Differentiating between comatose patients resuscitated from acute coronary syndrome-associated and subarachnoid hemorrhage-associated out-of-hospital cardiac arrest

BackgroundUpon initial evaluation in the emergency department (ED), it is often difficult to differentiate between comatose patients resuscitated following acute coronary syndrome (ACS)-associated and subarachnoid hemorrhage (SAH)-associated out-of-hospital cardiac arrest (OHCA). We assessed the clinical differences between resuscitated comatose ACS-OHCA and SAH-OHCA patients during initial evaluation in the ED.MethodsData of 1259 consecutive OHCA patients were analyzed retrospectively. Of these, 23 resuscitated comatose ACS-OHCA patients and 20 resuscitated comatose SAH-OHCA patients were included in the final analysis. Clinical data obtained during initial evaluation in the ED were compared between groups.ResultsPulseless electrical activity (PEA) or asystole as the initial cardiac rhythm, female gender, and preserved left ventricular ejection fraction (≥50%) on the echocardiogram were significantly more common in the SAH-OHCA group (p < 0.05 each). Although ST-T abnormalities suggesting myocardial damage (ST elevation and/or ST depression) were noted in most patients in both groups via 12-lead electrocardiogram (95%, ACS-OHCA group; 85%, SAH-OHCA group, p = 0.50), reciprocal ST depression was significantly more often absent in the SAH-OHCA group (p = 0.025). Initial PEA/asystole and presence of 1 other factor was sufficient to differentiate SAH-OHCA patients from ACS-OHCA patients (100% sensitivity, 91% specificity, 95% accuracy).ConclusionsInitial ED evaluation is sufficient to differentiate between comatose ACS-OHCA and SAH-OHCA patients prior to further diagnostic work-up (e.g. emergent coronary angiography and head computed tomography).