Abstract Sa1104: Head and Pulmonary Artery Chest CT Detect Most but Not All Causes of Sudden Death and Resuscitation Injury Compared to Head to Pelvis CT Angiography in Survivors of Out of Hospital Circulatory Arrest

Introduction: Head-to-pelvis “sudden death computed tomography” angiography (SDCT) has a high diagnostic yield to identify causes and complications of out-of-hospital cardiac arrest (OHCA). The differences in yields of non-contrast head CT (H-CT) and pulmonary embolism chest CT (CT PE) angiography alone or in combination is not clear. Methods: Our prospective observational cohort enrolled patients that survived OHCA resuscitation and had a SDCT (H-CT, ECG-gated chest CT, and non-ECG gated venous phase abdomen/pelvis CT) within 6 hours of arrival (December 2015 – February 2018). For this sub-study, we assessed the same scans for diagnoses obtainable from routine H-CT and CT PE axial coverage alone, excluding any added (SDCT) findings from ECG-gating and abdomen/pelvis assessment. The primary outcome was the difference in diagnostic yield of time-critical and non-time-critical diagnoses by CT PE with or without H-CT compared to SDCT. Results: SDCT identified 86 time-critical diagnoses in 104 enrolled patients, including 39 pneumonias (45% of diagnoses), 13 myocardial infarctions [MI] (15%), 8 pulmonary embolisms (9%), 8 pneumothoraces (9%), 8 abdominal catastrophes (9%), 3 intracranial hemorrhages (3%), and 1 vascular access hemorrhage (1%) [ Table ]. CT PE alone identified 61 of the 86 time-critical diagnoses (71%), missing 25 diagnoses (29%) compared to SDCT. Missing diagnoses included MI (13/13), abdominal catastrophe (8/8), and active vascular access hemorrhage (1/1). H-CT diagnosed all 3 intracranial hemorrhages. Of the 208 non-time-critical diagnoses identified by SDCT, CT PE identified 183 non-time critical diagnoses (88%), missing 25 diagnoses (12%). H-CT did not identify any non-time-critical diagnoses. Conclusions: CT PE imaging with H-CT identifies a majority—but not all—time-critical and non-time-critical diagnoses in OHCA patients, mainly failing to capture coronary and intra-abdominal pathologies. SDCT, which includes ECG-gated chest CT and abdomen/pelvis CT, improves total diagnostic yield, but its incremental utility requires further study.