Ischaemic electrocardiogram patterns and its association with survival in out-of hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA) is a leading cause of death.1 In patients with return of spontaneous circulation (ROSC), vital organ support and treatment of the underlying aetiology are paramount to improve survival. Ischaemic heart disease is the most common cause of cardiac arrest2 and accounts for approximately 70% of cases.3

The ST-segment elevation myocardial infarction (STEMI) on the post-resuscitation electrocardiogram (ECG) has shown to be a useful predictive marker for acute thrombotic occlusions, with a positive predictive value of >85%.3–6 In those presenting with STEMI, immediate reperfusion has demonstrated improved survival and thus this is advocated in the current guidelines.7

The recently published Coronary Angiography after Cardiac arrest (COACT) trial and the Immediate Unselected Coronary Angiography vs. Delayed Triage in Survivors of Out-of-hospital Cardiac Arrest Without ST-segment Elevation (TOMAHAWK) trial found that urgent coronary angiography was not beneficial in OHCA patients without STEMI.8–10 The results of the COACT trial were incorporated in the European Society of Cardiology guidelines.11

Repolarization abnormalities such as ST-depression and T-wave inversion on the post-resuscitation ECG are frequently encountered.12–14 In patients presenting with non-STEMI (NSTEMI) who are not resuscitated, ST-depression has shown to be an independent predictor for comorbidity and mortality.15,16 However, data on the prognostic value of ST-repolarization abnormalities on the post-resuscitation ECG in the absence of STEMI is scarce. So far, cardiac arrest studies have mainly focused on the presence of STEMI.6,17,18 Whether post-ROSC ST-repolarization disorders in the absence of STEMI are a predictor for mortality is yet to be determined.

In the present study, we compared angiographic outcomes, myocardial damage, left ventricular function, and survival in patients presenting with or without ischaemic ECG patterns on the first post-resuscitation ECG recorded in-hospital.