Thank you very much, John. We like to have case presentation. I think it's important to have brief snippets of things that people ought to know. And in 2016, Xiaoling and other operators from Asia and also the Europeans and I decided to publish this algorithm, which I still think makes sense. This is what I published. I'll go through this very quickly. So the most important thing is the criteria for left-main intervention. Remember, the side branch is a driver for the bifurcation PCI. For left-main, the criteria is the stenosis angiographically should be equal to or greater than 70%, or IVUS-OCT left-main MLA, minimum level area, less than or equal to 6 mm2, or by FFR, less than or equal to 0.80. For non-left-main, the criteria is different. The angiographic side branch stenosis should be equal to or greater than 90%. Again, the FFR should be equal to or less than 0.80. Important thing is to remember the Medina classification is important to tell you where the lesion location is. And it's important to also tell you that you have to classify them. So the way that works is that if there's any stenosis more than 50%, if it's in the main vessel, give it a 1. If it's below the branch, give it a 1. If it's side branch, give it a 1. And if there are no lesions here, then it goes to a 0. Typical bifurcation is a 1, 1, 1. And on the other end, you can have isolated osteostenosis, which is 0, 0, 1, meaning that no lesion in the main vessel or beyond the side branch, but a side branch. Now Chen and his group have defined lesion complexity based on this side branch classification stenosis, but they've also been inclusive of lesion length equal to or greater than 10 mm. And this has been used in many, many trials now. And the Definition 2 study really validated this and also validated that lesion complexity increases with moderate to severe classification, multiple lesions, bifurcation angle less than 45 degrees, main vessel reference vessel diameter less than 2.5 mm, thrombus containing lesions, or main vessel lesion length equal to or greater than 25 mm. And also Dr. Chen has defined that complexity bifurcation includes one major criteria or plus two minor criteria. And again, the Definition 2 study validated that. So we went on to define this and this algorithm is created that in simple versus complex left main bifurcation lesion, the simple lesion, once again, defined on this side of the screen demonstrating side branch lesion length, lesion less than 70% stenosis, and our lesion length less than 10 mm, that makes it simple. Complex lesion is a side branch lesion equal to or greater than 70% and our lesion length greater than 10 mm. And again, definition criteria increases complexity. So lesion classification and approaches to left main PCI are all determined by the side branch. So why is the 10 mm length important? Multiple studies have shown that more than or equal to 10 mm length of side branch lesion favors a two-stent technique. All these studies, EBC-2, DKPRESH-5, DKPRESH-2, BBK-1, and other small studies have all favored that if your lesion side branch is greater than 10 mm, there is a two-stent strategy. So this was the algorithm we created in 2017, again, defining simple versus complex. In the complex lesion, mostly initially an Asian approach, but now very much used throughout Europe and the Americas, you preferably go to a two-stent technique, preferably the DKCRESH, which was the consensus at that time. If it's a simple lesion, an easy side branch access, you do a provisional stenting, which occurs in the majority of the cases, or more than 75% of the cases. You generally use a one-stent technique. If the side branch compromise, or the FFR is equal to less than 0.80, or TV flow is less than 3, then you convert to a two-stent technique, which would usually be a T-stenting, or T with minimum protrusion or tap, or a coulotte. Or if the side branch has an angle that is not favorable, maybe you should think about a coulotte technique. But provisional is the important way to go with simple lesions, and two-stents for the complex lesion. So this is what we proposed, and this has been popular. Now, Valeria is going to talk to us in a minute about what they have done now a little differently to incorporate other aspects to just find lesion complexity. Thank you.

algorithm

left-main intervention

cardiology

stenosis

angiography