"Inositol Hexanicotinate is the true 'flushless niacin.' Unlike 'sustained-release' niacin, which is just regular niacin in a pill which dissolves more slowly, Inositol Hexanicotinate is a niacin complex, formed with the B-vitamin-like inositol. When you take an IHN supplement, the central inositol ring gradually releases niacin molecules, one at a time delivering true niacin. This, like “sustained-release” niacin, allows you to take niacin at clinically-proven doses without going crazy with the itch."

That above bit of nonsense adorns one manufacturers sales pitch for its no-flush niacin. No-flush niacin is one of the biggest scams in the health food store.

Ordinarily, I love health food stores. There's lots of fun and interesting things available that pack real power for your health program. Unfortunately, there's also outright nonsense. No-flush niacin is absolute nonsennse.

No-flush niacin is inositol hexaniacinate, or an inositol molecule complexed with 6 niacin molecules. So it really does contain niacin. However, although it works in rats, it exerts no known effect in humans.

Just Friday, a 41-year old woman came to my office for consultation because her doctor didn't know what to do with lipoprotein(a). She had seen a cardiologist who told her to take no-flush niacin. Both the cardiologist and the patient were therefore puzzled when lipoprotein(a) showed no drop and, in fact, was slightly higher on the no-flush preparation.

The lack of any observable effect and no studies whatsoever showing a positive effect (there is one study demonstrating no effect), manufacturers continue to manufacture it and health food stores continue to push it as an alternative to niacin that causes the flush. It's quite expensive, commonly costing $30-$50 for 100 tablets.

Don't fall for this gimmick. Niacin is among the most helpful of treatments for gaining control over coronary plaque. It raises HDL, corrects small LDL, reduces triglycerides (along with its friend, fish oil, of course), reduces lipoprotein(a), and dramatically contributes to reduced heart attack risk. No-flush niacin does none of this. Track Your Plaque Members: For a thorough discussion of niacin--how to use it, what preparations work and which do not, read Niacin: Ins and outs, ups and downs on the www.cureality.com website.

Lots of smokers, especially younger smokers, rationalize their habit by telling themselves that they'll stop if and when any hint of adverse health effects develop.

The problem is that, even in the first decade of smoking, dramatic and profound effects can develop--but you won't know it.

One of the most graphic examples of this I see every day in people who have heart scans. While CT heart scans are, of course, for identification of coronary plaque/coronary disease, they're also great for visualizing the lungs.

This man is a light smoker. The lungs are the black tissues (that's normal) on either side of the (white) heart in the center. Now, note the holes in the lung tissue. That's what they literally are: holes left by the destrucive, tissue-eating effects of cigarette smoking.

How common are the holes (or emphysematous "blebs", as they're called in medical lingo)? Very common. You'll even see them in 30-somethings who've smoked only a few years.

These are holes that have nothing in them. The lung tissue that was destroyed to create the hole will never grow back, even when smoking stops. The holes in this example are actually small to average in size. I've seen much bigger. And this only represents the early stages of lung tissue destruction. A long-time heavy smoker shows all other sorts of abnormalities.

Whenever I show these "black holes" to people who smoke, they are horrified and I've actually gotten many people to quit. Take the opportunity to quit as soon as you can if you smoke.

Sometimes, small LDL is easy to get rid of. Take niacin, for instance, and it can simply disappear from your body.

But other times, it can be aggravatingly persistent. Several times every day, in fact, I need to run through the checklist of strategies to reduce small LDL with patients.

How important is small LDL? In my experience, it is among the most potent causes behind coronary plaque known. It's a big part of the explanation why some people at an LDL of cholesterol of X mg/dl will have heart disease, while others with the same X mg/dl of LDL will not. When present, small LDL particles are much more likely to trigger atherosclerotic plaque formation. Small LDL particles magnify Lp(a)'s ill-effects tremendously. The data vary but small LDL probably increases heart attack risk at least three-fold.

Here's a checklist of strategies that I advise patients to consider to minimize the small LDL pattern:

--Lose weight to ideal weight--This is very important and effective.

--Fish oil--A relatively small effect unless triglycerides are high to begin with.

--Reduction of wheat products--This can provide a BIG effect. More precisely, a reduction in high-glycemic index foods is effective. But the biggest day-to-day high-glycemic food culprits are wheat products like breads, pasta, crackers, chips, pretzels, and breakfast cereals. "You mean whole wheat bread makes small LDL?!" Yup.

--Reduction of sweets--For the same reasons as reducing wheat products.

--Add raw almonds and walnuts--1/4 to 1/2 cup per day.

