Preventive cardiologists have a wonderful tool for noninvasively identifying plaque (atherosclerosis) in the arteries to the heart: the coronary artery calcium (CAC) scan.
Since 1/3 of Americans die from atherosclerotic cardiovascular disease (ASCVD, mostly heart attacks and strokes) and dropping dead is often the first symptom of ASCVD, it is incredibly important to identify early, “subclinical” ASCVD (see here) and begin measures to reduce risk.
How early to begin that process is open to debate. The sudden death of the 41-year-old son of a patient of mine, reinforced to me how crucial it is to begin risk assessment and potential treatments as early as possible, especially in individuals with a strong family history of premature ASCVD.
We use standard risk factors like lipids, smoking, age, gender, and diabetes to stratify individuals according to their 10-year risk of heart attack and stroke (using this online risk calculator) but many apparent low-risk individuals (often due to inherited familial risk) drop dead from ASCVD and many apparent high-risk individuals have no subclinical ASCVD and don’t need preventive therapy.
I’ve been utilizing CAC (also termed heart scan, coronary calcium score, or cardioscan) to help assess my patient’s risk of ASCVD for years although the procedure is not covered by insurance and until recently was not strongly endorsed by major guidelines.
“Searching for Subclinical Atherosclerosis: Coronary Calcium Score-How Old Is My Heart?” serves as a good introduction to the test (rationale, procedure, risks) but in the 9 years since the skeptical cardiologist wrote that article there has been a substantial body of data published on CAC and in 2018 it was embraced by ACC/AHA guidelines.
Overall, I’ve written >20 posts in which CAC plays a predominant role since then and this page contains the most important developments.
In 2021 I collaborated with graphic designer Scott Matthews on the content of this video on CAC
Below is an actual CAC on a patient of mine
Heavy calcium deposits (indicating advanced premature subclinical atherosclerosis and conferring a very high risk of heart attack and stroke) in the left anterior descending coronary artery (LAD CA) in an asymptomatic 45-year-old man
The CAC Can Help In Deciding Who Needs More Aggressive Treatment
The CAC is an outstanding tool for further refining the risk of heart attack and stroke and helping better determine who needs to take statins or undergo aggressive lifestyle reduction, something I described in detail in my post “Should All Men Over Sixty Take a Statin Drug”.
The updated AHA/ACC Cardiovascular Prevention Guidelines came out in 2013.
After working with them for 9 months and using the iPhone app to calculate my patients’ 10 year risk of atherosclerotic cardiovascular disease (ASCVD, primarily heart attacks and strokes) it has become clear to me that the new guidelines will recommend statin therapy to almost all males over the age of 60 and females over the age of 70.
As critics have pointed out, this immediately adds about 10 million individuals to the 40 million or so who are currently taking statins.
By identifying subclinical atherosclerosis, CAC scoring more precisely identifies those who do or don’t need statins.
This is particularly important for patients who have many reservations about statins or who are “on the fence” about taking them when standard risk factor calculations suggest they would benefit.
The Widowmaker
In 2015 I wrote about a documentary entitled “The Widowmaker” (see here and here) which is about the treatment and prevention of coronary artery disease and what we can do about the large number of people who drop dead from heart attacks; some 4 million in the last 30 years:
The documentary, as all medical documentaries tend to do, simplifies, dumbs down and hyperbolizes a very important medical condition. Despite that it makes some really important points and I’m going to recommend it to all my patients.
At the very least it gets people thinking about their risk of dying from heart disease which remains the #1 killer of men and women in the United States.
Perhaps it will have more patients question the value of stents outside the setting of an acute heart attack. This is a good thing.
Perhaps it will stimulate individuals to be more proactive about their risk of heart attack. This is a good thing.
Although CAC has some similarities to mammography (both utilize low-dose radiation and both are screening modalities) I concluded that CAC was not “the mammography of the heart” as the documentary proclaims.
What Can we Learn From Donald Trump’s CAC Score
In 2018 I noted that “Donald Trump Has Moderate Coronary Plaque: This Is Normal For His Age And We Already Knew It.”
In October, 2016 the skeptical cardiologist predicted that Donald Trump’s coronary calcium score, if remeasured, would be >100 . At that time I pointed out that this score is consistent with moderate coronary plaque build up and implies a moderate risk of heart attack and stroke.
Trumps’ score gave him a seven-fold increase risk of a cardiovascular event in comparison to Hilary Clinton (who had a zero coronary calcium score) .
