REVIEW INTERVIEW For reprint orders, please contact: [email protected]

Advances in the field of interventional cardiology: spotlight on transcatheter aortic valve implantation Philip MacCarthy* speaks to Alice O’Hare, Commissioning Editor Philip MacCarthy is the Clinical

Director of Cardiovascular Services at King’s College Hospital in London (UK) and is an interventional cardiologist with an interest in structural cardiac intervention. In 2003, he was appointed as the Consultant Cardiologist at King’s College Hospital and Honorary Senior Lecturer in Cardiology at the King’s College London School of Medicine. He was responsible for the development of the primary angioplasty service at King’s and is the lead cardiologist in the very successful transcatheter aortic valve implantation program. He has served as an international proctor for transcatheter aortic valve implantation and has taught 13 UK teaching hospitals the technique. In 2012, MacCarthy was appointed as the Clinical Director of Cardiovascular Services at King’s, and in 2014, he was promoted to Professor of Interventional Cardiology. His research interests include applied coronary physiology/endothelial function, left ventricular hemodynamics and emerging interventional therapies (including transcatheter valve therapy and primary angioplasty). QQ

Can you tell us a little about your career background?

I trained in medicine in Bristol and then did my cardiology training in Oxford and Cardiff before doing a PhD in endothelial function at the University Hospital of Wales. I then came to King’s for my interventional training, leaving transiently for an international fellowship in Aalst in Belgium. This was a British Heart Foundation-funded fellowship with Bernard de Bruyne and William Wijns. I then returned to King’s and was appointed as a consultant in 2003. I helped set up the primary angioplasty program and then the transcatheter aortic valve implantation (TAVI) program, the latter with my cardiothoracic surgical colleague Olaf Wendler. I was appointed Clinical Lead at King’s in 2007 and Clinical Director of Cardiovascular Services in 2012.

“In terms of coronary disease, I think that bioabsorbable stents have a huge future and that, as newer bioabsorbable stents come onto the market, the whole field becomes very exciting...”

KEYWORDS

• aortic • SAPIEN 3 • stenosis • TAVI • valve

What do you believe has been the biggest advance in interventional cardiology in the last 5 years? QQ

The single biggest advance in the last 5 years would have to be transcatheter heart valve therapy. Most people would agree that that is the area that has advanced the most. This includes TAVI, but also all of the things that have come along with the TAVI process in terms of treating other valves and the increased awareness of aortic valve disease.

Department of Cardiology, King’s College Hospital, Denmark Hill, London, SE5 9RS, UK *Author for correspondence: Tel.: +4420 3299 3750; [email protected] 1

10.2217/FCA.14.52 © 2014 Future Medicine Ltd

Future Cardiol. (2014) 10(5), 587–592

part of

ISSN 1479-6678

587

Interview  MacCarthy There have been important coronary advances as well, including physiological percutaneous coronary intervention with the pressure wire with the publication of the FAME studies [1,2] and also bioabsorbable stents, which are perceived to be a very major advance in interventional cardiology. To summarize, my top three would be: TAVI, physiological percutaneous coronary intervention and bioresorbable vascular scaffolds. You were recently involved in the European Association for Percutaneous Cardiovascular Interventions (EAPCI)/Stent for Life (SFL) group recommendations for invasive coronary treatment strategies for out-of-hospital cardiac arrest [3]. Can you outline the recommendations & the evidence that the group took into consideration? QQ

Out-of-hospital cardiac arrest is a major issue for interventional cardiologists at the moment. This is largely because paramedics and the general public are better at resuscitating people when they have cardiac arrests outside of hospital. Therefore, the number of out-of-hospital cardiac arrest patients that we are being asked to treat has increased very dramatically over the last 5 years. We have noticed this in London, but it is mirrored all over the world, with similar reports from European centers. We therefore felt that guidelines on the management of these patients were urgently needed and that is why the team got together for the consensus statement. The evidence that we looked at was mainly regarding the characterization of these patients and what should be done for them when they come to hospital. They broadly divide up into two groups: patients with ST elevation and patients without ST elevation on their postresuscitation ECGs. One of the leading figures in the evidence base for this condition is Christian Spaulding (who is also in the group). He published the proCAT study [4] , which reported several hundred patients with out-ofhospital cardiac arrests in Paris and found that lots of the patients without ST elevation also had quite significant coronary artery disease. Therefore, there needs to be a recognition that just because you do not have ST elevation on your ECG, this does not mean that you do not need to be treated as if you have critical coronary disease. What we wanted to do was to provide guidelines that would enable access to early imaging

