It is reasonable to use elective double stenting in patients with complex bifurcation morphology involving a large side branch where the risk of side-branch occlusion is high and the likelihood of successful side-branch reaccess is low.730 733 (Level of Evidence: B) Side-branch occlusion or severe stenosis after stenting the main artery in coronary bifurcation PCI occurs in 8% to 80% of unselected patients.732,734 The frequency of side-branch occlusion is related to complex bifurcation morphology (severe and/or long side-branch ostial stenosis, large plaque burden in the side-branch ostium, and/or unfavorable side- branch angulation).732,735,736 Side-branch occlusion after PCI is associated with Q-wave and non Q-wave MI.734,735 There- fore, preservation of physiologic flow in the side branch after PCI is important.736 There are 2 bifurcation PCI strategies: provisional stenting (stenting the main vessel with additional balloon angioplasty or stenting of the side branch only in the case of an unsatisfactory result) and elective double stenting of the main vessel and the side branch. When there is an unsatis- factory result in the side branch from the provisional stent in the main branch, sometimes balloon angioplasty alone in the side branch will improve the result and stenting the side branch is not necessary. Some experts have suggested that using the side- branch balloon alone will distort the main branch stent and thus this always needs to be a kissing balloon inflation. 