Yesterday it was revealed by the White House doctor , Ronny Jackson, that Trump’s repeat score was 133.
I was able to predict this score because we knew that Trump’s coronary calcium was 98 in 2013 and that on average calcium scores increase by about 10% per year.
What is most notable about the Trump CAC incident is that Trump, like all recent presidents and all astronauts underwent the screening. If the test is routine for presidents why is it not routine for Mr and Mrs Joe Q Public?
At a minimum, we should consider what is recommended for aircrew to the general public:
A three-phased approach to coronary artery disease (CAD) risk assessment is recommended, beginning with initial risk-stratification using a population-appropriate risk calculator and resting ECG. For aircrew identified as being at increased risk, enhanced screening is recommended by means of Coronary Artery Calcium Score alone or combined with a CT coronary angiography investigation.
The 2018 ACC/AHA guidelines Endorsed CAC
In late 2018 I noted that CAC had been embraced by major guidelines:
I was very pleased to read that the newly updated AHA/ACC lipid guidelines (full PDF available here) emphasize the use of CAC for decision-making in intermediate ris.k patients
For those patients aged 40-75 without known ASCVD whose 10 year risk of stroke and heart attack is between 7.5% and 20% (intermediate, see here on using risk estimator) the guidelines recommend “consider measuring CAC”.
If the score is zero, for most consider no statin. If score >100 and/or >75th percentile, statin therapy should be started.
But what about the individual who has a strong family history of premature CAD and is age say 35 or 39 years of age. Do we ignore advanced risk assessment? Very few individuals die in their 30s from ASCVD but I have a number of patients who suffered heart attacks in their forties.
The Importance of Being Proactive With Your Cardiovascular Health
First, it’s never too early to start thinking about your risk of cardiovascular disease. I have been using CAC more frequently in the last five years in individuals <40 years with a strong family of early sudden death or heart attack and often we find very abnormal values (see here for my discussion on CAC in the youngish and here for a combined imaging and biomarker approach.)
In addition, the earlier we can start risk modification the better as the process begins very early in life and accumulates over time.
The Coronary Artery Risk Development in Young Adults (CARDIA) Study published in 2017 has demonstrated the early development of a nonzero CAC score in the youngish and the predictive value of the high CAC score for mid-life ASCVD events. It was a prospective community-based study that recruited 5115 black and white participants aged 18 to 30 years from March 25, 1985, to June 7, 1986. The cohort has been under surveillance for 30 years, with CAC measured 15 (n = 3043), 20 (n = 3141), and 25 (n = 3189) years after recruitment. The mean follow-up period for incident events was 12.5 years,
The conclusions:
Any CAC in early adult life, even in those with very low scores, indicates significant risk of having and possibly dying of a myocardial infarction during the next decade beyond standard risk factors and identifies an individual at particularly elevated risk for coronary heart disease for whom aggressive prevention is likely warranted.
If heart disease runs in your family or you have any of the “risk-enhancing” factors listed above, consider a CAC, nontraditional lipid/biomarkers, or vascular screening to better determine where you stand and what you can do about it.
Included in my discussions with my patients with premature ASCVD is a strong recommendation to encourage their brothers, sisters, and children to undergo a thoughtful assessment for ASCVD risk.
There is ample support for making CAC a part of such assessment.
Hopefully, very soon, CMS and the health insurance companies will begin reimbursement for CAC. As it currently stands, however, the 125$ you will spend for the test at my hospital is money well spent.
If you want to be proactive about the cardiovascular health of yourself or a loved one, download the MESA app and evaluate your risk. Ask your doctor if a CACS will help refine that risk further.
More Questions and Answers on CAC
There are many other questions to answer with regard to CAC:
- Should they be repeated? If non-zero, I say no. If zero, I say yes, in 2-4 years. (Findings from the MESA study (mean age 58 ± 9 years , 63% women, mean 10-year atherosclerotic cardiovascular disease risk 14 ± 13%) in patients with an initial zero CAC showed that the prevalence of CAC >0 increased with time, from 11% at 2 years to 50% at 10 years. Using a testing yield of 25% (number needed to scan = 4 to detect CAC >0), the estimated time period to CAC conversion of low, intermediate, and high estimated risk men was 7, 4, and 3 years, respectively, and for women was 8, 5, and 3 years, respectively.)
