See Online Data Supplements 14 to 19 for additional data comparing PCI with CABG for left main CAD. 3.7.3. Revascularization Considerations for Left Main CAD Although CABG has been considered the gold standard for unprotected left main CAD revascularization, more recently PCI has emerged as a possible alternative mode of revascu- larization in carefully selected patients. Lesion location is an important determinant when considering PCI for unprotected left main CAD. Stenting of the left main ostium or trunk is more straightforward than treating distal bifurcation or trifur- cation stenoses, which generally requires a greater degree of operator experience and expertise.464 In addition, PCI of bifurcation disease is associated with higher restenosis rates than when disease is confined to the ostium or trunk.327,465 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.334 Physicians can estimate oper- ative 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 choos- ing among revascularization strategies for unprotected left main CAD and have been factored into revascularization recommendations. Use of a Heart Team approach has been recommended in cases in which the choice of revasculariza- tion is not straightforward. As discussed in Section 3.9.7, the ability of the patient to tolerate and comply with dual antiplatelet therapy (DAPT) is also an important consider- ation in revascularization decisions. The 2005 PCI guidelines466 recommended routine angio- graphic follow-up 2 to 6 months after stenting for uprotected left main CAD. 