Predictive value of electrocardiographic ST‑segment elevation myocardial infarction equivalents for detecting acute coronary artery occlusion in patients with non-ST‑segment elevation myocardial infarction.

Background: The sensitivity and accuracy of 12-lead ECG for the detection of acute total occlusion (TO) of the culprit coronary artery in non-ST-elevation myocardial infarction (NSTEMI) is still suboptimal, particularly for posterolateral circulation.   Aims: We evaluated the prevalence and predictive value of electrocardiographic STEMI-equivalents (i.e. de-Winter ST/T-wave complex, N-wave, T-wave precordial instability, and posterior myocardial infarction) for detecting acute coronary artery occlusion in NSTEMI patients referred for early invasive treatment.

Methods: A total of 165 NSTEMI patients were enrolled. The patients were grouped according to the coronary angiography findings into those with TO (TIMI 0) in the culprit artery (n=43) and those with preserved flow in this vessel (TIMI 1-3) (n=122).

Results: The main findings of this study were as follows: 1) 31.5% of patients had at least one STEMI-equivalent, mostly N-wave in lead II, III or aVF; 2) the most common STEMI-equivalent in subjects with acute TO was T-wave precordial instability; 3) there was a significant relationship between the prevalence of STEMI-equivalents and acute coronary artery occlusion; 4) among all evaluated ECG parameters, only ST-segment depression in leads I, aVL, V6 was an independent predictor of acute TO in multivariate analysis; 5) ST-segment depression in leads I, aVL, V6 had higher specificity, positive and negative predictive values as well as accuracy in predicting acute TO of the culprit vessel, as compared to STEMI-equivalents.

Conclusions: STEMI-equivalents do not seem to have a relevant advantage over classic ischaemic ECG changes in the prediction of acute coronary artery occlusion in NSTEMI patients.