ECG-less Coronary Computed Tomography Angiography in the Management of Patients Presenting With High-troponin Chest Pain

Chest pain represents a common reason for consultation to emergency room. This symptom can be explained by a broad spectrum of conditions, from benign musculoskeletal or esophageal pain to life-threatening disease such as aortic dissection, pulmonary embolism, and myocardial infarction. There are already different diagnostic tools to quickly identify most dangerous diseases, for example electrocardiogram, blood samples with specific markers of cardiac injury, chest X-ray and echography. In case a doubt of disease is raised after the first clinical evaluation, it is possible to proceed with more complex, expensive and invasive examinations, namely a computed tomography (CT) scan or an invasive coronary angiography (ICA). CT scan allows the diagnosis of various conditions such as pleural, pulmonary, pericardial and vascular disease such as pneumonia, pneumothorax, pleural and pericardial fluid, pulmonary embolism (PE), acute aortic dissection (AOD). In order to see the pulmonary, aortic and coronary arteries, a contrast injection is needed. Moreover, since the heart and the aortic root are continuously moving, specific technical measures to obtain good quality images are needed. Recently, a new CT scan system has been developed. It allows to obtain good quality images of the heart and aortic root using an estimated heart rhythm, without ECG-gating. This allows to perform a CT scan of the heart in a reduced amount of time, and without need for controlling heart rate. Moreover, it is possible to obtain information on both aortic, coronary, and pulmonary artery with the same contrast injection. This may be of great interest in the context of patients presenting at the emergency room with chest pain and with a suspicion of pulmonary embolism, myocardial infarction, or aortic dissection, since with a single fast exam it is possible to rule out all these conditions. Coronary arteries are very small vessels, and the accuracy of this new technique in identifying a significant obstruction is still to be proved. At present, patients with chest pain and a suspicion of myocardial infarction undergo an invasive coronary angiography. If this new tool proves to be reliable, it will be possible to reduce the number of useless invasive examination in patients in which the presence of coronary artery disease (CAD) is ruled-out. In addition, the CT scan can help quickly and effectively plan treatment when worrying abnormalities are detected in the coronary arteries that are associated with a higher risk. Therefore, this clinical trial (further on referred to as "trial") will evaluate the investigational medicinal product (IMP), ECG-less Revolution Apex Elite system (GE Healthcare, Waukesha, WI -USA) for the diagnosis of coronary artery disease. The purpose of this trial is to learn about: the accuracy of this new CT system compared to the gold standard invasive coronary angiography in diagnosing coronary artery disease. The number of patients receiving an alternative diagnosis such as pulmonary embolism, aortic dissection, pulmonary, pleural or pericardial disease will be evaluated. Finally, the prognostic predictive value of the CT compared with ICA, in predicting myocardial infarction, coronary revascularization, and cardiac death at a follow-up of 18 months will be assessed. Patient will undergo a computer tomography examination with this new technique, evaluating both pulmonary, aortic, and coronary arteries. Then, as indicated by current guidelines, they will undergo an invasive coronary angiography.