588

Future Cardiol. (2014) 10(5)

in these patients, in particular early coronary angiography. The final recommendations were that, if the patient has ST elevation, he/she should be taken directly to the catheterization laboratory for an urgent immediate coronary angiogram. If there is no ST elevation, then they should be taken to a resuscitation area within the emergency department and assessed in what we termed the ‘emergency room stop’. In this way, you could stop off at the resuscitation room for immediate assessment. If there was evidence that the cause of the arrest was possibly cardiac, rather than noncardiac, then that patient could then be directly transferred on to the catheterization laboratory. These are pathways that we have instituted at King’s College Hospital for the last 18 months with very good effect. We work together with the London Ambulance Service and our emergency room and intensive care colleagues so that ST elevation patients can come directly to our catheterization laboratory at all times. The non-ST elevation patients have immediate assessment in the ‘emergency stop’, where they might undergo a handheld echocardiogram with senior clinician input and then go on to have an immediate coronary angiogram if they need one. These are broadly the recommendations that are made, but clearly we need a lot more data. There is a lot we do not know and the whole area of whether these patients should be therapeutically cooled (in order to minimize neurological injury) is now very controversial after the publication of the latest cooling trial in the New England Journal of Medicine towards the end of last year [5] . We therefore need a lot more data in order to determine how to optimally manage these patients, but it is a growing area that affects us all. What future plans do you have to develop this study? QQ

There are lots of ongoing trials, and we certainly have plans to look at several aspects of this patient group. We are planning to look at all out-of-hospital cardiac arrests across London, not just at King’s. There is also active research looking into the survival of these patients [6] . A pan-London decision was made in 2012 that every out-ofhospital cardiac arrest with a return of spontaneous circulation and ST elevation on their ECG should go directly to a major heart attack

future science group

Advances in the field of interventional cardiology: spotlight on transcatheter aortic valve implantation  center (there are eight heart attack centers in London). The survival following this decision has been shown to be extremely good. In fact, there is a ‘survival to discharge’ of 66% in this patient group, which is remarkably good. It certainly seems that the way we are moving is to transfer these patients to major centers that manage these complex patients in high volumes. You are the lead cardiologist for the TAVI program at King’s & have been involved in teaching this technique to other hospitals. Can you tell us about how the technique has developed over the last 5 years? QQ

I have proctored 13 UK centers so far and I have hugely enjoyed the proctoring experience. Of course, most of the centers are now up and running and are doing good volumes of procedures. The technique has evolved hugely over the last 5 years, in a number of ways. The first is that the delivery system for the valve has become smaller – this means that the arterial injury rate has come down, because the catheter sizes are smaller. It also means that more TAVIs can be performed transfemorally. Moreover, the valves have become easier to deliver, in a more predictable way. There has also been an appreciation of the limitations of the technique, such as paravalvular aortic regurgitation, which has been addressed with the latest valve iterations – the most recent valve designs are very much oriented towards trying to eradicate paravalvular aortic regurgitation. Lastly, there has been an appreciation that complications such as stroke and renal injury are also extremely important and need to be minimized, and the incidence of both of these complications has decreased quite significantly over the last 5 years. I think the incidence of stroke has come down because the valves have become better – they have become easier to deliver and the need for aggressive balloon valvuloplasty prior to putting the valve in has decreased in recent years. You recently published a paper on the ‘heart team’ approach for TAVI – can you explain the interdisciplinary nature of the TAVI procedure & how you envisage this evolving in the future? QQ

