“Although an acute coronary syndrome is ultimately diagnosed in only 10 to 15% of patients who present with chest pain, the majority of these patients are admitted to hospitals, at an estimated cost of over $3 billion annually.”
This is, essentially, the statement of problem from the NEJM article, sponsored by Siemens, regarding the use of coronary CT angiograms in the Emergency Department on low-to-intermediate risk chest pain. They are clearly huge fans of CCTA up at the University of Pennsylvania, and I hate to think it has something to do with the parade of imaging technology companies and patent applications listed as disclosures by the authors.
In this study, the authors enrolled 1,392 patients with chest pain with the goal of testing the primary hypothesis that “patients without clinically significant coronary disease on CCTA (i.e., no coronary-artery stenosis ≥50%) would have a 30-day rate of cardiac death or myocardial infarction of less than 1%.”
Good news! They were right. Bad news: their entire enrolled cohort had a 30-day death or MI rate of only nearly 1%. It’s rather incredible, really, that they have this entire article in which they sing the praises of CCTA for identifying low-risk chest pain, when in reality, they gloss over the fact that they simply could have sent home every single patient in the study without doing a single additional test and only nearly 1% would have had death or MI within 30 days.
Going back to their essential statement of problem, it might be true that CCTA were valuable if they were looking to apply it in a population and practice environment in which we were actually hospitalizing patients with a 10-15% rule-in rate. However, the opposite of what these authors propose is the real truth – clinically identify all the low-risk chest pain and stop doing all these expensive tests! They claim it expedites discharge from the Emergency Department, which, in theory, saves money – but it isn’t! Despite 90% of their CCTA being negative for stenosis >50%, they still end up admitting half their CCTA cohort. Even the negative CCTA cohort, while their length of stay is reduced to 12 hours, still means they’re being placed in observation status and billed an additional separate observation code – which in many places is a protocolized chest pain observation unit run by the Emergency Department.
This is simply a bad solution to bad baseline practice patterns. The measurable benefit here isn’t to the patient, it’s to the malpractice risk of the physician, to Siemens and other sponsors of the study, and likely to the Emergency Departments whose billing increases for these short stay observation patients.
“CT Angiography for Safe Discharge of Patients with Possible Acute Coronary Syndromes”
http://www.nejm.org/doi/full/10.1056/NEJMoa1201163
"in reality, they gloss over the fact that they simply could have sent home every single patient in the study without doing a single additional test and less than 1% would have had death or MI within 30 days."
That's not true. We have no idea what would have happened if all the patients were sent home. Well over half the patients in the study were admitted (from both arms), an intervention which presumably prevents death/MI. Additionally, testing that was done made diagnoses of CAD which led to subsequent interventions such as medical management and revascularization, which also should reduce the risk of death/MI.
I think the bottom line here is that a negative CCTA makes ER docs feel better about sending SOME patients home, and there is no increase in death/MI from that 27% sent home in this study. As far as their primary hypothesis, yes, <1% of the pts with negative CCTA had death/MI, but many of those pts with negative studies were still admitted. Why were they admitted? Did the admission buy them some additional protection? If they had sent all the pts with a negative CCTA home, would the event rate in the CCTA arm have still been <1%?
Concluding from this study that "a negative CCTA means I can send the pt home safely" would be wrong, as many of the pts with negative CCTAs were not sent home in this study. A negative CCTA may provide a useful piece of information, but there are clearly still other factors at play in ER docs' minds about who is safe for discharge.
"in reality, they gloss over the fact that they simply could have sent home every single patient in the study without doing a single additional test and less than 1% would have had death or MI within 30 days."
That's not true. We have no idea what would have happened if all the patients were sent home. Well over half the patients in the study were admitted (from both arms), an intervention which presumably prevents death/MI. Additionally, testing that was done made diagnoses of CAD which led to subsequent interventions such as medical management and revascularization, which also should reduce the risk of death/MI.
I think the bottom line here is that a negative CCTA makes ER docs feel better about sending SOME patients home, and there is no increase in death/MI from that 27% sent home in this study. As far as their primary hypothesis, yes, <1% of the pts with negative CCTA had death/MI, but many of those pts with negative studies were still admitted. Why were they admitted? Did the admission buy them some additional protection? If they had sent all the pts with a negative CCTA home, would the event rate in the CCTA arm have still been <1%?
Concluding from this study that "a negative CCTA means I can send the pt home safely" would be wrong, as many of the pts with negative CCTAs were not sent home in this study. A negative CCTA may provide a useful piece of information, but there are clearly still other factors at play in ER docs' minds about who is safe for discharge.
