Inclusion Criteria:

1. Patients presenting with STEMI or type 1 NSTEMI and within 72 hours of successful culprit-lesion PCI

2. Residual coronary artery disease defined as at least 1 additional non-infarct-related coronary artery stenosis that meets all of the following criteria:

   1. Amenable to successful treatment with PCI
   2. At least 50% diameter stenosis by visual estimation
   3. At least 2.5 mm in diameter

3. Planned complete revascularization strategy for qualifying MI

Exclusion Criteria:

1. Planned or prior coronary artery bypass graft (CABG) surgery
2. Inability to clearly identify a culprit lesion for STEMI or NSTEMI based on angiographic appearance and/or ECG changes and/or regional wall motion abnormalities
3. Prior PCI of a non-culprit lesion in a different vessel from the culprit lesion within 45 days of randomization
4. Planned medical treatment of all qualifying non-culprit lesions (i.e., no PCI)
5. Presence of severe non-culprit-lesion stenosis with reduced epicardial flow (TIMI flow ≤ 2) or >90% visual diameter stenosis
6. Presence of a chronic total occlusion (CTO) if it is the only qualifying non-culprit lesion (patients with a CTO plus additional qualifying non-culprit lesions are eligible)
7. The only qualifying non-culprit lesion is in the same vessel territory as the culprit lesion
8. Baseline STEMI or NSTEMI was due to a suspected non-atherothrombotic mechanism such as type 2 MI (supply-demand mismatch), including spontaneous coronary artery dissection or coronary artery embolism
9. Non-cardiovascular co-morbidity with expected life expectancy <2 years
10. Any other medical, geographic, or social factor making study participation impractical or precluding 5 year follow-up