One of the best things to come out of TAVI, as a doctor, is the healthy multidisciplinary approach. This is fairly new for cardiology. It

future science group

Interview

started with the SYNTAX trial [7] , which was a coronary trial looking at multivessel angioplasty/stenting versus surgery. However, from the very beginning, it was appreciated that TAVI was multidisciplinary and required a heart team in order to discuss patients in detail. This heart team comprises cardiothoracic surgeons and interventional cardiologists, but also cardiac anesthetists, care of the elderly physicians, imaging specialists who specialize in echocardiography and computed tomography imaging of the heart, and nurses and fellows. The nurses and fellows are important because quite often they know the patients in a lot more detail than some of the other specialists involved. It is a big interdisciplinary team that looks at all of the investigations and decides whether TAVI (or indeed any other treatment) is the correct therapy and then makes these difficult decisions. It has been a real force for the good; I think one of the great legacies of TAVI has been its multidisciplinary nature. This has spread to other areas within cardiology, so all of the new technologies that are now emerging – for instance, mitral valve interventions or left atrial appendage closure – are now adopting the heart team approach; and in fact, commissioners are insisting that these new interventions are conducted in this way. Everyone agrees that this is a really healthy way to do things. What you often find with heart team discussions, however, is that the most important person in the heart team is not there – and that is the patient. So what we have done at King’s is to invite our patients to our heart team discussions. We have a clinic where we have our heart team discussions with all of the specialists there and we invite the patient and their relatives to come along as well, and they are involved in some of our reasoning. They can then understand some of the decisions that we make and whether they should have the TAVI or not. I am very keen to involve the patient in the heart team – for me, the patient is the most important member of this group. It is also worth noting that one of the other legacies of TAVI has been to draw attention to aortic valve disease and to the fact that patients need to be assessed by the heart team. When we first started on the TAVI journey, several cardiovascular surgeons thought that it was just another attempt by interventional cardiologists to ‘steal’ more work from them! In fact, an

www.futuremedicine.com

589

Interview  MacCarthy increased attention to the aortic valve and an increased awareness of aortic stenosis has meant that the number of surgical aortic valve replacements (AVRs) has gone up in the UK, as well as TAVI procedures. So we have not seen a decline in surgical aortic valve replacement in the TAVI era – quite the opposite. Now there is increased awareness of aortic stenosis. Patients are being exposed to a heart team and being assigned to the appropriate treatment, which might well be surgical AVR. For example, 13% of the referrals to our heart team went on to have surgical AVR and did extremely well, and these are patients that would not have been referred directly to a surgeon; so I really think that it is a great thing, and it is now here to stay – I think everyone has bought into it. Aortic regurgitation has been linked with poor outcomes after TAVI – can you tell us a little about this complication & how third-generation devices are addressing this? QQ

When we first started TAVI, we noticed that quite a lot of the patients did have an element of aortic regurgitation. This was with both the devices that we used, and initially operators felt that it was not too much of a big deal, because you were swapping critical aortic stenosis for maybe mild or occasionally moderate aortic regurgitation (which is paravalvular aortic regurgitation down the side of the device). However, it was realized about 3 or 4 years ago – initially from the PARTNER A data [8] – that having anything more than mild aortic regurgitation conferred a poor prognosis, and in fact, some data suggested that even mild aortic regurgitation affected outcomes. Once we started to realize this, we began to concentrate on minimizing paravalvular aortic regurgitation, which is particularly relevant when trying to compare TAVI with surgical aortic valve replacement. Clearly, this is a shortfall of TAVI, because up to 70% of the early TAVI devices left the patients with some element of paravalvular aortic regurgitation. Therefore, if TAVI is going to compete with aortic valve replacement, then this phenomenon has to be eradicated or at least minimized. In recent years, we have tried to address this and tried to minimize paravalvular aortic regurgitation, and this has been along a number of lines. The first step is appreciating how important it is. Secondly, we have concentrated on adequate sizing of the annulus – and there is

