Early CT signs in out-of-hospital cardiac arrest survivors: Temporal profile and prognostic significance

Aim: Although computed tomography (CT) signs of ischaemia, including loss of boundary (LOB) between grey matter and white matter and cortical sulcal effacement, in cardiac arrest (CA) survivors are known, their temporal profile and prognostic significance remains unclear; their clarification is necessary. Methods: Brain CT scans were obtained immediately after resuscitation in 75 non-traumatic CA survivors in a prospective fashion. They were divided into two groups according to the CA-return of spontaneous circulation (ROSC) interval: ≤20. min vs >20. min. The incidence of the CT signs and predictability of these signs for outcome, assessed 6 months after CA, was evaluated and compared. Results: The incidence of the positive LOB sign was 24% in the ≤20-min group and 83% in the >20-min group, and the difference was statistically significant (p<0.001). The interval of 20. min seemed to be the time window for the LOB development. The incidence of the positive sulcal effacement sign was 0% in the ≤20. min group and 34% in the >20-min group, and the difference was statistically significant (p=0.004). A positive LOB sign was predictive of unfavourable outcome with an 81% sensitivity and 92% specificity. A positive sulcal effacement sign was predictive of unfavourable outcome with a 32% sensitivity and 100% specificity. Conclusion: A time window may exist for ischaemic CT signs in CA survivors. The LOB sign may develop when the CA-ROSC interval exceeds 20. min, whereas the sulcal effacement sign may develop later. However, their temporal profile and outcome predictability should be verified by multicentre studies.