Random Thoughts from a Restless Mind

Dr. Darrell White's Personal Blog

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Posts Tagged ‘cardiac’

Sunday musings 8/12/18

Sunday musings…

1) Krispies. All of my snaps and crackles now have pops.

2) Relevant. “Who wants to be relevant? It just takes a lot of work.” –Andie MacDowell

In this day of social media driving said relevance I think Ms. MacDowell is spot on. When relevance is measured by something as ephemeral and lacking in any type of substance as retweets and follows, her take is prescient.

True relevance is substantive. Or should be.

3)  Games. What are we to make of the massive gap between the top 5 men and women and everyone else? What is it that separates them so completely from the rest of the very best? Is it just me or is this fundamentally different from all of the other truly individual athletic sports?

4) Summer. For anyone with school-aged kids summer if officially over. August 1st has come and gone, the CrossFit Games are over, and football camps are open all across America. Heck, school starts in parts of Ohio on Wednesday, and didn’t I see kids heading to school last week on FB?

Sorry, that’s all wrong. School is meant to start after Labor Day. Too much work too soon for kids who aren’t taking part in feeding a family.

5) Screening. It appears that I am a health tracker recidivist. Why? Well, it certainly has nothing to do with the truly actionable nature off the information a tracker gives me, because to date only heart rate variability (HRV) has any value and at that it appears only in elite athletes. No, I’m just having some fun with mine, playing around to see if my little n=1 studies might come up with something that might move my needle for some reason or other.

That, and they are fun to write about.

Screening for health risks is potentially a big deal, the across the board lack of success thus far notwithstanding. The most recent best example of that coin is an article published this month in the NEJM on cardiac testing of elite soccer players in England. Performed at age 16 between 1996 and 2006 the screenings were undertaken to see if an EKG and Echocardiogram could predict cardiac events that led to early death in athletes who compete in sports with “strenuous exertion”. In all more than 11,000 athletes were tested, the vast majority of whom were declared healthy.

1 in 266 were found to have an underlying, silent abnormality that put them at risk for sudden cardiac arrest. Most of these were Hypertrophic Obstructive Cardiomyopathy (HOCM), the same entity that was responsible for the tragic death of Boston Celtic Reggie Lewis. 2/3 of those who were found to be at risk had surgical procedures which allowed them to safely return to play; it appears that they are all alive and well. Of the originally screens players 8 did in fact die from cardiac arrest, but here’s the kicker: only 2 of those 8 were assesses as being at risk. The other 6 went through the screening and passed. Overall the results equal a risk of 6.8 deaths per 100,000 athletes.

What does this mean in the greater context of health screening? In general the problem with health screening of all kinds (remember, I am in the midst of a classic American cardiac health risk screening process at the moment) is the combination of inaccuracy as noted above, coupled with a fraught cost/benefit ratio in almost all instances. Believe it or not, though, the cost of screening relative to the accuracy and ultimate effect may be the lesser of the problems inherent in screening. Two of the athletes screened and found to be at risk refused to give up soccer and were among the cardiac deaths. You might ask if they were mad to have continued to play, but I would counter that it is quite likely that all they had as a means to provide was soccer; to not play was to choose to go hungry. Imagine an inner city kid destined to be a Lottery Pick in the NBA screened and told they could no longer play the game that would surely set them up financially for life on their rookie contract alone?

Not to mention the deep psychological issues inherent in being told that you are no longer the one, single thing that you have self-identified since early childhood. That’s rough.

One of the very first diseases one used to learn about in med school was Huntington’s Chorea, an inherited disease in which the afflicted exhibit violent, uncontrollable movements (chorea) before eventually dying a rather unpleasant death ¬†(any med students here? Is that still true?) Why? Well, partly because it’s such an interesting tale, equal parts detective story (the original cluster is in a tiny town in England) and history lesson (many of the townsfolk in England emigrated to Salem and were on the wrong end of the Salem witch trials). What makes this interesting in the context of screening is that Huntington’s Chorea is the first disease for which a single gene defect was identified, making it possible to screen with 100% accuracy to determine if you, like Woodie Guthrie and his siblings, would be so afflicted.

Would you want to know? Remember, even in this age of SPLCR technology there is still no cure for Huntington’s. Is there a difference between this and the cardiac risk of HOCM in athletes? How about the rather mundane and ridiculously common risk associate with elevated serum lipids? Given that there are things one can do to mitigate the risks in the latter one should probably answer “yes”, there is a difference. But emotionally, on an individual level, is there? That’s a really hard question to answer. I personally know families with Huntington’s and HOCM. Some family members get tested as a matter of course. Others, for any number of reasons, choose not to do so. In your life you know dozens of people who really need to be screened for diabetes and cardiac risk from elevated serum lipids who prefer the relative comfort of ignorance.

Who is to say who’s right?

In the end this is a question that is going to become more and more common as testing becomes both easier and less expensive. We are soon to see a lab test for HOCM which will be less expensive than an EKG/echocardiogram and more accurate to boot. The calculation will change as well because on the heels of this test is the likely approval of a gene therapy that will reverse the abnormality and presumably remove the risk. For some reason Huntington’s Chorea has defied this happy ending, but it has to be just a matter of time before it, too, is curable. Before any universal agreement is reached on screenings in general you can depend on tons of controversy which each new development. I shudder to think of the coming shit show that will be wrist-worn trackers that can detect afib in real time.

