The Three-eyed Radiologist (TR) has been asked by The Skeptical Cardiologist (SC) to discuss the epidemic of incidental pulmonary nodules that are found on routine cardiac diagnostic studies including coronary calcium CTs, coronary CTAs, and myocardial perfusion scans (using CT for attenuation correction), not to mention a whole host of other CT (computed tomography or “CAT”) scans and x-ray exams performed for many reasons that have nothing to do with inspecting lungs for pulmonary nodules. The TR will herein anticipate and answer common questions that might be asked by the SC audience.
What is a pulmonary nodule (and why should I care)?
A pulmonary nodule is a nonspecific “spot” or lesion or density seen in the lung (1). It could be nothing. It could indicate lung cancer, and that is why you should care. Larger nodules, say 8 mm or larger (bigger than one-third of an inch), are of greater concern than smaller ones, but size alone is not an indicator of malignancy or benignity.
A nodule may initially appear to be benign but upon further investigation be malignant—or vice versa. It could be a scar. It could indicate an old infection of no consequence. It could indicate an active infection or inflammation.
Again, it is a nonspecific finding that requires further thought, analysis and maybe additional testing.
2. Okay, you scared me by mentioning cancer. What should I do about a pulmonary nodule?
In many instances, the nodule can be dismissed if it has characteristic imaging features of a granuloma (calcium) or hamartome (fat) or if it can be shown to be stable over time (at least two years in many typical nodules). In most other cases, the nodule will require a follow up scan or two, and occasionally a PET scan and or a consultation with a lung doctor (a pulmonologist). Less frequently, the nodule will need a biopsy or to be removed, especially if it is likely or proven to represent cancer.
3. How common are pulmonary nodules?
Very common. In fact, last week the TR’s own 85 year old father texted him to tell him about the incidental pulmonary nodule discovered in the right lung when he was having a CT scan of the kidneys for blood in the urine.
The TR spends a good deal of his work day following pulmonary nodules with serial chest CT scans and discovers them regularly, too. The American Thoracic Society estimates that as many as one half of all people getting an x-ray or CT scan that includes part of the lungs has a pulmonary nodule (1). The TR’s experience is that the number is quite a bit lower in actual practice.
4. I have a pulmonary nodule. What should I do about it?
First, do not panic. Much of the time, this amounts to very little.
There are evidence-based consensus recommendations called, The Fleischner Society Guidelines (2), created with input from leading chest radiologists, pulmonologists, and chest surgeons, to advise the doctor and patient to manage these incidental lung nodules. It was updated in early 2017, and the new guidelines represent the state-of-the-art for handling this medically common scenario.
Based on the size and appearance, there are standardized work up and follow up protocols. The TR was positively pleased to see that the new recommendations are much less aggressive than the early version, previously requiring more frequent workup and monitoring for minuscule nodules that never seemed to amount for much. As the TR ages, his visual acuity for small things is naturally declining, and he is thrilled that the tiniest nodules can now usually be ignored.
5. While I have you here, TR, what’s the deal with lung cancer screening?
Lung cancer screening is a newer test, using low dose CT scans, for the early detection of lung cancer in a subset of people with a history of smoking (3). It was graded “B”, by the USPSTF, for its life saving potential (for comparison, screening mammography gets a “C” grade) and is offered to Medicare and commercial insurance patients who qualify, based mostly on age and smoking history. The CT scans are used to detect and follow the same nodules discussed above. If you are a smoker or former smoker, consider a discussion with your doctor as to whether or not lung cancer screening might benefit you.
6. Thank you, TR. What can I do to repay you for this useful information?
Do not tell the SC, but the TR loves salted caramel gelato and will accept gelato donations.
The skeptical cardiologist has had several of his readers submit stories and tracings of AliveCor Mobile ECG recordings which yield unclassified or unreadable recordings. In some cases this is due to excess noise but a lot of these tracings suffer from low voltage: the height of the tracing is very small.
John, a skepcard reader, is typical.
Recently, he noted his heart was racing and made an AliveCor recording which came back interpreted by the app as normal
Three hours later he made a second recording which has drastically lower voltage: the only deflections visible are tiny QRS complexes, the p waves have disappeared. I think this is also normal sinus rhythm but because p waves can’t be seen this came back uninterpretable and if there were any irregularity AliveCor would have called it atrial fibrillation:
John has a theory on the cause of some of his low voltage recordings which I shall reveal in a subsequent post after testing it.
In the meantime, if any readers have suggestions as to causes of low voltage recordings or have noted similar issues please comment below or send recordings and observations to DRP@theskepticalcardiologist.com.