--Replace wheat products with OAT products, especially oat bran. This does NOT mean oat-containing breakfast cereals with added sugar and wheat, e.g., Honey Nut Cheerios, Cracklin' Oat Bran Cereal, etc. You might as well eat candy. Buy oat bran as plain oat bran--nothing added. Use it as a hot cereal or added to yogurt, "breading" for chicken, etc.

--Vitamin D--A variable effect, likely resulting from its beneficial effects on "insulin resistance".

--Exercise

--Niacin--Very effective but not always enough.

Among the choices, my favorites are weight loss, niacin, and reduction of wheat products. Those will give you the biggest bang for your buck.

A group of 60- and 70-somethings were standing in the anteroom to the cardiac rehabilitation center. All (males) had their T-shirts pulled up, comparing their coronary bypass scars.

It reminds me of war veterans comparing their war wounds. The scars of suffering, of having "conquered" and won a war with a common enemy, a badge of courage.

This is part of the broad social acceptance of bypass surgery and other major procedures for heart disease. Hospitals support it. They do it for the psychological support for patients enduring a difficult process. Often, talking about a shared experience can be a helpful purge for the fears and frustrations of a traumatic event.

Curious thing, though. I've actually had people request bypass surgery simply because all their friends have had one. No kidding. "I just figure my time is coming. I might as well get it over with."

Get the picture? We've had a battle with heart disease and the hospitals have won. The enormous success of hospitals over the last 20 years is not because of delivering babies, it's not from psychiatric hospitalization, it's not from cancer treatment. It's from heart disease. The largest floors in the hospital are usually the cardiac floors. The bulk of revenues and profit are from heart disease.

If I manufacture widgets and each widget I sell makes me scads of money, guess what? I want to sell more and more widgets. I'll persuade people they need my widgets even if they don't. Perhaps I'll even persuade them that buying one is a noble cause. Maybe I'll subtly suggest that I am a charitable operation and I only sell my products for the public good. I could even name my company after a saint. Personal profit--absolutely not!

Ignore the hype. See hospitals and their "products" for what they are: A necessary service--some of the time; profitable products that they hope to sell to more and more people most of the time.

Tim's CT heart scan score was an earth-shattering 3,447, clearly in the upper stratosphere of percentile rank. Risk of heart attack: 25% per year. At age 58, it was a wonder that nothing had happened yet.

Tim went to the Cleveland Clinic for an opinion, long a powerful bastion of heart procedures. The consulting cardiologist told Tim, "We don't believe in heart scans. They're wrong too often."

An opinion from a widely-respected cardiovascular center. If they don't "believe" in heart scans, does that mean they "believe" in stents and bypass surgery? Does it mean that the thousands of research studies that have now been published on the value of heart scanning are pure fiction? Is there a choice to believe or not believe?

I continue to be shocked at the extraordinary ignorance on the topic of heart scanning among my colleagues. The number one killer of Americans and you still rely on stress tests?

Why this perception that heart scans are "wrong too often"? What this cardiologist means, I believe, is that when people are taken to the cath lab for catheterization, a substantial number of those with positive heart scan scores don't have "blockage". But I could have told him that even before the heart catheterization.

There is an expected and well-documented likelihood of finding significant "blockage" based on your heart scan score. At Tim's scary score of 3,447, what is the likelihood of "blockage" of 50% or more? It's around 40-50%. That means that half the people at this score will have a blockage sufficient to justify inserting stents or undergoing bypass surgery, half will not. There will indeed be many plaques, but none severe enough to block flow.

Does that make the heart scan wrong? I don't think it does. Just because you don't need a major procedure to "fix" blockages does not mean that no heart disease is present. Without preventive efforts, Tim's heart attack risk remains an alarming 25% per year--whether or not he gets stents or bypass. The only treatments that substantially reduce this risk (in an asymptomatic person) are preventive efforts, not procedures.

Yet cardiologists like the one Tim consulted at the Cleveland Clinic regard heart scans as something "he doesn't believe in". I would suggest a return to the textbooks and published literature and re-thinking how heart disease should be managed.

Heart scans should provide an opportunity for prevention, not an opportunity for profit.

Despite its apparent simplicity, there’s a lot of thought and wisdom in the Rule of 60.

What if you achieve only a single value in the Track Your Plaque “Rule of 60”? What if, for instance, you got LDL down to 60 mg/dl, but ignored the fact that your HDL was 41 mg/dl and triglycerides were up to 145 mg/dl? Can you still do pretty well?

