State-of-the-Art Coronary Artery Bypass Graft

Author's Accepted Manuscript

State of the Art CABG John D. Puskas MD, Harold L. Lazar MD, Michael J. Mack MD, Joseph F. Sabik III MD, David Paul Taggart MD, Todd Rosengart MD

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PII: DOI: Reference:

S1043-0679(14)00040-9 http://dx.doi.org/10.1053/j.semtcvs.2014.03.002 YSTCS687

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Semin Thoracic Surg

Cite this article as: John D. Puskas MD, Harold L. Lazar MD, Michael J. Mack MD, Joseph F. Sabik III MD, David Paul Taggart MD, Todd Rosengart MD, State of the Art CABG, Semin Thoracic Surg, http://dx.doi.org/10.1053/j.semtcvs.2014.03.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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State of the Art CABG

Moderator: John D. Puskas, MD E-mail: [email protected] Participants: Harold L. Lazar, MD, E-mail: [email protected] Michael J. Mack, MD E-mail: [email protected] Joseph F. Sabik, III, MD, E-mail: [email protected] David Paul Taggart, MD, E-mail: [email protected] Todd Rosengart, MD, E-mail: [email protected]

January 26, 2014 Marriott Orlando World Center Orlando, Florida

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DR. ROSENGART: On behalf of the Seminars in Thoracic and Cardiovascular Surgery, we are honored to have such a distinguished panel with us today. We encourage our panel to be as candid in your discussion as possible. Our readers will undoubtedly appreciate and benefit from the great knowledge, wisdom and experience on our topic of discussion today - on the performance of coronary bypass surgery - that is represented in this room. So with that, I will cede the forum to Dr. John Puskas, and I thank everyone for participation.

DR. PUSKAS: Thank you, Todd. I think it's a great format, and a great idea to bring this back to the Seminars, and I'm delighted to have these distinguished colleagues join us for a conversation about the state of the art of coronary bypass, specifically focusing on the roles of arterial grafts, off-pump, and minimally invasive approaches to coronary revascularization. It is important to note that CABG still represents the single largest component of surgical practice for cardiac surgeons worldwide with something on the order of three-quarters of a million cases done annually worldwide. BILATERAL INTERNAL THORACIC ARTERY GRAFTS To the first issue to discuss is the fact that bilateral ITA grafting still compromises less than 5% of isolated primary coronary artery bypass cases in the United States despite abundant evidence

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that it prolongs event-free survival. Why is this? What can or should be done to change this? Perhaps we ought to start with Joe Sabik to briefly recap that data, because much of the evidence for BITA grafting is derived, from very important papers by Dr. Sabik and his colleagues at the Cleveland Clinic. DR. SABIK: John, thank you. I couldn't agree more. Bilateral internal mammary artery grafting is a great tool to have as a coronary surgeon. It not only helps people live longer, but it helps them have a better event-free reoperations. We all know this, but despite that, 4 to 6% of all patients undergoing coronary surgery in the United States have bilateral internal mammary artery grafting performed. So it's really a question of why hasn't the data influenced surgeon behavior. This may be due to the observation that the benefits of bilateral internal mammary artery grafting present in the second decade after coronary surgery. Bilateral internal mammary artery grafting does not improve early results, and increase the risk of sternal wound infection. Also, they take more time in the OR and the surgeon is not be rewarded for that extra time, BIMA grafting, increase OR time, therefore increasing hospital costs. There are very specific negative short-term outcomes. So how do we influence behavior and focus surgeons on

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the long-term outcomes and not the short-term outcomes? We look at single IMA grafting to the LAD as a quality metric when we score in the STS database. Maybe BIMA grafting should be a quality metric in certain groups of patients, for instance, patients who are younger, nondiabetic, and have multivessel disease. Another way to influence surgeon behavior is through reimbursement? This is something we probably do not enjoy talking about, but if there was increased reimbursement for doing more arterial revascularization, surgeons may be more likely to perform BIMA grafting. The third way to increase BIMA might be through establishing coronary surgery as a sub-specialty of heart surgery? We have mitral valve specialists, we have aortic surgery specialists, we do not have coronary surgery specialists. Having surgeons who are specifically interested in coronary surgery, particularly multiple arterial grafting, will likely increase BIMA grafting. DR. PUSKAS: Thank you, Joe. David Taggart, Professor at Oxford, has completed enrollment and indeed reported one-year results with a large multicenter, mostly European-based, trial, for the first time prospectively randomizing patients to have a single bypass with an ITA graft versus double ITA grafting. Dr. Taggart, can you summarize results to date and perhaps add your thoughts to those of Dr. Sabik? DR. TAGGART: Well, let me, firstly, thank you for the

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privilege of being here at this very important seminar. We were very influenced by data from the Cleveland Clinic back in the late '90s, and at that time we did a meta-analysis of all the data in the literature looking at the outcomes of patients with bilateral or single internal thoracic arteries, and we matched these patients for age, gender, LV function, and diabetes, as those four factors by themselves give you a likely indication of longevity. And what we found was there was a strong reduction in the risk of death in patients with bilateral ITA grafts at a mean of six to seven years. And on the basis of that we also asked the question, when there is such powerful evidence, why do so few patients actually get bilateral ITA grafts? Europe is by and large similar to the United States, 5% perhaps 10% of patients. So we conducted a large trial, 3,100 patients, randomized to single or bilateral ITA grafts, and at that time that was the largest trial done in cardiac surgery, and we have published the one-year outcome. And the key point to make from this was that it dispelled the myth in the literature that using bilateral ITA grafts might increase your risk of death, major complications, myocardial infarction, but we did indeed find there was a small increase in the risk of sternal wound reconstruction. It went from 0.6% in the single mammary group to 1.9% in the bilateral ITA group. But if you excluded the patients with diabetes and obesity, there was in fact very little difference in sternal wound reconstruction.

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That trial was funded for 10 years' follow-up, and this year we will publish interim five-year outcome. DR. PUSKAS: Fantastic. Dr. Mack and Dr. Lazar, what are your practices now in terms of bilateral ITA grafting, for whom do you perform it, for whom do you not perform it, and where do you see the use of ITA grafting going in your own local institutions? DR. LAZAR: I'm a proponent of bilateral ITA grafting, and I'll be interested in knowing from my colleagues here, what would they consider to be the age cutoff for this? In preparation for this meeting, I actually did review our most recent cohort of CABG patients over the last three years, and we are averaging a mean age of about 70. Our incidence of diabetes now is 40%, and many of them do have comorbidities of obesity or increased BMI. And so one wonders what the survival benefit will be for those people. I also think that the distal targets are important. We have agreed with what has been published recently, that one should not go after just the distal right, as was done earlier, because usually there is progression of disease in the PDA and that's why a lot of these right internal grafts have gone down. I think in those younger patients if you are going to cross over with the right and use the left for the circumflex system, how would you protect it, because a number of these patients do come back with aortic valve disease. So I think in our practice it would be age, the presence of

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diabetes, and the quality of the distal targets that would determine how aggressive we're going to be. As far as treating coronary revascularization as subspecialty, I would not support that concept. It is important for all cardiac surgeons to be able to perform coronary revascularization procedures. There is currently no evidence to show that OPCAB, midCAB, or hybrid procedures result in any superior outcomes compared to on pump procedures. Since CABG surgery is still the most common procedure that is performed in cardiac surgery and is often performed on an urgent basis, all cardiac surgeons should be comfortable and proficient in performing this procedure. DR. MACK: I don't think age is a major predictor in our institution of whether we use a LITA graft, but it's very surgeon specific. I think you have to look at the individual patient situation and not necessarily the chronological age of the patient. There are a number of reasons why the adoption rate has not been higher. One is a lot of times there are difficulties getting an in situ graft to the appropriate target area on the RCA, and I think there was a lack of understanding early on that you didn't have to use an in situ right graft, that you could bring it off the left internal thoracic artery and put it to the circumflex system; a lot of surgeons got burned early on by putting a RITA graft to a large, right, non-totally occluded right coronary artery and having perioperative ischemia issues……. And I think that that hurt early adoption of the

