See Online Data Supplements 8 to 13 for additional data comparing PCI with CABG for left main CAD. 5.7.3. Revascularization Considerations for Left Main CAD Although CABG has been considered the gold standard for unprotected left main CAD revascularization, more recently Fihn et al Stable Ischemic Heart Disease: Full Text e419 PCI has emerged as a possible alternative mode of revascu- larization in carefully selected patients. Lesion location is an important determinant when PCI is considered for unpro- tected left main CAD. Stenting of the left main ostium or trunk is more straightforward than treating distal bifurcation or trifurcation stenoses, which generally requires a greater degree of operator experience and expertise.1091 In addition, PCI of bifurcation disease is associated with higher restenosis rates than when disease is confined to the ostium or trunk.971,1092 Although lesion location influences technical success and long-term outcomes after PCI, location exerts a negligible influence on the success of CABG. In subgroup analyses, patients with left main CAD and a SYNTAX score $33 with more complex or extensive CAD had a higher mortality rate with PCI than with CABG.949 Physicians can estimate operative risk for all CABG candidates by using a standard instrument, such as the risk calculator from the STS database. The above considerations are important factors when choosing among revascularization strategies for unpro- tected left main CAD and have been factored into revascu- larization recommendations. Use of a Heart Team approach has been recommended in cases in which the choice of revascularization is not straightforward. As discussed in Section 5.9.5., the ability of the patient to tolerate and comply with DAPT is also an important consideration in revascular- ization decisions. The 2005 PCI guideline987 recommended routine angio- graphic follow-up 2 to 6 months after stenting for unprotected left main CAD. 