Consultant Clinical Scientist Royal Wolverhampton NHS Trust UK High sensitivity cardiac troponin I at presentation enables early safe discharge Dr Clare Ford Consultant Clinical Scientist Royal Wolverhampton NHS Trust UK

Where is Wolverhampton? West Midlands 17 miles north west of Birmingham 14th highest index of multiple deprivation in 2015 in England V. high ED attendance rate per 100,000 population.

Commissioners keen to avoid unnecessary hospital admissions. ED chest pain pathway 2012 ? Cardiac chest pain AMU for 12hr cTn. Drivers for change Commissioners keen to avoid unnecessary hospital admissions. ED excessive workload Financial penalties as more than 5% patients exceeding 4hr ED wait

Where is Wolverhampton? West Midlands

Stafford Hospital Scandal 1st public enquiry report published in Feb 2010 By 2011 ED not longer had acceptable staffing levels for 24/7 service

Introduction of POCT cardiac troponin I in late 2012 Low risk patients with cardiac chest pain POCT cTnI measured on admission and 3 hours later. Loan analysers introduced on a trial basis post evaluation

Introduction of POCT cardiac troponin I in late 2012 Advantages Disadvantages Discharge from ED if POCT cTnI at 0 & 3 hr ≤ 99th centile Poor performance on EQA Reduction in admissions to AMU Unacceptable downtime & complex for POCT analyser In our hands didn’t have ≤ 10% CV at 99th centile

New Pathology Lab Apr 2013 New Abbott analysers All labs in the UK were using the conventional Abbott troponin assay Abbott were looking to slowly launch hs assay 8

Project Group Consultant in Acute Medicine Dr Kate Willmer Consultant Cardiologist Dr Mike Cusack Consultant in Emergency Medicine Dr Andy Morgan Company representatives Dr Agim Beshri; Gareth Stone; Gordon Avery Lab professionals Prof Rousseau Gama; Dr Simon Whitehead; Me

ARCHITECT STAT hs-cTnI assay Requirements and Recommendations for hs-cTn Assays Abbott hs-cTnI 99th centile with ≤ 10% CV* √ Ability to quantitate (i.e. not report as < LOD) at least 50% and ideally 95% of results in healthy individuals** √ 75% using the lower LOD in pack insert*** Gender specific cut offs* *3rd Universal definition of . Thygesen et al. Circulation 2012; 126: 2020-35. ** Task force of IFCC on Clinical Applications of cardiac biomarkers *** Krintus et al Clin Chem Lab Med. 2014 ; 52: 1657-1665.

Universal Definition of AMI At least one cTnT >99th percentile of the values found in a healthy population Rise and/or fall of cTnT Evidence of myocardial ischaemia AMI Evidence of myocardial ischaemia – symptoms; ECG change; imaging evidence If one then myocardial damage, if 1 and 2 then acute myocardial injury, if 1,2 and 3 then MI Can have acute changes in cTn that are not due MI e.g. pulmonary embolism, myocarditis Thygesen et al. Circulation 2012; 126: 2020-35

Decisions Made Gender specific 99th centiles 34ng/L in males 15ng/L in females Rule out on presentation sample for low risk patients if hs-cTnI ≤1.9ng/L (LoD) unless sample collected within 1 hour of onset of pain* 0 and 6 hour samples Significant delta 50% *Gimenez et al. Int. J. Cardiol. 2013; 168: 3896-3901

Recommended use of Abbott hs-cTnI assay for early rule out of AMI using a 0 and 3 hour troponin strategy

Risks & Benefits Risks Benefits Inappropriate early discharge for a few Appropriate early discharge from ED for many n=1 on EQA Reduction in admissions No IQC at the LoD cut off Better patient experience Modest increase in test costs Address male/female inequalities Failure to achieve required TRT Excessive cardiology workload

Implementation Chest pain pathway designed and agreed hs-cTnI algorithm designed and agreed Interpretative comments produced and agreed IT implemented and tested Communication strategy compiled

Chest Pain Pathway Immediate clinical assessment & ECG If low risk & hs-cTnI ≤1.9 ng/L or ≤99th centile if >12 hr post pain: Discharged If hs-cTnI >1.9ng/L and patient low risk: CDU If patient high risk: AMU Presentation Sample sent to lab for hs-cTnI (if needed) CDU not classed as an admission