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procedure, because there wasn't a good understanding of how to do it. I agree with Dr. Sabik that the adoption rate is all due to the fact that we have not treated coronary revascularization as a specific subspecialty, and I think that's a major oversight on the part of all of us. If you look at what we do in cardiac surgery, much more so than valve surgery, transplant, VADs, coronary surgery is the most technically demanding procedure and to not treat it as a super subspeciality I think is an oversight. It's changing in our institution; we hired a new surgeon this year, and her job is to focus on coronary revascularization. We have partnered her with our interventional cardiologists, and as a result of that, we hope that we see an increased adoption rate of bilateral internal thoracic artery grafting, off-pump procedures, as well as hybrid procedures. DR. TAGGART: I largely agree with my colleagues, but I think there is a misconception about age and bilateral ITA grafting. There is no age limit. And the reason I say that is you have different advantages with bilateral ITA grafts at different ages. In the younger cohort of patients, they can expect increased longevity, freedom from myocardial infarction, freedom from ischemia. But in the older population, in the 80-year-olds, bilateral ITA grafting is a wonderful operation, because if you use it as a no-touch aortic technique off-pump, you effectively dramatically reduce the risk of stroke in the elderly population. And the biggest threat to any elderly

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person undergoing cardiac surgery is the risk of stroke. If you have an octogenarian with a tight calcified left main, just to open the chest with a median sternotomy and put two internal mammary arteries on the two best left-sided vessels as an off-pump procedure, this is a quantum leap forward in coronary revascularization. STROKE PREVENTION AND NO TOUCH TECHNIQUE DR. SABIK: I could not t agree more with David. I believe more important than actual age is what the long-term predicted survival of the individual patient. One of the analyses that we did was to determine are there a group of patients that do not benefit from BIMA grafting? We found that elderly patients, those over the age of 80, did not get a survival advantage with BIMA over SIMA grafting, and in the short run there was a little decrement in survival. Now, this might have been due to selection? This was not a randomized analyses and it is possible that the 80-year-olds who had BIMA grafts were those who didn't have other conduit or had calcified aortas, or other comorbidities where BIMA grafting appeared to be the best option. . However, Dr. Taggart's comments are right on, and avoiding stroke in this elderly population is very important.

If we

talk about the Achilles heel of coronary surgery, it's really stroke, and it is our duty as surgeons to do what we can to prevent stroke.

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The most likely cause of stroke is due to aortic manipulation and embolization. In our analyses of patients having coronary surgery and stroke over 30 years at the Cleveland Clinic, one-third of the strokes occurred intraoperative. So they were likely due to technical reasons. Two-thirds of the strokes occurred after surgery, usually between day two and day three. I think this is very interesting. There are two reasons patients have CVA after CABG. There are those that occur in the operating room, for technical reasons, and those that occur two to three days after surgery. But epiaortic scanning is very important in preventing embolization. Aortic manipulation, cannulation, or clamping of an atherosclerotic aorta may lead to embolism and a stroke. DR. LAZAR: I would like to emphasize the importance of the single clamp technique. Since our group has gone to the single clamp technique, our stroke rate is 0.3%, it has almost vanished, which is consistent with data from other groups. So if you do it on- or off-pump or if you use bilateral mammaries, using a single cross clamp technique with epiaortic scanning for aortic cannulation has made a tremendous difference in decreasing the incidence of postoperative strokes and this data has to be re-examined.

Another area in which we can reduce postoperative strokes involves the treatment of A-fib. Perhaps we should be a little more aggressive with antiplatelet medications in our CABG patients, whether we do all arterialized grafts or not. Postop A-fib is not a

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benign event even if it's only for a couple of days postop, and that some of these patients may deserve more lifelong anticoagulation. As surgeons, we are responsible for patients in the hospital and the first postop visit, but I think if you look at the data from the studies that show that postop A-fib is not benign, those patients who have been maintained on anticoagulation, especially those that have been higher risk, tend to have a better survival. So I think that's an area where we can do a lot more to enhance the use of CABG surgery. DR. SABIK: It's interesting that you bring up about atrial fibrillation, because my expectation as to why patients were having a stroke on day two and day three, was due to atrial fibrillation. However, we found no relationship between postoperative atrial fibrillation and stroke, and, if anything, atrial fibrillation was protective for preventing a stroke. I think this was due to the reason Dr. Lazar was talking about: those patients were anticoagulated. We have done a little research into the vascular literature, and the theory is that when someone has an embolic stroke, let's say from a carotid plaque, that the inciting event is actually bleeding into the plaque, which then ruptures and embolizes. This may be one of the etiologies of strokes on day 2 and 3. During surgery and anticoagulation there may be bleedinginto a plaque, which then ruptures, and results in an embolic event. DR. PUSKAS: I've wondered whether some of those

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late strokes actually may arise from clamp injury to the aorta? DR. SABIK: Absolutely. DR. PUSKAS: We are going to talk about OPCAB in a little while, but I think the greatest mistake we OPCAB enthusiasts have made was for a decade to put a partial occlusion clamp on a pulsatile aorta and to think that that was somehow minimally invasive. I think in a small fraction of patients that disrupts the aortic intima and subsequently clot can form at the injury site and that clot may embolize on postoperative day two or three and the patient then has this mysterious stroke. It's infrequent, but we need to make it much less frequent still. DR. TAGGART: John, thanks. I agree with the comments of both Drs. Puskas and Sabik, but the other thing that was quite striking in terms of stroke is when you look at the SYNTAX trial, if you look at patients with three-vessel coronary disease not involving the left main, there was no difference at five years in the incidence of stroke between CABG and PCI, but if you look at the cohort of patients who had left main disease, there was a definite significantly higher incidence of stroke in that group. Now, whether that tells us that left main is a different type of pathophysiology from coronary disease not involving the left main is not clear, but there is an association of higher incidence of carotid disease in patients with left main disease. So it is quite striking that the patients in whom we should be really focused on in

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trying to reduce the incidence of stroke or be most careful with are those with left main disease. DR. MACK: And back to your original question, John, there is absolutely no excuse why every patient shouldn't have epiaortic scanning. It's the cost of a sterile sleeve over an echo probe. And I certainly agree with you that disease of the ascending aorta is a major cause of intraoperative strokes. And in those patients, especially the older patients with known cerebrovascular and peripheral vascular disease, doing a no-touch aortic technique is likely to yield the largest benefit. All of us have spent our careers debating the cardiologists and strokes have been held over our heads, and rightly so, for years and years, and I'm sick of trying to defend us against it. There is a national task force that was put together by the STS to address the issue of stroke and establish best practices, and I think it's long overdue. DR. PUSKAS: The easiest therapy most commonly denied to American patients with coronary artery disease is epiaortic scanning at the time of their coronary artery bypass operation. But it's an easy thing for the surgeon to adopt routine epiaortic ultrasound scanning. It takes very little time. It does not cost anything; these are renewable probes in a disposable plastic sheath. And once the OR team is used to doing this, this happens in literally a matter of seconds.

