Novel ECG changes in acute coronary syndromes. Would improvement in the recognition of 'STEMI-equivalents' affect time until reperfusion?
Current guidelines recommend that patients with non-ST elevation myocardial infarction (NSTEMI) are treated with medical management alone, or in combination with coronary angiography within 24 h. Recent research suggests that NSTEMIs show angiographic evidence of complete occlusion at rates comparable to STEMIs, suggesting a subgroup of NSTEMI patients who require urgent angiography. Novel ECG changes, termed 'STEMI-equivalents', have been described as a way of identifying this subgroup. The aim of this study was to determine whether patients with STEMI-equivalent ECG changes experience similar degrees of myocardial damage, and would thus benefit from urgent PCI. Cardiac catheterisation databases at The Wollongong Hospital were searched for STEMI, and NSTEMI patients with complete occlusion of the culprit vessel, between January 2011 and December 2013. A total of 1429 patients underwent angiography during this time period. Of these, 220 were eligible for ECG analysis. We found 10-25% of NSTEMIs with 'STEMI equivalent' ECG changes correlated with complete vessel occlusion on angiography. These patients demonstrated equivalent initial troponin readings. Recognition of STEMI-equivalents represent a chance for earlier intervention with prompt coronary angiography, as these findings are often associated with complete occlusion of the culprit vessel. These findings provide further evidence supporting the potential inclusion of STEMI-equivalents in future ACS guidelines.