Advances in interventional cardiology part two: Impella and TAVI for acute disease

Speaking at Hospital Healthcare Europe’s Clinical Excellence in Cardiovascular Care event, our panel of interventional cardiology specialists, including Drs Alex Zaphiriou and Sundeep Kalra and Pierluigi Costanzo, shared ideas and insights into the progress of techniques, procedures and devices for acute coronary disease, including Impella and TAVI. They continued their discussion about their evolving approaches to patients previously labelled as having no hope, the importance of multidisciplinary working, the trials set to transform clinical practice and lessons to be learnt from Europe and beyond.

Significant advances in interventional cardiology techniques and procedures have seen the likes of coronary sinus reducers and new techniques for revascularisation in advanced disease helping to manage symptoms in chronic coronary disease, as discussed in part one of this panel discussion. But what about in acute disease?

This question was put to our three Clinical Excellence event panellists by session chair Dr Brian Halliday, consultant cardiologist and clinical lecturer in cardiomyopathy, at the Royal Brompton and Harefield Hospitals and the National Heart and Lung Institute in London.

He was joined by Dr Alex Zaphiriou, consultant in interventional cardiology at Queen Elizabeth Hospital, Birmingham; Dr Sundeep Kalra, consultant interventional cardiologist at London’s Royal Free Hospital; and Dr Pierluigi Costanzo, consultant interventional and structural cardiologist and clinical lead for coronary intervention at Royal Papworth Hospital NHS Foundation Trust in Cambridge.

In the last year or so, we’ve seen a randomised trial that was positive in cardiogenic shock with Impella. How has that changed things, and how are we going to need to adapt?

Dr Zaphiriou: I work in a transplant centre, so we’ve been lucky enough to use the Impella technology for the last 12 years. So, what is it? It looks like a pigtail catheter that is implanted through the femoral artery all the way to the left ventricle. A small motor sucks blood from the left ventricle, ejects the blood to the ascending aorta in a non-pulsatile way and provides an extra cardiac output that, realistically, is around 3.5 litres per minute, on top of whatever cardiac output the patient has.

A large bore sheath is required, so there are complications, and the aftercare can be quite challenging. You need to be very familiar with possible complications and how to adjust, position and readjust the device as necessary. Sometimes you need to use echocardiography – either transoesophageal or transthoracic – to find the optimal position in the left ventricle, et cetera. So, it’s not a straightforward technology to use.

Having said all that, we had a positive outcome in a selected group of patients. A Danish study called DanGer Shock examined the impact of Impella in cardiogenic shock due to ST-elevation myocardial infarction (STEMI). They demonstrated, for the first time, a substantial drop in all-cause mortality – something like 58% without Impella to 46% with Impella. It’s a very important message.

I’m very pleased that this is the study outcome, but I’m really curious about how we’re going to implement this in our everyday practice. Do we have dedicated cardiogenic shock centres? How is shock recognised in the community? How do we know that the paramedics should bring a STEMI with shock to, for example, the Queen Elizabeth from another hospital that does STEMI? The logistical challenge to implement the positive findings in our everyday practice is going to be tremendous.

How can we implement the treatment of cardiogenic shock in the context of acute myocardial infarction?

Dr Kalra: DanGer Shock was a really significant trial because lots of people have been using Impella, but without the data to support its use. If we just look at London, there are seven heart attack centres, but not all have access to this device. One of the key things, again, with any advanced level treatment is you need to regionalise this to Centres of Excellence. Every heart attack centre offering every part of cardiogenic shock treatment may not be realistic.

You’ll have the highest level of support available in the transplant centre – in London that’s Harefield – which can offer absolutely everything to a patient. If you’re setting up a network with different levels of cardiogenic shock capability, a key thing to logistically look at is transporting patients between a heart attack centre without advanced cardiogenic shock treatment options and one that can offer it. That offers another big dilemma of how to transport these critically unwell patients.

There has to be a level of education as treatment of cardiogenic shock isn’t standardised. You’re going to get different levels of treatment depending on your postcode and which way your ambulance turns when it picks you up. So, being able to network and get hold of colleagues who are au fait with using Impella and getting patients to the right place at the right time, is absolutely key.

Pierluigi, what’s your take on Impella, and does this signal the end of balloon pumps as a treatment option?

Dr Costanzo: Good old balloon pumps! We use a lot of them and will still use them. I think the Impella will certainly be superior to balloon pumps in a selected population. The DanGer Shock trial has demonstrated a cluster of patients that, if intervened upon early enough, will actually survive. I agree that there is significant benefit mortality-wise, but it’s still 46%.

I had the chance to dig into the details of the trial for prepping a cardiogenic shock programme here at Royal Papworth Hospital and most of the mortality, even with Impella, was related to vascular complications or Impella being inserted when it’s too late.

There is a fairly new classification of cardiogenic shock, provided by the Society of Cardiovascular Intervention in the US, where understanding the level of cardiogenic shock and implanting the Impella early enough will probably lead to better results.

I was lucky enough to do my fellowship years at the Toronto General when the Impella programme was launched, and they did 30 Impellas for cardiogenic shock. The results were not good at all because the perception was that you have to put it in when the patient is in extremis, which is not the case as that’s too late.

We’re actually prepping data from our centre with all the cardiogenic shock presentations from 2015 and we will look at whether there is a cluster of patients that could potentially benefit.