590

Future Cardiol. (2014) 10(5)

great attention now to sizing the annulus of the valve accurately, both with 3D transesophageal echo (TOE; we published about this at King’s [9]), but also with computed tomography sizing of the annulus, so that you can get the sizing right. I believe that if you can get the sizing right, then that is the first major step to minimizing paravalvular aortic regurgitation. There is also immediate accurate assessment of the valve after implantation, and I am a great believer in using periprocedural TOE to do this. If you do have paravavlular regurgitation after implantation, you can postdilate the valve in order to minimize the aortic regurgitation you see on your TOE. The final thing is the new device design. The SAPIEN 3 has a cuff around the lower part of the frame that is designed to minimize aortic regurgitation – and other devices made by other companies are also designed with this specific feature, or certain variations of the feature, in order to minimize aortic regurgitation. A new advanced transcatheter aortic valve – SAPIEN 3 – has recently been released. What are the advantages of this valve for clinicians? QQ

For the clinician, it is a more sophisticated delivery system, and one of the major advantages – both for the clinician and the patient – is its smaller delivery sheath. You can deliver a 23- and a 26-mm valve through a 14-Fr sheath and a 29-mm valve through a 16-Fr sheath, so the whole sheath size has come down, and this means that the hole that you make in the artery is that bit smaller. Hopefully, and theoretically, the number of vascular complications will be lower as a result; it is a great thing, as a clinician, to have a smaller catheter. This also increases the number of patients who can have a transfemoral procedure – those patients with smaller arteries may now become eligible. The other thing is that the delivery system is very ‘ergonomic’ – it is a new delivery system, called the ‘Commander’. This has an extra flex point in the catheter, which means that you can deliver the valve very reliably to all kinds of anatomy – horizontal aortas, tortuous vessels and heavily calcified valves. Actually, quite often, you do not need to predilate the valve with a balloon valvuloplasty beforehand, because the valve is so easy to deliver with this new system. So, from the clinician’s point of view, it is easier to use, it is easier to deliver the valve and you have a more

future science group

Advances in the field of interventional cardiology: spotlight on transcatheter aortic valve implantation  predictable procedure. What are the advantages of SAPIEN 3 for patients? QQ

This links to the patient in three regards, but this has not been definitively proven yet, because we have only got 30-day outcomes. First, the delivery system is smaller, which should reduce the vascular injury rate. Second, it is easy to deliver – so, theoretically, you do not rough up the native valve quite as much, and I would hope that you would not need to predilate with a balloon valvuloplasty quite so often. This, theoretically, could reduce the risk of stroke, because stroke is related to sending showers of debris from the valve up into the brain, so the less you interfere with the native valve, the better. Finally, we see a reduction in aortic regurgitation, which will – again theoretically – be good for the patients in terms of their longer-term prognoses. In your opinion, what does the future hold for TAVI technology? QQ

I think that now we are moving into an era in which we are starting to compare TAVI with aortic valve surgery, in slightly lower-risk populations (and this would be high-risk and intermediate/high-risk patients), we have to address certain issues. These issues are paravalvular aortic regurgitation, stoke and vascular injury. Paravalvular aortic regurgitation really needs to be, if not eradicated, then absolutely minimized. I think the stroke risk is still an issue. Some TAVI operators say that stroke is a thing of the past, but I disagree with this. I think the stroke rate is still high enough to be a major concern to us. We do not fully understand it, but maybe pharmacology, certain ‘embolic protection’ devices or improved valve design will play a part in decreasing this. Moving on to vascular injury, even with 16/18-Fr sheaths, vascular injury rates are still around the 10% mark, and that is still too high. More attention to meticulous vascular access, with ultrasound guidance and percutaneous closure techniques, is decreasing the incidence of vascular complications. The future for TAVI should be to eradicate aortic regurgitation, minimize stroke and minimize vascular injury. It is only when we achieve these goals that we can truly compete with the surgical gold standard of AVR. Underlying all of my comments about TAVI, I would state that surgical AVR is a very good operation – maybe

future science group

Interview

the best cardiac operation – so the bar is set very high already. In order to compare TAVI with that, we really have to work on these remaining limitations. Having attended the EuroPCR meeting this year, what do you think will be the most exciting advancements in cardiology in the next few years? QQ

