Beyond STEMI: High-risk ECG patterns as predictors of occlusive myocardial infarction in out-of-hospital cardiac arrest patients.

Background/aim: Immediate coronary angiography (CAG) is recommended for patients with ST-elevation myocardial infarction (STEMI) after out-of-hospital cardiac arrest (OHCA). However, some occlusive myocardial infarctions (OMI) do not meet STEMI criteria. This study investigated whether additional ECG patterns beyond STEMI could more accurately identify OMI in OHCA patients, compared to using STEMI criteria alone.

Methods: This retrospective study categorised patients based on their first post-resuscitation ECG into two groups: STEMI and non-STEMI with high-risk ECG criteria and compared them for OMI by CAG.

Results: Among 97 patients OMI was identified in 55 % (53/97) of patients, specifically in 25 of 31 with STEMI (81 %), 24 of 29 with high-risk ECG (83 %), and 4 of 37 patients with neither (11 %). Combining STEMI and high-risk ECG criteria would have predicted OMI in 92 % (49/53) of cases. Patients with high-risk ECG experienced significantly longer median delays until CAG (101.5 [IQR 63-336.75] vs. 47.5 [25.75-71.25] minutes; p = 0.004) compared to those with STEMI on the ECG. Although 30-day mortality did not differ between STEMI and high-risk ECG patients (p = 0.973), survival-differences could be observed between groups. Syntax-I-Score was significantly higher in the high-risk ECG group (29 [IQR 19-38] vs. 15 [IQR 3-24.5]; p = 0.002).

Conclusion: Combining STEMI and high-risk ECG criteria improves OMI prediction compared to STEMI criteria alone, potentially enabling faster treatment and better OHCA survival.