On NPR.org: "Overshooting Obama's Health"
New writing of mine, posted elsewhere (and broadcast on All Things Considered on 3/4/10):
"It doesn't take a CT scan to know that President Obama should keep exercising, watch his diet, and quit smoking. So deciding not to do a test like a coronary artery calcium CT scan isn't just about avoiding the financial cost of the test. If the results of the test won’t change what we recommend, then the patient is taking risks for data that won’t make a difference."
20 comments:
Agree mostly. As citizen, I am concerned with Obama's performance for the next 3-7 years. Ultrasound of carotids would non-invasively see if he is developing plaque from unreported behaviors or adverse genetics and would be safer than CT. Obama's TC/HDL-C ratio is pretty good so he probably doesn't need to do much but stay away from Tyson's products and keep playing basketball.
Obviously you are not aware of the MESA trial in NEJM 2008 that suggested with Agatston score above 300 your risk for any cardiovascular event is greater than 2% per year, similar to the risk for cardiovascular events in patients with diabetes and PAD. This kind of finding would make for consideration of statin therapy. Standard risk factors are inaccurate in individual subjects but the calcium score does to some degree get around this. The cost of calcium scoring is minimal or $100-200 per patient and the risk of cancer is not proven, but rather speculated to be up to 0.2% if any. Yes incidental tumor findings lead to more scanning and unfortunate cost.
The calcium scoring approach for initiating statin therapy is not yet clinically proven and most likely will not be fully researched for another 10-15 years. Obama can not wait for this and others will need to be informed so they can fully participate in their own care.
Your views reflect the teaching over the last 10 years. Old dictum that is bound to change.
Gaddi,
Thanks for pointing out the MESA trial, of which I was aware, because it allowed me to read the accompanying editorial for that article, which I had not previously read. It urges caution in wide implementation of this test, for the same reasons that I do.
joe
Dauner, I agree that Obama should keep playing basketball. The carotid ultrasound is a hotly debated tool in cardiovascular research--but I'll stay out of that debate for today!
Thanks for reading.
joe
Carotid Intimal thickness measuring has no standardization and is really a tracking tool for reasearch studies. Very little clinical use. The coronary calcium score is the ONLY non invasive way to determine whether someone has a cholesterol transport error with atherosclerotic results. It does not measure or look for blockages, but for vascular disease. He is a perfect case, his doctors were leaning towards statin use in him, but as his calcium score is zero, he has no chance of having any benefit of treatment in the next 5 and likely 10 years, so if there is ANY risk of statin or untoward effects, the risk benefit is upside down and treatment is contraindicated. An electron beam coronary score emits between 20 and 55mrem. Absolutely meaningless in terms of dosing, and may even be good for you. The zero threshold exposure curves for radiation are not based on empiric data, but flawed theory. How one can argue against secureing good data in order to base clinical decisions is difficult for me to understand. What do you use for information, an ear lobe crease? The misstatements in this article reveal the authors ignorance and represent the usual, "if one is not up on it, they are down on it.
I've listened to you on NPR for several years while you were in med school and was very glad to hear you again especially with this piece. In my opinion the fear of death which is programmed into our biology to promote survival of the organism short circuits the analytical, thinking process for many of us who have not studied the brain. This is why it's so easy to sell another test. Good Luck, Joe!
There is already proof that treating patients based upon a calcium scan improves outcomes--it was a substudy of the St. Francis heart study (Arad and Guerci). Not surprising...given the fact that statins have been shown to lower risk in all groups, it is counterintuitive to believe that an imaging technique somehow finds a population of people with atherosclerosis who are uniquely unresponsive to plaque stabilizing therapy (statins). Nobody credibly doubts that a patient with high calcium score has a vasculopathy and is at HIGH risk...so we have to wait for a plaque rupture and only treat the survivors of that event? No, if one has a CHD-equivalent amount of atherosclerosis (based on great outcome studies), it is logical to treat patients. Bush would not be on statins (with his TC of 150) if he didnt get an EBCT like his father. If Clinton's docs did an EBCT 10 years before his bypass and treated him according to the recommendations we published (Hecht et al,AJC), he would likely be in much better shape.
Of course Obama should stop smoking,eat well and exercise and you don't need any test to tell him that.
I live and work in Boulder Colorado, the healthiest city in the healthiest state in the country. The leading cause of death in Boulder is coronary artery disease.
Evaluating risk beyond the basics is necessary if we want to make a difference in heart attack rates. EBT coronary calcium imaging is the best way to determine one's true risk.