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DR. LAZAR: I think you're right that the higher incidence of stroke has been held against us. The working groups that are going to be looking at this will actually get the real numbers, because I think if you look at these series now where epiaortic scanning and a single clamp technique is used, whether you use it on- or off-pump, the incidence of strokes are much lower, and number two, as you pointed out, there is definitely a direct incidence between left main disease and carotid disease. And in all those studies that looked at CABG versus PCI, the patients who underwent CABG were those with left main disease and more extensive SYNTAX scores, which is associated with cerebrovascular disease. These patients have higher plaque burden and that's why their stroke rate was higher and that really needs to be emphasized. RADIAL ARTERIES

DR. PUSKAS: Switching gears to a brief conversation about conduits. There is another nice paper here at the 50th Annual STS meeting from from Robert Tranbaugh and others from New York describing outstanding results with the radial artery in comparing it to the right internal mammary artery as a second arterial conduit. Of course, there is ongoing concern about the technique of endoscopic harvest for both veins and arteries and the possibility of harvest injury reducing the longevity of endoscopically harvested conduits. Thoughts from the panel on your choice of a second

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arterial conduit - radial artery or right internal mammary artery and, for that matter, a third arterial conduit. DR. TAGGART: Personally I do think the evidence in favor of a second internal thoracic artery in terms of long-term patency is unbeatable. If you look at the Tatoulis and Buxton data, they have now shown patency rates of the right internal thoracic artery over 90% at 20 years. So this kind of data is not reproducible with any other conduit. Saying that, there is accumulating evidence that if you look at the difference between patencies of radial artery and saphenous vein out to one year, they are identical. There are several studies showing this. However, there are also now several meta-analyses looking at the patency of the radial artery out to five years. And although there is no difference between saphenous vein and radial artery at one year, there are significant differences now in favor of the radial artery out to five years. And that's probably because the radial artery is not as susceptible to the same degree of attrition as a saphenous vein is every year. So if you're looking for longer-term outcomes, I think as long as you are cautious about using the radial arterial to a coronary artery with at least 70% stenosis, the evidence of superior patency of that conduit now is definitely convincing over veins out to five years. DR. TAGGART: We would use a radial artery in certain situations. For instance, in an obese diabetic, we do not use two internal thoracic

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arteries. So we would use a radial artery now in preference definitely to vein grafts as long as the coronary vessel we are grafting has at least 70% stenosis. I think the only time we would not do that is a right coronary artery with a moderate lesion, where I think the best conduit is still saphenous vein if you're not going to stent it. DR. PUSKAS: Dr. Sabik, you published a paper that helped to understand that issue. DR. SABIK: This is, again, one of the reasons why we need sub-specialists in coronary surgery. The key is to individualize the operation, just like you might individualize a mitral valve repair by the pathology you see of the mitral valve. You have to individualize your conduit selection by the patient, their comorbidities, and, importantly, the coronary anatomy. As Dr. Mack has pointed out, some of the early failures with IMA grafting is using a right internal mammary in situ to a moderately stenosed right coronary. We know that's not going to work. The radial artery has gotten bad press when it has been used in situations of competitive flow where there is only had moderate obstruction of the grafted coronary artery. So the key is to individualize your grafting strategy. I believe that if you have a young, healthy, nondiabetic patient with coronary disease we really should be doing two internal mammary artery grafts and add a radial graft if appropriate by the anatomy. However, if you feel the patient is at increased risk of sternal wound

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infection, that's a patient where you might use a radial artery graft over the right internal mammary. DR. LAZAR: I just want to comment on the harvesting of the conduits, because I think that's extremely important. As someone who is really an advocate of the no-touch technique for vein harvesting, I was a little doubtful about the endoscopic vein harvesting, but I must say that with changes in that technique, it has really become a pretty durable technique for harvesting veins. We use ultrasound to locate the vein, which I think makes it easier for the PAs to do the tunnel, and we will not ligate take any of the branches of the vein until the patient is heparinized to eliminate clots that might form in the branches. We've also instructed our PAs to leave as much fat on them as possible. So the manipulation of the veins is really minimal, and at least in our experience we have not seen an increase in any recurrence of angina, and our wound infection rate for legs has gone down to almost zero. And as far as the radials are concerned, one thing that we have seen, and I would be interested to see what the Cleveland Clinic experience is, is that we have gone to ultrasounding of the radial arteries, especially in older patients with diabetes and peripheral vascular disease, and we've seen a number of them that have had calcifications in the body of the radial artery that may not be apparent if you just cut down on the radial or did an Allens test. I think calcified radial grafts should not be used under

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any circumstances, because not only do they thrombose when you put them in, but they can act as a nidus for clot and embolize distally and result in a perioperative infarct. DR. SABIK: I agree with your comments completely. DR. MACK: It's seldom that I disagree with Professor Taggart, but I will take an exception here about the use of the radial artery. I'm old enough that I have now gone through two phases in my career in which we have developed enthusiasm for the radial artery and now seen it wane both times. Our second wave of enthusiasm was when we could harvest the radial artery with an endoscopic approach and decrease the morbidity. But I think we have seen too many patients come back with radial artery occlusions. I don't know what Dr. Buxton and Dr. Tatoulis are doing different than what we did, but we haven't been able to reproduce those results. I do think some of it is due to the fact that as we have learned from the right internal thoracic artery in placing it to a totally occluded or very tight vessel, the same thing holds true with the radial artery, and I think that also translates to saphenous vein grafts also. SAPHENOUS VEIN GRAFTS Dr. Mack: I think that the saphenous vein graft has gotten a bad reputation. Some of it is appropriate. Some of it, I think when we initially embarked on endoscopic vein harvest, the harvest was probably were more traumatic. And now with a refocus on those

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techniques, I think that has helped. But I also think a major reason why saphenous vein grafts don't stay open is they don't have the autoregulatory ability that arterial grafts do, and we are bypassing very frequently non-hemodynamically significant lesions, and it's competitive flow that occludes the vein grafts. So this is the subject of a proposed study through the CTSN network that Peter Smith and John Alexander are looking at functional flow reserve (FFR), and randomizing patients to angiographically-driven revascularization versus FFR-driven revascularization. So it's the FAME trial in surgery. Now, it's not clear that that's going to an increase vein graft patency, but it will probably also lead to fewer grafts, and also whether that's a better operation or not, because as has been well pointed out, one of the benefits of bypass surgery is we bypass the whole vessel, and the farther you go out from surgery, the more often the nonculprit lesion is the cause of cardiac events. So will we be losing something by not bypassing as many vessels? So I think it is totally appropriate for a trial to look at. But I think that some of the reasons for vein graft occlusion are not just because it's a vein and not just because there's traumatic harvest but because we are bypassing 50, 60, 70% lesion vessels that have an FFR of .83 or .85. DR. LAZAR: I think that's an excellent trial. As you

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know, I wrote an editorial in Circulation this fall based on a study which reported improved graft patency of vein grafts, and overall graft patency, by using an FFR-guided approach. There were a lot of limitations with that particular article. I think it would be a mistake for surgeons to embrace this concept, because cardiologists use a stent to revascularize a lesion and as surgeons we are actually bypassing territories. I think that's going to be very important. I just want to make one more statement about the conduits. As surgeons we are often looked upon as the technicians by our cardiology colleagues, but I think as surgeons we have been the ones at the forefront of using statins on CABG patients. And it's so important that we impress upon our cardiology colleagues and the other physicians taking care of these patients after we let them go that all these patients need to be on aggressive statin management. There's no question that all graft patency, especially vein graft patency, will be improved if these patients are kept on aggressive statin regimens, especially diabetics where their LDL should be less than 90. And too often we see these patients coming back with recurrent disease and graft occlusions, and you look at their LDL and you can see that they haven't met the targets. So I think part of our responsibility is to see that the Get With The Guidelines are followed by our medical colleagues. DR. PUSKAS: I couldn't agree more. I think that the way we manage patients after coronary bypass surgery is a part of our

