Editor's Choice-Is the pre-hospital ECG after out-of-hospital cardiac arrest accurate for the diagnosis of ST-elevation myocardial infarction?

Background: Current guidelines recommend that comatose out-of-hospital cardiac arrest patients with ST-segment elevations (STEs) following return of spontaneous circulation (ROSC) should be referred for an acute coronary angiography. We sought to investigate the diagnostic value of the pre-hospital ROSC-ECG in predicting ST-elevation myocardial infarction (STEMI).

Method: ROSC-ECGs of 145 comatose survivors of out-of-hospital cardiac arrest, randomly assigned in the Target Temperature Management trial, were classified according to the current STEMI ECG criteria (third universal definition of myocardial infarction).

Results: STEs were present in the pre-hospital ROSC-ECG of 78 (54%) patients. A final diagnosis revealed that 69 (48%) patients had STEMI, 31 (21%) patients had non-STEMI and 45 (31%) patients had no myocardial infarction. STE in ROSC-ECGs had a sensitivity of 74% (95% confidence interval (CI) 62-84), specificity of 65% (95% CI 53-75) and a positive and negative predictive value of 65% (95% CI 54-76) and 73% (95% CI 61-83) in predicting STEMI. Time to ROSC was significantly longer (24 minutes vs. 19 minutes, P=0.02) in STE compared with no STE patients. Percutaneous coronary intervention was successful in 68% versus 36% (P<0.001) of STE compared to no STE patients. No significant difference was found in 180-day mortality rates between STE and no STE patients (36% vs. 30%, Plogrank=0.37).

Conclusion: The pre-hospital ROSC-ECG is a suboptimal diagnostic tool to predict STEMI and therefore not a sensitive tool for triage to cardiac centres. This supports the incentive of referring all comatose survivors of out-of-hospital cardiac arrest of suspected cardiac origin to a tertiary heart centre with the availability of acute coronary angiography, even in the absence of STEs.