- Do statins influence the score? Yes. CAC score may actually be higher on statins than if you were not. This is because calcium is taken up into plaques as they “heal” or progress from active/inflamed/likely to rupture to scarred and quiescent.
- Will I benefit from a CAC if I have had a coronary stent/ coronary bypass surgery or other clinical event due to advanced ASCVD? No. We are going to treat you aggressively no matter what the CAC shows in this situation.
- Is there information in the scan beyond just the score that is important? Yes. The standard method of quantifying CAC from noncontrast cardiac-gated computed tomography (CT) scans is the Agatston score. The Agatston method, which up-weights the area of calcified plaque for greater calcium density, assumes that both the area and density of calcified plaques are positively related to ASCVD events. However, MESA (Multi-Ethnic Study of Atherosclerosis) has shown that CAC density was inversely associated with incident CVD events.
- Is a scan helpful after a normal stress test? It can be because stress tests are designed to identify tightly blocked coronary arteries. You can have loads of atherosclerotic plaque lining your arteries and have a totally normal stress test.
- “Should All Patients With A High Coronary Calcium Score Undergo Stress Testing? I now believe the answer to this is no. If the patient has symptoms suggestive of angina or ischemia then stress testing or coronary CT angiography is appropriate.
- Doesn’t CAC scanning miss early, soft plaque which can be easily identified on a coronary CT angiogram (CCTA)? Yes, it does. The CCTA gives us a complete picture of the coronary arteries including soft and calcified plaque along with a good estimate of the degree of narrowing of the arteries. However, a CCTA does not work well for screening purposes because 1) It’s expensive (typically >$800 out of pocket cost versus around $100 for CAC) 2) It uses much higher radiation doses (3-8 mSv versus 1 mSv for CAC and 3) IV contrast is needed.
Like most things in cardiology we have a lot to learn about CAC. There are many more studies to perform. Many questions yet to be answered.
A study showing improved outcomes using CAC guided therapy versus non CAC guided therapy would be nice. However, due to the long time and thousands of patients necessary it is unlikely we will have results within a decade.
We can blame a lot of heart disease on lifestyle: poor diets and lack of exercise are huge factors leading to obesity, diabetes, hypertension and hyperlipidemia, but in many patients I see who develop heart disease at an early age, lifestyle is not the issue, it is the genetic cards that they have been dealt.
Until we develop reliable genetic methods for identifying all those at high risk it makes sense to utilize methods such as vascular screening or coronary calcium to look for atherosclerosis in individuals with a family history of premature CAD.
The earlier we start looking, the earlier we can intervene and lower the slow and progressive build up of atherosclerotic plaque in the arterials beds.
Given, that we have extremely safe and effective medications that can help individuals dramatically reduce their lifelong risk of heart attack it makes sense to look early and intervene accordingly.
I don’t want to wait a decade to start aggressively identifying who of my patients is at high risk for sudden death, heart attack or stroke.
Apothanasically Yours,
-ACP
30 thoughts on “The Skeptical Cardiologist’s Guide To The Coronary Artery Calcium Scan Updated for 2023”
Is this the nuclear test?
Fran,
No. The CAC is a special X-ray, a CT scan. Nuclear imaging in cardiology involves injecting into a vein a radioactive isotope and is typically combined with some form of stress, either chemical or treadmill. CAC looks at the anatomy whereas nuclear stress testing looks at the physiology of coronary artery disease.
Dr. P
I’m 42 years old and had a CAC done recently and it classified me as 75-90%ile score for my age.
This was pretty surprising (upsetting) to hear as I’d been “whole food vegan” for the past 11 years, have exercised regularly, and my LDL cholesterol had never crossed above the bottom threshold for “recommend lifestyle modification and treatment”.
But, my father had a heart attack at 51 (he survived) and as soon as my physician heard that he recommended a CAC test. So, I’m on statins now.
Quite the head-trip.
Michael,
Yours is a common story. The general mantra on heart disease risk is about the standard risk factors like diabetes, hypertension, smoking. But many inherit their risk as you did.
If you haven’t already you must have your lipoprotein (a) level checked!
Dr. P
Is there any value in having a CAC done if the 2018 AHA/ACC Guidelines (10 year ASVCD risk = 7%, Lp(a) < 90 nmol/L, no risk enhancers present) don’t indicate the need for statins?
Craig,
Simple answer. Often.
What is age?
dr p
Thanks for the reply.
Age is 59.