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duty and our responsibility and it has a profound impact on the benefit that our surgery provides to those patients. DR. SABIK: Not to disagree with Dr. Mack, because I have always looked up to him, but I do disagree with him on this discussion of conduits. I think it's really important for us to go back and think about why arterial grafts fail and why vein grafts fail. If we take out the technical and early reasons, arterial grafts fail due to competitive flow. So the coronary artery stenosis is incredibly important. Vein grafts fail due to the development of atherosclerosis over time. Now, we have looked at over 10,000 vein grafts over a 20-year period, and we did not see any effect of competitive flow on vein graft patency. Similar findings were found from our colleagues in Australia. I would actually argue that it makes sense from a physiological point of view. The vein graft is just a pipe; it stays open if it's connected well. Again, I couldn't agree more with the importance that when all vein grafts are used, lipids should be managed aggressively post operatively. FFR AND GRAFT INDICATIONS DR. SABIK: I am a little worried, though, about the proposed FFR study. A cardiologist at the Cleveland Clinic named Dr. Proffitt who many years ago looked at the natural history of

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patients with coronary artery disease. And what he found was that if he divided patients by single, double or triple vessel disease, and significant disease was 50% or greater that survival was better in those with fewer stenosed coronary arteries. Fifty percent stenosis influenced survival. So even at this moderate amount of coronary stenosis, survival could not be stratified. One did not have to wait until the stenosis was 70 or 80% to identify an effect on survival. . Today, many of the recommendations for coronary intervention, that many of us have signed onto, including myself, state at 70% stenosis it is reasonable to graft the vessel. There is nolittle data to support this, because in '70s and '80s, most of the indications for grafting were at 50% lesions. Also, for FFR, it may not be appropriate to say what's good for PCI is good for surgery. Many of the negative events that occurred with stenting an artery with a non-signifcant stenosis occurred early, during or soon after PCI. Therefore, stenting a non-significant lesion resulted in a worse outcome due to procedural-related complications such as myocardial infarction, and acute and chronic stent thrombosis. If we graft a vessel that has a non hemodynamically significant stenosis and that graft occludes, we do not have the same complications, because we continue to have native vessel blood flow. Also, and this may be the most important point, if that graft stays open, it is protective in the future if we have a plaque rupture or worsening stenosis.

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DR. PUSKAS: I couldn't agree more, Joe. I'm participating in the protocol development committee for this trial. It's an interesting trial, but I have this great reservation about it. This trial from the cardiologists' perspective is based on the notion that they should apply the same rules derived from FAME to cardiac surgery just as they have been applied to PCI. But the negative impact of a thrombosed stent is very different from the negative impact of a closed graft if they both closed in coronary arteries without hemodynamically significant stenosis. Moreover, the longer-term benefit of a stent that you didn't really need is 0. The longer-term benefit of a graft to a vessel that was 60% stenosed and did not have a flow limiting lesion may in fact be dramatic as that graft may protect against future lesions in that vessel. So both the downside and the upside are different for grafting versus stenting hemodynamically borderline lesions, and therein lies my great concern about applying FFR to surgery. DR. MACK: So can we assume, therefore, that neither Emory nor Cleveland are going to enroll in the CTSN trial? DR. PUSKAS: We will enroll. DR. SABIK: It will depend on the length of follow-up. I've heard of some suggesting very short follow-up of one year. The follow-up needs to be at least five years, because if the follow-up is too short, we are not going to see the long term benefits of coronary surgery.

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If we compare the outcomes of PCI and CABG, particularly in FREEDOM, the difference in outcomes between PCI and CABG really starts happening around two to three years, and although not as dramatic in SYNTAX, we see the same thing. DR. LAZAR: As surgeons, we should all be aware of some of the limitations of FFR. It does not work well in smaller vessels where there is diffuse distal disease, and in those patients who have left ventricular hypertrophy. And these are the kind of patients who normally get referred to surgery and not PCI. DR. TAGGART: The one comment I would make, I think our philosophy of surgery is changing with regards to FFR in the sense that if you look at trials like FAME, it basically shows that trying to visually estimate a stenosis, if it's less than 90% we might as well toss a coin as to whether that lesion is 50, 60, 70, 80% stenosed. If it's barnstormingly obvious, like over 90%, then you don't need FFR. But I think one of the things we should encourage our cardiologists to do is provide us with FFR data for all patients coming to surgery who have intermediate lesions, because it then allows you to target what is the best way to deploy your arterial graft. So by knowing FFR values, it gives you the best bang for your buck in terms where to put the thoracic arteries and also the radial artery, which seems to be more susceptible to competitive flow than the internal thoracic artery.

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DR. PUSKAS: So what I'm hearing from you, Professor Taggart, is that you would like to use angiographically-driven decision-making to decide which coronary arteries to bypass, but you are going to parse out your conduits based on the estimate of competitive flow that is provided by FFR measures? DR. TAGGART: I think so, yes. DR. PUSKAS: Interesting. We have a whole new paradigm in surgical revascularization created right here. (Laughter). VEIN GRAFT PATENCY DR. ROSENGART: You are all talking about saphenous vein as a monolithic. Of course, we all know there are large veins and small veins and varicose veins, and yet this is never discussed in the literature, and in fact I think we are all suspicious it could be highly impactful. So how does the panel approach the quality of the veins? DR. SABIK: You should not use a bad vein, if possible. It is better to wait until you get a good vein harvested -- and I mean by good vein, it is vein of similar caliber without a bunch of valves, and preferably on the smaller side. DR. PUSKAS: If that means unbundling the arm and prepping and draping it and harvesting a radial artery that you hadn't planned to harvest or taking a second mammary in a patient who may have a relative contraindication, then that is clearly preferable to using

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poor quality saphenous vein conduit for coronary artery bypass grafting. You may just have to accept an incremental increase in risk for mediastinitis because you know that these kielbasa veins are not going to serve that patient well. DR. LAZAR: I think one of the limitations of a lot of these studies is that they did not characterize the quality of the veins that were used. In our center as part of the initial BARI demonstration project, we characterized the conduit that we used and we also do preoperative vein scanning, and if those veins don't look good, they shouldn't be used. DR. TAGGART: We did a pilot trial looking at external stenting of vein grafts hopefully to reduce the incidence of intimal hyperplasia, and we only used the best quality veins we could get for each patient, and sometimes that involved opening the whole leg. But what was interesting was that even with the best quality vein, at one year we saw a significant reduction in intimal hyperplasia measured by IVUS in those veins that we had externally stented. So even in good quality veins, there is still a disease process, intimal hyperplasia, which as Joe said, eventually leads to atherosclerosis in the majority of these veins independent of even statins. DR. MACK: I think there is a quality vein graft issue, however, defining that and quantifying the quality is virtually impossible. In the early days of the STS database, we used to have to categorize it as poor, fair or good, and every vein was poor and every

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vessel had severe distal disease. We knew that this wasn't accurate and did away with it because it is so hard to quantify. But I think one of the other consequences of endoscopic vein harvest may be the exact point you are making, Todd. Prior to EVH, we always harvested lower leg veins and very seldom thigh veins, while with EVH it is much easier to harvest thigh veins, and we have gone to using thigh veins much more than we used to, and there is a disproportion between the size of the saphenous vein from the thigh and the coronary artery more so than there is from the lower leg and coronary, and there may be something to that. DR. PUSKAS: I agree. OFF PUMP SURGERY DR. PUSKAS: Off-pump bypass presently represents about 17% of total coronary bypass procedures performed in the United States. That's down a little bit, from about 22% at its high. Is this the right number? And is the lack of greater penetration of off-pump bypass related to indications, outcomes in clinical trials, surgeon skill or lack of proper training? DR. SABIK: Well, I think the answer to your question, John, is all of the above. Off-pump bypass is, again, a tool that we have as surgeons, and I think some of the work that you have done has demonstrated its greatest utility. We have talked a lot about how reducing complications, such as stroke, is very important and that in some cases performing

