Acute Coronary Syndrome, Myocardial Infarction
Conditions
Keywords
High-sensitivity cardiac troponin I, Myocardial infarction, Acute coronary syndrome, Cluster-randomized trial
Brief summary
Patients with suspected acute coronary syndrome account for a tenth of all presentations to the Emergency Department and up to 40 per cent of unplanned hospital admissions. The majority of patients do not have a heart attack (myocardial infarction), and may be safely discharged from the Emergency Department. The investigators propose to evaluate whether the use of the HighSTEACS pathway in patients with suspected acute coronary syndrome reduces length of stay and allows more patients to be safely discharged from the Emergency Department. This pathways utilizes high-sensitivity cardiac troponin I testing and will rule out myocardial infarction if troponin concentrations are \<5 ng/L on presentation, with further testing indicated at 3 hours only in those presenting early or with troponin concentrations between 5 ng/L and the 99th centile. In six secondary and tertiary centres across Scotland, the investigators will introduce the pathway as part of a stepped wedge cluster randomized controlled trial. Sequential hypothesis testing will evaluate the efficacy and safety of the pathway. The primary efficacy end-point will be length of stay from time of presentation until final hospital discharge and the primary safety end-point will be survival free from type 1 or 4b myocardial infarction or cardiac death from discharge to 30 days. The study population will consist of those patients with cardiac troponin concentrations within the normal reference range (\<99th centile) at presentation.
Interventions
OTHERValidation Phase
Standard care across all sites during the validation phase will rule out myocardial infarction in those with presentation troponin below the 99th centile with greater than 6 hours of symptoms at the time of blood sampling. In those with less than 6 hours of symptoms, a second test will be measured 6- 12 hours after presentation.
OTHERRandomization Phase
Standard care or HighSTEACS pathway.
OTHERImplementation Phase
Implementation of the HighSTEACS pathway to rule out myocardial infarction in patients with suspected acute coronary syndrome. Myocardial infarction will be ruled out if presentation cardiac troponin concentrations are \<5 ng/L in those with at least 2 hours of symptoms at the time of blood sampling. In patients with less than two hours of symptoms, or where cardiac troponin concentrations are between 5ng/L and the 99th centile, repeat testing will be recommended at 3 hours. Myocardial infarction will be ruled out at 3 hours if cardiac troponin concentrations are unchanged (\<3 ng/L change) and remain ≤99th centile on retesting. Those remaining ≤99th centile on retesting but demonstrating a significant change will require admission for further testing at 6-12 hours.
Sponsors
NHS Lothian
NHS Greater Glasgow and Clyde
University of Edinburgh
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
DIAGNOSTIC
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Healthy volunteers
No
Inclusion criteria
* All consecutive patients with suspected acute coronary syndrome * High-sensitivity cardiac troponin I measured as part of routine clinical care
Exclusion criteria
* Patients who are not resident in Scotland * Patients with ST-segment elevation myocardial infarction * Patients presenting to hospital in cardiac arrest * Patients with presentation high-sensitivity cardiac troponin I concentrations greater than sex-specific 99th centile thresholds
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Length of hospital stay (minutes) | Length of time from initial presentation to the Emergency Department until final discharge from hospital, an average of 24 hours. | This time frame is unique to each patient |
| Type 1 or type 4b myocardial infarction or cardiac death after discharge and within 30 days of index admission | Hospital discharge to 30 days after initial presentation | — |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of patients re-attending the Emergency Department | Hospital discharge to 30 days and 1 year after initial presentation | — |
| All-cause death after hospital discharge | Hospital discharge to 30 days and 1 year after initial presentation | — |
| Unplanned coronary revascularisation after hospital discharge (from cardiac intervention databases and case note review) | Hospital discharge to 30 days and 1 year after initial presentation | We will identify any patients who require unplanned percutaneous coronary intervention or coronary artery bypass grafting. |
| Proportion of patients discharged directly home from the Emergency Department | Presentation to discharge from hospital, an average of 24 hours. | Time frame of initial hospital episode is unique to each patient |
| Type 1 or 4b Myocardial Infarction after hospital discharge (independently double adjudicated using all available clinical information) | Hospital discharge to 30 days and 1 year after initial presentation | An adjudicated diagnosis of type 1 and type 4b myocardial infarction will be made in line with the universal definition of myocardial infarction, using all available clinical information. |
| Cardiac death after hospital discharge (independently double adjudicated using all available clinical information) | Hospital discharge to 30 days and 1 year after initial presentation | — |
| Cardiovascular death after hospital discharge (independently double adjudicated using all available clinical information) | Hospital discharge to 30 days and 1 year after initial presentation | — |
Other
| Measure | Time frame | Description |
|---|---|---|
| Cost-effectiveness analysis | 1 year | Based on costs of investigation and management in the year after initial hospital presentation |
| Pre-specified sub-group analyses of the primary outcome | length of hospital stay defined as the length of time from initial presentation to the Emergency Department until final discharge from hospital; safety follow-up time frame of 30 days and 1 year after hospital discharge | We will evaluate if the effect of intervention is significantly stronger or weaker in pre-specified sub-groups by assessing the co-primary endpoints in those who present with cardiac troponin \<5 ng/L (low risk group), and in the whole population across different ages (considering age as a continuous variable), by duration of symptoms (considered as a continuous variable), by gender, by those who have or do not have a pre-existing history of ischaemic heart disease, by those with a presentation electrocardiogram suggesting ischaemia, by the GRACE risk score (considered as a continuous variable), and by day of patient presentation (assessing differences in weekday/weekend or routine/out-of-hours presentation). |
Outcome results
None listed