What is the problem
Cancer patients are a high cardiovascular risk cohort. Both cancer and cardiovascular disease have interlinked risk factors in common such as increasing age, obesity and smoking. Many oncological therapies also have associated cardiovascular side effects which further increase the cardiovascular risk profile of cancer patients.
Cancer therapy related cardiovascular toxicity (CTR-CVT) refers to any cancer treatment related effects that cause injury to the cardiovascular system. This injury can lead to both structural and/or functional injury to the myocardium.
Cardio-oncology
Cardio-oncology services arose in response to the identification of CTR-CVT and an increasing number of long-term cancer survivors affected by cardiovascular disease. The overarching aim is to allow patients with cancer to receive the best possible cancer treatment safely1. This involves a baseline cardiovascular risk assessment, surveillance and management of acute CTR-CVT during cancer treatment and guidance on management of long-term cardiovascular complications on completion of treatment.
The CTR-CVT graph (figure. 1) shows the timing of highest cardiovascular toxicity risk during cancer treatment. This often coincides with perioperative patients undergoing neoadjuvant therapy prior to cancer surgery. The cardio-oncology goals to minimise CTR-CVT and overall cardiovascular risk profile conveniently align with the period of perioperative optimisation of cardiac risk factors during prehabilitation.
Figure 1: Cardiovascular toxicity risk of patients over time, with the potential effect of cardioprotective strategies to reduce risk (arrows)2.
The majority of cardiotoxicity syndromes manifest within the first year of oncological treatment, which forms the majority of patients presenting for cancer surgery. The oncological factors that increase the risk of cardiotoxicity can be grouped into three categories3:
Delayed cardiotoxicity occurring 12 months or more after completion of oncological care is less likely to be encountered in the prehabilitation setting. A history of previous cancer therapies should be enquired for in a patient presenting with features of heart failure in the perioperative period.
Screening and assessment
The initial assessment of cardiovascular toxicity risk involves:
- Evaluation of the patient’s baseline cardiac risk factors
- Understanding the cardiovascular implications of a specific tumour aetiology
- Identification and treatment of unwanted cardiac side effects of oncological treatment.
This framework aims to reduce long term cardiovascular risk in cancer patients.
Routine perioperative cardiovascular risk evaluation utilising history, examination and investigations forms the foundation of a baseline cardiovascular toxicity risk assessment2.
- History of smoking, alcohol intake, diabetes, hypertension, dyslipidaemia, obesity, renal impairment and presence of existing cardiac disease
- Enquiry should be made for symptoms of exertional dyspnoea, chest pain, palpitations, pre-syncope/syncope, orthopnoea, paroxysmal nocturnal dyspnoea and peripheral oedema
- Evaluation of functional status through the Duke Activity Status Index (DASI) with a score ≤34 indicating increased risk of perioperative complications
- Cardiovascular examination including pulse, BP, SpO2, presence of murmurs, JVP, peripheral oedema
- Baseline cardiac investigations: ECG, FBC, U&E, HbA1c and BNP and troponin if appropriate (see section on biomarkers below).
Figure 2. 2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline6 – One potential approach to perioperative cardiovascular risk assessment
Carcinoid heart disease
Carcinoid heart disease can occur in patients with carcinoid syndrome secretory neuroendocrine tumours. Cardiac involvement is present in 37% of patients with carcinoid syndrome and typically leads to tricuspid regurgitation, pulmonary stenosis and/or pulmonary hypertension. An echocardiogram is required to determine the presence of valvular disease, pulmonary hypertension and left and right ventricular function. 5-HIAA levels can be useful as carcinoid heart disease is almost never seen if 5-HIAA levels are below 50mg/24 hours9.
Hepatic resection of metastatic carcinoid cancer can prolong survival and control symptomatic endocrinopathy10. The increased central venous pressure associated with tricuspid regurgitation significantly increases surgical risk due to increased blood loss during liver resection. Valve replacement should be considered if transpulmonary gradient is ≥10mmHg. It is safe and is association with similar outcomes as patients without carcinoid heart disease undergoing hepatic resection for carcinoid syndrome11.