Clinical characteristics of occluded culprit arteries and collaterals in patients with non-ST-segment elevation myocardial infarction and impact on clinical outcomes.

The presence of an occluded culprit artery or collaterals in non-ST-segment elevation myocardial infarction (NSTEMI) is relatively common; however, limited data are available regarding their clinical significance. The aim of the current study was to determine the clinical characteristics of occluded culprit arteries and coronary collaterals in patients with NSTEMI and their impact on patient outcomes. A total of 345 patients diagnosed with NSTEMI via coronary angiography between February 2006 and May 2013 were evaluated in the present study. Patient demographics, procedural characteristics and clinical outcomes of patients were analyzed according to the presence of an occluded culprit artery and coronary collaterals. A total of 78 (22.6%) and 166 patients (48.1%) exhibited an occluded artery and coronary collaterals, respectively. The left anterior descending artery is a more common location of culprit arteries in patients with NSTEMI with patent artery (NSTEMIPA) and distal parts of the artery are more common location of culprit arteries in patients with NSTEMI with occluded arteries (NSTEMIOA). Patients with NSTEMIOA exhibited higher peak creatine kinase-MB (CKMB) and troponin-I levels compared with patients that had NSTEMIPA. The presence of coronary collaterals is associated with a lower mean left ventricular ejection fraction, higher regional wall motion score index and extensive coronary artery disease. However, the clinical outcomes of patients with collaterals did not differ, irrespective of the presence of an occluded culprit artery or coronary collaterals. In the current study, ~25% of patients with NSTEMI had an occluded culprit coronary artery whereas 50% of patients with NSTEMI had coronary collaterals. The presence of an occluded artery and/or coronary collaterals did not affect clinical outcomes. Further studies are required to evaluate the long-term prognostic impact of an occluded artery and collaterals.