Donald Trump recently appeared on the Dr. Oz show and handed a letter to the celebrity medical charlatan and TV host, Mehmet Oz.
The letter was written by his personal physician , Dr. Harold Bornstein,
and summarized various laboratory and test results which led Bornstein to conclude that Mr. Trump is in excellent health (Bornstein did not repeat his earlier, bizarre statement that “If elected, Mr. Trump, I can state unequivocally, will be the healthiest individual ever elected to the presidency.”)
From a cardiovascular standpoint the following sentence stood out:
“His calcium score in 2013 was 98.”
Regular readers of the skeptical cardiologist should be familiar with the coronary calcium scan or score (CAC) by now. I’ve written about it a lot (here, here, and here) and use it frequently in my patients, advocating its use to help better assess certain patient’s risk of sudden death and heart attacks.
The CAC scan utilizes computed tomography (CT) X-rays, without the need for intravenous contrast, to generate a three-dimensional picture of the heart. Because calcium is very apparent on CT scans, and because we can visualize the arteries on the surface of the heart that supply blood to the heart (the coronary arteries), the CAC scan can detect and quantify calcium in the coronary arteries with great accuracy and reproducibility.
Calcium only develops in the coronary arteries when there is atherosclerotic plaque. The more plaque in the arteries, the more calcium. Thus, the more calcium, the more plaque and the greater the risk of heart attack and death from heart attack.
What Does Donald’s Trump’s Calcium Score Tell Us About His Risk Of A Major Cardiac Event?
We know that, on average, even if you take a statin drug (Trump is taking rosuvastatin or Crestor), the calcium score goes up at least 10% per year which means that 3 years after that 98 score we would predict Trump’s calcium score to be around 120.
Based on large, observational studies of asymptomatic patients, Calcium scores of 101 to 400 put a patient in the moderately high risk category for cardiovascular events.
When I read a calcium score of 101-400, I make the following statements (based on the most widely utilized reference from Rumberger
This patient has:
-Definite, at least moderate atherosclerotic plaque burden
-Non-obstructive CAD (coronary artery disease) highly likely, although obstructive disease possible
-Implications for cardiovascular risk: Moderately High
Since we know that Hillary Clinton recently had a calcium scan with a score of zero, we can estimate that Trump’s risk of having a heart attack or dying from a cardiac event is markedly higher than Clinton’s.
Clinton, born October 26, 1947 is 68 years old and we can enter her calcium score into the MESA calcium calculator to see how she compares to other women her age. A coronary calcium score of 6 is at the 50th percentile for this group.
Interestingly, Trump’s score of 98 at age 67 years was exactly at the 50th percentile. In other words half of all white men age 67 years are below 98 and half are above 98, creeping into the moderately high risk category.
So, based on his coronary calcium score from 2013, Donald Trump has a moderate build up of atherosclerotic plaque in his coronary arteries and is at a seven-fold higher risk of a cardiac event compared to Hilary Clinton.
The skeptical cardiologist received an email from the folks at AliveCor a few days ago with the subject line:
Dad’s heart matters – Kardia Mobile for Dad will give you peace of mind and make Dad happy
The email contains this image of an older well-dressed man (with lots of bling) standing in a beautiful meadow near the ocean. The man has decided to turn his back on the ocean and check his heart rhythm using the AliveCor/Kardia (AliveCor has changed the name of its ECG devices to Kardia) mobile ECG. This man is a happy dad! (Unless his heart rhythm is interpreted as atrial fibrillation. Then the beach walk is ruined.)
The email asks the question “What if Dad’s heart really was an open book?”
Uhh, he’d be dead? Clearly books don’t function well at pumping 5 or 6 liters of blood through the cardiovascular system every minute whether they are open or closed. Perhaps the question is using either the heart or an open book as a metaphor?
The advertisement goes on to suggest that I get my dad an AliveCor device for father’s day “So you always know what his heart is thinking.”
I believe this is the marketing person’s attempt to extend the metaphor of the open book, i.e., you know exactly what dad’s brain is thinking, now you can extend this knowledge to his heart. The metaphor of the heart “thinking” is quite poor but poor metaphors are the norm today.
Bad metaphors and bad writing abound on father’s day because 90 million greeting cards are purchased and given as (according to the Greeting Card Association) “a meaningful expression of personal affection for another person.” Despite the increasing use of Facebook and its ilk to transmit emotions, the Greeting Card Association assures us that “The tradition of giving greeting cards … is still being deeply ingrained in today’s youth, and this tradition will likely continue as they become adults and become responsible for managing their own important relationships.
