Manage the Cardiotoxic Effects of Cancer Therapies

Newly Published Guidance Aims to Strike a Balance Between Effective Cancer Therapy and Adverse Cardiovascular Effects; Guidelines in Practice Assesses the Recommendations  

Introduction

Advances in cancer treatment have led to the development of increasingly potent therapies that improve survival outcomes for cancer patients, but the trade-off is that many also create cardiovascular toxicity. Trastuzumab, a new targeted molecular therapy, has recognised cardiovascular complications for cancer patients, as has some longer-established treatments, such as anthracycline chemotherapy.¹Survivors of several solid cancers and lymphoma have a two-fold risk of fatal heart disease compared to their peers² and, with cancer increasingly being recognised as a chronic disease due to advances in cancer treatment and care,³ there are a growing number of cancer survivors. Cardiovascular and cancer care are both prioritised in the NHS Long Term Plan,⁴ and they are the two most common causes of death and disease worldwide.³

As life expectancy increases, so too will the burden of both cancer and cardiovascular disease. The sub-specialty of cardio–oncology has developed over the past 10 years in the UK; although many cardio-oncologists are cardiologists who specialise in the treatment of cancer patients, they work in close collaboration with oncologists and haematologists, who must assess the suitability of treatments that can cause heart problems, and determine which patients are most at risk. The British Cardio–Oncology Society, established in 2012, has a membership that includes cardiologists, oncologists, haematologists, and specialist oncology pharmacists.⁵

In August 2022, the first European Society of Cardiology (ESC) guideline on cardio–oncology was published at its annual congress.⁶ It aims to reduce the cardiac side effects of cancer treatment, with 272 specific recommendations on management before, during, and after administering cancer therapies that have the potential to cause cardiovascular problems (see Box 1). The guideline was developed in collaboration with the European Hematology Association, the European Society for Therapeutic Radiology and Oncology, and the International Cardio–Oncology Society, and is aimed at healthcare professionals looking after cancer patients and survivors.

Getting the Balance Right in Cardio–Oncology

The new ESC guidance⁶ emphasises the need to balance the most permissible (from a cardiovascular disease perspective) with the most effective (from an oncological perspective) cancer treatment. If cardiac dysfunction is detected during surveillance with echocardiograms and/or blood tests, oncology and cardiology teams are strongly recommended to discuss the pros and cons of continuing versus stopping cancer treatment.²

Dr Alexander Lyon, Consultant Cardiologist at the Royal Brompton Hospital in London, advised: ‘Multiple factors influence the decision to continue or stop therapy, including the magnitude and severity of the heart problem, how early or late in the cancer management plan the problem has developed, and how many more treatment doses are proposed, the response of the cancer to the treatment, the options for cardioprotection and their predicted benefit, the range of alternative non-cardiotoxic cancer treatments available, and the patient’s preference and concerns.’

Cardiovascular Assessment and Monitoring

The guideline recommends that a baseline cardiovascular assessment should be carried out to identify patients at high risk, and they should be referred to a cardiologist for further cardiac evaluation and optimisation of heart health and risk factors before starting therapy.² ‘This pre-assessment by the cardiologist must be performed urgently to minimise delays to starting cancer treatment,’ according to guidelines task force chairperson, Dr Teresa Lopez-Fernandez, Consultant Cardiologist at La Paz University Hospital in Madrid.

The frequency of cardiac monitoring during a treatment with potential to cause heart disease, and the option for starting heart medication upfront to act as protection during cancer treatment, can be tailored to each cancer patient based upon baseline risk, the nature and total duration and dose of cancer therapy, and any pre-existing heart disease.²

Monitoring in the first year after treatment is recommended in certain groups. These include those who developed a cardiac complication during treatment to assess whether the problem resolves or persists after the cancer drug has cleared from the body. For some patients, this will lead to a trial of weaning off cardiac medications started during cancer treatment while others will be recommended lifelong cardiac treatment. Another goal is to detect new heart problems; with some cancer therapies, for example, anthracyclines, the majority of cardiovascular side effects are detected in the first 12 months after completing treatment. Patients should continue healthy lifestyle habits, report potential cardiac symptoms, and keep blood pressure, diabetes, and high cholesterol under control.

Some patients require long-term surveillance for cardiovascular problems.² These include:

• survivors of paediatric and young adult cancers treated with high doses of anthracycline chemotherapy and/or high doses of radiotherapy to the chest
• adult cancer patients who developed moderate or severe complications during treatment
• survivors of leukaemia, myeloma, or lymphoma who required a bone marrow transplantation
• patients on long-term cancer treatments with the potential to cause heart problems after years of treatment.

Patient Education and Risk Reduction

Preservation and monitoring of heart health during cancer treatment is a key part of the guideline. Patients should be educated on the potential risks and how to reduce them, such as quitting smoking, exercising at least 150 minutes per week, but not to exhaustion, eating a healthy diet, and limiting alcohol to 100 g (12.5 units) weekly.²

Patients should be advised to report possible cardiac symptoms to the cancer team such as chest pain, breathlessness, fainting, blackouts, or palpitations. Tight control of high blood pressure, diabetes, and high cholesterol is recommended. Some patients are advised to monitor their blood pressure at home when starting a cancer therapy known to raise blood pressure.

Key Messages from the Guidance⁶

• Integration is a guiding principle of cardio–oncology; cardio–oncology providers must have knowledge of the broad scope of cardiology, oncology, and haematology, and communication between different healthcare professionals is critical to optimise patient care
• Cardio–oncology programmes minimise unnecessary interruptions to cancer treatment as well as cancer therapy-related cardiovascular toxicity
• Multidisciplinary team discussion should balance the risks and benefits of stopping cancer treatment for patients who develop cardiovascular toxicity
• Baseline cardiovascular risk assessment is recommended for all patients with cancer who are due to receive a potentially cardiotoxic anticancer therapy
• Measures are needed for both primary and secondary prevention of cardiovascular toxicity
• A cardio–oncology team must coordinate long-term follow-up of cardiovascular toxicity risk and surveillance planning once cancer therapy has finished
• Patients and their carers should be provided with guidance to promote healthy lifestyle and to recognise and report signs and symptoms of cardiovascular disease.⁶

Next Steps for Cardio–Oncology

Cardiovascular disease and cancer are major public health problems with huge economic and social impacts. However, the intersection of cancer and cardiovascular disease has only recently gained wider interest, according to the guideline committee.⁶ Cancer therapy-related cardiovascular toxicity is linked with excess mortality, especially when it limits patients’ ability to complete effective treatments. Despite this, there are few dedicated cardio–oncology services, with most patients being reviewed in general cardiology clinics.¹

The guideline committee called for ‘strategic investments in cardio–oncology care networks and cardio–oncology services provision’ to meet the projected increased clinical demand in the near future. The committee also advises that ‘a dedicated training core curriculum for a minimum of 1-year medical training is urgently needed’, as well as ‘collaboration between healthcare providers, clinical and basic investigators, healthcare authorities, regulatory bodies, advocacy groups, and patients’ associations’.

Finally, the committee said that more randomised controlled trials to guide decision-making are needed due to ‘the fast-moving pace of new oncology treatment developments against a background of dynamic cardiovascular toxicity likelihood’.