Purpose. International guidelines recommend to perform a 12-leads electrocardiogram (ECG) after the return of spontaneous circulation (ROSC) and to perform an emergent coronary angiogram at least in those patients presenting with ST segment elevation. However, the best timing for the acquisition of the ECG after ROSC has never been assessed.
Methods. We considered for analysis all patients enrolled in the Pavia CARe (out-of-hospital cardiac arrests registry of the province of Pavia) from January 2015 to December 2017 for whom a post-ROSC ECG and a coronary angiography were retrospectively available. Every ECG was blindly reviewed and then categorized as positive or negative for STEMI according to the latest edition of the universal definition of myocardial infarction.
Results. Among the 1403 resuscitation attempts in the study period, 149 patients arrived alive to our hub Hospital. In 139 of them a post-ROSC ECG was available and in 89 a coronary angiography was also performed. The median time interval from ROSC to ECG was 8 min (interquartile range 4.8-16 min); 45 (32%) ECGs were negative for STEMI and 94 (68%) were positive for STEMI. The time for acquisition of the ECG was a predictors for positive ECG [OR 0.97 (95%CI 0.97-0.99) p=0.01] and a cut-off time of less than 10 minutes was associated to the best sensitivity/specificity for positive ECG (AUC 0.65 p=0.02). Therefore having a positive ECG in the first 10 minutes after ROSC was not a predictor of coronary intervention [OR 2.9 (95%CI 0.7-11.9) p=0.14], whereas showing a positive ECG after 10 minutes after ROSC was a strong predictor of coronary intervention [OR 12.6 (95%CI 2.5-64.3) p= 0.002].
Conclusions. Post-ROSC 12-lead ECG is an essential step in the diagnostic flow after cardiac arrest, however its acquisition too early could increase the number of false positives.