Probably not. In fact, this specific combination of low HDL and high triglycerides tells me several things:

1) LDL is really much higher than suggested by the 60 mg/dl, which is a calculated value, often much higher. Recall that calculated LDL is prone to immense inaccuracy. When measured, the LDL is commonly somewhere between 120 and 160 mg/dl. However, when you raise HDL to 60 and reduce triglycerides to 60, much of the inaccuracy is removed, i.e., calculated LDL becomes more accurate. LDL can be measured as LDL particle number (NMR), apoprotein B, or direct LDL.

2) LDL particles are small. This is yet another reason why the weight-based LDL measures can be inaccurate. Imagine you have two identical glass jars full of marbles. One jar has small marbles, the other has large marbles, but both jars have the same weight in marbles. Which jar has more marbles? The one with small marbles, of course. The same phenomenon occurs with LDL particles: at the same weight, you can have different numbers of LDL particles. It’s the number of particles that better determine risk for heart disease, not the weight.

3) Triglycerides of 145 mg/dl is actually below the target advised by the National Cholesterol Education Panel Adult Treatment Panel-III guidelines, i.e., you’re okay by conventional standard. But look beneath the surface, and you’ll find that triglycerides at 145 mg/dl are associated with flagrant excesses of VLDL lipoprotein particles and a greater likelihood of a postprandial (after-eating) disorder (increased IDL or postprandial triglycerides), both of which add to coronary plaque.

4) This pattern is also commonly associated with higher blood sugar, higher blood pressure, increased inflammation (e.g., C-reactive protein), increased fibrinogen—all the facets of the metabolic syndrome, or pre-diabetes.

In fact, some of the most aggressive plaque growth—increasing heart scan scores—will occur with this specific pattern. So just achieving one facet of the Track Your Plaque Rule of 60 does not suffice. It’s the whole package that really stacks the odds in your favor of stopping or dropping your heart scan score.

The Track Your Plaque recommended targets for conventional lipids (i.e., LDL, HDL, triglycerides) are LDL 60 mg/dl, HDL 60 mg/dl, and triglycerides 60 mg/dl: 60-60-60.

Not only is this set of values easy to remember—60-60-60—but is grounded in science and the results of clinical trials.

LDL 60 mg/dl
The LDL target is based on experiences such as that of the Reversal Trial, the PROVE-IT Trial, and the Asteroid Trial, all of which showed that LDL cholesterol values in the range of 60 mg/dl dramatically enhance the likelihood of stopping plaque growth or achieving regression, reducing risk of heart attack more than more lenient LDL targets.

HDL 60 mg/dl
Achieving HDL cholesterol of 60 mg/dl is not as well grounded as LDL targets, mostly because increasing HDL is more difficult. There’s also no tremendously profitable way to raise HDL, as there is for reducing LDL (statin drugs). But epidemiologic observations strongly suggest that HDL of 60 mg/dl provides maximum control over both coronary plaque growth, as well as slashing rates of heart attack. Numerous smaller trials have borne this phenomenon out.

Triglycerides 60 mg/dl
Triglycerides of 60 mg/dl is based principally on studies that have shown a virtual elimination of abnormal lipoproteins, especially small LDL, when this value is achieved. Reduction of triglycerides is an effective means to reduce hidden lipoproteins like small LDL and VLDL. Triglycerides in the conventionally acceptable range of 100-150 mg/dl can be associated with dramatic abnormalities of lipoproteins.

Thus, the Track Your Plaque “Rule of 60”. In our day to day experience of trying to stamp out plaque growth from its terrifyingly rapid 30% per year, or reversing it—-dropping your heart scan score—-the Rule of 60 has held up time and again. Getting your lipids to 60 mg/dl does not guarantee that plaque growth stops, but it appears to be a necessary requirement that tips the scales heavily in your favor.

Those of you who’ve discussed lipid targets with your doctor will quickly recognize that the Track Your Plaque targets appear laughably ambitious, perhaps unnecessary. Recall that your doctor likely has no idea of what coronary plaque regression means. He/she likely conforms to the lax targets set by the National Cholesterol Education Panel (NCEP). (These targets depend on a number of factors such as whether you’re diabetic, sex, risk factors, etc.) Based on trial experiences like the few mentioned above, as well as my experience with purposeful coronary plaque reversal, the lipid guidelines as advocated by NCEP guarantee heart disease. Let me emphasize that again: Follow the guidelines set by the NCEP for your doctor to follow, and progression of heart disease is a virtual certainty. At best, it may slow growth of plaque and delay your heart attack or bypass surgery, but it will not stop it.

Now, that point made, let me make another: Just knowing about the targets and even becoming a member of the Track Your Plaque program does not mean that your lipids with automatically go to 60-60-60. We’ve actually had an occasional person tell us that they were disappointed that, by becoming Members, why hadn’t their lipids gone to 60-60-60?

