Cardiac stenting is achieved by PCI procedures in two distinct medical situations, when a patient has clearly suffered a heart attack and therefore PCI/stenting is being used in an emergency setting, termed 'primary PCI'. It is also a procedure used in patients that are exhibiting prolonged clinical symptoms of coronary artery narrowing (angina, evidence from stress test data, various imaging techniques etc.). Patients not undergoing primary PCI are usually awake during the placement of a coronary stent, thou.