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the surgery off pump to accomplish this may be the best way. However, we also have to be cognizant that there may be some costs associated with this. Off pump surgery is technically a more difficult operation, and this has been demonstrated in repeated studies where we find in patients undergoing off pump surgery, graft patency is lower and fewer grafts or more incomplete revascularizations are performed. So we have to weigh the risk of complications such as stroke and quality of revascularization. Another way to state this is whatare the early and late risks for this patient if the revascularization is done on-pump or off-pump and then make a decision for that individual patient. If you have a healthy 60-year-old with multivessel and diffuse coronary disease and that want to do many arterial grafts, that patient is probably better having their surgery on-pump. However, if you have an 85-year-old who has renal failure, COPD, a previous stroke, and a calcified aorta, he may be better done with an off pump, no aortic touch procedure. So, again, I don't know what the number is, but I think all of the above that you discussed are reasons why off-pump hasn't been adopted to a greater degree than it has been. DR. TAGGART: I largely agree with those comments but maybe from a different perspective. So, first, if 17% of all CABGs are done off-pump, that's a very skewed number, because what that means is you have some surgeons, a minority, doing 90%

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off-pump and a majority doing 10 or 20% off-pump. And the thing that's very clear about off-pump surgery is it is not an occasional operation. So for the surgeon who says, I reserve off-pump for my high risk cases, I think this is a strategic mistake. That's the worst time to change your technique. Now, what started making off-pump surgery seem to be inferior was initially the ROOBY trial, and that was heavily criticized, because it was felt the surgeons in that trial were quite inexperienced. Now, if you look at the two definitive trials, which are CORONARY, which has 4,500 patients but where the operating surgeon had to have done a minimum of 100 off-pump as entry criteria, and GOPCABE, the German trial, where most of the surgeons had done 500 off-pump cases, what these two large trials show is off-pump surgery is definitely not inferior to on-pump surgery when the surgeons were appropriately skilled. There was absolutely no difference in mortality, the number of grafts was identical in both groups, because these were experienced surgeons. So I think what you can say about off-pump surgery is for most patients it probably doesn't make a great deal of difference to clinical outcome as long as it's done by an experienced surgeon. The problem is I think there are a small minority of patients who really do benefit from off-pump surgery. For example, I mentioned the octogenarian with a tight calcified left main who I have absolutely no question the best operation is two mammary arteries

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done off-pump. However, these, as I've said, are not occasional operations, and unless you're doing it all the time, it means that you are out of your comfort zone when you have to do it in the high risk patient. So I think you either philosophically say you will use it in the majority of your patients or you don't do it at all. And I think Joe is right in the sense that there are some patients who definitely are done better on-pump. Patients where you angiographically see they have got a lot of smallish, diffusely diseased vessels, yes, you can do these technically off-pump, but is that best for that group of patients? Probably not. And I also feel the other group who I try to avoid doing off-pump surgery is the large dilated heart. While technically I can do that operation, I think they have quite a marked drop in cardiac output during the operation, and if you see these patients the next day, all of them have got severe renal impairment. So I think there are a cohort of patients who are better done on-pump. DR. LAZAR: I think even in the best of hands -- including and Dr. Puskas' long-term results which I reviewed -- there is really no major difference in survival and graft patency in expert hands. So I think we are really spending a lot of time talking about a technique that have some advantages in some select patients, but really we're talking about the entire population. One of the things that I want to emphasize is that over the past 10 years there have been a lot of improvements in the way we

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conduct cardiopulmonary bypass. For example, we use heparin-bonded circuits from tip to tip and we use miniaturized circuits and cell saving and RAP prime, and our transfusion rates have gone down tremendously with tranexamic acid, and a single clamp technique. Even in the older octogenarian, we're talking about a crossclamp time for three vessels of about 52 minutes and maybe 70 minutes on-pump with a controlled environment. DR. MACK: I think if you look at why the adoption rate has reached a plateau between 17 and 22%, as with any new technique or device, the adoption rate is directly related to three things: the validation of benefit; the ability to educate the users; and user friendliness. And of these three, user friendliness is the most important. And I think it has become very clear, despite the fact that some of us initially stated that it was not a more difficult operation, I think OPCAB actually is a more difficult operation, and it takes too many surgeons out of their comfort zone when they feel that there is not a clear validation of benefit. So why should they leave their comfort zone? We had a lot of initiatives early on to educate surgeons how to do off-pump surgery, and those have waned. So I think all three of those factors do play role in the adoption rate. I also agree with David. It's a very skewed 17 to 22%, because a few centers perform virtually all procedures off pump and most centers do a low percentage. Maybe 17 to 22 is the right number,

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but it should be based on a per-patient-need basis. And that probably is the right number of the patients clearly benefit. I also agree that the problem is that when there is a patient that really needs and the surgeon that's not conversant with how do it is likely to lead to worse outcomes rather than better outcomes. So my biggest concern is that we have surgeons that are not comfortable with off-pump techniques so that they can use it when the patient benefits the most, the 80-year-old with peripheral vascular disease that has been proven to have a higher stroke risk with on-pump surgery. I think Joe's suggestion of coronary revascularization specialists helps address these issues. So that patients that you know are high risk because they are 80 years old go to a coronary revascularization specialist within your institution, and if appropriate once there, that surgeon is comfortable doing it off-pump if that's in the best interest of the patient. That would be my suggestion as to how we move things. DR. PUSKAS: Obviously, I've had a particular interest in off-pump bypass surgery, but I don't consider it a religion. Our goal is to provide each patient with complete revascularization that's durable while minimizing upfront morbidity and mortality. That's why we go to work every morning as a coronary surgeon. I will comment that the Society of Thoracic Surgeons database has been a rich repository for investigation. We have done

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several large national STS database queries that have shown in the most carefully controlled retrospective statistical analysis -- and there's a caveat there -- a decrease in death, stroke, MI, renal failure, essentially any adverse event you choose to examine at the 30-day mark for risk-adjusted patients having off-pump versus on-pump. The concerns about graft patency and completeness of revascularization in inexperienced hands are real and they have been documented in multiple studies, and they probably have a negative impact on patient outcomes, survival and event-free survival over time. I think it's also true as Dr. Taggart and Dr. Sabik said that for patients at low risk for cardiopulmonary bypass, there is no survival benefit, with off-pump bypass. We have demonstrated that at Emory. That is to say that the healthiest patients in your cohort are likely to not have any survival benefit from off-pump bypass acutely. The benefits relate I think most demonstrably to shorter hospital stays, shorter intubation times, reduced transfusion and some other things in those low risk patients. In the higher risk patients, I think we can expect a benefit in terms of stroke and mortality, and those are the patients I think that clearly benefit most from off-pump bypass. I'm not sure that you need to do every one of your patients off-pump to remain facile with the technique but I agree with Dr. Taggart that if you wait for that high risk patient to do any

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off-pump bypass, you're making it more difficult on yourself and on that patient. So there has to be some happy medium, and I think that happy medium will be different for different surgeons based on their own inclinations, experience and training. DR. LAZAR: If you look at the initial use of the left internal mammary artery, when it first became more popular to use it in the early '80s, people said it's going to result in more sternal infections, you are opening the pleura, there will be more recurrent effusions, more pulmonary issues, patients stay in the hospital longer, it's a little bit harder to take down the anastomosis, it requires a little bit more time. But now if you look at it, 95-97% of all patients undergoing CABG surgery will have a mammary; everybody does it. The problem with ON versus OPCAB is it's not a home run. There are some subtle differences here and there, depending on the database, whether it's randomized, et cetera. But it's not the clear-cut advantage that you would see, for example, by using the left internal mammary to the LAD, and maybe that's why it really hasn't gained that much acceptance. DR. PUSKAS: As Mike Mack said, we were slow to acknowledge that this is a harder operation and requires a special skill set. It requires a different mindset, too, and it benefits different patients differently. Bottom line, OPCAB is not for every patient or for every surgeon, but I think it's very important for many patients and therefore for at least some surgeons.

