Table 1

Summary of usual rule-out strategies (control) by site

Site (All UK)	High-sensitivity troponin assay	Risk stratification tool and definition of low-risk	Troponin assay sampling times for low-risk patients	Troponin assay result to allow discharge if low-risk
Sites not using the LoD cut-off within usual rule-out strategies
Royal United Hospital, Bath	Roche Elecsys hs-cTnT*	GRACE28 score <1.5% six month mortality	Presentation and after 6 hours (or 6 hours from onset of pain)	Both results <14 ng/L OR 14–30 ng/L and no change >20% between tests
Southmead Hospital, Bristol	Roche Elecsys hs-cTnT*	TIMI score <2	Presentation and after 2 hours	Both results <14 ng/L OR 14–30 ng/L and no change >20% between tests
Derriford Hospital, Plymouth	Abbott Architect hs-cTnI†	HEART26 score ≤3	Presentation and after 3 hours	Both results <99th percentile (sex-specific)†
University Hospital, Southampton	Beckman-Coulter Access hs-cTnI‡	TIMI29 score <2	Presentation and after 3 hours	Both results <18 ng/L
Sites using the LoD cut-off within usual rule-out strategies
University Hospital of Wales, Cardiff	Abbott Architect hs-cTnI†	HEART26 score ≤2	Presentation and after 3 hours	Presentation <2 ng/L (LoD) and >2 hours after symptom onset OR both results <99th percentile (sex-specific)†
Royal Devon and Exeter Hospital, Exeter	Roche Elecsys hs-cTnT*	Absence of ECG changes and unstable angina symptoms	Presentation and after 1 hour	Presentation <5 ng/L (LoD) and >3 hours after symptom onset OR both results <14 ng/L
Royal London Hospital, Barts Health NHS Trust, London	Roche Elecsys hs-cTnT*	HEART26 score ≤3	Presentation and after 3 hours	Presentation <5 ng/L (LoD) OR both results <14 ng/L
Royal Berkshire Hospital, Reading	Roche Elecsys hs-cTnT*	HEART26 score ≤3	Presentation and after 1 hour	Presentation <5 ng/L (LoD) and >3 hours after symptom onset OR both results <14 ng/L

*Roche Elecsys hs-cTnT. This assay has a 99th percentile value of 14 ng/L and LoD of 5 ng/L.
†Abbott Architect hs-cTnI. This assay has 99th percentile value of 34 ng/L in men and 16 ng/L in women and LoD of 2 ng/L.
‡Beckman-Coulter Access hs-cTnI. This assay has a 99th percentile value of 18 ng/L and LoD of 2 ng/L.
GRACE, Global Registry of Acute Coronary Events; HEART, history, ECG, age, risk factors, troponin; hs-cTnI, high-sensitivity cardiac troponin I; hs-cTnT, high-sensitivity cardiac troponin T; LoD, limit of detection; TIMI, Thrombolysis In Myocardial Infarction.