Let's get this out of the way: Stress tests don't help ED patients who present with chest pain. We should not be ordering, arranging, or otherwise referring our patients for stress testing from the ED. I know you know this. So why I am bringing this up again?
Because we have a paper fresh from the Annals of Emergency Medicine that beautifully underlines and highlights this point (2019;74:216) on top of the already-bountiful evidence and extremely well-written analyses on the disutility of stress testing (like these articles from First10EM: http://bit.ly/2ZroK71; Emergency Medicine Cases: http://bit.ly/2Hm1FMX, and EMN: http://bit.ly/2kakABT).
The study by Natsui, et al. (including the inimitable Rita Redberg, MD, who has been a leading voice on reducing unnecessary cardiac testing and treatment for decades), was a retrospective analysis of nearly 25,000 patients with chest pain seen in 13 EDs in the Kaiser system in Southern California between 2015 and 2017. All of these patients had symptoms that warranted at least one troponin in the ED and an order for an outpatient cardiac stress test. Incredibly, about 16,000 of these patients got their stress test before they were discharged from the hospital, leaving 7988 subjects who were discharged and followed.
Of note, about halfway through the 2016 study, these EDs all started using the HEART score (history, ECG, age, risk factors, and troponin), and while these data were tucked away in a supplemental appendix, it looks like 72.5 percent of the 2000 or so patients who had a complete HEART score were low risk (score 0-3) and 27.2 percent were moderate risk (score 4-6), which tracks with the kind of chest pain patients we are sending home from the ED (although I'm not sure whether to be scared or impressed by the seven patients [0.3% of those with data] who had a HEART score of 7-10 and were still discharged with a plan for an outpatient stress test).
So we have a group of about 8000 ED patients who presented with chest pain concerning enough that they got a troponin and an outpatient stress test ordered. What did the authors find?
- Less than one-third of patients (31.3%) received their stress test within the ACA/AHA guideline recommended 72 hours with another 58.7 percent completing the test within four to 30 days.
- One in 10 patients did not receive a stress test in the 30 days after ED discharge.
- No one died during the 30-day study period. Zero deaths.
- The rate of acute MI was 0.7 percent.
- The rate of PCI was 0.1 percent, and CABG was 0.2 percent.
- Overall, major adverse cardiac events (MACE) were 0.9 percent.
- Early stress testing was not associated with fewer adverse outcomes. Period.
Let all of this sink in for a second. Not one of the 8000 patients sent home from these EDs after being seen for chest pain died, let alone died of a heart attack. The MACE rate was less than one percent. And perhaps most importantly, there was no difference in the already absurdly low adverse event rate regardless of whether the patient got a stress test within three days like the ACA and AHA recommend, within a month, or not at all. I would say this is shocking except it's actually perfectly in line with a wealth of other literature that's already demonstrated the incredibly low rates of badness in this population along with the lack of observable benefit from early noninvasive testing (think stress tests and coronary CT).
We want to help our patients, and we don't want to miss anyone at risk for an acute MI, but the truth is that cardiac stress tests don't help us help them. In reality, all they do is increase expense, time spent in the health care system, and the likelihood of unnecessary invasive procedures. So don't stress test. Seriously.
Runde Rant: If you take the time to read this excellent article by Natsui, et al., you might notice the following line in the intro, “Inappropriate discharge of patients with high risk for acute coronary syndrome is associated with high morbidity.” This is the concern that has driven much of our specialty's obsession with never missing a patient at risk for an MI. But this worry is based on a lie.
The authors referenced an article by Pope, et al., that has been cited almost 2000 times in the literature and purports to show a high rate of missed MI for patients evaluated in the ED and higher mortality for those missed patients. (N Engl J Med. 2000;342:1163; http://bit.ly/2Pgve9a.) But here's the thing: This paper showed neither of those things! In terms of “misses,” the authors found that only 19 of the nearly 11,000 patients in the study with AMI were sent home from the ED, which is a miss rate of 0.18 percent! And what about the increased mortality rate for these misses? The authors noted there was no statistical difference in mortality, but then cited an almost-doubled risk once a “statistical adjustment” was performed.
But here's the thing: In every case, the 95% confidence interval crosses 1, which means that even with the adjustment, there is no difference in mortality for these patients. How this garbage non-finding was published in the New England Journal of Medicine still boggles the mind, but the take-home is this: This supposedly damning paper actually shows we are amazingly good at evaluating patients with chest pain in the ED. Strong work, team! Keep doing what you're doing (unless you're ordering outpatient stress tests, that is).
Dr. Rundeis the assistant residency director and an assistant professor of emergency medicine at the University of Iowa Hospitals and Clinics, where he serves as co-director for the associate fellowship in medical education. He creates content for and is a member of the editorial board forwww.TheNNT.com, and is a content contributor forwww.MDCalc.com. Follow him on Twitter@Runde_MC, and read his past articles athttp://bit.ly/EMN-MythsinEM.
CRACE or MACE?
Read “Should CRACE Replace MACE for Chest Pain Admits?” by Gina Shaw on p. 6.Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.