High-Sensitivity Cardiac Troponin On Presentation to Rule Out Myocardial Infarction

University of Edinburgh31,492 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

DIAGNOSTIC

Masking

SINGLE

Enrollment

31,492

Conditions

Acute Coronary Syndrome

Interventions

Validation PhaseOTHER

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.

Randomization PhaseOTHER

Standard care or HighSTEACS pathway.

Implementation PhaseOTHER

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.

Outcomes

Primary Outcomes

Length of hospital stay (minutes)

This time frame is unique to each patient

Time frame: Length of time from initial presentation to the Emergency Department until final discharge from hospital, an average of 24 hours.

Type 1 or type 4b myocardial infarction or cardiac death after discharge and within 30 days of index admission

Time frame: Hospital discharge to 30 days after initial presentation

Secondary Outcomes

Proportion of patients discharged directly home from the Emergency Department

Time frame of initial hospital episode is unique to each patient

Time frame: Presentation to discharge from hospital, an average of 24 hours.

Type 1 or 4b Myocardial Infarction after hospital discharge (independently double adjudicated using all available clinical information)

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.