Utilization of Non-Gated Chest Computed Tomography Scans in Predicting Acute Coronary Occlusion in Out-of-Hospital Cardiac Arrest

Abstract

Coronary artery disease is thought to be responsible for up to 60%-80% of out-of-hospital cardiac arrests. The utility of Computed Tomography (CT) chest when it comes to identifying acute coronary occlusion in patients following an arrest has not been studied. We evaluated whether myocardial perfusion on a contrast-enhanced chest CT performed for a non-cardiac cause can predict culprit coronary occlusion as the cause of cardiac arrest and if the absence of a perfusion defect can exclude an ischemic etiology. A retrospective cohort of 53 consecutive patients presenting with VT or VF arrest and successful resuscitation who had contrast chest CT before angiography were identified. CT scans were reviewed for myocardial perfusion defects by a cardiologist and radiologist blinded to angiogram findings. CT results were then compared with angiograms. On coronary angiography, 22 (42%) of the patients presenting with out-of-hospital arrest had critical stenosis. Sensitivity and specificity of perfusion defect on CT in identifying critical stenosis on catheterization was 0.45, 95% CI [0.24, 0.68] and 0.77, 95% CI [59%, 90%], respectively. The positive likelihood ratio was 2.01 (0.91, 4.46) and the negative likelihood ratio was 0.70 (0.46, 1.08). The diagnostic accuracy was 64.2%. Our study did not show much utility for the use of myocardial perfusion defect on an incidental pre-angiography contrast chest CT to predict acute thrombotic occlusion in out-of-hospital cardiac arrest patients. However, this shouldn't discourage further studies evaluating the utility of contrast-enhanced CT images in predicting acute coronary occlusion.