The report is a product of the VA/HSR Evidence Synthesis Program.

Accelerated Diagnostic Protocols Using High-sensitivity Troponin Assays to "Rule In" or "Rule Out" Myocardial Infarction in the Emergency Department: A Systematic Review

Takeaway: Accelerated diagnostic protocols (ADPs) that incorporate high-sensitivity cardiac troponin (hs-cTn) discharge more patients from the emergency department (ED) to the community and have no difference in cardiovascular events and death compared with hs-cTn alone. ADPs with shorter hs-cTn testing intervals reduce ED length of stay more than longer testing intervals without compromising clinical outcomes. Among ADPs that reduce length of stay, there is no obvious best choice – and any ADP may need to be tailored to local context.

In the United States, 7 million people visit the emergency department (ED) for chest pain every year, but only 4% of these patients are diagnosed with myocardial infarction (MI). Rapid rule-in and rule-out of MI should reduce the time to correct patient diagnosis and reduce clinician, staff, and other hospital resource needs, along with ED overcrowding, unnecessary testing, and unnecessary hospitalizations. However, the clinical implications of missing an MI can be severe, including death.

High-sensitivity cardiac troponin (hs-cTn) assays were introduced in 2010 and are now the preferred troponin biomarker for diagnosing MI, as per the 2021 ACC/AHA Joint Committee on Clinical Practice Guidelines. Multiple accelerated diagnostic protocols (ADPs) have been devised to help ED providers quickly rule out MI. ADPs can incorporate hs-cTn, risk scores, and other clinical criteria (e.g., patient history or electrocardiogram findings) to stratify patients into categories that inform clinical management. Health systems, including VA, aim to implement ADPs with hs-cTn into clinical practice. The VA Evidence Synthesis Program (ESP) was asked by the VA Office of Emergency Medicine for an evidence review on ADPs that use hs-cTn to ‘rule in’ or ‘rule out’ MI. (I would bold here vs. below, since below is just a repeat)

The ESP Center located at the VA Providence Healthcare System conducted a systematic review to answer the following key questions regarding ADPs that use hs-cTn.

• Among adults presenting to the ED with suspected acute coronary syndrome, what are the effectiveness and comparative effectiveness of ADPs that use hs-cTn on clinical and health service use outcomes?
• What are the outcomes among adults presenting to the ED with suspected acute coronary syndrome who have indeterminant results of ADPs that use hs-cTn?

Relevant articles were searched for in Medline (via PubMed), Embase, ClinicalTrials.gov, and the Cochrane Database of Systematic Reviews from January 2008 to May 2022. Additional citations were identified from hand-searching reference lists of relevant systematic reviews and consultation with content experts. From more than 6,500 potentially relevant articles, 377 articles underwent a full text review and 17 studies (in 18 articles) that evaluated 23 ADPs were included in this systematic review. No studies were conducted in VA, and only 1 comparative study and 3 single group studies were conducted in the U.S.; therefore, there are some concerns regarding the generalizability of study results to VA patients.

Summary of Findings

ADPs using hs-cTn may increase the number of patient discharges to the community compared with hs-cTn alone, but may not impact clinical outcomes including 30-day major adverse cardiovascular event (MACE), MI, or death. ADPs with shorter compared to longer timing of hs-cTn measures may reduce ED length of stay, increase discharges to the community, and probably are not associated with changes in 30-day MACE, MI, or mortality. Among ADPs that reduce ED length of stay, there was no obvious best choice.

Limitations

The focus of this review was on the effect and not the implementation of hs-cTn ADPs. The organizational factors that affect implementation may be important for clinical and health service use outcomes. This review also did not evaluate the factors that might make an ED, hospital, or health system a strong candidate to implement an hs-cTn ADP. Because of variable terminology that was commonly not well defined, the review team often had to infer items, such as how ADPs were implemented, what factors were considered within ADPs, and the disposition (categorization) of patients.

Implications for VA

Supporting a common ADP could allow infrastructure developments in the electronic medical record, universal data collection, process measure construction, and outcome development necessary to create a high-reliability system for the management of chest pain. In addition, as a high-reliability organization, VA could automate a standard ADP that pulls data from the medical record to generate a disposition suggestion (e.g., rule in or rule out). In addition, VA could create a system for routing Veterans who are at high risk, but rule out into important programs such as preventive cardiology and cardiac rehabilitation. (I don’t understand this sentence.)

Future Research

Few studies have compared ADPs implemented in practice. There is a need to reduce the heterogeneity of study analyses to allow for better summarization, including possibly meta-analysis, across studies. Future studies should repeat comparisons of already-studied ADPs, with an eye toward clean comparisons of ADP duration and, separately, of ADP complexity. Given the complexity of ADPs, there is also a need for comparisons of ADP implementation in different hospital and geographic settings. Further, it is important to understand whether hs-cTn ADPs can be successfully and safely implemented in EDs that may not be part of large integrated health systems. There also is an opportunity to conduct secondary database analyses to identify the effects of ADPs in different subgroups (e.g., sex and chest pain duration). Greater standardization of risk stratification would greatly improve interpretation and clarity of findings

Jutkowitz E, Hsiao JJ, Celedon MA, et al. Accelerated Diagnostic Protocols Using High-sensitivity Troponin Assays to "Rule In" or "Rule Out" Myocardial Infarction in the Emergency Department: A Systematic Review. Washington, DC: Evidence Synthesis Program, Health Services Research and Development Service, Office of Research and Development, Department of Veterans Affairs. VA ESP Project #22-116; 2023.

To view the full report, go to: https://vaww.hsrd.research.va.gov/publications/esp/hs-troponins.cfm (Intranet only)

ESP is currently soliciting review topics from the broader VA community. Nominations will be accepted electronically using the online Topic Submission Form. If your topic is selected for a synthesis, you will be contacted by an ESP Center to refine the questions and determine a timeline for the report.

This Management e-Brief is provided to inform you about recent HSR&D findings that may be of interest. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs. If you have any questions or comments about this Brief, please email CIDER. The Center for Information Dissemination and Education Resources (CIDER) is a VA HSR&D Resource Center charged with disseminating important HSR&D findings and information to policy makers, managers, clinicians, and researchers working to improve the health and care of Veterans.

This report is a product of VA/HSR&D's Evidence Synthesis Program (ESP), which was established to provide timely and accurate synthesis of targeted healthcare topics of particular importance to VA managers and policymakers –; and to disseminate these reports throughout VA.

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