Mobile Ecg Monitor As A Father’s Day Gift
I have to say that despite the horror of the writing in this email advertisement it got me thinking about getting my father a Kardia device. I’ve suggested previously that an AliveCor device would make a good gift for Christmas for a loved one who has intermittent unexplained palpitations or atrial fibrillation but had not considered this for my dad.
For one thing he does not possess a smart phone which is required to make the Kardia device functional. For another, he doesn’t have atrial fibrillation (that we know of. Perhaps if I knew what his heart was thinking we would find out that it likes to fibrillate late at night,)
Perhaps it’s time to upgrade my Dad to an iPhone I began thinking.
But wait! He has an iPad mini (that he seems to only use for FaceTime conversations.)
Further research reveals that Kardia is not only compatible with iPhone and Android smartphones but apparently iPads and IPod Touch.
Taking Care of Dad’s Heart
What about the rest of the slick advertising copy in my email?
And now you can know the way to help take care of it. Kardia gives Dad a medical-grade EKG in only 30 seconds. It even gives him expert analysis and tracking, with reports getting shared directly with his physician
This part is pretty clear and correct. I use Kardia daily in my office to record patient’s heart rhythm and I have a dozen patients now who make recordings outside of the office. They can have their recordings read by a random cardiologist for a fee or establish a link with me as their provider and I can review them through my account for free.
Is It The First Father’s Day Gift That Leads To More Father’s Days?
The ad ends with the remarkably brazen statement that “It’s the first Father’s Day gift that leads to more Father’s Days.”
While I find the device more helpful in many instances than current expensive and intrusive long term monitoring devices for detecting and monitoring atrial fibrillation and other abnormal heart rhythms, it is a huge leap to suggest that this translates somehow into a longer life span.
To AliveCor’s credit, despite such ridiculous marketing drivel , studies presented at the recent Heart Rhythm Society Scientific Meetings suggest:
Kardia Mobile Superior to Conventional Monitoring: Researchers at the Leeds General Infirmary found that the AliveCor monitor is superior to conventional Holter monitoring in patients with palpitations, providing a higher diagnostic yield, more detected arrhythmias, with a similar workload.
Kardia Mobile Leads to Improved Patient Compliance:Researchers at the University of Buffalo found that AliveCor provides a diagnostic yield comparable to a 30-day ambulatory looping event monitor and that the smartphone-based ECG monitor can be used as a first approach for the diagnosis of palpitations.
Kardia Mobile provided more information resulting in changes in arrhythmia patient management than traditional external event recorders in a study from researchers at the University of Miami.
AliveCor’s AF algorithm was reported to be superior by researchers at Arizona State University to the patient’s own ability to detect AF via symptoms.
But even if these studies make it to publication they don’t suggest the device provides any improved longevity. In fact, such data, do not exist for any monitoring device.
Happy Father’s Day, Dad! Don’t be surprised when we FaceTime later today that I’ve found another use for your iPad.
N.B. Clearly I receive no consulting, speaking or P.R. writing fees of any kind from AliveCor. Nor do they provide me with any free devices. What’s more, when I lose one of their devices they don’t replace it. I am totally free of any conflict of interest.
It has for the most part taken the place of the more elaborate, but cumbersome and time-consuming, 12-lead ECG in patients where heart rhythm is my only concern.
I’ve also convinced about a dozen of my patients who have intermitent atrial fibrillation to obtain the device and they are actively using it to monitor at home their heart rhythm. Through the AliveCor website, I can view their recordings and see what their heart rhythm is doing when they have symptoms.
Last week, a patient of mine (I’ll call her Suzy) who has had significant prolonged episodes of atrial fibrillation associated with heart failure (but cannot tell when she is in or out of rhythm) notified me that her device was interpreting her rhythm as atrial fibrillation. She had not had any symptoms, but was making daily recordings for surveillance.
Suzy called our office and we brought her in the next day and confirmed with a 12-lead ECG that she was indeed in atrial fibrillation with a heart rate of 120 beats per minute.
It’s pretty amazing that this little, inexpensive device can now replace expensive and elaborate long term cardiac monitors for many of my patients.
AliveCor Rebrands Itself to Kardia
I’ve noticed that AliveCor has rebranded itself as Kardia. If you go to http://www.alivecor.com now you see the fourth generation device along with promotion of a “Kardia band” which apparently works with an Apple Watch to record your ECG.
The Kardia band is not available for purchase at this time but if and when I can get one, it might motivate me to purchase an Apple watch.
When I purchased my AliveCor device in June, 2015 it cost $74.99 from Amazon.com. The newer version is priced at $99 at both AliveCor and Amazon websites. I’m told by Dr. David Albert of AliveCor that this “fourth generation” version is more accurate, so I have purchased it to see if it reduces the problem of occasional bad recordings.