For me, improvements in TAVI technology are exciting, but I guess people in the structural field in the area of transcatheter valve therapy are all waiting to see what happens with the mitral valve. I think we are on the brink of a trans­ catheter mitral valve. The first-in-man implantations have been reported. I think we do not understand the kinds of patients who would benefit most yet, so we do not understand case selection and we do not quite understand the precise device that you need in different mitral valve diseases. However, certainly in general terms, transcatheter mitral valve intervention is going to come – there is no question about that – and I suspect it will be here in the next few years. There are also other interventions on valves that are exciting. I think the newest batch of aortic valve devices are also very exciting, and I think we are going to be looking at TAVI becoming a very straightforward procedure with short length of stay, fully percutaneous patients recovering quickly with minimal complications. I think the advances that we are seeing in the latest iterations of the aortic valve devices are going to lead to TAVI becoming a really low-risk and routine procedure. In terms of coronary disease, I think that bioabsorbable stents have a huge future and that, as newer bioabsorbable stents come onto the market, the whole field becomes very exciting because it will mean that patients do not have to have their coronaries lined with metalwork. The whole concept of an absorbing scaffold that can heal the ­atheroma and then disappear is an exciting prospect. Disclaimer The opinions expressed in this interview are those of the interviewee and do not necessarily reflect the views of Future Medicine Ltd.

Financial & competing interests’ disclosure P MacCarthy is a procedural proctor for Edwards Lifesciences. The author has no relevant affiliations or

www.futuremedicine.com

591

Interview  MacCarthy financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock

References 1

2

3

592

Tonino PA, De Bruyne B, Pijls NH FAME Study Investigators. et al.; Fractional flow reserve versus angiography for guiding percutaneous coronary intervention. N. Engl. J. Med. 360(3), 213–224 (2009). De Bruyne B, Pijls NH, Kalesan B FAME 2 Trial Investigators. et al.; Fractional flow reserve-guided PCI versus medical therapy in stable coronary disease. N. Engl. J. Med. 367(11), 991–1001 (2012). Noc M, Fajadet J, Lassen JF et al. Invasive coronary treatment strategies for out-ofhospital cardiac arrest: a consensus statement from the European Association for Percutaneous Cardiovascular Interventions (EAPCI)/Stent for Life (SFL)

ownership or options, expert testimony, grants or patents received or pending, or royalties. No writing assistance was utilized in the production of this manuscript.

groups. EuroIntervention 10(1), 31–37 (2014).

96–98 (2014). 7

Mohr FW, Morice MC, Kappetein AP et al. Coronary artery bypass graft surgery versus percutaneous coronary intervention in patients with three-vessel disease and left main coronary disease: 5-year follow-up of the randomised, clinical SYNTAX trial. Lancet 381(9867), 629–638 (2013).

Nielsen N, Wetterslev J, Cronberg T et al. Targeted temperature management at 33°C versus 36°C after cardiac arrest. N. Engl. J. Med. 369, 2197–2206 (2013).

8

Smith CR, Leon MB, Mack MJ et al. Transcatheter versus surgical aortic-valve replacement in high-risk patients. N. Engl. J. Med. 364, 2187–2198 (2011).

Fothergill RT, Watson LR, Virdi GK, Moore FP, Whitbread M. Survival of resuscitated cardiac arrest patients with ST-elevation myocardial infarction (STEMI) conveyed directly to a heart attack centre by ambulance clinicians. Resuscitation 85(1),

9

Smith LA, Dworakowski R, Bhan A et al. Real-time three-dimensional transesophageal echocardiography adds value to transcatheter aortic valve implantation. J. Am. Soc. Echocardiogr. 26(4), 359–369 (2013).

4

Chelly J, Mongardon N, Dumas F et al. Benefit of an early and systematic imaging procedure after cardiac arrest: insights from the PROCAT (Parisian Region Out of Hospital Cardiac Arrest) registry. Resuscitation 83(12), 1444–1450 (2012).

5

6

Future Cardiol. (2014) 10(5)

future science group

Advances in the field of interventional cardiology: spotlight on transcatheter aortic valve implantation.

Advances in the field of interventional cardiology: spotlight on transcatheter aortic valve implantation. - PDF Download Free
2MB Sizes 0 Downloads 7 Views