Focus on cardio-oncology and cardio-toxicity with Dr Rebecca Dobson

Speaking at Hospital Healthcare Europe’s Clinical Excellence in Cardiovascular Care event, Dr Rebecca Dobson discussed the need and demand for cardio-oncology services, how they’ve developed over time and the current state of play in this evolving field, as well as providing an overview of cardio-toxicity.

A decade or two ago, there was no such thing as cardio-oncology, and Dr Rebecca Dobson, consultant cardiologist specialising in imaging and cardio-oncology at Liverpool Heart and Chest Hospital and the Clatterbridge Cancer Centre, says things have ‘progressed somewhat from the days when all you were interested in was an ejection fraction’.

In fact, specialists like Dr Dobson – who also heads up her regional cardio-oncology service – now combine their wide-ranging cardiology expertise with close multidisciplinary working to allow cancer patients to receive the best possible treatments safely and minimise cancer therapy-related cardio-toxicity across the entire continuum of cancer care.

What is the role of cardio-oncology in contemporary medicine?

For a long time, everyone’s known that certain cancer therapies can affect the heart and, traditionally, these patients have been seen in heart failure clinics because we were looking for left ventricular systolic dysfunction.

But as the global burden of cancer has increased, and the treatments that we use to treat these cancers have increased, we’re seeing more and more patients with cancer who are exposed to more and more potentially cardio-toxic therapies, who would then potentially require the input of a cardiologist to maximise their cardiac health.

Previously, if a patient had cancer and was treated with cardio-toxic treatment, unfortunately, their outlook would have been relatively poor and a cardiologist would very rarely have to get involved with that patient’s treatment. Whereas now patients are living a lot longer with the effects of the cancer therapies.

And I think this is a real testament to the advances within oncology – the field is advancing at a really rapid pace, which is great for patients from a cancer point of view but it has important implications from a cardiology point of view.

What we don’t want to do with patients is cure their cancer and forget about their heart because it would be a real tragedy to cure someone’s cancer and then they end up having an avoidable cardio-toxicity.

It’s really important that we think about these patients’ cardiovascular health, and I think in the past, as cardiologists we’ve often almost shied away from patients with cancer. And I think we’ve probably done some of our patients a bit of a disservice because there is a lot we can do, and we need a rapid response service so that we can see these patients quickly.

What do you see as the role of the cardio-oncologist?

I think a lot of patients worry that when they come to a cardio-oncology clinic, that we’re going to put up barriers and say, ‘you can’t have your cancer therapy’. And sometimes we do have to do that, but it’s actually quite rare. Far more often, we can facilitate the necessary cancer therapy by optimising the cardiac side of things.

Then at the other end of the spectrum, we look after patients who have been happily cured of their cancer, but who are at risk of late effects. So, these will be, perhaps, children or young adults who’ve had cancer at a young age and had lots of cardio-toxic therapy, but who are living with that increased risk for the rest of their lives.

These are the patients that we really don’t want to lose track of – they need to stay on someone’s radar so that we can screen them at regular intervals and pick up any issues at the earliest possible point.

How do you manage demand for the cardio-oncology service and support patient care?

One of the service fundamentals, I would say, is that we provide prompt cardiology input. At the moment, the way we’ve set our service up means we can see patients within a week to two weeks, so it’s a very responsive service. There’s lots of moving patients around to try and make sure that the most urgent patients get seen most quickly.

It also has to be based upon collaborative, multidisciplinary working. There is no point me sitting in my hospital at Liverpool Heart and Chest doing my cardiac thing with the patients and not talking to the oncologist who’s three miles up the road. It’s all about efficient communication with the oncologists, with the surgeons, anaesthetists, whoever it is who’s involved in that patient’s care. It is a truly multidisciplinary specialty, and I think it has to be because these are complicated patients and the last thing we want to do is make a decision that denies someone that a potentially life-saving cancer therapy.

I’d like to think that we offer a really holistic approach to patient care. And I say that with a smile on my face as a cardiologist because I know we’re not known for that – cardiologists will often focus on the heart and nothing but the heart. And I think these patients have such a lot going on with them, it’s really important that we recognise that within the service and work with other specialties to make sure we treat all of the patient and not just their heart.

Traditionally, cardiologists and oncologists have not worked closely together; we speak different languages. Certainly, when I when I first started in this subspecialty, I had no idea what a TKI was or what CHOP meant. And similarly, cardiologists have their own language talking about DAPT and TAVI and GLS. It’s really important that we try and understand where each other is coming from, understand clinical priorities, and have that collaborative approach to bridge the gap between the two specialties.

I’d recommend reading the 2022 ESC guidelines on cardio-oncology. It’s a really comprehensive document that covers lots of different types of cardio-toxicity.

It also includes a diagram that illustrates quite nicely the role of cardio-oncology care pathway. It’s important that we see patients at the beginning of their diagnosis, we follow them through their treatment, and we follow them up in the long term.

The diagram really illustrates the importance of risk stratifying patients at baseline and tailoring their cardio-oncology input accordingly.

Tell us more about your cardio-oncology service and day-to-day work

I set up the service in 2019 and at that point, we were doing two cardio-oncology clinics a month. Now we’re running two and a half clinics a week and are looking to increase that further because the demand is there.

I also do a weekly ward round at Clatterbridge Cancer Centre, our local cancer hospital, which provides really useful input to the oncologists and radiotherapists there for inpatients with cancer who have a cardiac issue like atrial fibrillation or high blood pressure.

