Randomised controlled trial of the Limit of Detection of Troponin and ECG Discharge (LoDED) strategy versus usual care in adult patients with chest pain attending the emergency department: study protocol.

INTRODUCTION: Observational data suggest a single high-sensitivity troponin blood test taken at emergency department (ED) presentation could be used to rule out major adverse cardiac events (MACE) in 10%-60% of ED patients with chest pain. This is done using an 'undetectable' cut-off (the Limit of Detection: LoD). We combined the LoD cut-off with ECG findings to create the LoDED strategy. We aim to establish whether the LoDED strategy works under real-life conditions, when compared with existing strategies, in a way that is cost-effective and acceptable to patients. METHODS AND ANALYSIS: This is a parallel-group pragmatic randomised controlled trial across UK EDs. Adults presenting to ED with suspected cardiac chest pain will be randomised 1:1. Existing rule-out strategies in current use across study centres, using serial high-sensitivity troponin testing, will be compared with the LoDED strategy. The primary outcome is successful early discharge (discharge from hospital within 4 hours of arrival) without MACE occurring within 30 days. Secondary outcomes include initial length of hospital stay; comparative costs; patient satisfaction and acceptability to patients. To detect a 9% difference between the early discharge rates (assuming an 8% rate in the standard care group) with 90% power, 594 patients need to be recruited, assuming a 95% follow-up rate. ETHICS AND DISSEMINATION: The study has been approved by the Frenchay Research Ethics Committee (reference 18/SW/0038). Results will be published in an international peer-reviewed journal. Lay summaries will be made available to patients. TRIAL REGISTRATION NUMBER: ISRCTN86184521; Pre-results.

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.

Cost-Effectiveness Analysis of Natriuretic Peptide Testing and Specialist Management in Patients with Suspected Acute Heart Failure.

OBJECTIVES: To determine the cost-effectiveness of natriuretic peptide (NP) testing and specialist outreach in patients with acute heart failure (AHF) residing off the cardiology ward. METHODS: We used a Markov model to estimate costs and quality-adjusted life-years (QALYs) for patients presenting to hospital with suspected AHF. We examined diagnostic workup with and without the NP test in suspected new cases, and we examined the impact of specialist heart failure outreach in all suspected cases. Inputs for the model were derived from systematic reviews, the UK national heart failure audit, randomized controlled trials, expert consensus from a National Institute for Health and Care Excellence guideline development group, and a national online survey. The main benefit from specialist care (cardiology ward and specialist outreach) was the increased likelihood of discharge on disease-modifying drugs for people with left ventricular systolic dysfunction, which improve mortality and reduce re-admissions due to worsened heart failure (associated with lower utility). Costs included diagnostic investigations, admissions, pharmacological therapy, and follow-up heart failure care. RESULTS: NP testing and specialist outreach are both higher cost, higher QALY, cost-effective strategies (incremental cost-effectiveness ratios of £11,656 and £2,883 per QALY gained, respectively). Combining NP and specialist outreach is the most cost-effective strategy. This result was robust to both univariate deterministic and probabilistic sensitivity analyses. CONCLUSIONS: NP testing for the diagnostic workup of new suspected AHF is cost-effective. The use of specialist heart failure outreach for inpatients with AHF residing off the cardiology ward is cost-effective. Both interventions will help improve outcomes for this high-risk group.

Cost-effectiveness of presentation versus delayed troponin testing for acute myocardial infarction.

OBJECTIVES: To estimate the cost-effectiveness of delayed troponin testing for myocardial infarction compared with troponin testing at presentation. DESIGN: Decision analysis modelling of cost-effectiveness using secondary data sources. SETTING: Acute hospitals in the UK. POPULATION: Patients attending hospital with suspected myocardial infarction but a normal or non-diagnostic ECG and no major comorbidities requiring admission. INTERVENTIONS: Delayed troponin testing (10 h after symptom onset) compared with standard and high-sensitivity troponin testing at presentation and no testing. Sensitivity analysis evaluated high-sensitivity troponin testing 3 h after initial assessment. MAIN OUTCOME MEASURES: The incremental cost per quality-adjusted life year (QALY) gained by each strategy, compared with the next most effective alternative, and the probability of each strategy being cost-effective at varying willingness-to-pay per QALY gained. RESULTS: In all scenarios tested, presentation high-sensitivity troponin testing was the most effective strategy with an incremental cost-effectiveness ratio below the £20 000/QALY threshold. 10 h troponin testing was only likely to be cost-effective if a discharge decision could be made as soon as a negative result was available and the £30 000/QALY threshold was used, or if a lower sensitivity estimate for presentation high-sensitivity troponin was assumed. Sensitivity analysis showed that including high-sensitivity troponin testing at presentation and 3 h in the analysis makes this the most cost-effective strategy. CONCLUSIONS: Delayed troponin testing is unlikely to be cost-effective compared with high-sensitivity troponin testing at presentation in most scenarios. Current NICE chest pain guidelines do not promote cost-effective care.

Interhospital variation in the RATPAC trial (Randomised Assessment of Treatment using Panel Assay of Cardiac markers).

BACKGROUND: The RATPAC trial showed that using a point-of-care panel of CK-MB(mass), myoglobin and troponin at baseline and 90 min increased the proportion of patients successfully discharged home, leading to reduced median length of initial hospital stay. However, it did not change mean hospital stay and may have increased mean costs per patient. The aim of this study was to explore variation in outcome and costs between participating hospitals. METHODS: RATPAC was a pragmatic multicentre randomised controlled trial (N=2243) and economic analysis comparing diagnostic assessment using the panel to standard care for patients with acute chest pain due to suspected myocardial infarction at six hospitals. The difference in the proportion of patients successfully discharged (primary outcome) and mean costs per patient between the participating hospitals was compared. RESULTS: Point-of-care assessment led to a higher proportion of successful discharges in four hospitals, a lower proportion in one and was equivocal in another. The OR (95% CI) for the primary outcome varied from 0.12 (0.01 to 1.03) to 11.07 (6.23 to 19.66) with significant heterogeneity between the centres (p<0.001). The mean cost per patient for the intervention group ranged from being £214.49 less than the control group (-132.56 to 657.10) to £646.57 more expensive (73.12 to 1612.71), with weak evidence of heterogeneity between the centres (p=0.0803). CONCLUSION: The effect of point-of-care panel assessment on successful discharge and costs per patient varied markedly between hospitals and may depend on local protocols, staff practices and available facilities.