Well, thank you, Arnold. I really appreciate your overview. And this is a very long duration in coming in getting this to this point. And I really appreciate everybody's help on this. But I'm going to talk a little bit about how we got there and why we decided to do this document. So basically, we've evolved from surgical backup being absolutely necessary to now rarely necessary. And I'll step through why we think that. As we know, during the first case, first years of PCI using the fixed wire balloon technique with Andreas Grunzik catheters, the incidence of early CABG range from 10% to 25%. And in the late 1980s, the incident had decreased, but in some series, it was still like even over 5%. But since 1995, the rate of emergency bypass surgery has dropped dramatically. And many series pointed out that it was now less than 1%. As you'll see with subsequent documents that Don is going to discuss that it's now some series show 0.1% need for emergency bypass surgery. In addition, there's cost considerations. And in fact, when I was first doing angioplasty, there was active surgical backup. And what that meant is that the surgeons had to see the patient, review the films, there had to be a surgical consultation on the chart, the operating room was wide open, there was perfusionists and anesthesiologists sitting around waiting as well as a surgeon. And this was several thousand dollars worth of expenditures. However, way back in 1993, CMS stopped reimbursing for surgical standby. And so as you probably know, what we call surgical standby now, even in the tertiary and quaternary care centers, really means that there could be no surgeon in the house, no perfusionists, they just happen to have on-site surgical backup. And so it's really changed quite a bit over the timeframe. This is data from a national registry of early PCI. And what was remarkable is that the angiographic success rates back then in the 1980s was really only started out at 67%. And then over time, it improved to 88%. Overall success rates, however, which meant a reduction of at least 20% in all lesions attempted. Now keep in mind, we expect to get like a huge reduction in the stenosis and less than a 20% stenosis. But this was only a 20% reduction of lesions without death, MI or CABG. This only occurred in 61% of patients initially, and then finally approved to 78%. And they thought that this was a really, obviously, it was a great improvement. But looking back on this, it's really surprising the angioplasty stayed in existence. And at this time, emergency bypass surgery, of course, was quite high at 5.8%. So it was no big surprise that people were concerned and they thought we needed onsite surgical backup. In fact, in 2005, the ACC PCI guidelines said that elective PCI with no surgery in sight was a class three recommendation, meaning it was harmful, potentially harmful. In 2007, we put out our first Sky Expert Consensus document. And at that time, we allowed PCI to be done without surgical backup, but it was primarily in patients who had STEMIs. And we have recommendations, if they're going to do it electively, the very strict recommendations for the patient and lesion type operators had to do at least a minimum of 100 PCIs per year, and they had to have experience with more than 500 lifetime PCIs. And in fact, the document clearly states that they are not in support of widespread PCI without onsite surgery. So clearly times have changed. In 2014, we updated this document recognizing that PCI without surgical backup was very widespread and surprisingly to everybody, there was very good outcomes being reported. And if you see this data back in 2007, when the first document occurred, 10 states allowed no angioplasty whatsoever, 12 states allowed primary PCI only, and only 28 states allowed both low risk elective PCI and primary angioplasty. Whereas by 2013, this is in the continental United States, pretty much most of the states allowed both types of cases, both STEMI and low risk elective cases to be done without surgical backup. So recognizing this, we went on in 2014 to agree that it has expanded and it can be done safely. But we endorse many limitations on these procedures. In fact, cardiac surgeons were told they had to have privileges at the referring facility. And that's, as you know, how onerous that is. It's very difficult to get initial privileges. And then finally, to maintain the privileges, often there's clinical volume requirements. And so that was a real disincentive for any surgeon to want to back up our PCI colleagues. And there's many high risk lesions that we know now aren't that challenging and don't have high complication rates. But we emphatically stated in our document that they should not undergo PCI without onsite surgical backup. And these include unprotected left main stenosis, many of which can be easily done. Diffused disease, which was defined as really just a 20% lesion. And we do that every day. Extremely angulated or tortuous, which now we can manage very easily. And then also any degree of calcification or the perceived need for atherectomy. And unfortunately, so these restrictions that we stated, we just made them as recommendations, but many states and many hospitals took them for face value. And we had unintended consequences of these documents. The surgeons weren't willing to back us up. These lesions often were failed in these