You can see in this picture from the website that the formerly flat metal electrodes now have bumps. Dr. Albert says these result in more surface area for better contact with skin. We will see.
The Value of Early Detection Of Atrial Fibrillation
Meanwhile, I will be doing an electrical cardioversion (shocking or resetting the heart) on Suzy to get her back to normal sinus rhythm. If we had not detected the asymptomatic onset of her rapid atrial fibrillation using the AliveCor/Kardia device, chances are we wouldn’t have known about it until her heart muscle weakened again and she became short of breath from heart failure.
I have Suzy on blood thinners to lower her risk of stroke associated with her Afib but for my patients who are not on blood thinners, detection of silent or asymptomatic AFib is even more important.
p.s. The skeptician in me feels this post borders on infomercialese.
Let me make it clear that I have no connection with the company formerly known as AliveCor and have received nothing from them (not even free test devices or Apple Watch Kardia Bands!) but I’m just really excited about the device and how it can help my patients (oh, please excuse me, this really sounds like marketing) “empower” themselves to take control of their heart rhythm.
In the course of writing this, I’ve discovered an academic paper evaluating 13 ECG smart phone type ECG devices so there are other devices you could try. I haven’t had the time or resources to evaluate them.
My patients and I continue to receive mailings from SSM Health Care (here in St. Louis), informing us that they have “partnered with HealthFair to deliver ultrasound tests of the heart and arteries” in our neighborhood.
HealthFair’s financial model involves partnering with hospitals like SSM to promote these unnecessary screenings performed in mobile vans that travel to settings like Walgreen’s out in the community. The hospital system pays HealthFair (typically an “undisclosed amount”) to put the SSM name on their promotional flyers. SSM does not provide any review of the quality of the studies performed.
SSM benefits by having its “brand” spread around and when abnormalities are detected on the exams, these patients are then provided with the names of SSM physicians.
Both SSM and HealthFair benefit in this relationship by identifying as many abnormalities as possible. It doesn’t really matter to either if the abnormalities detected are real or important. The bottom line is getting more patients into the SSM system, getting down stream referrals and testing and adding to the SSM bottom line.
Steven Weinberger, MD executive vice president and chief executive of the American College of Physicians. and two co-authors wrote in the Annals of Internal Medicine journal, calling hospital involvement without disclosing potential downsides “unethical.”
“Because of a lack of counseling by these companies about the potential risks of an “abnormal” test result, the consumer is initially unaware that this may open a Pandora’s box of referrals and additional testing to monitor or treat these abnormal findings. Our medical system and society bear the cost of poor coordination of care and additional testing and treatment to follow up on unnecessary “abnormal” screening test results (10). That most of these tests are not medically indicated in the first place is left undisclosed to the consumer, nor is there a discussion of potential adverse consequences or additional costs.”
The Particular Dangers of Screening Echocardiography
In my previous post I warned in particular of the dangers of getting a screening echocardiogram, a test which I have spent my professional lifetime studying, writing on, teaching and interpreting.
I’ve also discussed in detail how easy it is to botch an echocardiogram and what to look for to guarantee that you are getting an accurate study.
Let me provide another example of how a poorly performed and/or interpreted echocardiogram can lead to a lifetime of unnecessary anxiety and inappropriate testing.
I saw a patient in my office recently who was changing cardiologists because of dissatisfaction with communication. Reviewing records from the prior cardiologists, I saw that an echocardiogram was performed in 2012 and read as showing enlargement of the aortic root and pulmonary hypertension.
A greatly enlarged aorta or aortic aneurysm can rupture or tear resulting in sudden death. It’s a very serious condition, consequently once enlargement of the aorta is identified, we counsel patients on appropriate activities, screening of relatives, and follow them lifelong with tests to monitor the size of the aorta.
I reviewed the echocardiogram which was performed in the cardiologists’ office and it was clear that an older echocardiographic technique called M-mode had been utilized, and that the measurement was invalid. When I repeated the echocardiogram in my hospital’s echocardiography laboratory, it was normal (we have a very rigorous quality assurance program and review on a regular basis with the sonographers and physicians best practice for recording and measuring the aorta by two-dimensional recordings).
Pulmonary hypertension (elevation of the pressures on the right side of the heart) can also be a sign of very severe and life threatening cardiac or pulmonary problems. If diagnosed, it typically requires extensive testing with associated risks. Like aortic root enlargement, it must be followed carefully, lifelong.
Pulmonary hypertension can be measured reasonably accurately by a well done echocardiogram utilizing a combination of Doppler flow measurements and imaging of the inferior vena cava. Because of the critical importance of getting these measurements right, I have devoted numerous educational conferences to reviewing them with our sonographers and reading physicians.