Knowing that the 60-60-60 targets provide real advantage is not the same as actually achieving them.

The British National Health Service (NHS) has announced that, in light of the substantial data documenting that omega-3 fatty acid intake from fish reduces likelihood of cardiovascular events by around 40%, that Brits discharged from hospital following a heart attack should be "prescribed" 1000 mg of prescription fish oil per day.

Hardly a revolutionary concept. Part of the timidity of the British NHS seems to relate to the potential cost to the government, since apparently much of the cost will be borne by the government-subsidized health system.

But prescription fish oil? Why prescription fish oil? Prescription Omacor, one capsule per day, costs around $70 (U.S.) per month. If I go to Sam's Club the same quantity of omega-3 fatty acids (in three capsules) will cost around $2.50. That's less than 5% of the cost of the prescription form.

Omacor is clearly more concentrated. But is the prescription form better--more effective, more purified, less contaminated, etc.? I have seen no independent verification of this. Of course, manufacturers make all sorts of claims. The only independent, unbiased testing I'm aware of comes from organizations like Consumer Reports and www.consumerlabs.com. Omacor has not been compared to non-prescription fish oil in any of their analyses. Head-to-head comparison of Omacor to nutritional supplement fish oil is unlikely to come from Solvay, the manufacturer of Omacor. Drug companies powerfully resist head-to-head comparisons, fearing it will not play out in their favor. Let the public remain ignorant and hope marketing conquers all.

Why would the NHS only recommend eating fish and prescription fish oil? I don't know, but it smells awfully fishy to me. As soon as an opportunity for profit is built into a treatment, all of a sudden it gains endorsement. Perhaps lobbying by those parties with potential for profit drove the process.

Nonetheless, despite the filthy politics and under-the-table dealings, some good comes out of the NHS's action: broader recognition of the power of fish oil. Perhaps when a British patient or an American patient gets discharged with a prescription for Omacor, the patient will take the initiative and go to the health food store instead and save him (or his insurer) $67.50 per month.

For your coronary plaque control program and control and/or reversal of your heart scan score, we start at 4000 mg per day of standard fish oil, providing 1200 mg per day of omega-3 oils. This amount as a nutritional supplement costs only a few dollars a month. And you have the satisfaction of not only taking a powerful step for your health, but also not enriching the overflowing pockets of drug companies.

Doctors "don't have enough time to educate their patients and to stop and think about what measures the patient really needs," says Dr. Raymond Gibbons, new head of the American Heart Association.

Dr. Gibbons highlighted how the system reimburses generously for performing procedures, but reimburses relatively little (often just a few dollars) for providing preventive counseling. He claims to have several ideas for solutions.

Good for Dr. Gibbons. There's no doubt that the lack of truly effective preventive information and counseling is a systemic, built-in flaw in the current medical environment. It is especially true in heart disease.

Another problem: "If a doctor didn't say it, it must not be true." That's the attitude of many of my colleagues. Despite their broad and systematic failure to provide preventive counseling, most physicians (my colleagues the cardiologists especially) pooh-pooh information that comes from other sources. Yet, it's my prediction that much of healthcare will go the way of optometry--direct access to care, often delivered in non-healthcare settings like a store or mall. People are hungry for truly self-empowering health information. Too many physicians can't or won't provide it. You've got to turn elsewhere for it.

That's one of the main reasons I set up the Track Your Plaque program. It's direct access to self-empowering information. A flaw: You still require the assistance of a physician to obtain lab values, lipoproteins, and to monitor certain treatments (e.g., niacin at higher doses). If I knew of a way around this, I'd tell you. But right now I don't. We remain constrained by legal and moral obligations.

Nonetheless, phenomena like CT heart scanning and the Track Your Plaque program are just a taste of things to come.

Since the recent reader question about Lp(a), I've had several other instances of confusion over Lp(a).

To help you navigate through some of the often confusing issues behind this complex genetic abnormality, here are some common sense rules to follow. When you ask your doctor to draw a Lp(a), try to be certain that:

--the same laboratory is always used. Just going from lab to lab can account for huge variation in Lp(a). As standardization proceeds internationally, this will be become less important. But in 2006, it's still an issue.

--you and your doctor resist the temptation to check Lp(a) frequently. I saw a patient recently who was having Lp(a) levels nearly every month. This is pointless. Lp(a) changes very slowly. Checking it frequently will not allow any treatment to be fully reflected. All you'll observe is random variation that can be frustrating. We wait at least 6 months before re-checking after a new treatment is introduced.

If you have a choice, I would recommend you opt for the measure provided by Liposcience (NMR). The technique they use is a particle count measure, rather than a weight-based measure. This may be more accurate, particularly when Lp(a) is small.

