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OBJECTIVES: To determine whether coronary computed tomography angiography (CCTA) can improve the diagnostic work-up of patients with acute chest pain and inconclusively high-sensitivity troponins (hs-troponin). METHODS: We conducted a prospective, blinded, observational, multicentre study. Patients aged 30-80 years presenting to the emergency department with acute chest pain and inconclusively elevated hs-troponins were included and underwent CCTA. The primary outcome was the diagnostic accuracy of ≥ 50% stenosis on CCTA to identify patients with type-1 non-ST-segment elevation acute coronary syndrome (NSTE-ACS). RESULTS: A total of 106 patients (mean age 65 ± 10, 29% women) were enrolled of whom 20 patients (19%) had an adjudicated diagnosis of type-1 NSTE-ACS. In 45 patients, CCTA revealed non-obstructive coronary artery disease (CAD) or no CAD. Sensitivity, specificity, negative predictive value (NPV), positive predictive value and area-under-the-curve (AUC) of ≥ 50% stenosis on CCTA to identify patients with type 1 NSTE-ACS, was 95% (95% confidence interval: 74-100), 56% (45-68), 98% (87-100), 35% (29-41) and 0.83 (0.73-0.94), respectively. When only coronary segments with a diameter ≥ 2 mm were considered for the adjudication of type 1 NSTE-ACS, the sensitivity and NPV increased to 100%. In 8 patients, CCTA enabled the detection of clinically relevant non-coronary findings. CONCLUSION: The absence of ≥ 50% coronary artery stenosis on CCTA can be used to rule out type 1 NSTE-ACS in acute chest pain patients with inconclusively elevated hs-troponins. Additionally, CCTA can help improve the diagnostic work-up by detecting other relevant conditions that cause acute chest pain and inconclusively elevated hs-troponins. CLINICAL RELEVANCE STATEMENT: Coronary CTA (CCTA) can safely rule out type 1 non-ST-segment elevation acute coronary syndrome (NSTE-ACS) in patients presenting to the ED with acute chest pain and inconclusively elevated hs-troponins, while also detecting other relevant non-coronary conditions. TRIAL REGISTRATION: Clinicaltrials.gov (NCT03129659). Registered on 26 April 2017 KEY POINTS: Acute chest discomfort is a common presenting complaint in the emergency department. CCTA achieved very high negative predictive values for type 1 NSTE-ACS in this population. CCTA can serve as an adjunct for evaluating equivocal ACS and evaluates for other pathology.
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INTRODUCTION: Current evaluation of patients suspected of a non-ST-elevation acute coronary syndrome (NSTE-ACS) involves the use of algorithms that incorporate clinical information, electrocardiogram (ECG) and high-sensitivity cardiac troponins (hs-troponins). While primarily designed to rule out NSTE-ACS safely, these algorithms can also be used for rule in of NSTE-ACS in some patients. Still, in a substantial number of patients, these algorithms do not provide a conclusive work-up. These patients often present with an atypical clinical profile and low-range positive hs-troponin values without a characteristic rise or fall pattern. They represent a heterogeneous group of patients with various underlying conditions; only a fraction (30%-40%) will eventually be diagnosed with a myocardial infarction. Uncertainty exists about the optimal diagnostic strategy and their management depends on the clinical perspective of the treating physician ranging from direct discharge to admission for invasive coronary angiography. Coronary CT angiography (CCTA) is a non-invasive test that has been shown to be safe, fast and reliable in the evaluation of coronary artery disease. In this study, we will determine the usefulness of CCTA in patients with acute chest pain and low-range positive hs-troponin values. METHODS AND ANALYSIS: A prospective, double-blind, observational, multicentre study conducted in the Netherlands. Patients aged 30-80 years presenting to the emergency department with acute chest pain and a suspicion of NSTE-ACS, a normal or non-diagnostic ECG and low-range positive hs-troponins will be scheduled to undergo CCTA. The primary outcome is the diagnostic accuracy of CCTA for the diagnosis of NSTE-ACS at discharge, in terms of sensitivity and negative predictive value. ETHICS AND DISSEMINATION: This study was approved by the Medical Research Ethics Committee of Erasmus Medical Center in Rotterdam, the Netherlands (registration number MEC-2017-506). Written informed consent to participate will be obtained from all participants. This study's findings will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov (NCT03129659).