In one study presented at last years AHA in Orlando, CAC was shown to re-assing risk to 76% of subjects deemed to be "intermediate risk" by Framingham.
Anonymous--thanks for remembering my earlier work--I appreciate the kind words.
In terms of the value of the CAC score:
Although I avoided getting in to the details in this commentary, based on the restrictions of time, Obama is not "intermediate risk" by Framingham score. I can't figure out how to get his score above 10% even by stretching. So, the evidence supporting CAC scoring for people in the group does not apply to President Obama--because his risk, despite his smoking, is relatively low.
There is no question that CAC (as well as some other measures) can slightly improve risk prediction in intermediate risk people, which Obama is not. But let's say he is. Even for intermediate risk people, I am not aware of strong evidence that slightly improving our predictive power in this way will also significantly improve our preventive power to improve mortality or even quality of life. So, for instance, in the presentation showing that reassignment of risk is common, the mere fact that CAC reassigns risk does not mean that the reassignment confers benefit.
If readers want to give citations for published articles that you think contradict that point, I'm glad to see them. I don't mean that in a snarky internet kind of way--I truly am glad to continue to read in this field and to continue to challenge my own assumptions.
Here are a few articles with one line abstracts.
1. Falk E, Shah PK, Fuster V. Coronary plaque disruption. Circulation 1995;92:657–71
This study shows that 86% of heart attacks occur in vessels with less than the 70% obstruction needed to make a stress test abnormal. If you want to criticize stress tests, I am with you.
2. Arad Y, Goodman KJ, Roth M, Newstein D, Guerci AD. Coronary calcification, coronary disease risk factors, C-reactive protein, and atherosclerotic cardiovascular disease events: the St. Francis Heart Study. J Am Coll Cardiol 2005;46:158–65.
This study demonstrated the lack of utility of HS-CRP the test promoted by Harvard and the remarkable predictive value of calcium imaging after considering all other risk factors.
3. Kondos GT, Hoff JA, Sevrukov A, et al. Electron-beam tomography coronary artery calcium and cardiac events: a 37-month follow-up of 5635 initially asymptomatic low- to intermediate-risk adults. Circulation 2003;107:2571– 6.
Incredibly strong incremental predictive value of coronary calcium. The more calcium, the greater the risk.
4. Percentage of individuals maintaining statin therapy according to baseline CAC score Kalia et al Atherosclerosis 2006;185:394-399
Study demonstrating 91% compliance with statin therapy after 3 years compared to the best reported by any other study of 50%. This improvement in compliance results in dramatic reduction in events.
5. Third report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation 2002;106:3143– 421.
Includes increased calcium score as an indication for improved lipid management.
6. Exercise-Induced Silent Myocardial Ischemia and Coronary Morbidity and Mortality in Middle-Aged Men. Laukkanen,J.A. MD et al. JACC Vol. 38, No. 1, 2001
Demonstrated that 83% of heart attacks occurred in the med who had passed their stress tests.
7. Berman DS, Wong ND, Gransar H, et al. Relationship between stress-induced myocardial ischemia and atherosclerosis measured by coronary calcium tomography. J Am Coll Cardiol 2004;44:923–30.
Demonstrated that 90% of subjects with severe coronary artery disease had normal nuclear stress tests.
8. Raggi P, Callister TQ, Shaw LJ. Progression of coronary artery calcium and risk of first myocardial infarction in patients receiving cholesterol-lowering therapy. Arterioscler Thromb Vasc Biol 2004; 24:1272–7.
Demonstrated a 17X greater risk of myocardial infarction based upon progression of EBT calcium score of >14% annually despite identical treatment and identical lipid results.
9. Arad Y, Spadaro LA, Roth M, Newstein D, Guerci AD. Treatment of asymptomatic adults with elevated coronary calcium scores with atorvastatin, vitamin C, and vitamin E: the St. Francis Heart Study randomized clinical trial. J Am Coll Cardiol 2005;46:166 –72.
Demonstrated that those with normal cholesterol treated with statins demonstrated a reduction in myocardial infarctions.
10. Hecht, Superko. Electron beam tomography and national cholesterol education program guidelines in asymptomatic women. J Am Coll Cardiol, 2001; 37:1506-1511
Demonstrated that EBT calcium NCEP guidelines mischaracterized the majority of individuals at risk for heart attacks.
11. Peter Libby, MD, Steven Nissen, MD Medical vs. Interventional Approaches to the Management of Coronary Artery Disease: The Clinical Application of Current Knowledge Medscape CME Release Date: November 22, 2000
Reviews the fact that revascularization has no benefit over medical management of atherosclerosis outside of treatment of myocardial infarctions.
