Partial revascularization: In principle, CABG should be the treatment of choice when total revascularization cannot be achieved with PCI and can be achieved with surgical vascular bypass grafting (CABG). PCI for partial revascularization is indicated in the following clinical situations: patients with acute coronary syndromes presenting with an emergency requiring emergency PCI; PCI is indicated for any lesion, such as coronary artery trunk near occlusion lesions; however, emergency PCI generally also addresses revascularization of ischemia-related vessels only. When one or two coronary arteries are completely occluded (chronic total occlusive lesions) and PCI of this vessel is not planned or is unsuccessful, whether to perform PCI of the non-occluded vessel depends on the following circumstances: if the non-occluded vessel is an ischemia-related vessel, the offender’s lesion is severely stenotic (>80%), and the plaque is in an unstable state, PCI treatment can reduce the cardiac event rate of these patients, but the operation needs to be very careful, so it is not necessary to perform PCI of this kind. PCI can reduce the incidence of cardiac events in these patients, but it needs to be performed with great care to shorten the time of blood flow blockage as much as possible. If the non-occluded vessel is a non-ischemia-related vessel, especially if the plaque morphology is stable and the stenosis is <80%, it is not advisable to perform PCI, because once restenosis occurs after stenting, the incidence of cardiac events can be significantly increased. When the ischemia-related vessel is a severe diffuse stenosis that is not amenable to interventional therapy, PCI of the non-ischemia-related vessel should not be performed and CABG should be chosen, and when the patient is not amenable to CABG, PCI becomes the only invasive treatment option. Even if PCI cannot solve the problem of total revascularization, partial revascularization PCI can be performed, but in principle, PCI of ischemia-related vessels should be performed first.