Lp(a) remains among the more difficult patterns to understand and correct. Don't be surprised if you encounter a lot of confusion from your doctor, as well. You may end up providing much of his/her education.

Another in a series of data extrapolations that attempt to predict long-term cancer risk from medical radiation exposure was published in the July 13, 2009 Archives of Internal Medicine, viewable here.

Over the years, I've fussed about the radiation dose used by some centers for CT heart scans. (Note: I'm talking about CT heart scans, not CT coronary angiograms, an entirely different test with different radiation exposure.) In the "old" days, when electron-beam devices (EBT) were the best on the block, the old single-slice CT scanners (the predecessor of the current 64-slice MDCT scanners) exposed patients to ungodly quantities of radiation, while the EBT devices required very small quantities (0.5 mSv or about the equivalent of 4 standard chest x-rays or one mammogram).

But CT technology has advanced considerably. While EBT has been phased out (although it was an exceptional technology, GE acquired the small California manufacturer, then promptly scrapped the operation; you can guess why), multi-detector CT (MDCT) technology has improved in speed, image quality, and radiation exposure.

While it has improved, radiation exposure still remains an issue. The authors of the study applied the scanning protocols used at three hospitals and those in several CT heart scan studies, then calculated radiation exposure. They found a more than ten-fold range of exposure, from 0.8 mSv to 10.5 mSv. (All scanners were MDCT, none EBT.)

That's precisely what I've been worrying about: In the rapid rush to develop new devices, radiation exposure has often been a neglected issue. While some scan centers do an excellent job and take steps to minimize exposure, others barely lift a finger and consequently expose their patients to unnecessary radiation.

However, it's not as bad as it sounds. For one, the study included 16-slice MDCT scanners, a scanner type that I warned people to not use because of radiation. On the current most popular 64-slice devices, much lower radiation exposure is possible, on the order of 0.8-1.2 mSv routinely--if the center takes the effort.

This study, while eye-opening, will achieve some good: CT heart scans are here to stay. But the day-to-day practice of heart scanning should be:

1) standardized
2) conducted with radiation exposure as low as possible, preferably <0.8 mSv

To read more about this issue, below I've reprinted a 2007 full Track Your Plaque Special Report, CT Heart Scans and Radiation: The Real Story.

CT heart scans and radiation: The real story

“My personal opinion is that many patients today who are receiving multiple CT scans may well be getting at least comparable doses to subjects that have now developed malignancies from x-ray radiation received in the 1930s and '40s. And, similar to those days when the doses were unknown, the dose that patients receive today over a course of years of multiple CT scans is also completely unknown . . .

“I recommend that all healthcare providers become familiar with the concept that 1 in 1000 CT studies of the chest, abdomen, or pelvis may result in cancer.”

Richard C. Semelka, MD

Professor and Vice Chairman, Department of Radiology

University of North Carolina–Chapel Hill

Is this just hype to generate headlines? Or is the truth buried in the enormous marketing clout of the medical device industry, among which the imaging device manufacturers reign supreme?

It’s been over 110 years since radiation was first used for medical imaging. Over those years, it has had its share of misadventures.

In the 1930s and 1940s, before the dangers of radiation were recognized, shoe shoppers had shoes fitted using an x-ray device of the foot to assess fit. High doses of radiation were used to shrink enlarged tonsils and extinguish overactive thyroid glands. Attitudes towards radiation were so lax that doctors commonly permitted themselves to be exposed without protection day after day, year after year, until an unexpected rise in blood cancers like leukemia was observed. As recently as the 1970s and 1980s, cancers like Hodgkins’ disease were treated with high doses of radiation, also leading to radiation-induced diseases decades later.

Not all radiation is bad. Radiation can also be used as a therapeutic tool and even today remains a useful and reasonably effective method to reduce the size, sometimes eliminate, certain types of cancer. Forty percent of people with cancer now receive some form of radiation as part of their treatment (Ron E 2003).

Just how much does medical radiation add to our exposure?

Estimates vary, but most experts estimate that medical imaging provides approximately 15% of total lifetime exposure. In other words, radiation exposure from medical imaging is simply a small portion of total exposure that develops over the years of life. Exposure can be much higher, however, in a specific individual who undergoes repeated radiation imaging or treatment of one sort or another.

For all of us, exposure to medical radiation is part of lifetime exposure from multiple sources, added to the radiation we receive from the world around us. Just by living on earth, we are exposed to radiation from space and naturally-occurring radioactive compounds, and receive somewhere around 3.0 mSv per year (U.S. Nuclear Regulatory Commission). (Doses for radiation exposure are commonly expressed in milliSieverts, mSv, a measure that reflects whole-body radiation exposure.) People living in high-altitude locales like Colorado get exposed to an additional 30–50% ambient radiation (1.0–1.5 mSv more per year).