10 more
12. Taylor et al: Coronary Calcium Independently Predicts Incident Premature Coronary Heart Disease... J Am Coll Cardiol.2005; 46: 807-814
13. Keelan, et al; Long-Term Prognostic Value of Coronary Calcification Detected by Electron Beam Computed Tomography in Patients Undergoing Coronary Angiography, Circulation 2001;104:412-417
EBT calcium imaging is more accurate than coronary angiography in predicting heart attack risk.
14. Tomomitsu Tani, MD et al; Comparison of coronary artery calcium progression by electron beam computed tomography and angiographically defined progression. The American Journal of Cardiology Volume 91 • Number 7 • April 1, 2003
Serial EBT calcium imaging correlates with angiographic progression by quantative angiography.
15. Michos E, Vasamreddy C, et al. Women with a low Framingham risk score and a family history of premature coronary heart disease have a high prevalence of subclinical coronary atherosclerosis; American Heart Journal 2005 Vol 150 No 6 1276-1281
Demonstrated value of calcium imaging in low risk women.
16. Prevalence of major risk factors associated with symptomatic atherosclerosis Khot, et al. Jama, 2003
Shows that most heart attacks occur in individuals who would be deemed low risk by Framingham predictors.
17. Lifetime risk (to age 95) for CVD and mortality at age 50 Lloyd-Jones DM et al. Circulation 2006
Demonstrated that the optimum Framingham risk categories at age 50 is associated with a greater lifetime risk for CAD than the average American has risk for colon cancer.
18. How Good Is NCEP III At Predicting MI? JACC 2003:41 1475-9
Demonstrated that of 222young patients with MI, 70% were Framingham “low risk” and only 25% of the study group would have qualified for lipid lowering therapy by NCEP-III
19. Organ and Effective Radiation Doses of Calcium Scoring wiht Electron-Beam CT and Multi-Detector Row CT;Radiology, Jan 2003\
Demonstrates the exquisitely low radiation dose of EBT imaging
20. Harvey S. Hecht, MD, FACC,a Matthew J. Budoff, MD, FACC,b Daniel S. Berman, MD, FACC,c,d,e James Ehrlich, MD, and John A. Rumberger, MD, PhD, FACC. Coronary artery calcium scanning: Clinical paradigms for cardiac risk assessment and treatment. American Heart Journal. June 2006
Should be required reading.
21. Cholesterol levels among subjects presenting with symptomatic coronary artery disease; Sachdeva A et al. Am Heart J 2009; 157:111-117
Demonstrated that 77% of heart attacks occur in subjects with LDL <130 and therefore would not qualify for lipid reduction by any guidelines.
Here is what renound Harvard researcher Chris Cannon said when interviewed by HeartWire internet medical newspaper:
Also reviewing Obama's cardiovascular details for heartwire, Dr Christopher Cannon (Brigham and Women's Hospital, Boston, MA) emphasized that Obama did not meet the criteria for a statin based on JUPITER criteria, since his hs-CRP is so low, and his overall risk factor profile is very good.
"His cholesterol is a bit high, but I calculated his Framingham risk score—it is 2%," Cannon said. "He apparently had an EBCT, but the exact result has not yet been released. I would be very interested in his calcium score. If it were 0, then I would likely recommend diet intervention and rechecking. But if his calcium score were elevated, that would suggest that the process of atherosclerosis had started, and a statin would be more reasonable."
Joe, Since someone of Dr Cannon's credentials finds value in EBT calcium imagimg, perhaps it is something you should reconsider.
You said “There is no question that CAC (as well as some other measures) can slightly improve risk prediction”. CAC measurement is 10 times more predictive of events that HS-CRP after consideration of all risk factors. A CAC > 300 has a hazard ratio of 9.6 for all events compared to all conventional risk factors alone (MESA). Compare this to Non-insulin dependent diabetes with a hazard ration of 3. This does not fit the definition of “slightly”.
You also wrote, “I am not aware of strong evidence that slightly improving our predictive power in this way will also significantly improve our preventive power to improve mortality”
First off, you need to take away the word “slightly” and replace it with “profoundly”. More importantly, primary prevention of heart attacks is based on stratifying risk and customizing treatment to the subjects’ defined risk. As CAC is dramatically more accurate than traditional risk factors, it is a tool that can help immensely in the prevention of heart attacks! It also dramatically improves compliance with therapies.
