The next presentation will be by Dr. Beatle on left-main disease considerations for surgical or pertaneous treatment. John is an extremely thoughtful individual. Through the writing committee meetings, I learned quite a bit from him. I admire his prodigious memory and the way that he recalls the information that he integrates. Thank you, John. I'm looking forward to your presentation. Well, thanks for that very kind introduction, Mauricio. Actually, too kind. But I'm delighted to talk about left-main coronary artery disease. It's a good segue from the excellent talk that Jennifer gave about the heart team. Because when a 60-year-old woman presented with a six-month history of angina and transradial catheterization showed isolated osteal disease of the left-main coronary artery, it was a pretty straightforward decision to proceed for revascularization to improve symptoms. After all, the 2021 revascularization guideline gives a class one recommendation to improve symptoms in patients with refractory angina on medical therapy with severe disease. The guideline also recommends revascularization to improve survival, but this is where things get a little more complicated because it is not always straightforward about choosing between bypass surgery, which actually has been the standard of care for left-main coronary artery disease for decades, versus coronary stenting, which is what patients tend to prefer. The original information and evidence supporting the use of bypass surgery over medical therapy dates back to almost 50 years. And it's kind of striking to go back and look at a threefold increase in one year mortality in the patients who are randomized to medical therapy with left-main disease as compared with bypass surgery. This is the VA cooperative study. And if we look at a timeline of all the evidence, all the trials for left-main coronary artery disease, we put the VA cooperative study and the context of other trials that compared bypass surgery with medical therapy that was available at the time, largely consisting of nitrates and propranolol, and then the patient level meta-analysis performed by Yusuf in 1994, all of which provided pretty solid evidence for the writing committees for the European guidelines and the American guidelines to consistently give class one recommendations for bypass surgery to improve survival for patients with left-main coronary artery disease. Well, what about the situation for stenting, using drug-eluting stents? Well, in the modern era, we're aware of many trials that have compared bypass surgery with stenting and looked at outcomes such as survival in this type of comparison, and some of those are shown here. But this notable omission is the fact that there's never been a study that compared stenting with medical therapy, which would be a strict way to support the claim that stenting improves survival in patients with left-main disease. Well, how do we take this information, where we have CABG versus medical therapy, CABG versus PCI, to come to the conclusion that stenting might actually improve survival as well? Well, no one could say it better than Steve Ellis, who said that if treatment A is better than treatment C and treatment B is as good as treatment A, then treatment B must be better than treatment C. In other words, when we go back to the very old trials looking at bypass surgery versus medical therapy, we see in one year a three-fold reduction in mortality in the patients who are randomized to bypass. The modern trials show pretty much even mortality rates after stenting versus bypass surgery, and this has been confirmed with newer trials like NOBLE and EXCEL. It's a pretty straightforward Bayesian process to do a network meta-analysis, which actually has yielded two important findings. One is that the mortality rate after stenting was found to be similar to that after bypass surgery, and secondly, the mortality rate after stenting was found to be three times lower than that after medical therapy in this network meta-analysis. So this supports actually a recommendation for stenting to improve survival in patients with left main disease, and over the years, as techniques have improved, you can see that the European guidelines have elevated the recommendation for stenting from 2b and 2a all the way up to class 1. The current guideline gives a class 1 recommendation for patients with low syntax scores and left main disease, a 2a recommendation for intermediate, and a class 3 recommendation for high syntax scores. The American guidelines, ACC, AHA, SCI guideline, has issued most recently a 2a recommendation. Stenting can be considered in patients with left main disease who are good surgical candidates. The reason that class 1 recommendation was not issued by the American writing committee was partly due to the results of the EXCEL trial, which is arguably the best trial in the current field in this area. And the EXCEL trial, I want to remind the reviewers, excluded patients with high syntax scores. So in patients with low and intermediate syntax scores, however, the five-year mortality rate was still higher in the patients who were randomized to stenting as compared to bypass surgery. I should also point out that the study stratified randomization based on syntax scores and found no relationship between outcome and syntax scores. So in our particular patient who is on the table and in our institution, families have been present for 30 years watching the cases, participating in decision making, a lot of which gets covered ahead of time during the informed consent process. Our patient with the osteolesian in the left main was impressed with the ease of the radial approach. She wished to avoid thoracotomy, although she understood that CABG had the best evidence for prolonging her life, and she elected to proceed with coronary stenting. This was based on the fact that the evidence we provided her and said that revascularization improves survival as compared with medical therapy, bypass surgery has been the standard of care, but in selected patients, drug-eluting stents are likely to be as successful as CABG. So on an ad hoc basis, we went ahead, switched out for a guide catheter, placed coronary stents, documented good results in all views, and she had no further symptoms of angina. She had a quick recovery. She was discharged to home the same day, and Jennifer talked about the transparency of the heart team, having the patient involved, and I like the setting that we had in Ocala, Florida, where the family was present for all the cases. So to summarize and to discuss for a moment future directions, there's been some renewed interest in the patients who have intermediate lesions involving the left main coronary artery. It makes sense to consider using IVUS or fractional flow reserve to study these in further detail, but the COURAGE group and the investigators from COURAGE and ischemia went back to some old data from one of the original left main trials in which patients were randomized to bypass surgery or medical therapy and pointed out that those patients who had intermediate stenosis, 50 to 75 percent, had a trend toward reduced mortality with surgery, but it wasn't statistically significant. I see. It's a borderline p-value and it's probably a type 2 error, but in any case, they are making some preliminary plans to create a randomized trial called COURAGE left main to study these patients with intermediate lesions in the left main coronary artery, randomizing them to revascularization or medical therapy. In all trials, longer follow-up is needed to evaluate the effect of revascularization on mortality. So thanks very much for your attention. Again, I'm delighted to be a participant in this lovely session tonight.

Dr. Beatle

left-main disease

surgical treatment

percutaneous treatment

2021 revascularization guideline