Once upon a time, it was believed important to perform cardiac stress testing in patients with chest pain and potential acute coronary syndrome. Intuitively, this makes little sense – a stress test may identify obstructive coronary disease, but this is rarely the culprit for acute coronary syndrome, and certainly only rarely the cause of chest symptoms in a patient at low-risk for coronary artery disease. Unfortunately, the American College of Cardiology/American Heart Association have had a nonsensical recommendation for noninvasive testing within 72 hours of an index visit on the books for quite some time – leading, to put it mildly, to a test or two.
This observational data set evaluates the outcomes of patients in the Kaiser Southern California system who were referred for outpatient stress testing following an encounter in the Emergency Department. They tracked 7,988 patients for a month after their ED encounter, 2,497 of whom underwent stress testing within 3 days, 4,695 within 4 to 30 days, and 796 who never showed up for their referred testing. Most stress tests were exercise or pharmacologic stress ECG, with the minority stress echocardiograms or myocardial perfusion imaging.
Patients undergoing testing were not devoid of risk factors: an average age of 55 years, most were overweight, and over half had at least one risk factor for coronary artery disease. Within 30 days, fewer than 1% were diagnosed with an acute MI, and a handful of those underwent PCI or CABG. There were tiny differences between groups, as none of the patients who skipped their stress test underwent subsequent revascularization. There were no deaths in any cohort.
The narrow view here in this article is there is no apparent benefit to undergoing stress testing within 72 hours as compared with a longer timeframe. The wider view is yet another piece of information showing the general disutility of stress testing. These are not randomized cohorts, nor is 30-days a long enough window to detect any potential benefits to the stress test – as measured by decreased morbidity or mortality as relating to a timelier PCI or CABG. However, even these interventions were rare enough the effect size from any benefit is bound to be so small as to represent low-value care. It is absolutely reasonable to suggest the Bayesian pendulum for the valuation of stress testing is swinging the other direction – and those who advocate for stress tests ought to generate data to support its targeted use, rather than for the opposition to generate data contrary to its assumed routine utility.
“Evaluation of Outpatient Cardiac Stress Testing After Emergency Department Encounters for Suspected Acute Coronary Syndrome”
https://www.sciencedirect.com/science/article/pii/S019606441930054X