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

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).

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).

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%, P_logrank=0.37).

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.