Much of the information on radiation exposure comes from studies like the Life Span Study that, since 1961, has tracked 120,000 Japanese exposed to radiation from the atomic bombs dropped in 1945 (Preston DL et al 2003). Although regarded as a high-dose exposure study for obvious reasons, there are actually thousands of people in this study who were exposed to lesser quantities of radiation (because of distance from the bomb sites) who still display a “dose-response” increased risk for cancer many years later in life. Radiation exposures of as little as 5–20 mSv showed a slight increase in lifetime risk.

Occupational and excessive medical exposure to radiation also provides a “laboratory” to examine radiation risk. Miners exposed to radon gas; patients exposed to the imaging agent, Thorotrast, containing radioactive isotope thorium dioxide and used as an x-ray contrast agent in the 1930s and 1940s and possesses the curious property of lingering in the body for over 30 years after administration; radium injections administered between 1945 and 1955 to treat diseases like ankylosing spondylitis and tuberculosis, all provide researchers an opportunity to study the long-term effects of various types of radiation exposure over many years (Harrison JD et al 2003).

The excess exposure of workers and several hundred thousand nearby residents to the Mayak nuclear plant in Russia has also revealed a “dose-response” relationship, with increasing exposure leading to more cancers, including leukemia and solid cancers of the bone, liver, and lung (Shilnikova NS et al 2003). Nuclear waste released into the Techa river between 1948 and 1956 contaminated drinking water used by over 100,000 Russians. A plant explosion in 1957 also released an excess of radiation into the atmosphere, yielding exposure via inhalation. Some sources estimate that at least 272,000 people have been affected by radiation from the Mayak plant. This unfortunate situation has, however, yielded plenty of data on radiation exposure and its long-term effects.

It’s also been known for several decades that people who receive therapeutic radiation for treatment of cancer, even with the reduced doses now employed, are subject to increased risk of a second cancer consequent to the radiation treatment.

From experiences like this, radiation experts estimate that an exposure of 10 mSv increases a population’s risk for cancer by 1 in 1000 (Semelka RC et al 2007).

This question was recently thrust into the spotlight with publication of a study from Columbia University in New York suggesting that a 20-year old woman would be exposed to a lifetime risk of cancer as high as 1 in 143 consequent to the radiation received during a CT coronary angiogram. (Important note: This was estimated risk from a CT coronary angiogram, not a simple heart scan that we advocate for the Track Your Plaque program.) The risk at the low end of the spectrum would be in an 80-year old man (because of the shorter period of time to develop cancer), with a risk of 1 in 5017. If “gating” to the EKG is added (which many scan centers do indeed perform nowadays), risk for a 60-year old woman is estimated at 1 in 715; risk for a 60-year old male, 1 in 1911 (Einstein AJ et al 2007). This study generated some criticism, since it did not directly involve human subjects, but used “phantoms” or x-ray dummies to simulate x-ray exposure. Nonetheless, the point was made: CT coronary angiograms in current practice do indeed expose the patient to substantial quantities of radiation, sufficient to pose a lifetime risk of cancer.

The media frenzy

The NY Times ran an article called With Rise in Radiation Exposure, Experts Urge Caution on Tests in which they stated:

"According to a new study, the per-capita dose of ionizing radiation from clinical imaging exams in the United States increased almost 600 percent from 1980 to 2006. In the past, natural background radiation was the leading source of human exposure; that has been displaced by diagnostic imaging procedures, the authors said."

“This is an absolutely sentinel event, a wake-up call,” said Dr. Fred A. Mettler Jr., principal investigator for the study, by the National Council on Radiation Protection. “Medical exposure now dwarfs that of all other sources.”

Radiation is a widely used imaging tool in medicine. Although CT scans of the brain, bones, chest, abdomen, and pelvis account for only 5% of all medical radiation procedures, they are responsible for nearly 50% of medical radiation used. It’s been known for years that increasing radiation exposure increases cancer risk over many years, but the boom of newer, faster devices that provide more detailed images has opened the floodgates to expanded use of CT scanners.

