The emerging role of CCTA in acute coronary syndrome evaluation: beyond invasive angiography

Coronary computed tomography angiography (CCTA) has emerged as a valuable non-invasive imaging modality for evaluating patients with suspected acute coronary syndromes (ACS), particularly in those without high risk features.

Previous studies have demonstrated that CCTA can effectively reduce unnecessary invasive coronary angiography while ensuring patient safety. However, its role in patients with an ACS remains less clearly defined.

The purpose of this study is to describe the role of CCTA in non-ST elevation acute coronary syndromes in low and intermediate risk patients.

We describe the results of 735 patients evaluated with a protocol that includes the use of CCTA in patients with an ACS. Patients over 18 years of age with a diagnosis of ACS without ST elevation who did not meet high-risk criteria (hemodynamic instability, dynamic changes in the ST segment or T wave, ventricular arrhythmia, GRACE score >140, refractory angina, heart failure or cardiorespiratory arrest) and consulted the emergency department were included. They underwent CCTA as the initial coronary evaluation. Data collection was carried out between May 11, 2022 and February 20, 2025.

735 patients were included, with a mean age of 58 years, of which 43% were women and 57% men. Among the admission diagnoses, 23% were NSTEMI and 77% were unstable angina according to the 4th universal definition of acute myocardial infarction (AMI). The median high-sensitivity cardiac troponin T value was 7 nanograms per litre (interquartile range, 4 to 14) for the first troponin sample, and 9 nanograms per litre (interquartile range, 6 to 22) for the second troponin sample. In 6% of them, a CCTA was not obtained due to a high coronary artery calcium score (>400 AU). It was observed that 26% did not have any coronary lesions or plaques. 40% had non-obstructive coronary artery disease (plaques <50%). The rest had significant lesions in at least one vessel (26%), predominantly in the left anterior descending artery, or were nondiagnostic (8%). Additionally, in 15% of the patients a high-risk plaque was found. 37% of the patients included underwent invasive coronary angiography and 24% required revascularisation.

This study shows that the prevalence of ACS with coronary arteries without significant lesions by CCTA was 66%, which suggests CCTA could have a predominant role in the diagnostic algorithm of acute coronary syndromes without high-risk criteria, implying a decrease in the need of invasive studies in these patients. Only 37% required invasive coronary angiography, while revascularisation was performed in 24% of the patients. CCTA was particularly useful in detecting non-obstructive coronary disease (in 40% of patients), potentially guiding the early initiation or optimization of preventive and medical therapies.Table 1

CCTA findings