Hello, much thanks for your blog. It has helped me a lot. I’m seeing a cardiologist to follow up on an ER visit I had 3 years ago. He was the on-call cardiologist, and after my ER visit, I saw him the next day in which he reviewed my charts and lab tests. I went to the ER when I suddenly developed acute and chronic PAC / PVC’s from doing a lot of pull ups one Thursday. Never had them before, and it was really quite a nerve wracking experience. Over the weekend, I became symptomatic with dizziness, light headedness, and constant PVC’s. The ER ran a bunch of blood tests which were pretty much negative for everything except high D-Dimer (about 3x higher than reference range). So, they decided to do a CT angio with dye contrast. In the radiologist report, it said I had some calcification in the LAD artery in mid and distal segments. I followed up with the cardiologist the next day, and he suggested to do calcium score and a bunch of other tests. I eventually saw another cardiologist, and he had me do a 24 hr holter. It came back not as bad as expected, with a few thousand PVC’s and PAC’s. He wanted to put me on a beta blocker, but I digressed and decided to live with it. 3 years later, it’s been much better. Anyways, I finally decided to see the original cardiologist again to follow up on the coronary artery disease, and here’s where I’m confused.
I asked him about the radiologist’s report on the CT angio, and was wondering what does it mean quantitatively speaking when they wrote “some calcification”. He said, well, that’s what the CAC scan will tell us. I thought that was bizarre, since I thought I had the more rigorous CT angio scan with dye injection. And he looked at me quizzically and said, “They were looking at your lungs for PE or clotting, not your heart.” So, I’m just wondering. Based on what I’ve read from your comments, is the CT angio a more detailed look at the coronary arteries vs the CAC scan? I read a comment of yours that said the CT angiogram would be good followup, except the extra radiation exposure. I’m kind of wondering whether I should find a new cardiologist.
Again, much thanks for all the helpful content. Really nice to have doctors like you field questions from the general public.
David,
Thanks for. your comments and sharing your story. Good question on the coronary calcium assessment from your CT angio.
Based on what you describe in the ER (elevated d-dimer which can be a marker for pulmonary embolism) and what your cardiologist is telling you it sounds like you had a CT angio for the diagnosis of pulmonary embolism.
Although the coronaries are visualized with this test and coronary calcium is sometimes reported out (often there is coronary calcium and it is not mentioned) it is not routinely quantified.
The quality of the CT angio should allow quantification but I have found it to be difficult to get that done on CT scans that were not ordered as CAC scans. This may be a technical reason or it may be laziness. I may post your question on the blog to get more feedback on this issue.
Bottom line-your cardiologist needs quantification of the CAC score and he probably can’t get it from the CT angio done a few years ago.
A CAC score will quantify the amount of calcium and compare it to normal men your age.
The CT angio I describe is a coronary CT angio which is specifically designed to visualize in detail the coronaries. The PE scan does not provide that information.
Much thanks, Dr Pearson! You’re truly a kind and helpful person for providing this blog.
Fascinating thread. My situation is different than other posts.
I am a 60 year old male, normal BMI, normal cholesterol levels. I have exercised regularly my entire adult life. I run, on average, 6 miles five days a week and also do resistance training 3 days per week. I eat a low fat diet. I have no physical symptoms of CVD.
I went for my annual physical in May, 2020. My PCP said, “You’re doing great. Keep up the good work!” I replied, “Doc, I turn 60 next month and I’ve never really had my heart looked at. Do you think I should?” He referred me to a cardiologist who requested I receive a Calcium Score prior to my appointment. Well… My score came back 1,130. That’s right. Over a thousand! The cardiologist looked at me as if I should be dead! He immediately placed me on a statin and ordered an Angiogram. Here’s the kicker. The Angiogram showed minimal plaque build-up and no restricted blood flow. He thought he would be inserting several stents but once he took a look, saw no need.
To summarize, I have a ridiculously high Calcium Score but clear coronary arteries. (I went for an 8 mile run this morning and feel great!). Am I living on borrowed time? Thoughts? Suggestions? Anyone else have a crazy high Calcium Score with no blockage? A final note: The high Calcium Score remains a great source of anxiety and the statin is causing muscle spasms. Thanks!
Jim,
I hope to write a post on situations like yours because I see this a lot. You can have a “ridiculously high” CAC score and have no symptoms and no significant blockages.
