Variation in the Adoption and Performance of High-Sensitivity Cardiac Troponin for Possible Myocardial Infarction in Practice

Abstract

Background: Guidelines recommend high-sensitivity cardiac troponin to risk stratify patients with possible myocardial infarction and identify those eligible for discharge. Whether the effectiveness and safety of this approach varies by sex, age, ethnicity, or deprivation status and how it has been adopted in practice is uncertain.

Methods: A multi-centre cohort study was conducted in 13 hospitals across the United Kingdom from November 1st, 2021, to October 31st, 2022. Routinely collected data including high-sensitivity cardiac troponin I or T measurements were linked to outcomes. The primary efficacy and safety outcomes were the proportion discharged from the Emergency Department, and the proportion dead or with a subsequent myocardial infarction at 30 days, respectively. Patients were stratified using peak troponin concentration as low (<5 ng/L), intermediate (5 ng/L to sex-specific 99th percentile), or high-risk (>sex-specific 99th percentile).

Findings: In total 137,881 patients (49% female) were included of whom 60,707 (44%), 42,727 (31%), and 34,447 (25%) were stratified as low-, intermediate- and high-risk, respectively. Overall, 65·8% (39,918/60,707) of low-risk patients were discharged from the Emergency Department, but this varied from 26·8% to 93·5% by site. The safety outcome occurred in 277 (0·5%) and 3,917 (11·4%) patients classified as low- or high-risk, of whom 18 (0·03%) and 304 (1%) had a subsequent myocardial infarction at 30 days, respectively. A similar proportion of male and female patients were discharged (52% versus 54%), but discharge was more likely if patients were <70 years old (61% versus 34%), from areas of low deprivation (48% versus 43%) or were black or asian compared to caucasian (62% and 56% versus 50%).

Interpretation: Half of all patients with possible myocardial infarction were identified as low-risk by high-sensitivity cardiac troponin, but only two-thirds of these patients were discharged with substantial variation by age, deprivation, ethnicity, and site across the United Kingdom.

Funding: MM is supported by the British Heart Foundation Clinical Research Training Fellowship (FS/CRTF/23/24491). DMK is supported by an Intermediate Basic Science Research Fellowship (FS/IBSRF/23/25161) and NLM is supported by a Chair Award, Programme Grant, and Research Excellence Award (CH/F/21/90010, RG/20/10/34966, RE/18/5/34216) from the British Heart Foundation. Further funding was provided by National Institute for Health and Care through Research Biomedical Research Centre awards to University Hospitals Birmingham NHS Foundation Trust and Imperial College Healthcare NHS Trust. This work was supported by DataLoch (https://dataloch.org/), which is funded by the Data Driven Innovation programme within the Edinburgh and South East Scotland City Region Deal.

Declaration of Interest: NLM has received honoraria or consultancy from Abbott Diagnostics, Roche Diagnostics, Siemens Healthineers, LumiraDx, and Pyros Laboratories. All other authors have no interests to declare.

Ethical Approval: The study was classified as a service evaluation with individual patient level data accessed and linked with approval of local Research Ethics Committees and Caldicott Guardians and in accordance with the Declaration of Helsinki following the Reporting of studies Conducted using Observational Routinely-collected Data (RECORD) guidelines.

Keywords: Healthcare data, data linkage, high-sensitivity cardiac troponin, healthcare outcomes, myocardial infarction