Thanks for the feedback! I do need to keep the hyperbole in check a little bit!
But, I do disagree with your assessment that we have no idea what would have happened if all the patients were sent home. In Table 3, which is the "Outcomes and Use of Resources", there is no significant difference between any of the cardiovascular event outcomes – death, AMI, or revascularization. You suggest that additional testing/treatment was performed at the index visit that enhanced their survival – but there was also no difference in the percentage undergoing cardiac catheterization, echocardiogram, or use of cardioprotective medications – ASA, thienopyridines, statins, etc.
Do I believe that admitting these patients offered some protection? No. Insignificant numbers of both groups met any of the outcome measures and few of them received interventions intended to decrease cardiovascular risk. A full 36% of the "traditional care" group had no additional testing and it appears they did just fine. The CCTA adds additional information, but I believe it still results in more false positives than true positives – and I don't think it has a place in the ED evaluation of the patient population selected for this study.
Thanks for the feedback! I do need to keep the hyperbole in check a little bit!
But, I do disagree with your assessment that we have no idea what would have happened if all the patients were sent home. In Table 3, which is the "Outcomes and Use of Resources", there is no significant difference between any of the cardiovascular event outcomes – death, AMI, or revascularization. You suggest that additional testing/treatment was performed at the index visit that enhanced their survival – but there was also no difference in the percentage undergoing cardiac catheterization, echocardiogram, or use of cardioprotective medications – ASA, thienopyridines, statins, etc.
Do I believe that admitting these patients offered some protection? No. Insignificant numbers of both groups met any of the outcome measures and few of them received interventions intended to decrease cardiovascular risk. A full 36% of the "traditional care" group had no additional testing and it appears they did just fine. The CCTA adds additional information, but I believe it still results in more false positives than true positives – and I don't think it has a place in the ED evaluation of the patient population selected for this study.
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(I deleted my previous comment after taking a closer look at table 3).
Re: table 3, you are right, there are no significant differences between the groups in terms of follow-up testing and treatment, but that is exactly the point! Both strategies equally identified pts who needed additional testing, and both strategies led to a significant number of pts undergoing other stress testing (14% in the CCTA group and 58% of trad care), cath (5% and 4%), echo (6% and 7%). All told 9% and 3% were diagnosed with CAD during the index visit, presumably leading to medical management being instituted at that time. Indeed, a full 22% and 25% of the pts were on ASA at 30 days so I don't see how you can say that "few of them received interventions intended to decrease cardiovascular risk." Yes, CCTA was no better than trad care at identifying pts who needed additional testing or treatment, but the real point of the study was that it wasn't any worse despite having reduced hospitalization and length of stay.
If I read your argument correctly, I think you're arguing that the CCTA strategy is equivalent to the traditional care strategy – and therefore, as this study claims, is a valid strategy to apply in the Emergency Department.
I am not directly disputing that – although, I think the CCTA group is probably harmed more than the traditional care group (increased rate of stenting of questionable benefit/harm, IV contrast, radiation, etc.). I am asserting that we're providing generally indefensible care to this cohort overall, and this CCTA strategy is just as bad.
These 1,370 patients receive 815 admissions/observations, 795 CCTAs, 425 stress tests, 85 echocardiograms, and 64 cardiac catheterizations – and the net benefit (after subtracting the iatrogenic harms) of this extraordinary resource outlay is minimal. If none of these tests or admissions are performed on this cohort, the adverse cardiovascular event rate at 30 days will not be significantly different.
Considering your argument that the diagnosis of CAD led to adverse outcomes prevented due to new medication prescriptions – I don't believe that's true, either. Half of this 50 year old cohort had a diagnosis of hypertension, 32% were smokers, 25% had hypercholesterolemia, and 14% had diabetes – I don't think the 25% of patients at ASA 30 days is a great increase from their baseline (which they don't tell us). Additionally, the NNT for ASA at one year to prevent a cardiovascular event is ~2000, and the NNT to prevent a cardiovascular event (in the setting of known heart disease) at five years is ~40 – so the net additional protective benefit on this patient cohort from the medication delta for ASA and the statins is nearly zero.
This article proves what it claims to prove – CCTA is just as good as traditional care. However, it misses the forest for the trees – this entire care strategy is absurd.
