aVR ST Segment Elevation: Acute STEMI or Not? Incidence of an Acute Coronary Occlusion

Background: Identification of ST elevation myocardial infarction (STEMI)is critical because early reperfusion can save myocardium and increase survival. ST elevation (STE)in lead augmented vector right (aVR), coexistent with multilead ST depression, was endorsed as a sign of acute occlusion of the left main or proximal left anterior descending coronary artery in the 2013 STEMI guidelines. We investigated the incidence of an acutely occluded coronary in patients presenting with STE-aVR with multilead ST depression. Methods: STEMI activations between January 2014 and April 2018 at the University of Arizona Medical Center were identified. All electrocardiograms (ECGs)and coronary angiograms were blindly analyzed by experienced cardiologists. Among 847 STEMI activations, 99 patients (12%)were identified with STE-aVR with multilead ST depression. Results: Emergent angiography was performed in 80% (79/99)of patients. Thirty-six patients (36%)presented with cardiac arrest, and 78% (28/36)underwent emergent angiography. Coronary occlusion, thought to be culprit, was identified in only 8 patients (10%), and none of those lesions were left main or left anterior descending occlusions. A total of 47 patients (59%)were found to have severe coronary disease, but most had intact distal flow. Thirty-two patients (40%)had mild to moderate or no significant disease. However, STE-aVR with multilead ST depression was associated with 31% in-hospital mortality compared with only 6.2% in a subgroup of 190 patients with STEMI without STE-aVR (p<0.00001). Conclusions: STE-aVR with multilead ST depression was associated with acutely thrombotic coronary occlusion in only 10% of patients. Routine STEMI activation in STE-aVR for emergent revascularization is not warranted, although urgent, rather than emergent, catheterization appears to be important.