The arrival of hs troponins in ED did not cause test cascades


A few years ago, while some U.S. emergency departments (EDs) were preparing to implement the newly approved high-sensitivity heart test troponines, there was still apprehension about the widespread application of the substantially mass-sensitive test to patients who would present with chest discomfort.

Would the test’s ability to detect myocardial damage, whether from acute ischemia, trigger test cascades and downstream and often unnecessary downstream services?

Now, two new analyzes, from U.S. regional health systems that fully adopted the cardiac troponin T test by high-sensitivity assay (hs-cTnT) shortly after regulatory approval, suggest that these fears may have unjustified state.

Together, they found that the implementation of the new trials expanded the identification of high-risk patients with myocardial injury, including acute myocardial infarction (MI), in most cases without promoting further consultations, testing, or other uses of hospital resources. In contrast, some downstream testing and other items of great importance, such as hospitalizations, declined in most cases.

One study compared patient ED visits to five centers, approximately 7,500 for chest pain and more than 100,000 for other symptoms, both before and after the large-scale implementation of the new trials on April 1, 2018. The rate of cascading events increased globally for patients with chest pain, but driven by the demand for hs-TnT series testing and electrocardiography while other tests, procedures, and services were discontinued.

“When we delved into the different cascading events, we found lower rates of hospitalization and coronary intervention and lower use of cardiac medications such as beta-blockers, statins, and antithrombotics. They were less likely to participate in cardiology, either. in ED or even admission to the cardiology service, ”said Ishani Ganguli, MD, MPH, Brigham and Women’s Hospital, Boston. | Cardiology Medscape.

“And the length of the stay was shorter, both the length of the ED visit and the total length of the stay, including any hospitalizations,” said Ganguli, who is the lead author of the study. published May 3 at Journal of the American College of Cardiology.

Downstream tests Mostly unchanged

An independent analysis, published in tandem and programmed by presentation On May 16, during the 2021 scientific sessions of the virtual American College of Cardiology (ACC), it was based on more than 4000 ED presentations before and after the launch of high-sensitivity trials in two hospitals in the same regional system.

In it, the proportion of patients with at least one positive hs-cTnT trial increased sharply from 15% before implementation to 47% after (Pg <.0001). But the use of the new trials resulted in less stress testing (4.9% vs. 6.5%, Pg = .02) and less echocardiography (6.5% vs. 12%, Pg <.0001). No other escalations of resources or services were observed downstream, except for an increase in referrals to coronary angiography, from 2.3% before implementation to 3.5% after (Pg = 0.02).

It is important to note that the lead author, Yader Sandoval, MD, said for the | Cardiology Medscape, “There was a noticeable increase in patients sent directly home from the emergency department” among those who did not get a positive trial. Its rate went from 60% to 74% (Pg <.0001).

These patients “would otherwise have been admitted and could have had more troponin testing, perhaps a stress test, etc.,” said Sandoval, of the Mayo Clinic, Rochester, Minnesota.

“Many of the benefits of high-sensitivity testing is that they are very good at identifying higher-risk patients,” he said. More recently, it has been shown to be “very, very good evidence for identifying low-risk patients.”

Also in the analysis, the rate of diagnosed acute MI generally went from 3.3% before the implementation of the high-sensitivity trials to 8.1% after (Pg <.0001); non-ischemic myocardial injury jumped from 11% to 38% (Pg <.0001).

Rates for both events increased for men and women separately, but disproportionately for women. The rate of acute MI before the implementation of high-sensitivity trials was much higher in men than in women, 4.4% and 2.3%, respectively (Pg = .008). But the difference faded after the new trials were taken over, when rates were 8.5% for men and 7.7% for women (Pg = .46).

The finding, then, is corroborated previous research suggesting that high-sensitivity trials may partially reverse the problem of underdiagnosis of MI in women, Sandoval said, and may expand “opportunities to assess them further.”

Economic impact

Contrary to previous European reports in which the emergence of high-sensitivity assays led to substantial financial savings, the analysis of Ganguli and its partners saw no overall cost benefit after its implementation despite the fall of subsequent tests and other services.

The group believes any cost savings from the study may have been offset by the relatively small increase in coronary artery bypass surgeries. “Because this surgery is much more expensive than the other services that were examined, it offset any of the expense reductions,” Ganguli said when interviewed. “If you look at spending on individual services before and after, you would see that, for many of them, the cost was going down overall.”

