"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"