Great blog on the use of CCTA for the evaluation of chest pain. David Newman and Ashley Shreves of SMART EM have had a number of discussions regarding risk assessment and stress testing of Chest pain patients. I like to give these blogs and discussions an additional label of "Stop the madness" In the Feb 2012 edition of Annals of emergency Medicine there was an article risk stratifying chest pain patient and what the authors concluded was that if you had no hx of CAD, a story that was not typical for angina, a nonischemic EKG, a negative tropoinin and age less than 40 then your 30 day risk of an adverse outcome was 0% (if you were 40-50 with 2 negative troponins your risk was still small) Certainly that group of patients don't need to be held in the ED for a 5000 dollar test. I think we as emergency physicians need to start doing some intelligent risk stratifying of patients who present to the ED with chest pain and abandon our current "chicken little (the sky is falling)" approach to the low risk chest pain patient in which "anyone could have CAD" and "everyone needs to be admitted". There are a number of decision rules out there that would aid us in risk stratifying these patients (with no addition cost or radiation to patient). Thanks for the great post.
Great blog on the use of CCTA for the evaluation of chest pain. David Newman and Ashley Shreves of SMART EM have had a number of discussions regarding risk assessment and stress testing of Chest pain patients. I like to give these blogs and discussions an additional label of "Stop the madness" In the Feb 2012 edition of Annals of emergency Medicine there was an article risk stratifying chest pain patient and what the authors concluded was that if you had no hx of CAD, a story that was not typical for angina, a nonischemic EKG, a negative tropoinin and age less than 40 then your 30 day risk of an adverse outcome was 0% (if you were 40-50 with 2 negative troponins your risk was still small) Certainly that group of patients don't need to be held in the ED for a 5000 dollar test. I think we as emergency physicians need to start doing some intelligent risk stratifying of patients who present to the ED with chest pain and abandon our current "chicken little (the sky is falling)" approach to the low risk chest pain patient in which "anyone could have CAD" and "everyone needs to be admitted". There are a number of decision rules out there that would aid us in risk stratifying these patients (with no addition cost or radiation to patient). Thanks for the great post.
From the first author: I'm not going to address any of your comments regarding the science, you clearly have a point of view to which you are entitled and as I am not an ER doc it wouldn't be appropriate for me to argue with you. However, you have an inaccurate statement about the funding for the study, which came from the Pennsylvania Department of Health primarily with a small amount from the American College of Radiology Imaging Network Foundation. No funding came from Siemens, though I do work with them on other projects so had to include them in my disclosure. Please adjust the content of your post to reflect this inaccuracy.
I will also note that the 50% discharge rate from the ED reflects only that many of the CT studies were done after an obs unit admission, because the scan wasn't available at the time of presentation. The pts were not admitted after or despite a negative ct. We haven't analyzed this yet for this multicenter trial, but based upon our experience at HUP, over 95% of pts are discharged after a negative ct. Also overall event MI rate was just over 1%, your statement above is incorrect. That MI rate with our sample size would result in upper limit of the confidence interval of over 2%, compared to 0.57% after negative CT. If the article doesn't state these facts clearly enough, that is my fault, but you may want to read it again and correct your post above.
Thanks for the feedback! You are probably correct that the issue is not so much with the article itself – but rather a philosophical point that precludes debate over the utility of expending additional resources to take a low-risk patient and make them a zero-risk patient instead of a nearly-zero risk patient. As you gathered, the ~1% (with the CI of up to 2%) risk in your overall cohort is absolutely a reasonable risk assumption to many people – and it feels like surrendering to defensive medicine to perform further work-up on these folks.
As far as the conflict of interest is concerned, Siemens contributes to yourself, Dr. Gastonis (via the Medical Imaging and Technology Alliance), Dr. Miller, and Dr. Hollander. I certainly don't mean to be of the ilk of "This guy on the internet thinks we're all crooks for taking money from industry!" but in my purist viewpoint, that's enough COI to support my hyperbole of "sponsored by Siemens."
Thanks for clearing up the reason for LOS in the negative CCTA folks – that didn't come through in the article.
Thanks for the feedback! You are probably correct that the issue is not so much with the article itself – but rather a philosophical point that precludes debate over the utility of expending additional resources to take a low-risk patient and make them a zero-risk patient instead of a nearly-zero risk patient. As you gathered, the ~1% (with the CI of up to 2%) risk in your overall cohort is absolutely a reasonable risk assumption to many people – and it feels like surrendering to defensive medicine to perform further work-up on these folks.
As far as the conflict of interest is concerned, Siemens contributes to yourself, Dr. Gastonis (via the Medical Imaging and Technology Alliance), Dr. Miller, and Dr. Hollander. I certainly don't mean to be of the ilk of "This guy on the internet thinks we're all crooks for taking money from industry!" but in my purist viewpoint, that's enough COI to support my hyperbole of "sponsored by Siemens."
Thanks for clearing up the reason for LOS in the negative CCTA folks – that didn't come through in the article.