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One of the things that patients want is a less invasive treatment for their coronary disease. This is the primary driver why so many choose PCI over surgery. One of the things that many of our colleagues have sought to do is to limit the invasiveness of the approach by making a smaller incision in a different part of the chest. We call this MIDCAB or robotic-assisted endo-ACAB. MIDCAB DR. PUSKAS: Dr. Mack, you were one of the earliest practitioners of the MIDCAB technique. DR. MACK: Well, I think this is another lesson about how new technologies and techniques are adopted in clinical practice. At the time that PCI was becoming a much more common form of revascularization, we took an operation which most surgeons did extremely well with reproducible results and we took the safety net out from under it. We changed two variables at the same time. We said, you can do a great operation with full exposure through a median sternotomy in an arrested bloodless field, and now not only are you going to do it on a beating heart with blood in the field but through a tiny little incision through which you can barely see. It's the way the world happened, but changing two variables like that at the same time I think was a strategic mistake in terms of adoption of minimal access surgery. It should have been one or the other. The more appropriate way would have been to go to off-pump surgery, and then when the surgical community was comfortable with that, moving it to a

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minimal access approach, or vice versa. I had a lot of enthusiasm in the late 1990s for hybrid revascularization, because I thought it would take what we did best, the left internal thoracic artery to the LAD, and combine it with what cardiology did best by PCI of the other vessels and avoid a sternotomy that way. For a whole host of reasons I was wrong about that and it never took off, some of which was logistics, some of which was lack of demonstration of benefit. I think that we are coming back to a renewed interest in this with your study proposal, John, for this being at the forefront. I think we have a lot of enthusiasm for participating in this study. I think using videoscopic and/or robotic techniques to harvest the left internal mammary artery and then doing the operation through a small incision under direct vision is probably a better way to do it. I think one of the other reasons that MIDCAB waned was because although it was a little incision and it wasn't a sternotomy, very frequently it was a more painful incision than a sternotomy approach and therefore the benefit was not clear. So I think with endoscopic harvest and no rib spreading, it may be a better operation and it may be a very interesting alternative. I do have equipoise about this, about participating in a study that looks at hybrid revascularization.

HYBRID PROCEDURES

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DR. LAZAR: I really have some concerns about hybridization, because, again, I think it takes away from the major theme which was so eloquently reported by Dr. Taggart a number of years ago at this meeting when he said that CABG is the superior approach and it's important that we let everybody else know that. DR. TAGGART: Even I'm beginning to believe it. (Laughter). DR. LAZAR: I think the important thing is that CABG is the superior method for three-vessel disease. And I think that there is this attempt to try to compete with the cardiologists by letting them stent non-LAD lesions, because in some databases there appears to be no difference as far as rate of revascularization or survival with a non-LAD approach. I think that's wrong, and I think the concept that we can stent these vessels and if they don't work you can come back and have an uneventful CABG is fallacious, because patients who have multi-stenting, for multiple territories, and come back for CABG surgery have increased morbidity and mortality. I think that for three-vessel disease, CABG is the superior approach using as many arterial grafts as possible. If a surgeon can do it with a minimally invasive technique, fine, but I don't think it should be at the expense of graft patency. And I don't know about you, but my patients complain more from a lateral thoracotomy than they do for a median sternotomy.

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I think the other thing about the hybrid approach, which hopefully will be addressed at some of these meetings, is the cost that doesn't get reported, the use of the hybridization room, and also the timing, because that room is used by the interventional radiologists, the cardiologists, and the vascular surgeons. This becomes an issue especially if patients who are unstable. In addition, there is the cost for the stents. So I think that those things are important when you look at the entire cost. DR. PUSKAS: Just to clarify, we have designed this proposed NIH-funded hybrid revascularization trial to compare multivessel PCI versus hybrid revascularization, not hybrid revascularization versus CABG. The target population are those patients with essentially two-vessel disease; proximal LAD disease with stenosis in the circumflex or right coronaries; or bifurcation distal left main disease with or without proximal LAD disease. So we are targeting patients who are frequently treated completely in the cath lab, and we are hoping instead to offer their cardiologists -- an opportunity to do a diagnostic cath, then for the surgeon to provide the patient with the longevity that comes with a LIMA to the LAD, and then the cardiologists to stent the other vessel. This hybrid approach is proffered as an alternative to multivessel stenting, which is the treatment of most commonly provided to such patients presently. That's the mindset behind the design of the trial. I

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completely agree with you; I think that the young patient with multivessel disease needs multiple arterial grafts as a first and probably only intervention in their lifetime. DR. LAZAR: The concept that we should be doing CABG and only one CABG in a patient's lifetime is probably our best policy to capture these patients. Let me ask you, would you feel comfortable having your cardiologist do multivessel stenting? In other words, if you were told you just do the LAD and we will take of this right and this OM, what do you think about that? DR. PUSKAS: I'm a lot less comfortable with that than I am with LIMA-LAD grafting and stenting single type A focal lesion in a non-LAD coronary artery. Now, there are a few other cases. For instance, a patient who has an ostial LAD lesion and diffuse disease in the right with a poor target for grafting in the PDA territory. In this scenario, I think a robotic LIMA to the LAD and a stent in the most tight lesion in mid-RCA is a reasonable approach. I think there is room for compromise and discussion, and, again, I think that if the hybrid procedure proves its worth, it will do so by having more patients get a LIMA to the LAD than are presently getting a LIMA to the LAD. If it ends up eating into the volume of multivessel, all arterial bypass surgery, I think it will have done a net disservice to patients with coronary disease.

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DR. TAGGART: I would like to kind of reinforce these opinions, and I'm going to start by quoting Dr. Mack when he was President of the STS. He said, what is the difference between cardiologists and cardiac surgeons? He said, cardiologists have used innovation and technology to make their life easier; cardiac surgeons have used innovation and technology to make their life harder. Small incisions, more arterial grafts, off-pump surgery, robotics, everything we have done makes our life harder. In terms of the MIDCAB procedure, we see very few patients a year who need a single IMA graft. And I will always do it through a median sternotomy. I have had people come and do MIDCABs with me, so-called experts in the UK, and I couldn't see anything they were doing, so I was unconvinced, whereas with a median sternotomy, okay, what does it actually mean for the patient? Well, it means they have a longer scar but a less painful wound. So I think the short painful thoracotomy wound, which doesn't really allow you to see what you are doing well, at least the people who came and showed me did not convince me, I think it's a false economy. If I was doing 40 or 50 of these a year and I could learn to do it properly, then fine. But no operation which is an occasional operation is a good operation. So doing three or four MIDCABs a year is not in my patients' interest. Doing an occasional off-pump operation is not in the patient's interest, particularly, as we said, when it's high risk. In terms of hybrid procedures, I'm against them at this

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point in time, because I think most patients have multivessel disease, and I think if you have not used two internal thoracic arteries in most of those patients, you have shortchanged them, and you have shortchanged them for what is essentially a cosmetic change. So I largely agree with my colleagues. DR. SABIK: I know most of my colleagues at this discussion may not believe this, but I may be a little bit more moderate on this one than all of you. There are two things I think we don't want to forget. First, the most important thing we do as heart surgeons and as coronary surgeons is placing the LIMA to the LAD, and second, is the best revascularization strategy of the LAD is an IMA to the LAD. I do a lot of MIDCABs. I enjoy the operation. I also ensure that the graft is patent prior to leaving the operating room. And, again, this is again developing that argument about the need for coronary surgeon as a subspeciality, because we cannot have the surgeon who occasionally performs a MIDCAB. The population of patients is similar to what Dr. Puskas has described.