In the case of my patient (and I presume, numerous patients undergoing less rigorously performed screening echocardiograms) the initial echocardiogram did not truly show pulmonary hypertension and the echocardiogram I did confirmed this.
The Profit Factor
Ultimately, these types of screenings done in the name of promoting wellness, are being done for money.
HealthFair is strictly in it for profit; they want to get as many patients as possible paying for these screenings. Their bottom line is not enhanced by spending time and money on guaranteeing that good equipment, trained sonographers and experienced physician readers are involved.
SSM is only interested in getting more patients funneled into their system. They are paying HealthFair to identify abnormalities and therefore, abnormalities will be found. SSM in this relationship is going against good medical practice and recommendations of national medical organizations in order to make money.
A program that on the surface is promoting wellness, therefore, in the final analysis may be promoting unwellness.
If you have had one of these echocardiographic screenings and had an abnormality detected, I would be happy to review the initial recordings and provide my opinion on their accuracy. I would do this gratis as the skeptical cardiologist in the interest of research and knowledge, not to accumulate patients or revenue.
The skeptical cardiologist was in New Orleans last weekend. There is no breaking low carb news to report but I did make it to Commander’s Palace for lunch.
There the eternal fiancée of the skeptical cardiologist (EFOSC) and I enjoyed delicious food, delightful company (Dave and Barb, who I wrote about last year when they dramatically improved their longevity by tying the knot in The Big Easy) and several oddly colored $0.25 martinis.
During a lull in the activities I pulled out my iPhone and was asked by the lovely Barb what the funny looking thing stuck on the case was. This necessitated demonstrating my Alivecor mobile ECG device and recording her electrocardiogram.
Strangely enough, the recording was full of an odd artifact.
There was much discussion on the source of the artifact and we repeated the recording having her use her third and fourth fingers on the electrodes instead of the second and third fingers she used the first time. Same result.
Barb speculated that it was due to the absence of husband Dave who had left the table to use the facilities.
When Dave returned we recorded his ECG and there was no artifact whatsoever.
I repeated the recording on Barb and lo and behold it was now free of artifact.
What was the source of this mysterious ECG artifact noted after an outstanding lunch and multiple 25 cent oddly colored martinis?
High blood alcohol level?
Strange electrical devices being utilized intermittently at Commander’s Palace?
Or perhaps I was recording the actual adverse electrical signals created by the absence of Barb’s devoted spouse, something heretofore not reported.
Further studies are clearly needed to fully define and characterize these waves which I have decided to call Commander’s electromagnetic marriage disruption waves or CEMDW’s.
If you’ve had a coronary stent implanted or undergone bypass surgery, it is common to wonder about the status of the stent or the bypass grafts or the coronary arteries that maybe had a 50 or 60% blockage and were left alone.
This is especially likely if there was little or no warning that you had really severely blocked coronary arteries.
After all, you are thinking: “doesn’t it make sense to monitor these things and stay on top of them; be proactive?”
It certainly seems reasonable on the surface, and for many years, routine stress testing of patients without symptoms on an annual basis, was the norm.
However, this practice is much more likely to cause harm than to benefit patients and is recognized by the American College of Cardiology as one of 5 things that patients and physicians should question as part of the “Choosing Wisely” campaign (see here).
“Performing stress cardiac imaging or advanced non-invasive imaging in patients without symptoms on a serial or scheduled pattern (e.g., every one to two years or at a heart procedure anniversary) rarely results in any meaningful change in patient management. This practice may, in fact, lead to unnecessary invasive procedures and excess radiation exposure without any proven impact on patients’ outcomes.”
Studies have shown that stress testing less than two years after a coronary stent, very rarely change management.
The American College of Cardiology, American Society of Echocardiography and the American Society of Nuclear Medicine are all in agreement that stress testing less than two years after a coronary procedure is “inappropriate,” and more than two years after the procedure is “uncertain.”
Why Do Cardiologists Order These Tests If They Are Inappropriate?
There are 3 reasons, and they are representative of the major factors driving all over-testing in medicine.
Financial. Cardiologists frequently benefit from stress tests they order in multiple ways. First, they may own the nuclear camera used in the test and the more stress tests performed in their office, the more money they will make from the technical remuneration for the procedure. The cardiologist also frequently interprets the test results and receives a professional fee for both supervising and interpreting the nuclear images. Finally, if the test is abnormal, the cardiologist may then recommend additional testing, which he may perform (cardiac catheterization, stent) or interpret (coronary CT angiogram).
Defensive medicine. It is not uncommon for cardiologists to be sued for NOT performing a test or procedure when the patient’s outcome is bad. On the other hand, I have never heard of a cardiologist being sued for DOING an inappropriate stress test.
