Previous studies found that patients with an acute coronary syndrome (ACS) due to occlusion of the left circumflex (LC) coronary artery often present without ST-elevation, leading to a delay in diagnosis and revascularization, a larger infarct size, and a worse prognosis. In this subgroup analysis of the ELISA-3 study (early or late intervention in high-risk non-ST-segment elevation acute coronary syndromes [NSTE-ACS]) incidence, characteristics and prognosis of LC-related NSTE-ACS was investigated, and the outcome of early versus late invasive strategy was compared. In 383 of 542 patients the culprit vessel could be identified, with the LC artery in 112 (29%) of them. Patients with LC-related ACS had more often single vessel disease and underwent percutaneous coronary intervention more and CABG less frequently. The primary end point of the combined incidences of death, myocardial infarction, and recurrent ischemia at 30-day follow-up occurred in 9.0% of LC versus 16.5% of non-LC-related ACS (p = 0.057). Enzymatic infarct size and incidence of bleeding were comparable. Of patients with LC-related ACS, 62 were assigned to an early and 50 to a late invasive treatment with a median time from admission to angiography of 5.5 and 65.7 hours, respectively. The primary end point occurred in 9.7% and 8.0%, respectively (p = 1.00) with comparable enzymatic infarct size and bleeding. In conclusion, no significant differences in outcome were found between patients with an LC- and a non-LC-related NSTE-ACS. In LC-related NSTE-ACS, angiography within 12 hours of admission is feasible but not superior to angiography after more than 48 hours. (C) 2018 Elsevier Inc. All rights reserved.