There are many patients with stents that have been

re-stenosed who do not have a good option in the cath lab. In terms of the hybrid procedure, it's an opportunity for us. There are patients who will benefit from a hybrid procedure. One such patient might be a patient with an ostial LAD stenosis and a 70% right coronary artery stenosis. We do not have a good arterial

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conduit for the RCA. So, again, I think that the hybrid may play a role in these types of cases, where the LIMA is used tograt the LAD and the RCA is stented. We should view the Hybrid procedure as a tool in our armamentarium, just like off-pump surgery, on-pump surgery, and arterial grafting. I think we are going to learn who benefits from this procedure. DR. TAGGART: My one indication where I think hybrid surgery is good is, again, I go back to the octogenarian with a tight calcified left main and a moderately diseased right. I leave the right alone, so that that patient would have two mammary arteries done through a median sternotomy, and then we will discuss with the cardiologist whether we think the right lesion needs to be stented. But I will not risk putting a vein graft in an 80-year-old and doing a top end to the aorta. But could I ask Joe briefly, Joe, how many MIDCABs do you need to be doing a year to be competent with that, would you say? DR. SABIK: That's a great question, David, and I don't want to pretend that I know the answer. I remember when I saw Dr. Mack at a meeting in Montreal with the first retractor designed specifically for the MIDCAB procedure, I was very excited to get one. And so I have been doing them a long time, and essentially do most of them in my institution, I'm training one of my younger surgeons, who is interested in robots, and we are doing them together when we have the opportunity. But I'm very familiar with the procedure having

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done it for a long time. I think it's not something you want to do once or twice a year but maybe two, maybe three times a month. DR. PUSKAS: I think if you're doing it once a week or almost once a week, you can remain facile at it. That's about the pace at which I do robotic MIDCAB, and we are going to talk about the use of the robot in a few minutes. I think if you're doing it less than once a month, that's not enough. GRAFT ASSESSMENT DR. MACK: Joe, you brought up a point that we haven't talked about at all today, and this is the issue of graft assessment. I think one of the benefits of a hybrid procedure, either done simultaneously or staged, is completion angiography. If you really think about it, coronary bypass is the only major vascular operation done in a hospital in which there is not completion angiography at the end, and one of the benefits of hybrid is there is the opportunity to do that. But most of the time we don't, and most surgeons do not assess their grafts afterwards, and we just assume that everything is okay. DR. SABIK: I agree with Dr. Mack. I think it's important to assess your grafts in the operating room. To me, I enjoy doing it and I also use it to teach the residents about graft blood flow. We look at the flow curves, discuss the diastolic and systolic flow patterns, we may alter the blood pressure and evaluate how that

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influences blood flow. It's a wonderful teaching tool. Angiography is difficult. It's obviously cumbersome. If you have a patient who has had a pretty big operation and now you are giving them a dye load, more operating time, that mightlead to renal failure. So I just flow probes. I think that once you gain experience with assessing graft flow, you usually have good idea of what the flow is going to be in that graft from the characteristics of distal vessel. If your flow assessment is very different than your expectations are, then there might be something wrong with your graft. But I think it's a useful both in teaching and an important quality tool in the operating room. DR. PUSKAS: Do you use it on every single case, Joe? DR. SABIK: On all the coronary cases, yes. DR. PUSKAS: How about an AVR CABG, are you checking your grafts there? DR. SABIK: I have to say I haven't been. DR. PUSKAS: So isolated coronary bypass gets careful scrutiny; a bypass done as an adjunct to a valve or a double valve doesn't. Ditto with me. Full disclosure, exactly the same. Ditto. (Laughter). DR. PUSKAS: Dr. Taggart and I just came from a meeting trying to design a clinical trial to test the utility of intraoperative transit time flow measurement. David, how often do you use it?

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DR. TAGGART: We use it routinely in our practice now. About five, six years ago we published two papers in JTCVS saying that there was a problem with TTFM measurements, and the problem was that in 90% of patients you get great results; large flows, low pulsatility index, and you knew your graft was fine. Our problem was in about 10% of grafts we had ambivalent flows, so flows of maybe 15 to 20 ml's with slightly high pulsatility indices. And then you had to decide, do I revise this graft or not, even when you felt that you had done the graft properly. And the problem has now been effectively solved by Medistim, because with their new VeriQ system, you actually get an epicardial echocardiography. So it's a little probe that you put on the anastomosis, and you can look clearly at the anastomosis and you can see it's widely patent with flow in and out of it. So that immediately means you do not need to revise this graft. So I think they have solved the problem. I think as a standard of care, every patient should have measurement of the IMA to LAD flow and check that anastomosis, because it's the one thing in all of coronary revascularization that changes a patient's life expectancy. And in most studies in the literature, the incidence of failure of the IMA graft is somewhere 2 to 4% by the time the patient has left the operating room. So if by just checking that you know the patient is leaving the OR with a patent IMA graft, you have changed that

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patient's life expectancy for a very small additional time in theatre, two or three minutes, to do this. And equally so, as a very keen user of two internal thoracic arteries, I like to make sure both of those are patent, because if the patient leaves the operating room with two patent internal thoracic arteries, the risk of them ever having to have any other intervention in their heart diminishes dramatically. I think it should be a standard of care. DR. LAZAR: Well, I have to chuckle, because whenever we do a TEVAR and a branched stent for an aortic arch surgery, we always get an angiogram, but for a smaller coronary we don't. Because we do the LIMA last and we are warming up, we are almost at 37 degrees, and we take the clip off, we have looked at the difference in temperature between the two areas as a crude measurement of patency. We don't do that anymore. DR. MACK: I routinely check flows in every isolated CABG patient, and I also have to admit guilt in that I don't do it in AVR CABG either. I can't tell you why other than the fact that it just doesn't seem to be the main part of the operation. So it's kind of like a “deer caught in the headlights”. The other thing I would say is, we perform a lot less aortic valve coronary bypass than we used to, and this was a lesson from the TAVR, that so frequently the coronary disease seems to be bystander disease and we don't need to treat it, and I think that has proven nationally in the databases, too, that the number of isolated

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aortic valve replacements is going up but the number of AVR post-CABG is going down. I think we are much less aggressive at treating the coronary disease in the face of aortic stenosis. DR. LAZAR: Do you stent them beforehand? DR. MACK: Sometimes or frequently do nothing. If we do a mini aortic, which we do very frequently, and they have significant coronary disease, then yes, we will stent them first. But there is a lot we do not treat, especially in the elderly patient in their 80's, that we treat as bystander disease and are less aggressive at coronary revascularization than we used to be. I don't know whether that's right or wrong but it's what we've evolved to. ROBOTIC PROCEDURES

DR. PUSKAS: Joe, you described a long and happy experience with MIDCAB. Are you performing it with the robot or with a minithoracotomy and an uplifting retractor? Is there a role for the robot? DR. SABIK: I don't have robotic skills, and so I use the uplifting retractor and dissect the mammary in its entirety; we always make sure we see the innominate vein. However, the new generation of surgeons do have robotic skills. As I said a little bit earlier, one of our younger surgeons has experience with the robot and we have been worked on some of these together with her dissecting the mammary with the robot.

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One of the things that I have learned over time with the MIDCAB is you really do not need to spread that retractor very much. In addition, I have learned that to make my incision more lateral.

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believe one of the mistakes is making your incision too close to the sternum; you can't see very well. If you stay more lateral, you will get a very nice exposure of the LIMA. And I teach my residents, it's just like taking down the RIMA. DR. PUSKAS: I have personally found that harvesting the IMA with the robot allows you to make a smaller incision, and I actually find it easier and more pleasant to harvest it with the robot than to harvest it through a MIDCAB incision. DR. SABIK: It's probably easier on your back. DR. PUSKAS: It is. Sitting down is nice. (Laughter). DR. TAGGART: Well, I'm very pleased to say in our cash-strapped NHS there never will be a problem for me because we simply can't afford them, and if you look at just the cost of the consumables, in our health care system it just will not happen. DR. MACK: We got involved with the robot very early, probably too early and probably the wrong robot, and we quickly abandoned it, because I thought that we were reinventing an operation to accommodate technology. And as a matter of fact, we were involved with the Leipzig Heart Center very early, and one night there was a fire in the room where the robot was kept, and many people

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accused Fred Mohr, tongue in cheek, that he set the fire to burn the robot so he wouldn't have to use it. (Laughter). DR. MACK: Be that as it may, when Tommy Mihaljevic presented the excellent results of the Cleveland Clinic experience in robotic mitral valve surgery, we got back into robotics again. And we have three separate programs now, one robotic mitral, one robotic coronary revascularization, and one robotics VATS lobectomy, all done by three different surgeons. And I don't know what the outcome is going to be, of course, but we are taking a hard look at it again and are embracing these programs and see where it leads us. DR. PUSKAS: Fantastic. Well, we have had a far-ranging conversation focused on state of the art outcomes in contemporary coronary revascularization. I want to thank all of our panelists, Professors Sabik, Taggart, Lazar and Mack, and Dr. Rosengart for organizing this. It has been a very stimulating conversation. We hope it has been of benefit to the reader.

