The Shownotes on Low Risk Chest Pain
The management of low risk chest pain in the US is founded on a number of tenets:
- If low risk chest pain patients are sent home and they have unstable angina, they will do worse than if we admitted them
- Provocative testing will identify patients who are safe for discharge
- A positive stress test identifies patients who will have benefit from PCI
- PCI is the standard of care for UA/NSTEMI as it reduces patient important adverse events
The problem is that all of these are false. But I wouldn’t expect you to believe me; instead listen to the masters of Emergency EBM: David Newman and Ashley Shreves of SMART EM. Here is what we cover:
If low risk chest pain patients are sent home and they have unstable angina, they will do worse than if we admitted them
But where is the evidence? The one trial I can find (see below) shows no difference.
Stress testing will risk stratify these patients, so we know which ones are safe for discharge
Low risk chest pain patient (as deemed by EM Physician judgment) with 2 sets negative and non-specific EKGs has a risk of <1% already, so what does the stress test add to this w/u?
A positive stress test identifies patients who will have benefit from PCI
Nope, not in low risk patients…Most of the time the cards folks will get a positive stress and still not intervene. Instead the patient gets started on aspirin with instructions for lifestyle modification. It might even wind up worsening adverse events b/c patients will have false positives and may get unnecessary caths.
PCI is the standard of care for UA/NSTEMI as it reduces patient important adverse events
If there is any benefit at all, it is for the outcome of the need for unplanned revascularization at 6-12 months. Ashley discovered that actually, for UA patients (troponin negative) there may be increased mortality in order to get that benefit
For all of the evidence behind this podcast, immediately go to these SMART EM Podcasts:
- Chest Pain Risk
- Stress Testing – A Moment of Clarity (If you are just going to listen to one, this is it)
- The Update Show
Perhaps, you want a summary of all of the evidence presented on stress testing from those Smart EM Episodes
–well how about 2 of them:
An excellent summary by one of my excellent residents, Will Fleishman
Literature Mentioned in this Podcast
The only study I can find that directly addresses the question of what happens if you discharge patients is by Pope et a. . There was no statistically significant increase in mortality in the patients who were mistakenly sent home with MI or ACS despite a rather questionable attempt at retrospective risk adjustment. This was the study that the AHA predicated most of its recommendations that UA is a dangerous disorder to miss and patients must be tested or admitted.
Goldman looked at an incredibly simple risk stratification. In patients with:
- a normal or non-specific ekg
- no SBP<110
- no rales above the bases
- no known ischemic heart disease
- no pain that was similar to a prior mi (which seems encompassed by the previous, but there you go)
- negative enzymes
The risk of a major event (v-fib, cardiac arrest, complete heart block, need for pacemaker, emergency cardioversion, cardiogenic shock, need for an IABP. or recurrent ischemic chest pain getting CABG or PCI) within 72 hours was 0.6% in their validation set. 
Montalescot et al. looked at what happens to NSTEMI patients if they were randomized to immediate PCI vs. delayed PCI . Turns nothing happens in terms of increased heart damage.
Here is the Josh Kasowsky review article mentioned by Ashley 
- 2,107 admissions to yield 9 (supposedly) beneficial interventions – how crazy is that?
- What about the 88.4% of patients with abnormal stress tests that didn’t undergo an invasive test within 30 days – why are we using an evaluation strategy we don’t act on?
The Hoenig Cochrane Review from 2010 is here . In patients with negative troponins (the so-called unstable angina patients) mortality is greater if they are stented.
Increased mortality in females undergoing PCI for NSTEMI 
More Evidence of Interest Not Mentioned
Here is a gamechanger:
Scheuermeyer, et al. “Safety and Efficiency of a Chest Pain Diagnostic Algorithm with Selective Outpatient Stress Testing for Emergency Department Patients with Potential Ischemic Chest Pain.” Annals of Emergency Medicine 59, no. 4 (April 1, 2012): 256–264 
(summary from EM Ireland)
- 1255 pts
- 50% discharged with no planned provocative testing
- didn’t miss a single ACS by 30 days (overall rule in rate was 10% and most picked up in ED, only a few by provocative testing after the initial assessment)
- 2% lost to FU who didn’t attend ED or die in the region
Here is another one:
J Am Coll Cardiol. 2012 Apr 30. [Epub ahead of print] 2-Hour Accelerated Diagnostic Protocol to Assess Patients With Chest Pain Symptoms Using Contemporary Troponins as the Only Biomarker: The ADAPT Trial
How about you let the patient decide with the help of a decision aid
Hess et al. 
Stress testing young patients is probably worthless
Hamilton et al. 
Hermann et al.