Joe, I assume that Harvard has some sort of forum for debate, perhaps a Medical Grand Rounds. I herby throw down the gauntlet and challenge you to an open debate on the topic of primary prevention of heart attacks and the role of coronary calcium imaging and HS-CRP. As a clinician with 30 years experience, it would be unfair for you , still a resident, to debate me alone, therefore I suggest that you and one of your academic mentors together face off against me, (an Internist in private practice).
I know this will not happen because the thought leaders at Harvard know that they will lose this debate as their position is not valid. I would be interested in hearing the reasons why they refuse to do it. On the very remote chance that they would be willing to host a fair debate, I will make myself available and show up whenever you can arrange this (with 4 weeks notice). I would request that it be recorded and published on the WEB.
Harvard Medical School is a large and diverse institution, with fiercely competing hospitals and health systems within it. I am in one corner of that institution, in one hospital, and neither my bosses nor I derive royalties from anyone's CRP assays. I'm not speaking as a representative of "Harvard", nor is my point of view a veiled promotion of CRP, since I am following USPSTF guidelines.
It would doubtlessly be a more productive use of your time (and mine) for you to have a debate with the United States Preventive Services Task Force, which has recommended neither CAC scoring nor CRP testing for routine use, stating that both have insufficient evidence to support their use in routine screening. Unlike me, the USPSTF has the power to influence public health policy on a wide scale. And they have opportunities for public comment, here:
http://www.ahrq.gov/clinic/tfcomment.htm
I would in all earnestness suggest this as a more fruitful avenue for your objections to the point of view I promoted in this piece. You regularly impugn my expertise, which is fine since I'm not an expert, but not fine since you're doing so as a way of ignoring all those with a lot more expertise who agree with me.
I hope that unlike here or NPR.org, you will also declare your commercial interests when you comment to the USPSTF.
Again, the question is not whether CAC predicts risk. It does. But when you look at its performance with Framingham Risk Score vs FRS alone, the additional value as a test is modest. I would direct readers to Table 5 of Detrano et al (citation below) which shows an increase of the area under its receiver operating characteristic curve for all ethnic groups from 0.79 to 0.83 in predicting major coronary events (death or myocardial infarction). [http://en.wikipedia.org/wiki/Receiver_operating_characteristic for explanation of this statistic]
To quote the accompanying editorial,
"is this relatively small improvement in accuracy worth it? Does calcium scoring provide value? Here the issue is uncertain. There can be value only if patient outcomes improve (i.e., if calcium scoring can be shown to change care in such a way that there are fewer events in the future). This could happen if, for instance, control of blood pressure or lipid levels was made more aggressive in the presence of coronary calcium. Even if outcomes are improved, this does not establish value without additional consideration of the direct and indirect costs of care."
We don't need to stage a debate at Harvard Medical School; I think my point of view has been articulated clearly and strongly already, not only by me, but by other experts in the field.
Detrano R et al, Coronary calcium as a predictor of coronary events in four racial or ethnic groups. N Engl J Med. 2008 Mar 27;358(13):1336-45.
Joe, I am not trying to minimize you when I refer to your inexperience, and I do not impugn you as having any conflict of interest. You do however listen to your mentors at Harvard who have very significant conflicts of interest.
Regarding my own conflict of interest, I have nothing to hide; indeed I am proud of what I have accomplished. No one has previously asked for this and I feel that it distracts from the real issues of medical value.
I am an Internist in private practice. I have an ownership interest in an imaging facility that performs EBT calcium imaging and ultrasounds. I invested in this center after my hospital decided it was not a financially feasible investment for them and I could not adequately treat my patients without having EBT technology available.
Over the years, anyone who could recognize the value of EBT calcium imaging was accused of self promotion by the cardiology community (even those who had no ownership in any facility). The irony here is that every cardiologist that I know has a financial interest in a nuclear stress camera. Any nuclear stress camera in any reasonably busy cardiologist’s office is much more profitable than any EBT facility in the country. In addition, the vast majority of nuclear stress tests are self referred by the cardiologist, a conflict of interest that everyone seems to ignore. Considering the fact that nuclear stress tests have 20 times the radiation of an eBT heart scan for a fraction of the value, I am not apologetic of owning interest in a technology that works.
I personally never expect to make a profit from my facility however the value that I add to my medical community makes that OK.