But before we join in the hysteria, let's first take a look at exposure measured for different sorts of tests:

Typical effective radiation dose values for common tests

Computed Tomography

Head CT 1 – 2 mSv
Pelvis CT 3 – 4 mSv
Chest CT 5 – 7 mSv
Abdomen CT 5 – 7 mSv
Abdomen/pelvis CT 8 – 11 mSv
Coronary CT angiography 5 – 12 mSv

Non-CT

Hand radiograph Less than 0.1 mSv
Chest radiograph Less than 0.1 mSv
Mammogram 0.3 – 0.6 mSv
Barium enema exam 3 – 6 mSv
Coronary angiogram 5 – 10 mSv
Sestamibi myocardial perfusion (per injection) 6 – 9 mSv
Thallium myocardial perfusion (per injection) 26 – 35 mSv

Source: Cynthia H. McCullough, Ph.D., Mayo Clinic, Rochester, MN

A plain, everyday chest x-ray, providing less than 0.1 mSv exposure, provides about the same quantity of radiation exposure as flying in an airplane for four hours, or the same amount of radiation from exposure to our surroundings for 11–12 days. Similar exposure arises from dental x-rays.

If you have a heart scan on an EBT device, then your exposure is 0.5-0.6 mSv, roughly the same as a mammogram or several standard chest x-rays.

With a heart scan on a 16- or 64-slice multidetector device, exposure is ideally around 1.0-2.0 mSv, about the same as 2-3 mammograms, though dose can vary with this technology depending on how it is performed (gated to the EKG, device settings, etc.)

CT coronary angiography presents a different story. This is where radiation really escalates and puts the radiation exposure issue in the spotlight. As Dr. Cynthia McCullough's chart shows above, the radiation exposure with CT coronary angiograms is 5-12 mSv, the equivalent of 100 or more chest x-rays or 20 mammograms. Now, that's a problem.

The exposure is about the same for a pelvic or abdominal CT. The problem is that some centers are using CT coronary angiograms as screening procedures and even advocating their use annually. This is where the alarm needs to be sounded. These tests, as wonderful as the information and image quality can be, are not screening tests. Just like a pelvic CT, they are diagnostic tests done for legitimate medical questions. They are not screening tests to be applied broadly and used year after year.

It’s also worth giving second thought to any full body scan you might be considering. These screening studies include scans of the chest, abdomen, and pelvis. These scans, performed for screening, expose the recipient to approximately 10 mSv of radiation (Radiological Society of North American, 2007). Debate continues on whether the radiation exposure is justified, given the generally asymptomatic people who generally undergo these tests.

Always be mindful of your radiation exposure, as the NY Times article rightly advises. However, don't be so frightened that you are kept from obtaining truly useful information from, for instance, a CT heart scan (not angiography) at a modest radiation cost.

Heart scans, CT coronary angiograms and the future

Unfortunately, practicing physicians and those involved in providing CT scans are generally unconcerned with radiation exposure. The majority, in fact, are entirely unaware of the dose of radiation required for most CT scan studies and unaware of the cancer risk involved. It is therefore up to the individual to insist on a discussion of the type of scanner being used, the radiation dose delivered (at least in general terms), the necessity of the test, alternative methods to obtain the same diagnostic information, all in the context of lifetime radiation exposure.

Our concerns about radiation exposure all boil down to concern over lifetime risk for cancer, a disease that strikes approximately 20% of all Americans. Many factors contribute to cancer risk, including obesity, excessive saturated fat intake, low fiber intake, lack of vitamin D, repeated sunburns, excessive alcohol use, smoking, exposure to pesticides and other organochemicals, asbestos and other industrial exposures, electromagnetic wave exposure, and genetics. Radiation is just one source of risk, though to some degree a controllable one.

Some people, on hearing this somewhat disturbing discussion, refuse to ever have another medical test requiring radiation. That’s the wrong attitude. It makes no more sense than wearing lead shielding on your body 24 hours a day to reduce exposure from the atmosphere. Taken in the larger context of life, radiation exposure is just one item on a list of potentially harmful factors.

It is, however, worth some effort to minimize radiation exposure over your lifetime, particularly before age 60, and by submitting to high-dose testing only when truly necessary, or when the potential benefits outweigh the risks. Thus, with heart scans and CT coronary angiography, some thought to the potential benefits of knowing your score or the information gained from the CT angiogram need to be considered before undergoing the test. Often the practical difficulty, of course, is that your risk for heart disease simply cannot be known until after the test.

In our view, in the vast majority of instances a simple CT heart scan can serve the simple but crucial role of quantifying risk for heart attack and atherosclerotic plaque. CT heart scans yield this information with less than a tenth of the radiation exposure of a CT coronary angiogram. In people without symptoms and a normal stress test, there is rarely a need for CT coronary angiography with present day levels of radiation exposure. Perhaps as technology advances and the radiation required to generate images is reduced, then we should reconsider.

Early experiences are suggesting that the newest 256-slice scanners, now being developed but not yet available, will cut the dose exposure of 64-slice CT angiograms in half (from 27.8 mSv to 14.1 mSv in a recent Japanese study). The 256-slice scanners will allow scanning that is faster over a larger area in a given period of time.

