High-Sensitivity Troponins Improve HEART Pathway in Chest Pain Workup

Incorporating high-sensitivity cardiac troponin (hs-cTn) testing into the traditional HEART pathway may improve detection of acute MI in patients presenting to the emergency department (ED) with chest pain, and decrease resource use, according to observational data.

While hs-cTn assays have been commonplace in Europe since 2015, their prevalence in US hospitals has been limited but growing since the 2021 American College of Cardiology/American Heart Association (ACC/AHA) guidelines for the evaluation and diagnosis of chest pain gave them a class 1 (level of evidence of B) recommendation. Data from last year show that about one in three US hospitals currently deploy them.

“Our results suggest a useful role for an hsTn pathway for helping assess which patients have a lower risk of near-term major adverse cardiac events, allowing them to be safely managed without hospital admission or invasive testing and also perhaps allowing for earlier diagnosis of patients with acute MI (eg, during the ED visit),” write Mackensie Yore, MD (Veterans Affairs/University of California Los Angeles National Clinician Scholars Program, CA) and colleagues in a paper published in JAMA Network Open this week.

“This study provides further reassurance regarding the benefits of high-sensitivity cardiac troponins in terms of detecting MIs that may otherwise be missed,” said Cian McCarthy, MBBCh, BAO (Massachusetts General Hospital, Boston), who commented on the findings for TCTMD. “Because high-sensitivity cardiac troponin assays allow for the use of sex-specific cutoffs, they increase the detection of MI in women in particular, and I think that's important.”

Also, he continued, the data confirm what has been observed in prior US studies—namely, that hs-cTn assays compared with usual care can decrease hospital length of stay “and cardiac testing that may not be necessary without compromising safety.”

More MIs, But What Impact on Mortality?

For the study, Yore and colleagues included 17,384 patients (median age 58 years; 56.2% women) who presented to an emergency department at one of 16 Kaiser Permanente Southern California hospitals with chest pain between January and September 2021. The EDs had recently phased in hs-cTn assays (Access hsTnI; Beckman Coulter Inc), and 28.4% of patients were risk-stratified with a HEART pathway that incorporated the hs-cTn results, with the rest assessed using the traditional HEART pathway and conventional troponin testing.

Within 30 days, detection of MI was higher for those who received hs-cTn testing compared with conventional testing (5.8% vs 4.4%; P < 0.001). However, there was no difference in the rate of 30-day all-cause mortality (0.3% vs 0.4%; P = 0.50). The high-sensitivity assays did a better job than conventional troponins at diagnosing acute MI in the emergency department (4.6% vs 2.0%) and reduced the number of acute MI diagnoses made in the following 30 days (1.2% vs 2.4%; P < 0.001 for both).

Also, healthcare use was less in patients in the hs-cTn group compared with conventional troponins. That included lower rates of hospital admission (12.2% vs 15.0%), stress testing within 7 days (10.2% vs 12.8%), and coronary revascularization within 30 days (1.0% vs 2.0%; P < 0.001 for all).

“Further analyses are needed to determine whether, and to what extent, the small decreases in healthcare use seen using the more-involved hsTn HEART pathway translate to meaningful cost savings with more widespread implementation,” the authors write, adding that larger studies are also needed to look at how hs-cTn assays might affect mortality.

“An important next step will be to test the replication in other US health systems and to examine outcomes of hsTn implementation specific to the ED (eg, length of ED stay) and other areas within the healthcare system,” they add.

It’s clear that these tests are picking up more MIs, but the study “does beg the question as to whether finding these extra MIs is impacting mortality,” McCarthy said, adding that more long-term data might help to clarify that question.

He added that it was “reassuring to see” a drop in both stress testing out to 7 days and coronary revascularization out to 30 days with hs-cTn use, as these were both novel findings.

Troponin testing isn’t exclusively done in patients presenting with chest pain in the real world—about 40% of hospitals that use hs-cTn assays also use a risk score, with most using the HEART score, McCarthy said. As such, this study “will be relevant to a lot of hospitals in the US.”