   JohnD.Puskas,MDcurrentlyservesastheQualityOfficerandAssociateChiefofCardiothoracicSurgery atEmoryUniversitySchoolofMedicine,ChiefofCardiacSurgeryatEmoryUniversityHospitalMidtown andProfessorofSurgeryatEmoryUniversitySchoolofMedicine.Dr.PuskasreceivedhisA.B.degree fromPrincetonUniversityandhisM.D.fromHarvardMedicalSchoolbeforecompletinghisresidencyin generalsurgeryattheMassachusettsGeneralHospital.Hewasthenaresidentandfellowin cardiothoracicsurgeryatEmoryUniversitySchoolofMedicineinAtlanta.Healsodidaresearch fellowshipinthelungtransplantationlaboratoryattheTorontoGeneralHospitalandearnedaMaster ofSurgicalSciencedegreefromtheUniversityofToronto.AfterhisresidencyandfellowshipatEmory UniversityhejoinedtheEmoryfacultyin1996.Dr.Puskasisboardcertifiedingeneralsurgeryand thoracicsurgeryandisaFellowoftheAmericanCollegeofSurgeonsandtheAmericanCollegeof Cardiology.   AmongthemanyhonorsthatDr.PuskashasreceivedaretheprestigiousJ.MaxwellChamberlain MemorialAwardforthebestpaperinadultcardiacsurgeryfromtheSocietyofThoracicSurgeons AnnualMeetingandtheawardforbestoralpresentationfromtheInternationalSocietyforMinimally InvasiveCardiothoracicSurgery(ISMICS).HeispastpresidentofISMICSandservesonthegoverning CounciloftheAmericanAssociationforThoracicSurgeryandontheBoardofDirectorsoftheThoracic SurgeryFoundationforResearchandEducation.Dr.Puskasservesonnumerouscommitteeswithin nationalandinternationalsocieties.   Dr.Puskashasauthoredapproximately100scientificpapers,numerousbookchaptersandeightissued U.S.patents.HefoundedtheClinicalResearchUnitwithintheDivisionofCardiothoracicSurgeryat EmoryandservesanactiveroleintheNHLBICardiothoracicSurgeryClinicalTrialsNetwork.Apioneerin offpumpcoronaryarterybypasssurgeryandminimallyinvasivesurgicaltreatmentforatrialfibrillation, Dr.Puskas’areasofinterestincluderobotichybridrevascularization,devicedevelopment,and innovativeclinicaltrialstoguidepracticeofevidencebasedcardiothoracicsurgery. 

Michael J. Mack, M.D. Michael Mack, M.D. has practiced cardiothoracic surgery in Dallas, TX since 1982. He is board certified in Internal Medicine, General Surgery, and Thoracic Surgery and is currently the Medical Director of Cardiovascular Surgery for the Baylor Scott & White Health, Chair of the Baylor Scott & White Health Cardiovascular Governance Council and Director of Cardiovascular Research at The Heart Hospital Baylor Plano. He also co-founded and is Chair of the Cardiopulmonary Research Science and Technology Institute (CRSTI) and is on the Steering Committee of the Cardiothoracic Surgery Network (CTSN) of the NIH. He has over 400 peer reviewed medical publications. Dr. Mack was President of the Society of Thoracic Surgeons (STS) 2011, as well as Past President of the Thoracic Surgery Foundation for Research and Education (TSFRE) 2009-2011, the Southern Thoracic Surgical Association (STSA) 2009 and the International Society for Minimally Invasive Cardiothoracic Surgery (ISMICS) 2000. He has served on the Board of Directors of the STS and is currently on the Board of CTSNet. Dr. Mack is currently a member of the American College of Cardiology Foundation (ACCF) Board of Trustees and is a member of the ACC Interventional Scientific Council. He is an honorary member of the German Society for Thoracic and Cardiovascular Surgery. He is currently the Chair of the STS/ACC National Transcatheter Valve Therapy (TVT) Registry Steering Committee and is a member of the FDA MDEpiNet Advisory Committee.

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Joseph F. Sabik III, MD, is Chairman of Thoracic and Cardiovascular Surgery and Director of the Cardiothoracic Residency Training Program in the Sydell and Arnold Miller Heart & Vascular Institute. He is board-certified in surgery and thoracic surgery and has specialty interests in adult cardiac surgery, valvular heart disease, coronary artery disease, surgery of the thoracic aorta, minimally invasive cardiac surgery, and off-pump coronary artery bypass surgery. A Massachusetts native, Dr. Sabik earned a BS in Life Sciences from Massachusetts Institute of Technology and received his medical degree from Harvard Medical School. He completed his surgical internship and residency at Massachusetts General Hospital, where he was named Chief Resident in Surgery. During his surgical training, Dr. Sabik was appointed a Clinical Fellow and a Research Fellow in Surgery at Harvard Medical School and a Research Fellow in Cardiovascular Surgery at Children’s Hospital, Boston. Following his general surgery training, Dr. Sabik completed a residency in thoracic and cardiovascular surgery at Cleveland Clinic, and during his final year of training was the Chief Resident in Thoracic and Cardiovascular Surgery. In 1996, he was appointed to the Cleveland Clinic Department of Thoracic and Cardiovascular Surgery as a staff physician. He was named department chair in 2008. In 2004, Dr. Sabik was inducted into the American Association for Thoracic Surgery. He is a Fellow of the American College of Surgeons and the American College of Cardiology and is a member of the Society of Thoracic Surgeons, the Massachusetts General Hospital Alumni Society and the Ohio State Medical Association. He has in the past or continues to serve on the Program Committees of the American Association for Thoracic Surgeons, The Society of Thoracic Surgeons, the American College of Cardiology and the American Heart Association.

Professor David Taggart MD(Hons) FRCS PhD FESC David Taggart is currently Professor of Cardiovascular Surgery at the University of Oxford. He qualified from Glasgow University in 1981 and pursued his basic surgical training in Glasgow. In 1989 he was awarded an MD with Honours for studies on the effects of hypothermia on the metabolic response to cardiac surgery. He was subsequently appointed the Senior Registrar at the Royal Brompton Hospital under Professor Yacoub and Mr Lincoln. In 1995 he was appointed consultant cardiac surgeon at the John Radcliffe hospital in Oxford where he was also awarded a PhD (from Strathclyde) for studies of the inflammatory response during cardiac surgery. In 2004 he was appointed Professor of Cardiovascular Surgery at the University of Oxford. His main interests are coronary revascularization, arterial grafts and off pump surgery. He has authored around 150 peer reviewed scientific papers and is the PI of the MRC and BHF funded ART trial- one of the largest surgical trials ever conducted (a randomized trial of 3000 CABG patients to single or bilateral IMA grafts during CABG). He was President of the Society for Cardiothoracic Surgery of GB and Ireland (April 2010-April 2012), Chairman of the European Society of Cardiology Cardiovascular Surgery Working Group, a member of the Adult Domain of the European Association for Cardiothoracic Surgery and a member of the AATS and STS. He was recently appointed as the lead for cardiothoracic Surgery in the UK by the Royal college of Surgeons of England