Who knows what kind of mischief I will manage to get into with my little HRV monitor?

I predict I’ll see you next week…

 

–bingo

 

Measuring Health Part 2:The Traditional Metric ‘M’

Any measurement of health must provide some sort of predictive value with regard to the likelihood that one will remain healthy. While the entire idea of screening tests is fraught with controversy–both false positives and false negatives bring with them real risks–there are still a number of health measurements in the realm of traditional medical care that have a proven value when trying to predict downstream adverse health events. The trick, of course, is to decide which ones matter, filter that group to come up with tests that are as close to universally available as possible, and then decide how much weight each particular test in the group of survivors should receive in the single cumulative metric that is then created. This measurement, call it “M”, will be one of the variables in our calculated health measurement.

Let’s start with the simplest of all medical inquiries, a medical history. More specifically, let’s include a brief family history in our calculation of M. While it is becoming increasingly easy to obtain a very accurate genetic profile that identifies very specific health risks, these genetic tests are both controversial and expensive. Until the very real societal issues of knowing your exact genome and the risks it includes have been worked out by both ethicists and elected government, we should take a simpler and more narrow approach and ask two very simple questions: Has anyone in your family died from heart disease? Has anyone in your family died from cancer? Equally simple follow-up questions (How young were they? What kind of cancer) would allow us to add risk (reduce M) or ignore the historical note since the disease is not hereditary.

From here we move to an equally spartan individual medical history. Again, just two questions in this part: Do you smoke? Do you drink alcohol? The negative effect of smoking on an individual’s health, both in the present and future tense, must be accounted for in any measurement of health. It weighs so heavily on what we know about future risks that we will see it as a negative integer in M. Too many studies to count exist pointing out the deleterious effect of excess alcohol consumption to count. One compelling study, The Eight Americas Study in PloS One, found alcoholism to be the single most powerful lifestyle variant after smoking when predicting the life expectancy of groups studied. A recently published study of Harvard men found that alcoholism was the greatest second greatest influence on the happiness of the men studied, just behind the presence of loving friendships. Unlike smoking, however, there is a volume component to alcohol consumption. Indeed, a modest intake actually INCREASES longevity, while no intake DECREASES longevity. So M will see a small bump from moderated alcohol intake, an equally small decrease for teetotalers, and a dramatic negative effect from heavy alcohol intake.

So far we’ve managed to obtain some variables underlying M through the use of simple inquiry, costing only the time it takes a subject to fill out a questionnaire. At least two other variables are as accessible and inexpensive: blood pressure (BP) and a measurement of body habits. Once upon a time you had to visit a doctor or hospital to get your blood pressure checked. Now? Heck, for $20 you can buy a reasonable accurate BP monitor and take your BP at home! Minute Clinics in pharmacies, health clinics in the workplace, and coin-operated machines in the local Mall now make it easy to get a BP without visiting a doctor. While there is ongoing controversy in the medical world about what constitutes Hypertension it is safe to say that health risks are higher with a systolic pressure >140 and a diastolic >90. Above or below these levels is our toggle for M, positive or more healthy for lower and the opposite for higher BP.

Using body habitus is controversial, mostly because the measurement that is routinely utilized is so inadequate. The Body Mass Index, or BMI, is wildly inaccurate when it is applied to the fit. 4-time winner of the CrossFit Games Rich Froning, arguably the fittest man on the planet, would be deemed obese at 5′ 10″ and roughly 195 pounds with a % body weight fat of around 4%. Ridiculous, huh? The temptation, of course, is to use % BW fat as the preferred method of measuring body composition risk, but measurements that are accurate enough to be useful tend to be very expensive and difficult to access. On the other hand, all you need to determine the waist/hip ratio is an 89 cent paper tape measure and a calculator. A waist/hip ratio of >1.0 is associated with an increased risk to health from myriad metabolic illnesses including diabetes and heart disease, especially in men. Greater health in M for measurements under 1.0, and progressively less as that number increases.

It is impossible to utilize all that modern medicine has to offer when it comes to measuring health without spending a little bit of money. Several simple blood tests can be obtained with or without the input of a physician. The presence or control of diabetes can be ascertained with a HbA1c and a fasting glucose level. In the presence of a normal HbA1c an elevated fasting glucose may indicate a problem with insulin sensitivity, so it is important to include both. While it is far from settled whether or not it is cholesterol itself which is responsible for heart disease there is simply too much evidence that serum lipids can help predict cardiac events to leave them out of any health measurement. Our basic health index should therefore include the basic measurement of total cholesterol, HDL, LDL, and triglycerides, and M should reflect the negative effect of elevated Total Cholesterol, LDL and triglycerides and the positive effect of a high HDL.

How should we put all of these together to come up with our traditional health variable, M? This one is fairly simple; there are a number of “risk factor” measurements online that are good models. I envision a rather simple form on which one would add up weighted values for the measurements above, arriving at a straight forward mathematical sum. The final formula is being developed with the assistance of cardiologists at my medical school alma mater, the University of Vermont.