Left circumflex artery-related myocardial infarction: Does ST elevation matter? Results from the Euro Heart Survey PCI registry

Background/objectivesLittle is known about angiographic and clinical differences in patients presenting with left circumflex artery (LCX)-related ST elevation myocardial infarction (STEMI) and non ST elevation myocardial infarction (NSTEMI). We sought to determine the clinical significance of ST elevations in patients with LCX-related myocardial infarction.Methods and resultsBetween 2005 and 2008 10,503 consecutive patients with acute STEMI and NSTEMI undergoing percutaneous coronary intervention (PCI) were prospectively enrolled into the Euro Heart Survey PCI-Registry. For the present analysis patients with LCX-related STEMI (n = 1100, 54.7%) were compared to those with LCX-related NSTEMI (n = 910, 45.3%). NSTEMI-patients were older, more often female and had a higher incidence of prior cardiac events. Patients with STEMI more frequently presented with shock (8.0 versus 3.9%, P < 0.001) or had been resuscitated (8.5 versus 2.7%, P < 0.0001). TIMI 0-1 before PCI was much more often found among those with STEMI (58.2 versus 25.1%, P < 0.0001). In the univariate analysis there were no significant differences in hospital mortality (STEMI: 4.8%, NSTEMI: 3.5%, P = 0.17), however after adjustment for age, female gender, diabetes and chronic renal failure hospital mortality was significantly higher in STEMI patients (odds ratio 1.71, 95%-CI 1.08-2.72, P < 0.05).ConclusionsOver 50% of the patients with LCX-related myocardial infarction treated with PCI had ST elevations in the initial electrocardiogram. STEMIs were more often associated with total vessel occlusions or haemodynamic instability. In-hospital mortality was significantly higher in patients with LCX-related STEMI.