Keeping the customer happy. Too often patients feel that if their doctor is performing frequent tests on them, he is being vigilant, proactive and “staying on top of things.” They don’t realize the down sides to the extra testing and the lack of benefit.
Not uncommonly, patients switching to me from another cardiologist indicate that they have been getting an annual stress test and are disappointed to hear that I am not recommending one.
They may think that I’m lazy or not up on the latest techniques in cardiology. Usually in this situation I have to spend a fair amount of time trying to teach them about the possible downsides of over-testing.
In the case of stress nuclear testing, harm comes from two sources:
Radiation. Stress nuclear tests typically utilize the radio tracer Technetium-99 and result in a radiation dose of around 15 mSv. This is about 10 times the radiation from a typical coronary calcium scan. A chest x-ray gives 0.02 mSV and the annual background radiation in the US is 3 mSv.
False positives. Nuclear imaging is very susceptible to images which appear to show abnormalities of blood flow, which in reality are just due to soft tissue (breast, diaphragm, fat) interposed between the heart and the camera. These can be interpreted as due to a heart attack or blocked coronary artery when everything is actually fine with the artery. False positives then lead to additional testing such as a cardiac catheterization, which carries risks of bleeding, heart attack, stroke and death.
One important point to remember is that coronary stenting has not been shown to reduce heart attacks or prolong survival outside the setting of an acute heart attack. Therefore , if you’ve already had a cardiac catheterization that either resulted in bypass surgery or a stent of one artery, it is highly unlikely that a subsequent catheterization/further procedures will lower your heart attack or dying risk.
Certainly, if you have a change in symptoms that suggest that your coronary artery disease has progressed, this is an appropriate reason to consider stress testing. Such symptoms include shortness of breath on exertion and chest discomfort, especially if it occurs during activity. Diabetics often don’t have symptoms that warn them of a problem, therefore, we should consider stress testing more frequently and at a lower threshold for them.
For most people, however, more is not always better when it comes to cardiac testing and, in many circumstances, can be worse.
These members of the “calcium club” are portrayed as unbiased self-less promoters of the prevention of heart attacks and sudden death, fighting an uphill battle against the evil procedure and money-driven forces who push coronary stents-greedy interventional cardiologists and the device, hospital and insurance industries.
A constant theme in the documentary is that CAC scanning should be to the heart what mammography is to the breast. It should be done on all patients over a certain age and should be covered by insurance.
As a non-invasive cardiologist with a strong interest in prevention, I am definitely a strong proponent of CAC scans in the right population. As the skeptical cardiologist, however, I find flaws with the mammography comparison.
Let’s review some of the established science regarding CAC scans.
What Is A CAC Scan?
The CAC scan utilizes computed tomography (CT) X-rays, without the need for intravenous contrast, to generate a three-dimensional picture of the heart. Because calcium is very apparent on CT scans, and because we can visualize the arteries on the surface of the heart that supply blood to the heart (the coronary arteries), the CAC scan can detect and quantify calcium in the coronary arteries with great accuracy and reproducibility.
A preventive cardiologist, Dr. Arthur Agatson, who is interviewed in the film (and who is also the creator of the South Beach Diet, a low carbohydrate, high fat diet), developed a method for counting up the amount of calcium in the coronary arteries (the Agatson or calcium score).
Calcium only develops in the coronary arteries when there is atherosclerotic plaque. The more plaque in the arteries, the more calcium.
What Is The Risk Of A High CAC Score
Multiple observational studies have shown that a high versus low calcium score is indicative of high risk for heart attack and death.
For example, a large study published in 2008 (the MESA study), followed 6,814 individuals for 3.8 years. Compared with patients with a CAC score of 0, patients with a CAC score of 101-300 had a 7.7 fold increase risk of a coronary event (heart attack). CAC score of >300 conferred almost a tenfold increase risk.
Based on data from 5 large studies and almost 15,000 patients, we can put patients with CAC score in very low to high risk categories for cardiac events over the next 10 years.
What Is The Value Of A Zero Calcium Score?
Just as important as identifying patients with advanced or premature atherosclerosis who should be getting intensive therapy for prevention of cardiac events, is identifying those patients who may not warrant therapy.
A CAC score of zero puts a patient in an extremely low risk category. A recent study, with the provocative title of:
A 15-Year Warranty Period for Asymptomatic Individuals Without Coronary Artery Calcium
…demonstrated that a zero calcium score confers this low risk of cardiac events for up to 15 years.
Thus, many patients, who are considered intermediate risk based on standard risk factors, do not have significant plaque by CAC score and may not need otherwise indicated statin therapy.