Dr Halliday: Moving on now to the area of valves and minimally invasive valve interventions – an areas that seems to be exploding at the minute. At ESC, there were some transcatheter aortic valve implantation (TAVI) trials, including the first TAVI trial in women showing it’s not a male-specific benefit.

Where do you see TAVI’s current role, where will we end up, and what’s your route for selecting patients?

Dr Zaphiriou: When we first started TAVI, patients were extremely frail or very elderly. It’s been very interesting seeing how the criteria have changed, obviously always supported by data. Now, data are much more favourable in putting patients of intermediate risk forward for TAVI.

I can see that there will be a point where the lowering of the threshold will stop because we should never forget that surgical treatment for aortic heart disease is a very good and established treatment.

It’s crucial that we have a multidisciplinary team (MDT) approach and that we invite the patients to participate in the decision-making. There are positive and negative, no matter which approach we follow, for patients who are suitable for both procedures.

I’m also slightly worried that perhaps newer generations of cardiac surgeons are becoming less keen to take on challenging cases because of the ‘TAVI effect’’ where they have stopped operating on elderly multimorbid patients because there’s another option. But there are cases where surgical intervention is the only option, and we end up with a patient who is not suitable for TAVI and the surgeons won’t take them on.

That’s my area of concern, but otherwise, it’s tremendous to see how the TAVI service has expanded. In my institution, it’s been great to see how much discussion takes place behind the scenes to make sure the patient selection is appropriate.

There are a couple of UK trials looking at intervening earlier in aortic stenosis for certain patients. What’s your current approach to selecting patients, and should we be considering even asymptomatic groups?

Dr Kalra: In terms of treatment for asymptomatic patients, we can extrapolate the prognostic data from the surgical experience. We know that with severe aortic stenosis, there is a prognostic implication for untreated disease, so I’m not too worried about treating asymptomatic patients.

In South London, they’ve changed the funnel referring in severe aortic stenosis and it’s combined now for surgery and for TAVI. It’s an age-based criteria so if you’re over the age of 75 or 80, you go to see a TAVI operator first.

At the age of 80, I think it’s reasonable. We know that it’s a safe device in the right patient, they can be discharged very quickly and it’s got longevity of 10 to 15 years – what more are you looking for in an 80-year-old? Why put them through cardiac surgery?

You can propagate, you can think and talk a lot about patients in MDTs, and should they have surgery, should they have TAVI? But I think we should be looking at how we actually get these patients to the right place and be more prescribed in directing the patients to the correct person.

Are there patients over the age of 70 that you wouldn’t offer TAVI to who are maybe better served by surgery?

Dr Costanzo: That’s a great question and local policies will usually dictate that. But certainly, someone aged between 70 and 75 is a surgical candidate by default and shouldn’t even see the TAVI operator, they should see a surgeon first.

We’re seeing from the US that they’re actually explanting TAVI valves that they put in too early in patients’ 60s, and TAVI valve explanation comes up with mortality risk. We should probably be looking at that if we want to understand our future in terms of lowering the bar for age and learn the lesson that the Americans have already learned.

We’ll finish on treatment of aortic valve regurgitation. Where do you see transcatheter edge-to-edge repair (TEER) of the mitral valve fitting in the management of patients with heart failure?

Dr Zaphiriou: It’s very exciting and very promising. I want to continue the theme of patients who previously had no hope and focus a little bit on tricuspid valve regurgitation. We’ve all come across these patients and sometimes it’s desperately difficult to keep them out of hospital, particularly if they have torrential tricuspid regurgitation, and to offer them a little bit of a quality of life. And I think, apart from edge-to-edge repair for tricuspid valve disease, there is new technology now with TAVI-style implantable valve, which can be safely anchored in the tricuspid valve position. This shift from using technology initially designed to treat multiple regurgitation to treat tricuspid valve regurgitation, and the new dedicated valve for tricuspid valve, gives a lot of hope in patients who are really difficult to treat.

Now, there is not yet solid evidence to suggest that there is tangible prognostic benefit but there are ongoing trials. Anecdotally, a lot of patients who have been done in our centre on compassionate grounds, if you like, have felt much better and the results have been really impressive, but we are desperate for some trial data.

Dr Kalra: If we wait for randomised control trials, we’re going to be a long way off offering these treatments to patients. That’s certainly the gold standard and that’s what we should be aspiring to.

On pragmatic terms, we know regulation can delay the introduction of treatment. If we’ve got the safety data about the actual procedure, it’s safe and we can effectively deliver this technology, I think there’s definitely a case to be made for using it on a case-by-case basis. But ideally, you’d want these to be done within the confines of a trial so you can be certain of the treatment strategy you’re offering patients.

Finally, since we’ve been talking about patients without hope, have you used mitral TEER in patients with very advanced heart failure and reduced ejection fraction, who are almost at point of needing transplant, to postpone transplant or as a holding measure?

Dr Costanzo: The short answer is no, although there are some data, such as that TEER for mitral valve in advanced heart failure might be beneficial in postponing the potential heart transplant or requirement of left ventricular assist devices (LVAD).

In actual fact, I find it difficult because once you treat the severe mitral regurgitation in a patient with a very bad ventricle, the ventricle takes a hit with an increased preload, and patients tend to do quite badly. Sometimes you even need mechanical support, and it’s difficult to predict which patient can be delayed for the requirement of LVAD or transplant by doing a TEER.

At least in this centre, we really find it difficult. We’ve done it a couple of times, and we had to insert a mechanical support device afterwards and then wait for a heart for transplant.