sites. You see, there's a lesion here that cannot be dilated. And if we just had the ability to use atherectomy or something, it would not have been a failed PCI. And many individuals thought that perhaps we're harming the patients by not allowing us to do what we would have normally done had surgical backup been available. Now, in 2020, we actually had a complex PCI document that came out. And in this document, you can see there are many, many reasons why patients would be considered complex. But of course, you know, with regard to anatomy, there's multivessel disease, calcified lesions, bifurcations, CTO, saphenous vein grafts. And in addition, there's other things to consider. So for example, if you're surgically ineligible, there's six to seven fold increased risk in mortality, chronic kidney disease or impaired LV function, big increases in mortality. And these are some of the things that one needs to consider when contemplating performing these type of PCI procedures in hospitals, particularly with the type one hospitals with minimal capabilities or in the OBLs or ASCs. And interestingly enough, despite the need for decreased surgery over time, the reports on outcomes after emergency surgery have been very poor. And there's reports on excessive delays in surgery, regardless of the PCI setting. So as I mentioned before, some of the contemporary rates of emergency bypass are now down to 0.1% in many series, raising the question, why do we need surgical backup? In addition, emergency bypass after PCI is associated with very high mortality ranging between 7% and 21%. And interestingly enough, there are time delays to emergency bypass surgery. And even in hospitals that have onsite surgical backup, the time for bypass is 160 minutes from the time that the surgeons are called. And of course, in hospitals without onsite surgical backup, it's longer, it's 306 minutes, which sounds awful. But interestingly enough, despite more rapid emergency bypass surgery in hospitals with onsite surgical backup, there's a huge increase in mortality. And nobody really knows why that is. Are we sending more inappropriate cases to surgery because surgeons are available? Or are we not trying hard enough to salvage these cases in the cath lab because surgeons are available? It's hard to say, but it's just interesting food for thought. And then finally, I want to finish with there's despite an increase in complexity of the cases that are being done both in hospital with surgical backup, as well as in these no SOS hospitals, there's no increase in the complication rates. And I think Don's going to go over this in greater detail. And I think to large part, this might be due to the fact that we have better recognition of the severity of illness, we have careful patient selection, and that we have both availability and training and the use of mechanical circulatory support devices. Our stents are now thin strut and very deliverable, allowing us to manage dissections. And we have new generation covered stents to manage perforation. So it's very unusual that that you have to send a patient for emergency surgery just for perforation. We have better wires to wire the lesions, body wires, more trackable devices, wider selection of guiding catheters, telescoping techniques, and devices to manage calcium. So it's unusual for us to be unable to deliver a device to where it wants to go. And then we have more effective antithrombotic agents, which will of course, reduce the risk of stent thrombosis. And then, of course, the most one of the most important things is the use of radial access, which dramatically reduces the need for transfusion. And this is extremely important in the ASC and the OBL situation where you do not have a blood bank, you do not have the opportunity to transfuse for retroperitoneal bleed. And so because of all these improvements and techniques and devices, I think it's really timely to expand our use of PCI and more complex cases in settings such as OBL and ASCs and other hospital situations. Thank you very much. Thank you, Dr. Grines. And as we bring up Dr. Don Abbott's slides, I wanted to ask you, you know, you started this process, what, three years ago for this writing group. Is that about right? That's how long it takes. So maybe you can discuss as you, you know, as Dawn is sharing her screen, what, what drove you? Was there any one incident that drove you that to say that this is the time that we need to update this document? Well, I was getting, I was during my presidency, and actually even before that, I was getting a lot of communication from the membership with a number of concerns. For example, one of the concerns is that there's a huge increase in, there's not just a hospital anymore. There's this hospital system. And so all these systems are buying up hospitals and then they're consolidating services. So whereas you might've had five different bypass surgery programs among 10 hospitals, now there might be one. And these physicians who had, were performing very good angioplasty with almost no emergency surgery, they were being told that they can no longer perform angioplasty. Or if they did perform angioplasty, it was only very simple type A lesions. And there are a lot of other reasons that we can get into, but I'll let Dawn get started at this point.

surgical backup

PCI procedures

cost considerations

advancements

expanded use