The comparison of mammography to CAC scanning is appropriate in that both have created considerable controversy and are at the epicenter of discussions on the value of mass screenings in the prevention of life-threatening disease.
In contrast to CAC, mammography has been widely accepted and promoted by most professional organizations. In recent years, however, the value of mammography for all women over the age of 40 has been questioned.
In 1980, a randomized controlled trial of screening mammography and physical examination of breasts in 89, 835 women, aged 40 to 59, was initiated in Canada. It was called the Canadian National Breast Screening Study.
The findings published last year were:
Annual mammography in women aged 40-59 does not reduce mortality from breast cancer beyond that of physical examination or usual care when adjuvant therapy for breast cancer is freely available. Overall, 22% (106/484) of screen detected invasive breast cancers were over-diagnosed, representing one over-diagnosed breast cancer for every 424 women who received mammography screening in the trial.
Downsides of breast cancer mammography screening include:
-Over-diagnosis: finding and treating breast cancer that would not have been a threat to the patient.
-False positives: the test identifies a possible cancer which is not subsequently confirmed. False positives lead to breast biopsies, which are not needed and often cause needless anxiety and stress.
Is CAC Screening The Cardiac Equivalent Of Mammography?
CAC scans differ fundamentally from mammography because atherosclerosis is a continuous and diffuse arterial process, whereas breast cancer is (most often) localized, and either present or not.
The development of atherosclerosis starts with fatty streaks in multiple arterial beds fairly early in life, followed by progressive plaque development with progressive build up of calcium in the plaques.
Thus, the CAC score ranges continuously from zero up to several thousand.
The calcium score is not subject to false positives-if calcium is detected, atherosclerotic plaque is present.
A mammogram is either abnormal, suggesting cancer and requiring a biopsy, or it is normal. There is no continuous grading of risk.
The second fundamental difference in the two disease processes is that atherosclerosis can kill suddenly without warning.
As pointed out in numerous examples in The Widowmaker, an individual can seem fit and hearty one minute, and be dead the next, from a heart attack caused by a lethal abnormal rhythm.
Breast cancer deaths on the other hand, occur slowly after diagnosis, and are generally predictable.
Nuclear Stress Tests are the Mammography of the Heart
If we are looking for a cardiac test that has characteristics similar to mammography, the nuclear stress test is much closer than CAC.
With a nuclear stress test we are using a radio tracer injected intravenously, which subsequently traverses the coronary arteries into the heart muscle. Subsequent imaging of the photons emitted by the radio tracer allows assessment of the status of blood flow down the coronary arteries.
The test is designed to identify coronary arteries with flow limiting blockages (usually >70% blocked), caused by atherosclerotic plaques. Such blockages are more likely to be causing symptoms and therefore more likely to require treatment with coronary stents or bypass surgery.
Like mammography, then, nuclear stress tests are either abnormal or normal, and when abnormal they can be falsely abnormal.
Nuclear stress tests have a very high incidence of false positives. These false positives result in invasive catheterization procedures to more directly image the arteries, and may result in inappropriate coronary stenting or bypass procedures with associated risks.
It is because of the high risk of false positives and attendant harm that in the last decade, all cardiac societies recommend against the routine use of stress testing in asymptomatic patients.
As pointed out in the Widowmaker, there is no data which suggest that stress testing improves outcomes for cardiac patients.
Stress tests by design tell us nothing about the noncritical build up of atherosclerotic plaque. You can have a normal stress test and have a huge burden of plaque in your arteries.
It is this silent build up of atherosclerosis, with sudden rupture of plaque, which results in sudden death in most cardiac patients.
What Is The Breast Cancer Equivalent Of CAC?
A CAC of the breast would identify abnormal cells as soon as they began on the presumably multi-year road to becoming a full flown cancer.
To be fully equivalent to the CAC, the breast CAC would have to have a proven treatment that could be instituted once a certain stage of cell transformation had been reached.
For atherosclerosis, that treatment is statin drugs, which are recommended for those with high risk CAC scores.
For breast cancer, the treatment of choice is mastectomy.
Would Widespread Institution of CAC Screening Save Millions of Lives?
For mammograms based on a review of all the evidence, the US PTF concluded:
Over a 10-year period, screening 10,000 women ages 50 to 59 years will result in 8 (95% confidence interval [CI], 2 to 17) fewer breast cancer deaths, and screening 10,000 women ages 60 to 69 years will result in 21 (95% CI, 11 to 32) fewer deaths.
To scientifically determine how many lives are saved by CAC screening, we would need an extremely large randomized controlled trial lasting for at least 6 years.
