not ethical. 

Next…what about imaging?

Tags: SHAPE Guidelines
Posted in Cholesterol, Coronary Artery Disease, High Blood Pressure, diabetes | No Comments »