We run four weekly cardio-oncology echo lists and a weekly cardio-oncology MDT, which we do virtually and that’s probably the most important part of the service. Any patient who is particularly complex, where we’ve got important clinical decisions to make, will come through our MDT, and that will always have oncology, cardiology, radiology and usually cardiothoracic surgical representation.

We’ve recently taken over surveillance and management of all the region’s carcinoid heart disease patients. We’ve set up immunotherapy baseline screening programme so we can try and detect cardio-toxicity at an early stage. And we’ve worked with the radiotherapists at Clatterbridge to educate them and enable them to do their own cardiac monitoring for patients with cardiac devices when they’re receiving radiotherapy.

We’re quite busy, and we’re getting busier all the time, which is why we’re looking to bring in a cardio-oncology nurse specialist as soon as possible. We’re going to be running a physiologist-led echo clinic for those patients that don’t need to see a cardiologist. And we are also looking to improve our baseline ECG review for patients who are receiving immunotherapy.

What is cardio-toxicity and how does it manifest?

I could talk for days about this! In the past, we’ve always thought about left ventricular systolic dysfunction being what we mean when we say ‘cardio-toxicity’. Certainly, a lot of what I deal with is cardiac dysfunction or heart failure, but it’s not the only thing I deal with.

It’s a real broad church of different manifestations of cardio-toxicity, which I think is probably another reason why I really enjoy my job – it keeps me on my toes. The more I do in this field, the more I realise that I’ve got a lot to learn and I’m always coming across another cardio-toxicity with a different type of drug.

From a cardiac dysfunction point of view, the drugs that we worry about the most are anthracyclines, the anti-HER2 therapies like herceptin.

From an arrhythmia point of view, oncologists do use arsenic to treat some types of cancers, and arsenic and tyrosine kinase inhibitors (TKIs) are very good at causing atrial fibrillation and arrhythmias. And TKIs and mTOR inhibitors are the main offenders for causing hypertension.

For vascular toxicity, it’s usually the drugs that we use to treat bowel cancer so 5FU, which can cause coronary artery spasm, which can be incredibly dramatic. We’ve seen patients who’ve presented with the peri-arrest with ST elevation that’s all settled down as that spasm is released.

And myocarditis is usually caused by checkpoint inhibitors or immunotherapies, but there are other drugs that can do it as well.

When does cardio-toxicity manifest?

Cardio-toxicity does not always occur at the beginning when someone has commenced on systemic anti-cancer therapy. Patients who present very acutely within hours or days of commencing their therapy, although they tend to have a very dramatic presentation, ironically, they seem to have the best prognosis. Everything usually settles down with some treatment and is reversible.

It’s the patients who present months to years after having their treatment, who can be most challenging. This is why it’s so important to take a proper medical history for all patients and think outside the box.

Keep an open mind and remember that cardio-toxicity has lots of manifestations but also has a very variable timescale. If you’ve got a patient with any of these cardiovascular problems, always think: are they a cancer patient? Have they had treatment? When was the treatment?

Demand for collaborative cardio-oncology services is only going to go in one direction and it’s not just for cardio-oncologists, either. All clinical cardiologists are going to see patients with cancer in their clinics, whether that’s valve clinics, percutaneous coronary intervention clinics, heart rhythm clinics or hypertension clinics, because, as I’ve said, cardio-toxicity is much broader than left ventricular systolic dysfunction.

How do you classify high-risk patients before chemotherapy, and do these patients still receive this treatment?

ESC’s position paper on baseline cardiovascular risk assessment in cancer patients from a few years ago is a really useful document.

If we can identify patients at high risk of cardio-toxicity from the beginning, we can optimise things as much as possible. It’s really important that we work with the oncologist to persuade them to take a blood pressure, to do an ECG and to take a history at the beginning of cancer therapy so that we can focus our energies and resources on those that probably need us most.

The ESC guideline published in 2022 comes with a risk calculator. You can download the app onto your phone, and then you put in the patient’s variables: age, troponin, previous history, whatever it might be. Then it will tell you whether they’re low, medium, high or very high risk.

In terms of what that means for their cancer therapy, we will sometimes make a decision with the oncologist and the patient that their risk is too high to proceed with cancer therapy. These are usually patients who are not due to receive curative chemo. If the chemotherapy makes the difference between life and death and is potentially lifesaving then it would be unusual for us to say we can’t give it.

Usually, we will do everything in our power to enable the oncologist to give what they need. But there are certain circumstances where that wouldn’t be the case. For example, I’d be very reluctant for patients who’ve had coronary artery spasm with cardiac arrest to have more of the same chemo because we know that the risk of recurrence is significant. But that would be quite extreme and, as I say, we would work hard to enable the chemo or other treatment to continue.

Sometimes there might be two different treatment options with different risks and benefits. We’ll always bring the patient into that conversation and say, ‘look, we’ve got two different options from a cancer point of view, one is associated with a risk to your heart, the other isn’t’, and we’ll talk a bit about the risk and benefit from the cancer and cardiology sided, and then make that decision together.  

Nobody should be making unilateral decisions about these patients; it should be a real collaborative, multidisciplinary approach.

The spring 2024 Clinical Excellence in Cardiovascular Care event will take place on 19 March, with Dr Rebecca Dobson as chair. Registrations for all members of the multidisciplinary team are now open.