Individuals with low or intermediate risk from standard risk factors for atherosclerosis would receive a standard approach to management or would undergo CAC screening with treatment determined by calcium score.
Such trials have been proposed but to date have not been funded by the NIH thus we may not have a definite answer for a long time.
Should CAC Scans Be Covered Like Mammography?
I am very conflicted on this question.
On one hand I do believe that appropriate use of CAC scans prevents heart attacks and sudden death. How many, remains to be seen. As we saw for mammography, only large scale randomized trials will tell us for sure who will benefit and how much.
On the other hand, I can see potential for abuse, and in the wrong hands, excessive downstream invasive testing, which will minimize the benefits of early detection.
If CAC scans are covered by insurance and used widely, they could become a method for unscrupulous cardiology centers and doctors to proceed to unnecessary testing that would ultimately increase the amount of inappropriate coronary stenting.
Indeed, it is quite ironic that the major theme of The Widowmaker, that of the medical-industrial stent complex suppressing CAC scan usage, is quite illogical, for widespread, injudicious use of CAC scanning would be a boon for stent inserters and makers.
The inappropriate use of CAC scan information is limited currently because most of the doctors ordering them are primarily interested in prevention, not in generating more testing and procedures.
The other limit on its use is cost. For 99% of my patients the $125 for a CAC scan at my hospital is not a limiting factor.
On the other hand, in a less affluent population, this would be a large and limiting expense; the poor would be getting a lesser standard of care.
The cases of patients in The Widowmaker who feel like a CAC scan saved their lives are very similar to those of breast cancer patients who feel mammography saved theirs.
These patients often become passionate advocates for a specific test based on their own experience. The Widowmaker, in fact, was funded by David Bobbett, an Irish millionaire who discovered that he had an extremely high calcium score and now feels like everyone should get the test.
Bobbett is convinced that the test saved his life, but all anecdotal patient stories about CAC scans “saving their life” have to be taken with a grain of salt.
After this (far too long) discussion I have to conclude that although they share many features, CAC scans are not the mammography of the heart.
Atrial fibrillation (AF) is a common abnormal rhythm of the heart which causes 1 in 4 strokes. Those afflicted with AF may lack any symptoms or only have a vague sense of irregularity of their heartbeat and thus the first symptom of AF can be stroke.
The gold standard for diagnosing AF has long been the electrocardiogram (ECG or EKG) and typically the ECG involves placing 12 electrodes on the chest/arm/legs and recording the electrical activity of the heart on an expensive device.
I’ve been checking out a device made by Alive Cor which works with your smart phone to record a single channel ECG and is capable of accurately diagnosing if you are in the normal (sinus) rhythm or in AF. You can purchase the third generation (significantly smaller then earlier versions) AliveCor Mobile ECG from Amazon or from AliveCor directly for 74.99$ and it works with an app with both iOS and Android devices.
I used mine with my iPhone 6. At first I carried it separately, fearing the added bulk when stuck on to my iPhone case but after a while I realized that it was never with me when I wanted to use it and that there was a huge risk of losing it and so I used the backing adhesive to attach it to my case.
After pairing the device with the app you put two fingers on each of the metal pads and the smartphone screen displays the recording. After 30 seconds of recording it then interprets the rhythm.
Above is a typical recording I made in my office on a patient who had a history of AF. The quality is good and I can clearly see that he is in normal sinus rhythm. The app correctly made the diagnosis of NSR and calculated his heart rate at 68 beats per minute.
One day I had most of my patients record their ECG’s using AliveCor and compared it to the standard 12-lead ECG we normally record. The device correctly identified the two patients with AF out of this group and correctly identified the normals.
This recording is from a patient with persistent AF which had recurred two weeks earlier. The device correctly identified AF.
Studies have documented that AliveCor Mobile ECG can accurately diagnose AF in a screening setting and the FDA approved the device for AF screening in 2014.
Given the high prevalence of silent AF, the strong association of AF with stroke and the availability of anticoagulants which reduce AF associated stroke by 70%, screening for AF with devices like AliveCor holds the promise of preventing large numbers of stroke.
(For my comments on taking the pulse and stroke prevention see here and on the inadvisability of a routine 12-lead ECG see here)
AliveCor allows physicians utilizing the Mobile APP and ECG to have a “dashboard” into which their patients can transmit their AliveCor ECG recordings.
I will be discussing this remarkable new device with my AF patients who are smartphone enabled. I think it will advance our ability to more efficiently and quickly diagnose AF in them.
My standard approach if a patient with AF calls and says that they feel like they are out of rhythm is to have them come into the office for a full 12-lead ECG. If they are AliveCor enabled, they could make their own recording, and we could review that remotely and make a diagnosis without the office visit.