Troponin in Acute Chest Pain to Risk Stratify and Guide EffecTive Use of Computed Tomography Coronary Angiography (TARGET-CTCA)

Troponin in Acute Chest Pain to Risk Stratify and Guide EffecTive Use of Computed Tomography Coronary Angiography

Troponin in Acute Chest Pain to Risk Stratify and Guide EffecTive Use of Computed Tomography Coronary Angiography

Most patients presenting to hospital with symptoms of a heart attack are sent home without further tests once a heart attack has been ruled out. Current strategies to assess patients with a suspected heart attack involve blood tests to measure troponin, a protein released into the bloodstream when the heart muscle is damaged. Despite having had a heart attack ruled-out, some patients have unrecognised heart disease and are at risk of having a heart attack in the future. However, clinicians do not know what is the best approach to identify and treat these patients. This study will use a heart scan known as computed tomography coronary angiogram (CTCA) to look for unrecognised heart disease in patients who have had a heart attack ruled out. In an earlier study, the Investigators performed this scan in patients referred to the outpatient cardiology clinic with stable chest pain and found that this improved the diagnosis of heart disease, leading to improvement in patient care that prevented future heart attacks. Previous research from the Investigators has also found that troponin levels below those used to diagnose a heart attack may help to identify those who are at greater risk of having a heart attack in the future. The aim of this study is to find out if patients with these low levels of troponin, where a heart attack has been ruled out, will benefit from CTCA to look for unrecognised coronary heart disease.

The first event of myocardial infarction (MI). MI will be defined according to the 4th Universal Definition of Myocardial Infarction

Cardiac death will be defined as death resulting from an acute myocardial infarction, sudden cardiac death, or death due to heart failure.

Cardiovascular death will be defined as death resulting from an acute myocardial infarction, sudden cardiac death, death due to heart failure, death due to stroke, death due to cardiovascular haemorrhage, and death due to other cardiovascular causes

Unscheduled urgent coronary revascularisation will be identified via record linkage from central NHS registers (e.g. the Scottish Morbidity Register by the Information Services Division (ISD) Scotland) or from extracts obtained from the participating hospitals electronic patient record system.

Reattendance with suspected ACS will be defined as any unscheduled hospital attendance where cardiac troponin testing is performed for suspected ACS following randomisation

Bleeding will be defined according to the Bleeding Academic Research Consortium (BARC) definition of bleeding. We will use pre-defined codes from International Classification of Diseases (ICD-10) and Office of Population Censuses and Surveys (OPCS) to classify each bleeding event as per the BARC definition.

Inclusion Criteria: Presenting to hospital with symptoms of suspected acute coronary syndrome Age 18 years and over Maximum high-sensitivity cardiac troponin concentration between 5ng/L and the 99th percentile Exclusion Criteria: Diagnosis of myocardial infarction during index presentation Clear alternative diagnosis or participant requires further inpatient clinical assessment Recent CTCA or invasive coronary angiogram (within 1 year) Patient inability to undergo CT scanning, e.g. due to severe renal failure (estimated glomerular filtration rate <30 mL/min) or major allergy to iodinated contrast media Current pregnancy or breast feeding Inability to give informed consent Further investigation for coronary artery disease would not be in the patient's interest, e.g. due to limited life expectancy, quality of life or functional status Previous randomisation into the trial

Following publication of the primary paper, a deidentified individual participant data set will be will be made available for data sharing purposes, subject to necessary governance approvals. Access to the deidentified dataset will be under a controlled access model.