I typically do not recommend getting an angiogram in the absence of symptoms plus significant abnormalities on a stress test.
You are not living on borrowed time and with proper medical management you will do fine.
There is evidence that really dense calcification (which leads to super high scores like yours) is actually more a sign of healed plaque and lower risk.
I’m presuming you have a family history of CAD and hopefully you have been checked for a lip(a).
Thank you, Dr. Pearson. I enjoyed a wondrous 7 mile run this morning. There was a beautiful crescent Moon and Orion is rising in the pre-dawn sky. I will continue to live a “heart healthy” lifestyle and enjoy life to it’s fullest. Thank you for calming my fears and anxieties.
Interesting. Here’s an observation regarding statins for the skeptic. I am not on statins. After my doctor suggested I go on a low dose of simvastatin about 7 years ago I got horrible inflammatory side effects. My upper body was frozen. I stopped taking them. I also took an angiogram that showed zero plaque which followed two CACs taken 5 and 10 years prior that showed zero plaque. By the way the angiogram at Cedars Sinai in LA cost $500. I paid for it out of pocket and thought it quite cheap relative to the cost of taking statins for the rest of my life. At that point, I did more research on statins and realized that far too much of the research going back to the Framingham study was sophomoric, scientifically dubious at best and was incapable of ascertaining long term ancillary impacts to the body. I became a huge skeptic. When the FDA finally said in 2015 that dietary cholesterol had no material impact on serum cholesterol there was some vindication and an admission of a point that cholesterol skeptics had been saying for years. I also note that the FDA announcement got little coverage.
One of the things I came across in my research was the chart below in the US National Institute of Health Chart Book for 2012. Here’s what jumped out at me from Chart 3-9. This is a linear chart, not logarithmic, so the data are pretty simple to visualize. (not able to post)
While the data begin in 1979 it indicates a linear decline in age-adjusted CVD deaths from1979 through 1987) when statins first came on the market (I believe it was Lovastatin on 9/1/87). Readings suggest that this decline (I do not have prior data) is attributable to prior anti-smoking campaigns begun as far back as the 1960s and ongoing improved medical procedures. Once statins hit the market in late 1987 and their use grew to what I would call epidemic proportions, the rate of decrease did not change. There was no significant “bending of the curve” and there is no indication of millions or even tens of thousands of lives saved. THe decrease isvirtually a straight line. If statins were the panacea that they have been cracked up to be, the curve should have plunged to the lower right between 1988 and 2008. It doesn’t. I have looked for updated numbers and can’t find any. In fact, I can’t find this chart in more recent National Institute of Health publications.
While there can be many interpretations of this chart i.e. someone taking statins in 1987 doesn’t die of CVD until 2000 or they live long enough to die of something else or be classified as something else at death, there is no clear demarcation that suggests that statins have anything to do with CVD deaths.
I have one other observation. When I started taking simvastatin I got a bad case of trigger finger in my right index finger…very annoying but not life threatening. Almost as soon as I stopped taking Simvastatin the trigger finger went away completely and has not returned. The connection was obvious and immediate. That made me look into statins even more and convinced me that these mystery drugs had side effects that were totally unknown probably at least some related to inflammation. The other thing that came to mind was dementia which may or amy not be inflammation related– most bad things are. I am just recently starting to see suggestion that there may be a connection. I had learned that 25 percent (I have seen higher numbers) of the body’s cholesterol was in the structure of brain cells, and as the FDA admits serum cholesterol, is not materially influenced by dietary cholesterol (i.e., natural cholesterol). My ake is that cholesterol levels are probably not something you want to mess without a damn good reason. While there is nothing scientific about that is, IF I saw, data suggesting that cases of dementia started increasing in the western world beginning in the late 1980s I would not be shocked. That may be somewhat Ancel Keyesian but let’s just say it wouldn’t come as a surprise.
Always interesting to see that a researcher from I-Googled-It-U has discovered evidence to overturn decades of medical science in cardiology, lipidology, pharmacology, and Alzheimer’s research. Give this man a Nobel prize!
this is a fascinating thread – obviously to those of us with Heart Disease. My question: as an asymptomatic 60YO with a CAC > 90th percentile there is not much information or guidance online. After a year of research + a good cardiologist I have the exact same prescription as someome with a total score of 100+. Seems like something is missing.
So does a cac scan of 0 coupled with aortic calcium denote an increased risk of heart attack needing an intervention of some sort or is the CAC of 0 reassuring at all?
