Let's say that any one of these profiles is yours. Should you be getting your affairs in order, preparing for your cardiac catastrophe? Should you demand a stress test from your doctor, hoping that it will shed some light on your dilemma? Should you go ahead and go to the all-you-can-eat rib restaurant, content that you will be attending your granddaughger's wedding in 2020 in full health?
If you can tell, you're a lot better at this than I am.
I provide consultation to other physicians and patients on complex hyperlipidemias in my area. In other words, if someone has a difficulty to manage lipid disorder, the doctor sends the patient to me.
Managing these wildly variable values is the easy part. Deciding whether or not heart disease is concealed within the patient . . . well, that's the hard part.
Let's take it a step further: Suppose all three profiles also have 50% of all LDL particles as the abnormal small particles. And they all have a lipoprotein(a) level of 50 mg/dl, an abnormally high level.
How about now: Can you tell whether any or all of these people have hidden heart disease?
What if they are 20 years old? Does that make a difference?
What if they are all females over 65 years--how about now?
If the only tool you have to divine the presence of hidden heart disease is a lipid panel, or even a lipoprotein panel, then the best you can manage is to hazard a guess based on statistical probability. You also assume that this "snapshot" represents the sorts of values someone has had for their entire lives. You cannot factor in the fact that the first person gained 60 lbs in the last three years since completing menopause. You can't factor in that patient 2 smoked two packs of cigarettes a day for 25 years, but quit 10 years ago.
It's also foolhardy to believe that every known cause of heart disease is currently identifiable and revealed by modern-day blood testing.
A heart scan is simply a means to quantify the sum-total of risk factors--causes--that have exerted an effect up until the moment of your scan. It will reveal the quantity of coronary atherosclerotic plaque present, regardless of whether you stopped smoking 20 years ago or lost 30 lbs last year.
For these reasons, nothing can replace the value of quantifying plaque: not cholesterol, not the Framingham risk calculation, not measures of small LDL or lipoprotein(a), not the presence or absence of symptoms. In 2008, the method of choice for measuring plaque remains a CT heart scan. Perhaps in 10 years it will be some other method.
As always, let me remind Heart Scan Blog viewers that I make this point NOT to sell heart scans, which I have no reason whatsoever to do. I say this because we require a tool to track this potentially fatal disease. We require a yardstick for tracking progression or regression. The only tool that suits these purposes in 2008 is a CT heart scan.
In other words, knowing the right person provides you strategic advantage in business, social advancement, etc.
In health, it was often true. Knowing who the better doctors were, for instance, in your city might provide you with access to better care.
Enter the Information Age. You now have access to medical information equal to that of your doctor. You now have access to patient discussions about doctors, their practices, their performance records. There is now a depth and breadth of information on health that was never available before.
I’d therefore turn the old saying into the new Health 2.0 version:
It’s not who you know, it’s what you know.
In health, information now reigns supreme, not knowing somebody else who has the right connections.
Positive: Everybody now theoretically has access to an equal amount of information, since you can access information on any topic just as easily as I can.
Negative: It puts more of the burden on you. If you screw up in health, perhaps you didn’t try to get the best information hard enough.
I love this new development, this emergence of empowerment in health. I call it self-directed health, the individual capacity to exert enormous influence over the quality of your healthcare.
This is obviously a work in progress. All the answers and tools for self-directed care, self-empowerment are not yet available, some haven’t even yet been imagined.
“Do you really think I need a heart scan?” asked Terry.
“My doctor said that heart scans show too many false positives. He says that many people end up getting unnecessary heart catheterizations because of them.”
At age 56, Terry was becoming increasingly frightened. His father had suffered his first heart attack at age 53, Terry’s paternal uncle had a heart attack at age 56, his paternal grandfather a heart attack at age 50.
Is this true? Do heart scans yield too many false positives, meaning abnormal results when there really is no abnormality?
No, it is not. What Terry’s doctor is referring to is the fact that, in the decades-long process that leads to heart attack, heart scans have the ability to detect early phases of developing coronary atherosclerotic plaque.
Let’s take Terry’s case, for example. Given his family history, it is quite likely that he does indeed have coronary atherosclerotic plaque. Will it be detectable by performing a stress test? Probably not. In fact, Terry jogs and feels well while doing so. While a stress test abnormality that fails to reach conscious perception is possible, it’s fairly unlikely given his exercise routine.
Will Terry’s coronary atherosclerotic plaque be detectable by heart catheterization? Very likely. But why perform an invasive hospital procedure just as a screening test? Should a woman wishing to undergo a screening test for breast cancer undergo breast removal? Of course not.
