Retrospective Analysis of Incidental Myocardial Perfusion Defects on Non-ECG-Gated Contrast-Enhanced CT in Emergency Settings.

Background and Objectives: Coronary heart disease is a leading cause of death in developed countries. While ECG-gated coronary CT is commonly used to detect coronary artery stenosis, the potential of non-ECG-gated CT (NECE-CT) to reveal incidental myocardial perfusion defects indicative of acute myocardial infarction (AMI) remains underexplored, particularly in emergency settings where rapid diagnosis is crucial. Materials and Methods: We retrospectively analyzed 22 suspected AMI patients from the emergency department who underwent NECE-CT without either an initial AMI diagnosis or available cardiac enzyme or ECG data. Results: AMI was confirmed in 45% (n = 10) of patients, with 30% (n = 3/10) showing elevated troponin I levels only after the CT exam. In the AMI group, all patients had perfusion defects, with 20% (n = 2) showing transmural defects and 80% (n = 8) showing endocardial defects. In contrast, all patients in the non-AMI group exhibited endocardial defects. Coronary artery calcification was significantly higher in the AMI group (70%) compared to the non-AMI group (25%, p < 0.05). Conclusions: These findings suggest that NECE-CT may reveal myocardial perfusion defects as an ancillary sign of AMI. While not a standalone diagnostic tool, careful evaluation of the myocardium in emergency CT scans may raise suspicion of AMI in patients with atypical presentations, offering more insight than standard methods. Further prospective studies with larger cohorts are needed to validate the clinical utility of these incidental findings.