PCI is reasonable in a noninfarct artery at a time separate from primary PCI in patients with inter- mediate- or high-risk findings on noninvasive test- (Level of Evidence: B) Multivessel coronary artery disease is present in 40% to 65% of patients presenting with STEMI who undergo primary PCI and is associated with adverse prognosis.381,382 Studies of staged PCI of noninfarct arteries have been nonrandomized in design and have varied with regard to the timing of PCI and duration of follow-up. These variations have contributed to the dispa- rate findings reported, although there seems to be a clear trend toward lower rates of adverse outcomes when primary PCI is lim- ited to the infarct artery and PCI of a noninfarct artery is under- taken in staged fashion at a later time.216,224,225,383,384 The largest of these observational studies compared 538 patients undergo- ing staged multivessel PCI within 60 days of primary PCI with propensity-matched individuals who had culprit-vessel PCI Multivessel PCI was associated with a lower mortality rate at 1 year (1.3% versus 3.3%; P=0.04).A nonsignificant trend toward a lower mortality rate at 1 year was observed in the sub- set of 258 patients who underwent staged PCI during the initial Table 10. 