Published on behalf of The Society for governed by the applicable Creative Commons License CI: 0.21 to 0.58; P<0.001). In the CvLPRIT (Complete Versus Culprit-Lesion Only Primary PCI) trial, [18] 296 patients were randomized to culprit artery only or multivessel PCI during the index hospitalization (72% underwent multivessel primary PCI). The composite primary outcome of death, reinfarction, heart failure, and ischemia-driven revascularization at 12 months occurred in 15 patients (10%) who underwent multi- vessel PCI, compared with 31 patients (21%) receiving culprit artery only PCI (HR: 0.49; 95% CI: 0.24 to 0.84; P 0.009). In the DANAMI 3 PRIMULTI (Third Danish Study of Optimal Acute Treatment of Patients with ST-segment Elevation Myocardial Infarction) trial, [17] the composite primary outcome of all-cause death, nonfatal MI, or ischemia-driven revascularization of nonculprit artery disease occurred in 40 of 314 patients (13%) who underwent multivessel staged PCI guided by angiography and fractional flow reserve before dis- charge, versus 68 of 313 patients (22%) treated with culprit artery only PCI (HR: 0.56; 95% CI: 0.38 to plasty in Patients Transferred From General Commu- nity Hospitals to Specialized PTCA Units With or Without Emergency Thrombolysis) trial, [27] 214 patients with STEMI were randomized to staged (3 to 40 days after the index procedure) revascularization of all 70% diameter stenosis noninfarct lesions or culprit-only PCI. Preliminary results at 38 months mean follow-up showed no between-group differences in the composite primary endpoint of all-cause death, nonfatal MI, and stroke. On the basis of these findings, [17,18,24,27] the prior Class III (Harm) recommendation with regard to multivessel primary PCI in hemodynamically stable patients with STEMI has been upgraded and modified to a Class IIb recommendation to include consideration of multivessel PCI, either at the time of primary PCI or as a planned, staged procedure. 