CDU Inclusion Criteria Cardiac sounding chest pain within 24 hr TIMI-RS score <3 Pain free on admission Age >16 yrs Clear hx Safe for discharge No suspected or proven alternative diagnosis No social reason for admission No evidence of heart failure No haemodynamic instability No ECG or hs-TnI elevation No coronary revascularisation within 6 weeks ED Consultant sign off for CDU admission In Oct 2013 audit 51/529 patients to CDU One subsequently admitted to AMU for ACS unrelated issue None had discharge diagnosis of ACS

hs-cTnI Interpretation 0 and/or 3 hr Tn >99th centile and change >50% 0 hr Tn ≤1.9ng/L or 0 & 3 hr Tn ≤99th centile 0 and /or 3 hr Tn >99th centile and change ≤50% 0 hr Tn >260ng/L Indicative of cardiac damage, clinical assessment required. Tn change ≤50% makes acute myocardial injury and therefore, MI unlikely in an appropriate clinical context but does not exclude Indicative of cardiac damage, clinical assessment required. Tn change >50% makes acute myocardial injury and therefore MI likely in an appropriate clinical context Supports a diagnosis of MI in an appropriate clinical context Normal, cardiac damage unlikely in an appropriate clinical context

Project group members communicated to their teams Communication Project group members communicated to their teams Communication sent out by email (more than once) to all hospital staff. Targeted emails to clinical directors Clinical scientist in ED in the first week of roll out and visited other wards if problems Algorithm available in ED/wards and on intranet

Turnaround Time of samples within the laboratory

Impact of New Pathway on Length of Stay and Admissions Differences between groups Asprin; B blocker use and ST depression higher in before than after patients Pulse rate lower in before than after ST depression

Impact of pathway on Cardiology The cardiology input of all patients presenting to ED with chest pain was assessed for all presentations in October 2013.

Study of Patients presenting to ED with Chest pain in Oct 2013 529 ACS possible from hx, exam &ECG? No 257 Yes 272 (51%)

Study of Patients presenting to ED with Chest pain in Oct 2013 ? ACS 272 ACS possible post hs-cTnI? No 224 Yes 48 (9%)

Study of Patients presenting to ED with Chest pain in Oct 2013 ?ACS 48 Cardiology input? No 13 Yes 35 (7%)

Study of the safety of the pathway Study Group Consecutive patients presenting to ED with chest pain for 6 months (Jul 13 – Jan 14) Exclusions < 16 yrs Trauma calls Self discharge

Study of the safety of the pathway Study Design Evaluation of NPV of hs-cTnI ≤1.9ng/L for MACE (defined as death; myocardial infarction; symptom driven revascularisation and readmission for ACS) At 30 days At 9 months

Study of the safety of the pathway Patients presenting to ED with chest pain 3853 ACS possible from hx, exam &ECG? No 1280 (33%) Yes 2573 (67%)

Study of the safety of the pathway ? ACS at Presentation 2573 Presentation hs-cTn>1.9ng/L? No 849 (32% of ?ACS) Yes 1724

Study of the safety of the pathway Patients hs-cTn>1.9ng/L 849 Discharged immediately? No 161 Yes 688 (27% of ?ACS)

30 day review of MACE in all 849 patients 2 deaths 1 unrelated malignancy 1 peri-arrest sample 1 PCI Negative predictive value of hs-cTn ≤1.9ng/L at presentation for MACE at 30 days 99.6% (95% CI 98.9-99.9) Cardiac arrest In ED within 30 min of arrest Asystole in ED & unsuccessful resuscitation PM showed heart failure due to three valve disease but no AMI

9 month review of MACE in all 849 patients 11 additional MACE 9 deaths 8 unrelated malignancy 1 pulmonary fibrosis 2 PCI Negative predictive value of hs-cTn ≤1.9ng/L at presentation for MACE at 9 months 98.4% (95% CI 97.2-99.1)

9 month review of MACE in all 849 patients One discharged patient had a MACE; elective PCI following ED referral to cardiology There were no MI or ACS re-presentations

Conclusion ARCHITECT STAT hs-cTnI at presentation may be used to safely discharge over 25% of low clinical risk patients attending ED with possible ACS This strategy together with the introduction of a CDU improved patient flow in ED and reduced hospital admissions. Safe earlier discharge has a positive impact on patient care, both for the individuals concerned and by releasing resources for the benefit of other patients.

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