Detrano’s assessment of the MESA study makes certain inaccurate assumptions and misses one major reality. How accurately does Framingham direct preventive therapy compared to EBT imaging. The fact is that there are several studies sited above that demonstrate that the vast majority if individuals experiencing heart attacks would not have been determined at risk by Framingham testing. 77% of heart attacks occur in subjects with LDL < 130 which would result in no treatment by any current protocols. In fact there is reason to believe that comparing lipids to those with heart attacks and those without, the difference does not reach statistical significance in a study of 150,000 subjects.
Conversely, between 70 to 83% of heart attacks occur in the top quartile of coronary calcium and would result in initiation of more aggressive preventive strategies as referred to in NCEP-III guidelines. Virtually everyone who dies from heart attacks have calcium in their coronary arteries.
I had 2 cousins neither of whom qualified for cholesterol lowering by conventional risk factor stratification. One of them died in his mid 40s leaving a wife and 2 young children behind. The other got an EBT heart scan, was identified to be in the top 10th percentile of risk and is on statin and niacin and remains symptom free.
I am surprised by your affection for the US preventive service task force. Do you recall the fiasco they brewed this year when they said that physicians should choose which women should have a mammogram but was unable to say what reasons a physician might use to make that determination.
I knew you would not be willing to have a real debate on this and neither would Harvard. In print, you can continue to repeat unfounded misconceptions, in a real debate, they can be appropriately dispatched.
Final post, I promise.
Obviously you are an articulate and bright physician. I also know with every fiber in my being that EBT calcium imaging can save thousands of lives annually if properly applied. It will also save money by reducing invasive cardiovascular procedures. It is apparent that I am not going to be able to convince you about the value on this blog and honestly, I am getting ticked off trying.
I therefore am offering you and a guest airfare (coach purchased 2 weeks before flight) plus weekend accommodations in Boulder CO, if you allow me to present to you the DATA behind why I feel this is so important. I would also like to show you how this has made a difference in my practice.
In exchange, if after this presentation you feel that I am still wrong and that the reason I believe in this technology is to make money as your last post implies, I encourage to post that. If you are swayed by my presentation, then I request that you use your prodigious power to convince NPR to allow you a second shot at criticizing (perhaps praising) Obama’s physician’s choice to do an EBT heart scan.
I actually don't think we're going to change each other's minds--and I can tell you for sure that NPR isn't going to have me on again to talk about the same topic a second time, even if I did personally change my mind about it. So, I'd suggest taking the money you'd spend on my trip to Boulder (which is a kind offer, which I appreciate) and instead donate it to whoever you think would promote your point of view most ethically and effectively.
To summarize, because this is likely going to be my last reply in this thread:
1. Obama is low-risk by Framingham Risk Score, and his risk factors are modifiable without further testing.
2. Even in people who are intermediate-risk by FRS, the additional benefit of CAC scoring versus its costs and unknown risks (most of which will probably be risks of patients being treated differently in the future, rather than of the CAC scan itself) in terms of generating _actual_ mortality benefits (as opposed to inferred benefits) is unproven.
3. Though the absence of evidence is not an evidence of absence, in the absence of a *direct* proven mortality benefit of this kind of screening (as opposed to the many types of data you cite which provide possible indirect evidence), I argue that we are better served by making different kinds of investment in healthcare until that evidence is there.
A prevention method must be judged on a rigorous standard which includes not only the lives it saves but the lives it unintentionally, unknowingly, or indirectly harms.
And it must do well in comparison to the other prevention methods which might be pushed to the side by the cost and time taken by a particular method. And taking these considerations together, a prevention method must be judged on its overall cost and benefit to society as well as to individuals. Many experts in the field of primary prevention do not see CAC as having met that standard for general use, particularly for someone with a low-risk Framingham risk score. I understand that you disagree.
I am indeed a product of my training and environment--but it's a different kind of training and environment than you are assuming by my institutional affiliation alone. Just as with many policy viewpoints in the university as a whole--ranging from the value of military intervention to the role of feminism in contemporary society, about which there are sharply differing views even within the same departments within the faculty of arts and sciences--there are many viewpoints about cardiovascular disease prevention represented within Harvard Medical School and its affiliated hospitals.
And though your reaction to my original piece was understandably focused on the particular example I used to illustrate a point, I could have used other examples to make the same point. I wasn't interested in writing this piece, and NPR wasn't interested in running it, because it was about CAC. Instead, it was an argument with a case example of how the American healthcare system could (and should) be more restrained in its use of testing than it is. I understand that you think it was unfair to use CAC as the example of this. I am not alone, however: a recent Archives of Internal Medicine editorial makes a similar point about Obama's physical:
http://archinte.ama-assn.org/cgi/content/full/2010.81?home
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