Is waiting for symptoms a rational way to approach diagnosis of heart disease? Well, when symptoms appear, it means that coronary blood flow is reduced. Stents and bypass surgery may be indicated. The risk of heart attack and death skyrocket. Sudden death becomes a real possibility.
In the 30 or so years required to establish sufficient coronary plaque to permit the appearance of symptoms or the development of an abnormality detectable by stress testing, there were many years when the disease was early--too early to generate symptoms, too early to be detectable by stress testing.
That’s when heart scans uncover evidence for silent coronary atherosclerotic plaque.
Should we call this a “false positive” just because it doesn’t also correlate with “need” for a catheterization, stent, bypass operation or result in heart attack within the next few weeks?
The detection of early plaque is just that: early disease detection.
Imagine, for instance, that the breast cancer that will grow into a palpable nodule or mass detectable by mammogram is detectable by a special breast scan 15 years before it becomes a full-blown tumor, metastasizing to other organs. What if effective means to halt that earliest evidence of cancer could put a stop to this devastating disease decades ahead of danger? Is this a “false positive” too?
In my view, this is the knuckleheaded thinking of the conventional practitioner: “Don’t bother me until you’re really sick.” Prevention is a practice that has become fashionable only because of the push of the drug industry. Nutrition is an afterthought, a message conceived through consensus of “experts” with suspect motivations and allegiances.
So, no, heart scans do not uncover “false positives.” They uncover early disease--true positives--years before it is detectable by standard tests or by the appearance of catastrophe. But that is the whole point: Early detection means getting a head start on prevention.
Do heart scans lead to unnecessary heart catheterizations? Yes, sadly they do. But not because heart scans are false positive. It happens because of unscrupulous or ignorant cardiologists who use the information wrongly. In my view, heart scans should NEVER lead directly to heart catheterization in an asymptomatic patient. Heart scans, as helpful as they are, do not modify the standard reasons for performing heart procedures.
If a car mechanic is dishonest and fixes a carburetor that didn't need fixing, should we condemn all car mechanics? No, of course not. We only need to develop the means to weed out the bad apples. The same applies to heart scans.
Here's a bit of lipid tedium that might nonetheless help you one day decipher the meaning of shifts in your cholesterol panel.
Recall from prior discussions that conventional LDL cholesterol is a calculated value. Contrary to popular opinion, LDL is usually not measured, but calculated from the Friedewald equation:
LDL cholesterol = Total cholesterol - HDL cholesterol - triglycerides/5
For the sake of simplicity, let's call total cholesterol TC; HDL cholesterol HDL, and triglycerides TG.
You're advised to follow a standard low-fat, whole grain-rich diet advocated by "official" agencies (the diet I bash as knuckleheaded). Another panel a few months later shows:
(Obviously, I've oversimplified the response for the sake of argument. HDL would likely go down, LDL would change more depending on body weight, small LDL tendencies, and other factors. You'd also likely get fat.)
Now your doctor declares that your LDL has gone up and you "need" a statin agent.
Nonsense, absolute nonsense.
What has really happened is that the increased dietary intake of wheat and other "healthy whole-grain foods" has caused triglycerides to skyrocket. LDL increases, in turn, by a factor of TG/5, or 40 mg/dl. Thus, LDL has been inflated by the triglyceride-raising effect of whole grains.
This is yet another reason why the standard lipid panel, full of hazards and landmines, needs to be abandoned. But calculated LDL in particular is an exercise in frustration.
Though the example used is hypothetical, I've witnessed this effect thousands of times. I've also seen many people placed on statin drugs unnecessarily, due to the appearance of a high LDL cholesterol that really represented increased TG/5, usually induced by an excessive carbohydrate intake, including those commonly misrepresented as healthy such as whole grains.
In the Heart Scan Blog, I am often guilty of speaking out loud of my varied thoughts on this crazy thing that we've created called the cardiovascular healthcare machine. But I discuss it in the context of asking "How could this be done better--better outcomes, more patient-friendly, more accessible . . . more do-it-yourself?
The last part is the part that throws most people. Do-it-yourself? My colleagues would claim I'm nuts, suggesting that coronary heart disease is something manageable by yourself. In the conventional pathway, after all, coronary disease is that unpredictable, poorly detected by standard tests, condition that then leads to heart catheterization, stents, bypass , and the like.
Several factors distinguish the readers of The Heart Scan Blog that surprised me:
--Nearly 60% are women --There are a disproportionate number of Asian people. (Can someone explain this to me?) --A great number have graduate degrees
I believe this tells me that The Heart Scan Blog appeals to a somewhat more sophisticated audience. This, to some degree, warms my heart, since it means that I've captured the attention of some people who may be more discriminating and thoughtful in their Internet surfing.
However, I also lament the fact that these conversations are not achieving the mainstream. After all,