In addition, the study included spending estimates only for documented tests and services and did not take into account the cost of hospitalizations, he said. “If we could have done that, we sure would have seen a cost reduction.”

In other findings, patients with chest pain were 10.5% more likely than patients with other symptoms to perform multiple troponin tests after implementation of high-sensitivity trials. Its net increase in electrocardiographic examinations was 7.1 per 100 patient visits.

These first increases in tests were offset by the net decrease in CT scans (CTA) (1.5 such tests per 100 patient visits), stress tests (5.9 per 100 visits). to the patient), percutaneous coronary interventions (0.65 procedures per 100) Ganguli and colleagues reported that visits to the patient), hospitalizations (5.8%) and the average length of stay (0 , 24 days).

Transatlantic differences

Both studies used the Roche Gen-5 cTnT assay, the first of several high-sensitivity troponin assays to gain approval in the United States. And both interpreted biomarker concentrations using the Fourth Universal Definition of Myocardial infarction (UDMI-4), using sex-specific cut-off values ​​for myocardial injury, which was defined as at least one assay with levels> 99th percentile of normal.

However, there is an “ongoing controversy over whether uniform cuts or sex-specific cuts,” the former preferred in a statement by the European Society of Cardiology (ESC) and the latter by UDMI-4 writers, “They should be used in the assessment of patients with acute chest discomfort,” says an editorial accompanying the two reports.

“Given the broad differential diagnosis in women with acute chest discomfort,” sex-specific cuts in the two current reports “resulted in a disproportionate increase in the regulation of conditions for which there is currently no evidence-based therapy, such as MI 2 type and myocardial injury“, write the authors, directed by Christian Mueller, MD, Basel University Hospital, Basel, Switzerland.

Sex-specific cuts “will also invariably lead to an insufficient diagnosis of type 1 MI in men (due to the higher sex-specific cut), a condition for which evidence-based therapy is available,” the findings continue. authors, who recommended the criteria supported by the ESC over those based on UDMI-4.

Guidance for American clinicians based on the experience of high-sensitivity trials in Europe, for example, where testing had been widely used for at least a decade, has been useful, but in some ways limited. by differences with respect to the United States in hospital processes and the economy and culture of health care.

These differences help explain the frustrating delay before high-sensitivity trials reached U.S. physicians, who, compared to their European counterparts, were considered more likely to use them in patients with less specific symptoms for whom perhaps the diagnosis of myocardium was not so high. probably.

Acute MI “is a diagnosis you can’t miss. So there are reasons why we act based on that possibility,” Ganguli said. “There is the picture of malpractice and our interest in looking for technology and doing more diagnostic services that can make a different history than in Europe.”

Or, as she and her colleagues bluntly say in their report, in the United States it was learned that high-sensitivity trials, “which are more likely to detect heart injuries caused by conditions other than acute MI, they could increase their physician-driven use concern for the lack of an acute MI in a health ecosystem that places more emphasis on exhaustive diagnosis and risk management of malpractice. “

But, “having a test that gives you prior assurance that is not a misdiagnosis can reduce some of the need for further testing,” Ganguli noted. “That’s what we’re learning.”

Ganguli has received consulting fees from Blue Cross Blue Shield Massachusetts and has been awarded funding by International Business Machines; in his report there are disclosures for the other authors. Sandoval has previously been a member of the advisory boards of Roche Diagnostics and Abbott Diagnostics without personal compensation, and as a speaker without personal financial compensation for Abbott Diagnostics; in the report there are disclosures for the other authors. Mueller reports that he has received research support from Abbott, Beckman Coulter, Brahms, Novartis, Ortho Diagnostics, Quidel, Roche, Siemens, Singulex, Sphingotec, and speaker fees / honorary consultants from Amgen, Astra Zeneca, Boehringer Ingelheim, and Bristol-Meyers Squibb; in his report there are disclosures for the other editorialists.

American College of Cardiology (ACC) 2021 Scientific Sessions: Session 2249. Filed May 16, 2021.

J Am Coll Cardiol. Published online May 3, 2021. Sandoval et al, Summary; Ganguli et al, Summary; Editorial

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