Page linked below is a research letter on using the PREVENT calculator to give an estimated age equivalent for cardiovascular disease (CVD) risk. Basically, the idea is that if your age for CVD risk is higher than your actual age, your heart is “older” than your chronological age.
The PREVENT calculator that gives age equivalent for CVD risk:
The regular PREVENT calculator:
Note that these calculators want (in addition to other common lab numbers) an eGFR, which is often reported as “>60” when the actual estimate is greater than 60. But if you have your measured creatinine level, you can use a calculator to get the estimate:
Cardiology is seriously lagging other specialties when it comes to screening and prediction.
All of the calculators use LDL-C as a correlate for risk. Cholesterol per se is not atherogenic. It’s the apoprotein that encapsulates it to make it mix in an aqueous solution that is. Since there is a wide array size within the spectrum of low density lipoproteins, knowing the total amount of cholesterol isn’t nearly as important as knowing the number of particles.
Using eggs as an analogy, it’s the shell that’s harmful, not the yolk and white. Let’s say 50 quail eggs has the same total yolk and white content as one ostrich egg. By standard LDL measures they’d be seen as equivalent. They aren’t because there are 50 shells or apoproteins, vs one.
That can be measured directly using a test called ApoB. In most cases LDL-C and ApoB are in agreement, but in as many as 20% they are discordant. In that case LDL underestimates risk. No calculators use ApoB even though it’s the superior metric.
Lp(a) is another cholesterol carrying particle. It’s elevated in as much as 30% of the population and is five times more atherogenic than LDL-C. It isn’t incorporated in any calculator. In fact, because it isn’t currently treatable, most US physicians don’t even check it. It’s important to know though because there is very good evidence that extra aggressive management of LDL, below 55, can compensate for the Lp(a) risk.
The MESA calculator at least incorporates a calcium score, but that too is imperfect. Ca is a measure of stable, end stage atherosclerosis. It tells nothing of soft, vulnerable plaque.
What would be ideal would be to simply look inside the heart to see what’s actually there. We have that technology in CT angiography, but it’s labor intensive and human read, so its repeatability for following chronologically isn’t great.
There’s a newish test that uses AI to over read CTA. It’s called CLEERLY.
If we’d just look, like we do with colonoscopy now, we’d be WAY better at predicting risk than any calculator.
A CT scan for coronary artery angiography exposes one to ionizing radiation equivalent to four years of background radiation, which can increase the risk of cancer.
It is also much more expensive than blood work, so using it as routine screening will add to the cost of medical care for everyone and/or consume money that could be used for other medical purposes.
So is the extra risk of cancer and extra cost worth using CT angiography as routine screening?
Are there any studies/analyses on using this test as screening in all?
Do you know if there is any US group (guideline developers/physicians, insurers, NIH, et al?) that recommends CT angiography as routine screening? Or any country’s health authorities (NICE, EMA, MHLW, etc?)
Just asking because I’m curious. Obviously I can do a search if you don’t know of any studies/data.
Primary screening with colonoscopy appears to be about twice as expensive as primary screening with yearly FIT (including colonoscopies induced by positive FIT results), but appears to be only about 10% more effective at catching colorectal cancer. Worth it?
The only reference to this that I can find is from a study years ago that said that this is for those with previous history of heart disease (i.e. known high risk factor otherwise, and probably more likely to be on LDL-lowering drugs).
Almost no one recommends CTA for screening in asymptomatic patients. Yet, roughly 50% of the time the first symptom is a heart attack and roughly half of those are fatal.
At a minimum I would say check ApoB to verify concordance with LDL-C. If they are discordant, follow ApoB. Measure Lp(a) and aggressively lower ApoB/LDL-C if it’s above 50 mg/dl. Finally, get a Calcium Scan and dig deeper if it’s not zero.
The flaw in that paradigm is that non-calcific plaque is the highest risk. The only way to find that is to look.
BMI is a calculation based on just your height and weight: BMI Calculator
It is a proxy for obesity, although it is not that good of one on an individual level (versus population level), as mentioned many times in other threads. This is because it cannot distinguish between being heavy with fat versus being heavy with muscle and/or bone.
For those that are interested, Medicare covers the labs for LP(a). I happen to ask my PCP at my last check up about it, as my father had his first MI at 45, and I had elevated cholesterol 20 years ago. I have been on meds since then and never had an issue, still on the same low dose all this time.
PCP wasn’t sure Medicare would cover the lab, but I was willing to pay if they didn’t. I was very happy to see that my results were normal and Medicare paid!
I have far more atherosclerosis than my risk factors would suggest. Fortunately my LDL-C and ApoB are concordant. On 40 mg of Rosvastatin both now hover around 59. Pretreated, it was slightly elevated at 130, but my fractionation showed a predominance of large fluffy particles, indicating low risk. It was primarily from Lp(a). Fortunately, I have wide open pipes, with minimal high risk plaque. It’s been stable on CLEERLY 2 years apart even with a calcium score close to 1000.
According to the BMI calculator, I would be around a 24"or 25" inch waistline in order to just barely qualify for “healthy”. I would be considered “overweight” with a 26" waistline.
BMI calculations may be appropriate for those with a slight build or, possibly, a moderate build, but wildly inappropriate for a healthy male athlete unless a marathon runner.
A different measure, waist / height, does use it. But that measure is much less commonly used as a proxy of obesity. (A ratio of >0.5 suggests too high body fat.)
Yes, I know. However, as an athlete who has had experience at various weights, I know what my waistline would be (and actually was) at various weights.
When I ran at least 10 miles per day at a brisk pace (trained with a D-1 track/cross-country team), lifted weights & swam daily, had very well developed six-pack abs, and a very healthy diet, I would have been classified as “overweight” by the BMI calculations. This shows how outdated the BMI figures are. Totally worthless.
And, please, do not get me on the subject of buying collared shirts as most manufacturers do not make my neck size–even the case when I had a 28" waistline.
