Prognosis of Patients With Left Circumflex Artery Acute Myocardial Infarction in Relation to ST-Segment on Admission Electrocardiogram.

Abstract

BACKGROUND\nTotal thrombotic occlusion of the left circumflex (LCX) artery may present without ST-segment elevations; the clinical outcomes of such patients remain unclear.\n\n\nOBJECTIVE\nTo examine the difference in clinical outcomes between patients with acute myocardial infarction (MI) due to LCX occlusion or stenosis with and without ST-segment elevation.\n\n\nMETHODS\nThe present study is based on an observational, retrospective cohort comprising all patients admitted to 2 centers between 2009 and 2019 with MI due to LCX disease. Clinical outcomes included recurrent percutaneous coronary intervention (PCI), hospitalization due to acute coronary syndrome (ACS), and mortality. Risk factors for mortality were assessed using logistic regression analysis.\n\n\nRESULTS\nDuring the study period, a total of 897 patients with LCX-related MI were treated. Most (56.6%) presented with non-ST segment elevation MI (NSTEMI), which was associated with higher rates of 1-year hospitalization for ACS (15.8% vs 11.1%; P=.05) and PCI (20.9% vs 14.4%; P=.05) compared with ST-segment elevation MI (STEMI) patients. STEMI was associated with higher 30-day mortality compared with NSTEMI (3.9% vs 1.7%, respectively; P=.05), with no difference in mortality after 1 year (6.7% vs 5.6%, respectively; P=.55). Multivariate analysis found left dominant circulation (odds ratio [OR], 2.62; 95% confidence interval [CI], 1.4-4.7) and diabetes mellitus (OR, 2.13; 95% CI, 1.2-3.6) to be independent predictors for 1-year mortality.\n\n\nCONCLUSION\nPatients suffering from NSTEMI and STEMI related to LCX occlusion or stenosis have similar 1-year mortality. Left dominant circulation was associated with higher short- and long-term mortality. These results suggest that a substantial population of patients who present as NSTEMI should be treated as promptly and aggressively as STEMI patients.