Thankfully, the scanner manufacturers are increasingly sensitive to the radiation issue and have been working on methods to reduce radiation exposure. However, it still remains substantial.

References:
Einstein AJ, Henzlova MJ, Rajagopalan S. Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography. JAMA 2007 Jul 18;298(3):317–323.

Harrison JD, Muirhead CR. Quantitative comparisons of cancer induction in humans by internally deposited radionuclides and external radiation. Int J Radiat Biol 2003 Jan;79(1):1–13.

Hausleiter J, Meyer T, Hadamitzyky M et al. Radiation Dose Estimates From Cardiac Multislice Computed Tomography in Daily Practice: Impact of Different Scanning Protocols on Effective Dose Estimates. Circulation 2006;113:1305–1310.

Kalra MK, Maher MM, Toth TL, Hamberg LM, Blake MA, Shepard J, Saini S. Strategies for CT radiation dose optimization. Radiology 2004;230:619–628.

Mayo JR, Aldrich J, Müller NL. Radiation exposure at chest CT: A statement of the Fleischner Society. Radiology 2003; 228:15–21.

Mori S, Nishizawa K, Kondo C, Ohno M, Akahane K, Endo M. Effective doses in subjects undergoing computed tomography cardiac imaging with the 256-multislice CT scanner. Eur J Radiol 2007 Jul 10; [Epub ahead of print].

Preston DL, Pierce DA, Shimizu Y, Ron E, Mabuchi K. Dose response and temporal patterns of radiation-associated solid cancer risks. Health Phys 2003 Jul;85(1):43–46.

Ron E. Cancer risks from medical radiation. Health Phys 2003 Jul;85(1):47–59.

Shilnikova NS, Preston DL, Ron E et al. Cancer mortality risk among workers at the Mayak nuclear complex. Radiation Res 2003 Jun;159(6):787–798.

Semelka RC, Armao DM, Elias J Jr, Huda W. Imaging strategies to reduce the risk of radiation in CT studies, including selective substitution with MRI. J Magn Reson Imaging 2007 May;25(5):900–9090.

Copyright 2007, Track Your Plaque.

Anne
7/16/2009 11:38:08 AM |

I remember those x-ray devices at the shoe store. It was fun looking at the bones in my feet. I also got to play with mercury when I visited an amateur chemist in the neighborhood. He would pour a little mercury in our hands and we would roll it around.

I wonder what my radiation dose was in the years I was having coronary blockage. I went through 6 coronary caths - 4 were stents. Then I had bypass. Yearly mammograms and dental xrays. Bone density testing every 3 yrs. There are websites where one can add up all their radiation exposure including and estimate of environmental exposure too.

Brate
7/17/2009 5:46:33 AM |

Sometimes for a patient, it is more a comfort than the technology which we generally try to run for. And does it really matter for a heart patient having an artery blockage or having their valves dismantled that what amount of radiation they are incurring. The question is, is there any feasible reason to question the ability of such tests. These tests have been a boon for both doctors to help them diagnose the problems, and for the patients to help them have a better life. But yes, advancements in the technology should be a possible solution. But itâ€™s not always the best solution to the problem. Advancements in the technology have greatly diversified the perception of people towards healthcare. People used to be frightened when they were prescribed for any test, or were forwarded to hospital. But now, because of the amount of advancements in technology and also the amount of soft-care has changed the age-old perception of healthcare. Now, people feel free to have a medical checkup. The amount of comfort they feel though surrounded by some most complex machineries in the world is the achievement that technology has got. The concepts like concierge medicine and Boutique medical practice has revolutionized the basic fundamentals of healthcare. Many hospitals and medical service providers: Cleveland clinic, Mayo Clinic, Elite health, to name a few, have completely revolutionized the concept of older concierge medicine. The amount of care added with treatment makes a trip to hospital a better journey. All the requirements starting from transportation, stay in the hotel, appointments, etc are one phone away with these concierge plans. Increasingly people are opting for concierge facilities. The overall information regarding concierge plan is described here:
https://www.clevelandclinic.org/thoracic/Concierge/Concierge.htm
http://www.mayoclinic.org/travel-rst/concierge-services.html
http://www.elitehealth.com/concierge_healthcare.php

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11/3/2010 4:57:15 PM |

However, it's not as bad as it sounds. For one, the study included 16-slice MDCT scanners, a scanner type that I warned people to not use because of radiation. On the current most popular 64-slice devices, much lower radiation exposure is possible, on the order of 0.8-1.2 mSv routinely--if the center takes the effort.

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