It depends….primarily on age.
And if theoretical person was , say.. mid 40s?
It’s not clear if this question is referring to aortic valve calcification versus calcification of the aorta. A little calcification on the aortic valve is common in the echocardiograms of older individuals, especially if they have hypertension. All of the factors that influence that aren’t clear but high Lp(a) should be considered.
I recently had a patient who had a marked area of calcification in the proximal aortic root. Further evaluation revealed a markedly elevated CAC.
I would consider significant calcification in the aorta as a marker of atherosclerosis.
Thank you Dr. The actual comment on CAC scan was “a few punctate calcifications noted in ascending aorta just above level of the sinuses of Valsalva. Otherwise no significant vascular abnormalities”.
I had my calcium test done after going to er several times with chest pain and having a stress testing done(witch I told them I would pass). My score came back saying that 90% of me my age were in better shape than me. I went several more times to er no one took me serious. I was 40ish 5′ 5″ 135lb. People looked at me as healthy. This last December I went back to er with bad pain. They put me in the waiting room. When the blood work came back I had a heart attach. The Dr that night was going to do a stress test again and I just started crying. Well he listened to me and did a heart catheterization. It was not long before they were telling me I needed cabg x 5. I’m still having problems and don’t think anyone is listening. They tried sending me home after surgery and I told them something was wrong. No one would listen. They did x-ray couple of times with nothing. The last one they did a nurse looked and said I have been doing this a long time and something is there. She got things done. They took a litter of fluid out of my chest. I think it’s same thing now and who ever is reading it just can’t see it. I don’t want something else to go wrong. I did not show normal signs with any of this. I have a high tolerance for pain. Just wanted to share with you. Having the heart scan done is something every one should do and it should be taken seriously. I really appreciate what you have wrote and what you are doing. You are making a big difference. If I can help in any way. Thank you!
How does CAC compare to stress testing? If a stress test is negative (after say 12 min) but CAC is high, what should we think?
https://academic.oup.com/eurheartj/article/40/24/1906/5521840
https://newatlas.com/artery-stiffening-calcium-minocycline-cambridge/60088/
https://jamanetwork.com/journals/jamacardiology/article-abstract/2722746
???
Jeff,
Three fascinating articles!
I was aware of the first which I think yields some insight into the process of calcification in arteries. Of course, the calcium is not the primary problem but more a marker of a repair process.
The second I find absolutely fascinating. The lab that provided that false 2013 score should be investigated!
The third I’ve touched on with at least one reader. My take right now- long duration exercise may lead to more calcium deposition in the coronary arteries but the overall benefits confer a benefit to CV risk. More studies needed.
Fascinating. I wonder if aortic calcium could be an artifact of someone’s decade of marathon training?
Under what circumstances would CT coronary angiography be indicated in addition to, or in lieu of, a CAC? What are the pros and cons of the former compared to the later test?
PMV,
This is a great question, worthy of a scholarly review article (or skepcard post).
CCTA (CT coronary angio) requires a venous injection of contrast, more radiation and is more expensive than CAC so it has generally not been considered a screening tool for coronary disease.
CCTA precisely outlines the coronary anatomy, soft plaques, calcified plaques, lumen diameter as good or better than invasive coronary angiography whereas CAC just shows us very crudely where calcium is in the coronaries.
The reference that Jeff Patten provided in his comment on this post (https://academic.oup.com/eurheartj/article/40/24/1906/5521840) has a fantastic figure which nicely demonstrates the differenc graphically.
I am not sure how many times I have to keep posting this….
I had a CAC test and my score was zero
I had a PLAC test and my score was in the top 2% in other words very very high risk
I had a stroke
The above three were all in May/June 2018
The CAC test is meaningless without a PLAC test and can give a totally false sense of security
Chris,
I don’t recommend the PLAC test. I agree with this Harvard Health assessment. “A repair enzyme that rides around the bloodstream attached to LDL (bad) cholesterol particles has been identified as a possible marker of atherosclerosis. This enzyme, called lipoprotein-associated phospholipase A2 (Lp-PLA2) appears to be involved in the release of substances from LDL that promote inflammation. Some (but not all) studies show a connection between high levels of the enzyme and heart disease.
An FDA-approved test for the enzyme, called the PLAC test, is commercially available. It costs $150–$175, or about three times more than a test for C-reactive protein. Whether it adds important information remains to be seen.”