Assessment of the 2016 National Institute for Health and Care Excellence high-sensitivity troponin rule-out strategy.

Objective: We aimed to evaluate the limit of detection of high-sensitivity troponin (hs-cTn) and Thrombolysis In Myocardial Infarction (TIMI) score combination rule-out strategy suggested within the 2016 National Institute for Health and Care Excellence (NICE) Chest Pain of Recent Onset guidelines and establish the optimal TIMI score threshold for clinical use.
Methods: A pooled analysis of adult patients presenting to the emergency department with chest pain and a non-ischaemic ECG, recruited into six prospective studies, from Australia, New Zealand and the UK. We evaluated the sensitivity of TIMI score thresholds from 0 to 2 alongside hs-cTnT or hs-cTnI for the primary outcome of major adverse cardiac events within 30 days.
Results: Data were available for 3159 patients for hs-cTnT and 4532 for hs-cTnI, of these 376 (11.9%) and 445 (9.8%) had major adverse cardiac events, respectively. Using a TIMI score of 0, the sensitivity for the primary outcome was 99.5% (95% CI 98.1% to 99.9%) alongside hs-cTnT and 98.9% (97.4% to 99.6%)%) alongside hs-cTnI, identifying 17.9% and 21.0% of patients as low risk, respectively. For a TIMI score ≤1 sensitivity was 98.9% (97.3% to 99.7%)%) alongside hs-cTnT and 98.4% (96.8% to 99.4%)%) alongside hs-cTnI, identifying 28.1% and 35.7% as low risk, respectively. For TIMI≤2, meta-sensitivity was <98% with either assay.
Conclusions: Our findings support the rule-out strategy suggested by NICE. The TIMI score threshold suggested for clinical use is 0. The proportion of patients identified as low risk (18%-21%) and suitable for early discharge using this threshold may be sufficient to encourage change of practice.
Trial Registration Numbers: ADAPT observational study/IMPACT intervention trial ACTRN12611001069943.ADAPT-ADP randomised controlled trial ACTRN12610000766011. EDACS-ADP randomised controlled trial ACTRN12613000745741. TRUST observational study ISRCTN no. 21109279.
Competing Interests: Competing interests: RB was funded by a Fellowship from the United Kingdom National Institute for Health Research (NIHR). JWP was funded by the Emergency Care Foundation, Canterbury Medical Research Foundation, and Canterbury District Health Board. EC reports grants from the Royal College of Emergency Medicine, UK and Bournemouth University; grants and personal fees from Abbott Diagnostics. JG reports grants from the Queensland Medical Research Foundation during the conduct of the study. LC reports grants from Roche during the conduct of the study; grants and personal fees from Abbott Diagnostics, personal fees from Alere, and personal fees from Siemens outside the submitted work. MPT reports grants and personal fees from Abbott and Alere, grants from Beckman, and personal fees from Roche outside the submitted work. RB has undertaken research under collaborative agreements with Roche, Siemens Diagnostics, Alere and Randox Laboratories and has accepted travel and accommodation for conferences from Roche Diagnostics and Randox Laboratories. WAP received funding from the Queensland Emergency Medicine Research Foundation, Abbott Diagnostics, Roche, Alere and Beckmann Coulter for research.
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